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1

Top Quark Measurements  

E-Print Network (OSTI)

Ten years after its discovery at the Tevatron collider, we still know little about the top quark. Its large mass suggests it may play a key role in the mechanism of Electroweak Symmetry Breaking (EWSB), or open a window of sensitivity to new physics related to EWSB and preferentially coupled to it. To determine whether this is the case, precision measurements of top quark properties are necessary. The high statistics samples being collected by the Tevatron experiments during Run II start to incisively probe the top quark sector. This report summarizes the experimental status of the top quark, focusing in particular on the recent measurements from the Tevatron Run II.

A. Juste

2005-12-20T23:59:59.000Z

2

Top Quark Mass Measurements  

Science Journals Connector (OSTI)

First observed in 1995 the top quark is one of a pair of third?generation quarks in the Standard Model of particle physics. It has charge +2/3e and a mass of 171.4 GeV about 40 times heavier than its partner the bottom quark. The CDF and DØ collaborations have identified several hundred events containing the decays of top?antitop pairs in the large dataset collected at the Tevatron proton?antiproton collider over the last four years. They have used these events to measure the top quark’s mass to nearly 1% precision and to study other top quark properties. The mass of the top quark is a fundamental parameter of the Standard Model and knowledge of its value with small uncertainty allows us to predict properties of the as?yet?unobserved Higgs boson. This paper presents the status of the measurements of the top quark mass. It is based on a talk I gave at the Conference on the Intersections of Particle and Nuclear Physics in Puerto Rico May 2006 which also included discussion of measurements of other top quark properties.

A. P. Heinson; CDF Collaboration; DØ Collaboration

2006-01-01T23:59:59.000Z

3

Top Quark Condensate Revisited  

Science Journals Connector (OSTI)

......hence a strong connection with the Higgs boson itself. Such a situation can be...the top quark condensate. The Higgs boson emerges as aft bound state and...at A~ 1019 GeV. (3 19) The Higgs boson was predicted as a ft bound state......

Koichi Yamawaki

1996-02-01T23:59:59.000Z

4

Top quark physics at CDF  

SciTech Connect

We present the recent results of top-quark physics using up to 6 fb{sup -1} of p{bar p} collisions analyzed by the CDF collaboration. The large number of top quark events analyzed, of the order of several thousands, allows stringent checks of the standard model predictions. Also, the top quark is widely believed to be a window to new physics. We present the latest measurements of top quark intrinsic properties as well as direct searches for new physics in the top sector.

Potamianos, Karolos

2011-12-01T23:59:59.000Z

5

Top Quark Current Experimental Status  

E-Print Network (OSTI)

Ten years after its discovery at the Tevatron collider, we still know little about the top quark. Its large mass suggests it may play a key role in the mechanism of Electroweak Symmetry Breaking (EWSB), or open a window of sensitivity to new physics related to EWSB and preferentially coupled to it. To determine whether this is the case, precision measurements of top quark properties are necessary. The high statistics samples being collected by the Tevatron experiments during Run II start to incisively probe the top quark sector. This report summarizes the experimental status of the top quark, focusing in particular on the recent measurements from the Tevatron.

A. Juste

2006-03-04T23:59:59.000Z

6

Top quark properties at ATLAS  

E-Print Network (OSTI)

The ATLAS potential for the study of the top quark properties and physics beyond the Standard Model in the top quark sector, is described. The measurements of the top quark charge, the spin and spin correlations, the Standard Model decay (t-> bW), rare top quark decays associated to flavour changing neutral currents (t-> qX with X = gluon, Z, photon) and ttbar resonances are discussed. The sensitivity of the ATLAS experiment is estimated for an expected luminosity of 1fb-1 at the LHC. The full simulation of the ATLAS detector is used. For the Standard Model measurements the expected precision is presented. For the tests of physics beyond the Standard Model, the 5 sigma discovery potential (in the presence of a signal) and the 95% Confidence Level (CL) limit (in the absence of a signal) are given.

Dilip Jana; for the ATLAS Collaboration

2008-10-20T23:59:59.000Z

7

Top quark production at ATLAS and CMS  

E-Print Network (OSTI)

A review of the main recent results on top quark production from the ATLAS and CMS experiments is presented. Results on both electroweak single top quark production and strong top pair production are presented.

Luca Lista; on behalf of the ATLAS; CMS collaborations

2014-05-20T23:59:59.000Z

8

Top quark studies at hadron colliders  

SciTech Connect

The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

1997-01-01T23:59:59.000Z

9

Observation of the Top Quark  

DOE R&D Accomplishments (OSTI)

Top quark production is observed in{bar p}p collisions at{radical}s= 1.8 TeV at the Fermilab Tevatron. The Collider Detector at Fermilab (CDF) and D{O} observe signals consistent with t{bar t} to WWb{bar b}, but inconsistent with the background prediction by 4.8{sigma} (CDF), 4.6a (D{O}). Additional evidence for the top quark Is provided by a peak in the reconstructed mass distribution. The kinematic properties of the excess events are consistent with the top quark decay. They measure the top quark mass to be 176{plus_minus}8(stat.){plus_minus}10(sys.) GeV/c{sup 2} (CDF), 199{sub -21}{sup+19}(stat.){plus_minus}22(sys.) GeV/c{sup 2} (D{O}), and the t{bar t} production cross section to be 6.8{sub -2.4}{sup+3.6}pb (CDF), 6.4{plus_minus}2.2 pb (D{O}).

Kim, S. B.

1995-08-00T23:59:59.000Z

10

Top Quark Production at the LHC  

E-Print Network (OSTI)

Top quark production in proton proton collisions at the Large Hadron Collider (LHC) is reviewed using data collected by the ATLAS and CMS detectors. Most recent results on searches for new physics related to top quark production mechanism are included.

Francesco Spanò; for the ATLAS; CMS collaborations

2011-12-16T23:59:59.000Z

11

Top quark physics at the LHC  

E-Print Network (OSTI)

The physics perspectives of the production and decay of single top quarks and top quark pairs at the CERN Large Hadron Collider (LHC) are reviewed from a phenomenological point of view.

Werner Bernreuther

2008-05-09T23:59:59.000Z

12

Top quark physics expectations at the LHC  

E-Print Network (OSTI)

The top quark will be produced copiously at the LHC. This will make both detailed physics studies and the use of top quark decays for detector calibration possible. This talk reviews plans and prospects for top physics activities in the ATLAS and CMS experiments.

Andrei Gaponenko; for the ATLAS Collaboration; for the CMS Collaboration

2008-10-22T23:59:59.000Z

13

Theory of top quark production and decay  

SciTech Connect

Direct and indirect information on the top quark mass and its decay modes is reviewed. The theory of top production in hadron- and electron-positron-colliders is presented.

Kuehn, J.H. [Universitaet Karlsruhe (Germany)

1997-01-01T23:59:59.000Z

14

CP violation in top-quark physics  

E-Print Network (OSTI)

In this talk I review how to search for CP violation in top-quark pair production and decay using T-odd correlations. I discuss two examples which illustrate many of the relevant features: CP violation in a heavy neutral Higgs boson; and CP violating anomalous top-quark couplings. I present some numerical results for the LHC and some for the Tevatron.

German Valencia

2010-07-27T23:59:59.000Z

15

Review of Top Quark Physics Results  

SciTech Connect

As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of V{sub tb}. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits on potential anomalous production and decay mechanisms. This review presents an overview of recent theoretical and experimental developments in this field. We also provide a brief discussion of the implications for further efforts.

Kehoe, R.; Narain, M.; Kumar, A.; ,

2007-12-01T23:59:59.000Z

16

Top Quark Production at the Tevatron  

SciTech Connect

The top quark is the most recently discovered of the standard model quarks, and because of its very large mass, studies of the top quark and its interactions are important both as tests of the standard model and searches for new phenomena. In this document, recent results of analyses of top quark production, via both the electroweak and strong interactions, from the CDF and D0 experiments are presented. The results included here utilize a dataset corresponding to up to 6 fb{sup -1} of integrated luminosity, slightly more than half of the dataset recorded by each experiment before the Tevatron was shutdown in September 2011.

Mietlicki, David J.

2011-12-01T23:59:59.000Z

17

The Top Quark, QCD, And New Physics.  

DOE R&D Accomplishments (OSTI)

The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a laboratory for perturbative QCD. As examples of the relevance of QCD corrections in the top quark sector, the calculation of e{sup+}e{sup -}+ t{bar t} at next-to-leading-order QCD using the phase space slicing algorithm and the implications of a precision measurement of the top quark mass are discussed in detail. The associated production of a t{bar t} pair and a Higgs boson in either e{sup+}e{sup -} or hadronic collisions is presented at next-to-leading-order QCD and its importance for a measurement of the top quark Yulrawa coupling emphasized. Implications of the heavy top quark mass for model builders are briefly examined, with the minimal supersymmetric Standard Model and topcolor discussed as specific examples.

Dawson, S.

2002-06-00T23:59:59.000Z

18

Top Quark Mass Measurements at the Tevatron  

SciTech Connect

We report the latest results on the top-quark mass and on the top-antitop mass difference from the CDF and D0 collaborations using data collected at the Fermilab Tevatron p{bar p} collider at {radical}s = 1.96 TeV. We discuss general issues in top-quark mass measurements and present new results from direct measurements and from top-pair production cross-section. We also report new results on the top-antitop mass difference.

Ye, Zhenyu; /Fermilab

2011-07-01T23:59:59.000Z

19

Production and decay of heavy top quarks  

SciTech Connect

Experimental evidence indicates that the top quark exists and has a mass between 50 and 200 GeV/c{sup 2}. The decays of a top quark with a mass in this range are studied with emphasis placed on the mass region near the threshold for production of real W bosons. Topics discussed are: (1) possible enhancement of strange quark production when M{sub W} + m{sub s} < m{sub t} < M{sub W} + m{sub b}; (2) exclusive decays of T mesons to B and B{asterisk} mesons using the non-relativistic quark model; (3) polarization of intermediate W's in top quark decay as a source of information on the top quark mass. The production of heavy top quarks in an e{sup +}e{sup {minus}} collider with a center-of-mass energy of 2 TeV is studied. The effective-boson approximation for photons, Z{sup 0}'s and W's is reviewed and an analogous approximation for interfaces between photons and Z{sup 0}'s is developed. The cross sections for top quark pair production from photon-photon, photon-Z{sup 0}, Z{sup 0}Z{sup 0}, and W{sup +}W{sup {minus}} fusion are calculated using the effective-boson approximation. Production of top quarks along with anti-bottom quarks via {gamma}W{sup +} and Z{sup 0}W{sup +} fusion is studied. An exact calculation of {gamma}e{sup +} {yields} {bar {nu}}t{bar b} is made and compared with the effective-W approximation. 31 refs., 46 figs.

Kauffman, R.P.

1989-08-01T23:59:59.000Z

20

Top Quark Properties from Top Pair Events and Decays  

SciTech Connect

Over a decade since the discovery of the top quark we are still trying to unravel mysteries of the heaviest observed particle and learn more about its nature. The continuously accumulating statistics of CDF and DO data provide the means for measuring top quark properties with ever greater precision and the opportunity to search for signs of new physics that could be manifested through subtle deviations from the standard model in the production and decays of top quarks. In the following we present a slice of the rich program in top quark physics at the Fermilab Tevatron: measurements of the properties of top quark decays and searches for unusual phenomena in events with pair produced tops. In particular, we discuss the most recent and precise CDF and DO measurements of the transverse polarization of W bosons from top decays, branching ratios and searches for flavor-changing neutral current decays, decays into charged Higgs and invisible decays. These analyses correspond to integrated luminosities ranging from 0.9 to 2.7 fb{sup -1}.

Ivanov, A.; /UC, Davis

2008-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Press Pass - Press Release - Single top quark  

NLE Websites -- All DOE Office Websites (Extended Search)

9-04 9-04 March 9, 2009 For immediate release Media Contacts: Judy Jackson, Fermilab, +1-630-840-3351, jjackson@fnal.gov Kurt Riesselmann, Fermilab, +1-630-840-3351, kurtr@fnal.gov Graphics and photos are available at: http://www.fnal.gov/pub/presspass/images/Single-Top-Quark-2009.html Fermilab collider experiments discover rare single top quark Batavia, Ill.-Scientists of the CDF and DZero collaborations at the Department of Energy's Fermi National Accelerator Laboratory have observed particle collisions that produce single top quarks. The discovery of the single top confirms important parameters of particle physics, including the total number of quarks, and has significance for the ongoing search for the Higgs particle at Fermilab's Tevatron, currently the world's most powerful operating particle accelerator.

22

Evidence for production of single top quarks  

Science Journals Connector (OSTI)

We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron pp¯ collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top-quark partner that is always produced from strong-coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top-quark production has been searched for in ever larger data sets. In this analysis, we select events from a 0.9??fb-1 data set that have an electron or muon and missing transverse energy from the decay of a W boson from the top-quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and tt¯ events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix-element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top-quark production of ?(pp¯?tb+X,tqb+X)=4.7±1.3??pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top-quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find |Vtbf1L|=1.31-0.21+0.25, where f1L is a generic vector coupling. This model-independent measurement translates into 0.68<|Vtb|?1 at the 95% C.L. in the standard model.

V. M. Abazov et al. (The D0 Collaboration)

2008-07-14T23:59:59.000Z

23

Uncovering the single top: observation of electroweak top quark production  

SciTech Connect

The top quark is generally produced in quark and anti-quark pairs. However, the Standard Model also predicts the production of only one top quark which is mediated by the electroweak interaction, known as 'Single Top'. Single Top quark production is important because it provides a unique and direct way to measure the CKM matrix element V{sub tb}, and can be used to explore physics possibilities beyond the Standard Model predictions. This dissertation presents the results of the observation of Single Top using 2.3 fb{sup -1} of Data collected with the D0 detector at the Fermilab Tevatron collider. The analysis includes the Single Top muon+jets and electron+jets final states and employs Boosted Decision Tress as a method to separate the signal from the background. The resulting Single Top cross section measurement is: (1) {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.74{sub -0.74}{sup +0.95} pb, where the errors include both statistical and systematic uncertainties. The probability to measure a cross section at this value or higher in the absence of signal is p = 1.9 x 10{sup -6}. This corresponds to a standard deviation Gaussian equivalence of 4.6. When combining this result with two other analysis methods, the resulting cross section measurement is: (2) {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.94 {+-} 0.88 pb, and the corresponding measurement significance is 5.0 standard deviations.

Benitez, Jorge Armando; /Michigan State U.

2009-08-01T23:59:59.000Z

24

Top Quark Physics at the LHC  

E-Print Network (OSTI)

An overview of the prospects of top quark physics at the LHC is presented. The ATLAS and the CMS detectors are about to produce a large amount of data with high top quark contents from the LHC proton-proton collisions. A wide variet y of physics analyses is planned in both experiments, and a number of useful insights have already been obtained regarding their detector performance and physics potential. This summary is based on the talk presented at the Hadron C ollider Physics Symposium 2008, Galena, Illinois, May 27-31, 2008.

Akira Shibata

2008-07-31T23:59:59.000Z

25

Measurements of top quark properties at the Tevatron collider  

SciTech Connect

The discovery of the top quark in 1995 opened a whole new sector of investigation of the Standard Model; today top quark physics remains a key priority of the Tevatron program. Some of the measurements of top quark properties, for example its mass, will be a long-standing legacy. The recent evidence of an anomalously large charge asymmetry in top quark events suggests that new physics could couple preferably with top quarks. I will summarize this long chapter of particle physics history and discuss the road the top quark is highlighting for the LHC program.

Margaroli, Fabrizio

2011-05-01T23:59:59.000Z

26

Top quark jets at the LHC  

Science Journals Connector (OSTI)

We investigate the reconstruction of high pT hadronically decaying top quarks at the Large Hadron Collider. One of the main challenges in identifying energetic top quarks is that the decay products become increasingly collimated. This reduces the efficacy of conventional reconstruction methods that exploit the topology of the top quark decay chain. We focus on the cases where the decay products of the top quark are reconstructed as a single jet, a “top jet.” The most basic “top-tagging” method based on jet mass measurement is considered in detail. To analyze the feasibility of the top-tagging method, both theoretical and experimental aspects of the large QCD jet background contribution are examined. Based on a factorization approach, we derive a simple analytic approximation for the shape of the QCD jet mass spectrum. We observe very good agreement with the Monte Carlo simulation. We consider high-pT tt¯ production in the standard model as an example, and show that our theoretical QCD jet mass distributions can efficiently characterize the background via sideband analyses. We show that with 25??fb-1 of data, our approach allows us to resolve top jets with pT?1??TeV, from the QCD background, and about 1.5 TeV top jets with 100??fb-1, without relying on b-tagging. To further improve the significance we consider jet shapes (recently analyzed in 10), which resolve the substructure of energy flow inside cone jets. A method of measuring the top quark polarization by using the transverse momentum of the bottom quark is also presented. The main advantages of our approach are (i) the mass distributions are driven by first principle calculations, instead of relying solely on Monte Carlo simulation; (ii) for high pT jets (pT?1??TeV), IR-safe jet shape variables are robust against detector resolution effects. Our analysis can be applied to other boosted massive particles such as the electroweak gauge bosons and the Higgs.

Leandro G. Almeida; Seung J. Lee; Gilad Perez; Ilmo Sung; Joseph Virzi

2009-04-16T23:59:59.000Z

27

edited1_TopQuarkMass  

NLE Websites -- All DOE Office Websites (Extended Search)

CALCULATE THE TOP QUARK MASS CALCULATE THE TOP QUARK MASS TEACHER NOTES DESCRIPTION Students use momentum conservation, energy conservation and two-dimensional vector addition to calculate the mass of the heaviest of the six known quarks. They gather data from data plots from the DØ experiment at Fermilab. The events were chosen carefully; all of the decay products moved in a plane perpendicular to the beam. This makes the vector addition much simpler. STANDARDS National Science Education Standards (U.S. National Research Council) * Physical Science Content Standard B: As a result of this activity . . . students should develop an understanding of: o Conservation of energy and increase in disorder. o Interactions in energy and matter. LEARNING OBJECTIVES Students will know and be able to:

28

Top quark pair cross section prospects in ATLAS  

E-Print Network (OSTI)

The observation of the top quark will be an important milestone in ATLAS. This talk reviews methods that ATLAS plans to use to observe the top quark pair production process and measure its cross section.

Andrei Gaponenko; for the ATLAS Collaboration

2009-10-20T23:59:59.000Z

29

Review of recent top-quark LHC combinations  

E-Print Network (OSTI)

A review of recent combinations of top-quark measurements performed at the LHC, by the ATLAS and CMS collaborations, is provided. The typical uncertainty categorisations, and their assumed correlation patterns are presented, together with the results of the combinations of the top-quark pair and single top-quark production cross sections, the top-quark mass, as well as of the $W$ boson polarisation and the charge asymmetry in $t\\bar t$ events.

Cortiana, Giorgio

2014-01-01T23:59:59.000Z

30

Search for Single Top Quark Production at HERA  

E-Print Network (OSTI)

A search for single top quark production is performed in the full ep data sample collected by the H1 experiment at HERA, corresponding to an integrated luminosity of 474 pb^-1. Decays of top quarks into a b quark and a W boson with subsequent leptonic or hadronic decay of the W are investigated. A multivariate analysis is performed to discriminate top quark production from Standard Model background processes. An upper limit on the top quark production cross section via flavour changing neutral current processes sigma (ep -> etX) < 0.25 pb is established at 95% CL. Limits on the anomalous coupling kappa_{tu gamma} are derived.

Aaron, F D; Alexa, C; Alimujiang, K; Andreev, V; Antunovic, B; Asmone, A; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; de Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; De Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, S; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jonsson, L; Jung, Andreas Werner; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H U.; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schmitz, C; Schoeffel, L; Schoning, A; Schultz-Coulon, H C; Sefkow, F; Shaw-West, R N; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U.; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F; Zus, R; 10.1016/j.physletb.2009.06.057

2009-01-01T23:59:59.000Z

31

Top-quark mass measurements: Alternative techniques (LHC + Tevatron)  

E-Print Network (OSTI)

Measurements of the top-quark mass employing alternative techniques are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at the LHC. The alternative methods presented include measurements using the lifetime of $B$-hadrons, the transverse momentum of charged leptons and the endpoints of kinematic distributions in top quark anti-quark pair ($t\\bar{t}$) final states. The extraction of the top-quark pole mass from the $t\\bar{t}$ production cross-section and the normalized differential $t\\bar{t}$ + 1-jet cross-section are discussed as well as the top-quark mass extraction using fixed-order QCD predictions at detector level. Finally, a measurement of the top-quark mass using events enhanced in single top t-channel production is presented.

Adomeit, Stefanie

2014-01-01T23:59:59.000Z

32

The Top Quark, Its Discovery, and Subsequent Research  

Office of Scientific and Technical Information (OSTI)

The Top Quark, Its Discovery, and Subsequent Research The Top Quark, Its Discovery, and Subsequent Research Resources with Additional Information 'Ever since the existence of the bottom (or b) quark was inferred from the discovery of the Upsilon family of resonances at Fermilab in 1977, particle physicists have been on the lookout for its partner, called top (or t). The long search, which occupied experimenters at laboratories around the world, came to a successful conclusion in February 1995 with the announcement that the top quark had been observed in two experiments at the Tevatron proton-antiproton collider at Fermilab. ... Top Quark Courtesy Fermilab Top is the last of the fundamental constituents of subnuclear matter that theories of the strong, weak, and electromagnetic interactions and a wealth of experimental information had led particle physicists to expect. Theoretically, top's existence was required to make the electroweak theory internally consistent.'1

33

Dynamical electroweak symmetry breaking and the top quark  

SciTech Connect

In this talk, I discuss theories of dynamical electroweak symmetry breaking, with emphasis on the implications of a heavy top quark on the weak interaction {rho} parameter.

Chivukula, R.S. [Boston Univ., MA (United States)

1997-01-01T23:59:59.000Z

34

Top quark charge asymmetry measurements with ATLAS detector  

E-Print Network (OSTI)

The top quark charge asymmetry measurements performed with ATLAS detector at a centre-of-mass energy of 7 TeV are presented.

U. De Sanctis; for the ATLAS Collaboration

2014-11-13T23:59:59.000Z

35

Top quark charge asymmetry measurements with ATLAS detector  

E-Print Network (OSTI)

The top quark charge asymmetry measurements performed with ATLAS detector at a centre-of-mass energy of 7 TeV are presented.

De Sanctis, Umberto; The ATLAS collaboration

2014-01-01T23:59:59.000Z

36

Search for baryon number violation in top-quark decays  

E-Print Network (OSTI)

A search for baryon number violation (BNV) in top-quark decays is performed using pp collisions produced by the LHC at [sqrt s]=8 TeV. The top-quark decay considered in this search results in one light lepton (muon or ...

CMS Collaboration

37

Measurement of the Top Quark Mass With 2012 CMS Data  

E-Print Network (OSTI)

The mass of the top quark was an active topic of research at CMS using 2011 data, and remains so as the 2012 data analysis campaign proceeds. Here we discuss some of the earliest results on the top mass using 2012 sqrt(s) = 8 TeV CMS data, including measurements of the top mass from semileptonic t\\bar{t} decays and the lifetime of the B-hadron, as well as a measurement of the top-antitop mass difference.

Richard Nally

2014-09-01T23:59:59.000Z

38

Observation of $t$-channel electroweak top quark production  

SciTech Connect

The top quark is the heaviest known fundamental particle, with a mass of 172.0{sub -1.3}{sup +0.9}GeV. This is nearly twice the mass of the second heaviest known particle, the Z boson, and roughly the mass of a gold atom. Because of its unusually large mass, studying the top quark may provide insight into the Higgs mechanism and other beyond the standard model physics. Only two accelerators in the world are powerful enough to produce top quarks. The Tevatron, which first accelerated protons in 1983, has produced almost 400,000 top quarks, roughly half at each of its two detectors: DO and CDF. The LHC is a much newer accelerator which currently has accumulated about 0.5% as much data as the Tevatron. However, when running at full luminosity, the LHC is capable of producing a top quark about once every second and will quickly surpass the Tevatron as the leading producer of top quarks. This analysis uses data from the D0 detector at the Tevatron, which are described in chapter 3. Top quarks are produced most often in pairs of top and anti-top quarks through an interaction of the strong force. This production mode was first observed in 1995 at the Tevatron. However, top quarks can also be produced though an electroweak interaction, which produces just one top quark. This production mode was first observed at the Tevatron in 2008. Single top quark production can occur in different channels. In this analysis, a measurement of the cross section of the t-channel production mode is performed. This measurement uses 5.4 fb{sup -1} of data and uses the technique of boosted decision trees in order to separate signal from background events. The t-channel cross section is measured to be: {sigma}(p{bar p} {yields} tqb + X) = 3.03{sub -0.66}{sup +0.78}pb (0.0.1). Additional cross section measurements were also performed for the s-channel as well as the s + t-channel. The measurement of each one of these three cross sections was repeated three times using different techniques, and all three methods were combined into a 'super-method' which achieves the best performance. The details of these additional measurements are shown in appendix A.

Triplett, Nathan; /Iowa State U.

2011-04-01T23:59:59.000Z

39

Testing ETC Generation of the Top Quark Mass  

E-Print Network (OSTI)

We consider constraints on models in which a top quark mass is generated through unenhanced extended technicolor interactions. The deviation in the $\\rho$ parameter from unity and $B$--$\\overline{B}$ mixing could be large, but given the uncertainties in strong dynamics and variations in the parameters of models, no conclusive statement can be given. We conclude that the low technicolor scale which is required to generate the top quark mass is not ruled out.

L. Randall

1992-10-13T23:59:59.000Z

40

Gluon Radiation and Energy Losses in Top Quark Production  

E-Print Network (OSTI)

The emission of energetic gluons in $\\tt$ production in $\\ee$ annihilation can have important experimental consequences, in particular on top quark mass measurements. We present compact, analytical expressions for the gluon energy distribution and its average value at first order in QCD perturbation theory. Our results are valid for arbitrary masses, collision energies and production currents. We pay particular attention to top quark production near threshold, and show that in certain cases the soft gluon approximation is insufficient to describe the radiation spectrum.

Yu. L. Dokshitzer; V. A. Khoze; W. J. Stirling

1994-05-06T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Observation of the top quark with the DO detector  

SciTech Connect

The DO Collaboration reports on the observation of the top quark in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron. We measure the top quark mass to be 199{sub -21}{sup -19}(stat){sub -21}{sup +14}(syst.) GeV/c{sup 2} and its production cross section to be 6.4 {+-}2.2 pb. Our result is based on approximately 50 pb{sup -1} of data. We observe 17 events with an expected background of 3.8 {+-} 0.6 events. The probability of an upward fluctuation of the background to produce the observed signal is 2 x 10{sup -6} (equivalent to 4.6 standard deviations). The kinematic properties of the events are consistent with top quark decay, and the distribution of events across the seven decay channels is consistent with the Standard Model top quark branching fractions. We describe the analysis that led to the observation of the top quark as well as the properties of the top quark events.

Hadley, N.J. [Univ. of Maryland, College Park, MD (United States)

1997-01-01T23:59:59.000Z

42

Top Production  

NLE Websites -- All DOE Office Websites (Extended Search)

Top Principal ESTOY PERDIDO!!! Top Principal ESTOY PERDIDO!!! Protón + Antiprotón --> Top + Antitop Un quark (perteneciente a un protón) y un antiquark (perteneciente a un antiprotón), colisionando a alta energía, pueden aniquilarse para producir un quark top y un antiquark top, los cuales decaen luego hacia otras partículas. Cuadro 1: un quark de un protón y un antiquark de un antiprotón se precipitan uno al encuentro del otro. Cuadro 2: los quarks colisionan y se aniquilan.... Cuadro 3: ...en gluones virtuales. Cuadro 4: de la nube de gluones emergen un quark top y un antiquark top. Cuadro 5: los quarks comienzan separarse, estirando el campo de fuerza de color (campo de gluones) entre ambos. Cuadro 6: antes de que el quark top y el antiquark top se hayan separado mucho, ambos decaen hacia un quark bottom y un antiquark bottom

43

Top quark mass measurement using the template method at CDF  

We present a measurement of the top quark mass in the lepton+jets and dilepton channels of tt? decays using the template method. The data sample corresponds to an integrated luminosity of 5.6 fb-1 of pp? collisions at Tevatron with ?s = 1.96 TeV, collected with the CDF II detector. The measurement is performed by constructing templates of three kinematic variables in the lepton+jets and two kinematic variables in the dilepton channel. The variables are two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the W decay in the lepton+jets channel, and a reconstructed top quark mass and mT2, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the lepton+jets and dilepton channels to the data yields a measured top quark mass of Mtop = 172.1±1.1 (stat)±0.9 (syst) GeV/c2.

Aaltonen, T [Helsinki Inst. of Phys.; Alvarez Gonzalez, B [Oviedo U.; Cantabria Inst. of Phys.; Amerio, S [INFN, Padua; Amidei, D [Michigan U.; Anastassov, A [Northwestern U.; Annovi, A [Frascati; Antos, J [Comenius U.; Apollinari, G [Fermilab; Appel, J A [Fermilab; Apresyan, A [Purdue U.; Arisawa, T [Waseda U.; Dubna, JINR

2011-06-03T23:59:59.000Z

44

A Precision Measurement of the Mass of the Top Quark  

E-Print Network (OSTI)

The Standard Model of particle physics contains about two dozen parameters - such as particle masses - whose origins are still unknown and cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top (t) quark (M_t) and W boson constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of the top-quark mass can therefore point to where to look for the Higgs, and indeed whether the hypothesis of a SM Higgs is consistent with experimental data. Since top quarks are produced in pairs and decay in only ~10^-24 s into various final states, reconstructing their mass from their decay products is very challenging. Here we report a technique that extracts far more information from each top-quark event and yields a greatly improved precision on the top mass of 5.3 GeV/c^2, compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the onl...

Abazov, V M; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alton, A; Alves, G A; Arnoud, Y; Avila, C; Babintsev, V V; Babukhadia, L; Bacon, Trevor C; Baden, A; Baffioni, S; Baldin, B Yu; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beaudette, F; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blekman, F; Blessing, S; Böhnlein, A; Bozhko, N; Bolton, T A; Borcherding, F; Bos, K; Bose, T; Brandt, A; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Bühler, M; Büscher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Claes, D; Clark, A R; Connolly, B; Cooper, W E; Coppage, D; Crepe-Renaudin, S; Cummings, M A C; Cutts, D; Da Motta, H; Davis, G A; De, K; De Jong, S J; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doulas, S; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dyshkant, A; Edmunds, D; Ellison, J; Eltzroth, J T; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Ferbel, T; Filthaut, F; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gallas, E; Galjaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Yu; Ginther, G; Gómez, B; Goncharov, P I; Gounder, K; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Grinstein, S; Groer, L; Grünendahl, S; Grünewald, M W; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Han, C; Hansen, S; Hauptman, J M; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, J; Huang, Y; Iashvili, I; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jöstlein, H; Juste, A; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Kesisoglou, S; Khanov, A; Kharchilava, A I; Klima, B; Kohli, J M; Kostritskii, A V; Kotcher, J; Kothari, B; Kozelov, A V; Kozlovskii, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M A; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G L; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K A; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Mattingly, S E K; Mayorov, A A; McCarthy, R; McMahon, T; Melanson, H L; Melnitchouk, A S; Merkin, M; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mokhov, N V; Mondal, N K; Montgomery, H E; Moore, R W; Mutaf, Y D; Nagy, E; Narain, M; Narasimham, V S; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Nomerotski, A; Nunnemann, T; O'Neil, D; Oguri, V; Oshima, N; Padley, P; Papageorgiou, K; Parashar, N; Partridge, R; Parua, N; Patwa, A; Peters, O; Petroff, P; Piegaia, R; Pope, B G; Prosper, H B; Protopopescu, S D; Przybycien, M B; Qian, J; Rajagopalan, S; Rapidis, P A; Reay, N W; Reucroft, S; Ridel, M; Rijssenbeek, M; Rizatdinova, F K; Rockwell, T; Royon, C; Rubinov, P; Ruchti, R; Sabirov, B M; Sajot, G; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simák, V; Sirotenko, V I; Slattery, P F; Smith, R P; Snow, G R; Snow, J; Snyder, S; Solomon, J; Song, Y; Sorin, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbruck, G; Stoker, D; Stolin, V; Stone, A; Stoyanova, D A; Strang, M A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Talby, M; Taylor, W; Tentindo-Repond, S; Trippe, T G; Turcot, A S; Tuts, P M; Van Kooten, R; Vaniev, V; Varelas, N; Villeneuve-Séguier, F; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, Z M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; Whiteson, D; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Xu, Q; Yamada, R; Yasuda, T; Yatsunenko, Y A; Yip, K; Yu, J; Zanabria, M; Zhang, X; Zhou, B; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

2004-01-01T23:59:59.000Z

45

Precision Top-Quark Mass Measurements at CDF  

SciTech Connect

We present a precision measurement of the top-quark mass using the full sample of Tevatron {radical}s = 1.96 TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb{sup -1}. Using a sample of t{bar t} candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the W boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with in situ calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, mtop = 172.85 {+-} 0.71 (stat) {+-} 0.85 (syst) GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U.; Artikov, A.; /Dubna, JINR /Texas A-M

2012-07-01T23:59:59.000Z

46

Top quarks as a probe for heavy new physics  

E-Print Network (OSTI)

The heaviest fermion is expected to couple strongly to new physics and appears therefore as a natural probe in many BSM scenarios. Moreover, top physics has now entered in a precision era thanks to the huge amount of top quarks produced at hadron colliders, advanced experimental methods and accurate theoretical predictions. In this talk, we will used effective field theory to search for heavy new physics in a model independent way. This method can also be used to quantify the room left for new physics if no deviation from the SM is found.

Celine Degrande

2014-07-11T23:59:59.000Z

47

Top Quark Studies with the first CMS Data  

E-Print Network (OSTI)

Studies are presented of the selection of events consistent with top quark pair production in data recorded by the CMS detector at the LHC, corresponding to an integrated luminosity of 0.84+/-0.09 1/pb and at center-of-mass energy sqrt{s}=7 TeV. Results are presented for the lepton+jets as well as dilepton channels. Event yields in data are compared to those in simulation, and several background processes are estimated using data-driven techniques. The observed yields of top-antitop candidate events are roughly consistent with the Standard Model.

Frank-Peter Schilling

2010-10-12T23:59:59.000Z

48

Forward-backward asymmetry in top quark-antiquark production  

SciTech Connect

We present a measurement of forward-backward asymmetry in top quark-antiquark production in proton-antiproton collisions in the final state containing a lepton and at least four jets. Using a dataset corresponding to an integrated luminosity of 5.4 fb-1, collected by the D0 experiment at the Fermilab Tevatron Collider, we measure the t{bar t} forward-backward asymmetry to be (9.2 ± 3.7)% at the reconstruction level. When corrected for detector acceptance and resolution, the asymmetry is found to be (19.6 ± 6.5)%. We also measure a corrected asymmetry based on the lepton from a top quark decay, found to be (15.2 ± 4.0)%. The results are compared to predictions based on the next-to-leading-order QCD generator mc@nlo. The sensitivity of the measured and predicted asymmetries to the modeling of gluon radiation is discussed.

Abazov, Victor Mukhamedovich [Dubna, JINR; Abbott, Braden Keim [Oklahoma U.; Acharya, Bannanje Sripath [Tata Inst.; Adams, Mark Raymond [Illinois U., Chicago; Adams, Todd [Florida State U.; Alexeev, Guennadi D [Dubna, JINR; Alkhazov, Georgiy D [St. Petersburg, INP; Alton, Andrew K [Michigan U.; Augustana Coll., Sioux Falls; Alverson, George O [Northeastern U.; Alves, Gilvan Augusto [Rio de Janeiro, CBPF; Aoki, Masato [Fermilab; Louisiana Tech. U.

2011-12-12T23:59:59.000Z

49

Search for electroweak single top quark production with CDF  

SciTech Connect

We report on a search for Standard Model t-channel and s-channel single top quark production in p{bar p} collisions at a center of mass energy of 1.96 TeV. We use a data sample corresponding to 162 pb{sup -1} recorded by the upgraded Collider Detector at Fermilab. We find no significant evidence for electroweak top quark production and set upper limits at the 95% confidence level on the production cross section, consistent with the Standard Model: 10.1 pb for the t-channel, 13.6 pb for the s-channel and 17.8 pb for the combined cross section of t- and s-channel.

Kemp, Y.; /Karlsruhe U.

2005-01-01T23:59:59.000Z

50

Calculation of the cross section for top quark production  

SciTech Connect

The authors summarize calculations of the cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the strong coupling strength. In their approach they resume the universal leading-logarithm contributions, and they restrict the calculation to the region of phase space that is demonstrably perturbative. They compare the approach with other methods. They present predictions of the physical cross section as a function of the top quark mass in proton-antiproton reactions at center-of-mass energies of 1.8 and 2.0 TeV, and they discuss estimated uncertainties.

Berger, E.L.; Contopanagos, H. [Argonne National Lab., IL (United States). High Energy Physics Div.

1996-06-21T23:59:59.000Z

51

QCD and Top Quark Physics at the LHC  

E-Print Network (OSTI)

The expected performance of the ATLAS and CMS detectors at the Large Hadron Collider (LHC) in QCD and top quark measurements is discussed, with a focus on the early data taking phase. Such processes are amongst the primary backgrounds in the searches for new physics, and thus must be understood very well before discoveries can be made. In addition, they serve as useful detector calibration candles.

Frank-Peter Schilling

2009-01-30T23:59:59.000Z

52

Collider Detector at Fermilab (CDF): Data from the Top Group's Top Quark Research  

DOE Data Explorer (OSTI)

The Collider Detector at Fermilab (CDF) is a Tevatron experiment at Fermilab. The Tevatron, a powerful particle accelerator, accelerates protons and antiprotons close to the speed of light, and then makes them collide head-on inside the CDF detector. The CDF detector is used to study the products of such collisions. The CDF Physics Group at Fermilab is organized into six working groups, each with a specific focus. The Top group studies the properties of the top quark, the heaviest known fundamental particle. Their public web page makes data and numerous figures available from both CDF Runs I and II.

53

Z?bb¯ excess and top quark decay  

Science Journals Connector (OSTI)

The apparent excess of Z?bb¯ events at CERN LEP may be an indication of new physics beyond the standard model. However, in either the two-Higgs-doublet model or the minimal supersymmetric standard model any explanation would lead to an important new decay mode of the top quark and suppresses the t?Wb branching fraction, which goes against what has been observed at the Fermilab Tevatron. In the two-Higgs-doublet model, the branching fraction of Z?bb¯+a light boson which decays predominantly into bb¯ would be at least of order 10-4. © 1995 The American Physical Society.

Ernest Ma and Daniel Ng

1996-01-01T23:59:59.000Z

54

Constraints on Top Couplings in Models with Exotic Quarks  

Science Journals Connector (OSTI)

The extension of the standard model with exotic quark singlets and doublets introduces large flavor changing neutral couplings between ordinary fermions. We derive inequalities which translate the precise determination of the diagonal Z couplings, in particular, at LEP, into stringent bounds on the off-diagonal ones. The resulting limits can be saturated in minimal extensions with one vector doublet or singlet. In this case, 23 and 6 single top events, respectively, are predicted at LEP2 for an integrated luminosity of 500 pb-1 per experiment.

F. del Aguila; J. A. Aguilar-Saavedra; R. Miquel

1999-02-22T23:59:59.000Z

55

A Search for the Standard Model Higgs Boson Produced in Association with Top Quarks.  

E-Print Network (OSTI)

??We have performed a search for the Standard Model Higgs boson produced in association with top quarks in the lepton plus jets channel. We impose… (more)

Wilson, Jonathan S.

2012-01-01T23:59:59.000Z

56

Search for pair production of excited top quarks in the lepton + jets final state  

E-Print Network (OSTI)

A search is performed for pair-produced spin-3/2 excited top quarks (t[superscript ?][¯ over t][superscript ?]), each decaying to a top quark and a gluon. The search uses data collected with the CMS detector from pp ...

Apyan, Aram

57

Associated production of a top quark and a charged Higgs boson  

Science Journals Connector (OSTI)

We compute the inclusive and differential cross sections for the associated production of a top quark along with a charged Higgs boson at hadron colliders to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD) and in supersymmetric QCD. For small Higgs boson masses we include top-quark pair production diagrams with subsequent top-quark decay into a bottom quark and a charged Higgs boson. We compare the NLO differential cross sections obtained in the bottom parton picture with those for the gluon-initiated production process and find good agreement. The effects of supersymmetric loop contributions are explored. Only the corrections to the Yukawa coupling are sizable in the potential discovery region at the CERN Large Hadron Collider (LHC). All expressions and numerical results are fully differential, permitting selections on the momenta of both the top quark and the charged Higgs boson.

Edmond L Berger; Tao Han; Jing Jiang; Tilman Plehn

2005-06-28T23:59:59.000Z

58

Finding the charge of the top quark in the dilepton channel  

SciTech Connect

There is a question about the identity of the top quark. Is it the top quark of the Standard Model (SM) with electric charge 2/3 or is it an exotic quark with charge -4/3? An exotic quark has been proposed by D. Chang et al. [1]. This analysis will use the standard CDF run II dilepton sample. The key ingredients of this analysis are the correct pairing of the lepton and b-jet, the determination of the charge of the b-jet. The analysis proceeds by using a binomial distribution and is formulated so that rejecting one hypothesis means support for the other hypothesis.

Beretvas, A.; Antos, J.; Chen, Y.C.; Gunay, Z.; Sorin, V.; Tollefson, K.; Bednar, P.; Tokar, S.; Boisvert, V.; Hopkins, W.; McFarland, K.; /Fermilab /Kosice, IEF /Taiwan,

2006-08-01T23:59:59.000Z

59

Precise measurement of the top quark mass in the lepton+jets topology at CDF II  

SciTech Connect

The authors present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. They analyze events from the single lepton plus jets final state (t{bar t} {yields} W{sup +}bW{sup -}{bar b} {yields} lvbq{bar q}{bar b}). The top quark mass is extracted using a direct calculation of the probability density that each event corresponds to the t{bar t} final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb{sup -1} of integrated luminosity, they achieve the single most precise measurement of the top quark mass, 170.8 {+-} 2.2(stat.) {+-} 1.4(syst.) GeV/c{sup 2}.

Abulencia, A.; /Illinois U., Urbana; Adelman, J.; /Chicago U.; Affolder, T.; /UC, Santa Barbara; Akimoto, T.; /Tsukuba U.; Albrow, M.G.; /Fermilab; Amerio, S.; /Padua U.; Amidei, D.; /Michigan U.; Anastassov, A.; /Rutgers U., Piscataway; Anikeev, K.; /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U. /Tsukuba U.

2007-03-01T23:59:59.000Z

60

Search for New Particles Decaying to Dijets, Bottom Quarks, and Top Quarks at CDF  

E-Print Network (OSTI)

We present three searches for new particles at CDF. First, using 70 pb^-1 of data we search the dijet mass spectrum for resonances. There is an upward fluctuation near 550 GeV (2.6 sigma) with an angular distribution that is adequately described by either QCD alone or QCD plus 5% signal. There is insufficient evidence to claim a signal, but we set the most stringent mass limits on the hadronic decays of axigluons, excited quarks, technirhos, W', Z', and E6 diquarks. Second, using 19 pb^-1 of data we search the b-tagged dijet mass spectrum for b anti-b resonances. Again, an upward fluctuation near 600 GeV (2 sigma) is not significant enough to claim a signal, so we set the first mass limits on topcolor bosons. Finally, using 67 pb^-1 of data we search the top quark sample for t anti-t resonances like a topcolor Z'. Other than an insignificant shoulder of 6 events on a background of 2.4 in the mass region 475-550 GeV, there is no evidence for new particle production. Mass limits, currently in progress, should be sensitive to a topcolor Z' near 600 GeV. In all three searches there is insufficient evidence to claim new particle production, yet there is an exciting possibility that the upward fluctuations are the first signs of new physics beyond the standard model.

Robert M. Harris

1995-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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61

TC corrections to the single-top-quark production at the Fermilab Tevatron  

E-Print Network (OSTI)

We calculate one-loop corrections to the single-top-quark production via $q\\overline{q}' \\to t\\overline b$ at the Fermilab Tevatron from the Pseudo-Goldstone bosons ( PGBs ) in the framework of one generation technicolor model. The maximum correction to the total cross section for the single-top-quark production is found to reach -2.4% relative to the tree-level cross section, which may be observable at a high-luminosity Tevatron.

Gongru Lu; Yigang Cao; Jinshu Huang; Junde Zhang; Zhenjun Xiao

1997-01-29T23:59:59.000Z

62

Supersymmetric electroweak corrections to top quark production at the Fermilab Tevatron  

Science Journals Connector (OSTI)

We calculate the genuine supersymmetric electroweak corrections of order ?mt2/mW2, which arise from loops of the chargino, neutralino, and squark, to top quark production at the Fermilab Tevatron in the minimal supersymmetric model. The observable hadronic cross section can be enhanced by 20% for a top quark mass of 170 GeV and squark mass of 100 GeV. When the squark mass gets larger, the corrections decrease rapidly.

Jin Min Yang and Chong Sheng Li

1995-08-01T23:59:59.000Z

63

Measurement of the Top Quark Mass Simultaneously in Dilepton and Lepton + Jets Decay Channels  

SciTech Connect

The authors present the first measurement of the top quark mass using simultaneously data from two decay channels. They use a data sample of {radical}s = 1.96 TeV collisions with integrated luminosity of 1.9 fb{sup -1} collected by the CDF II detector. They select dilepton and lepton + jets channel decays of t{bar t} pairs and reconstruct two observables in each topology. They use non-parametric techniques to derive probability density functions from simulated signal and background samples. The observables are the reconstructed top quark mass and the scalar sum of transverse energy of the event in the dilepton topology and the reconstructed top quark mass and the invariant mass of jets from the W boson decay in lepton + jets channel. They perform a simultaneous fit for the top quark mass and the jet energy scale which is constrained in situ by the hadronic W boson resonance from the lepton + jets channel. Using 144 dilepton candidate events and 332 lepton + jets candidate events they measure: M{sub top} = 171.9 {+-} 1.7 (stat. + JES) {+-} 1.1 (other sys.) GeV/c{sup 2} = 171.9 {+-} 2.0 GeV/c{sup 2}. The measurement features a robust treatment of the systematic uncertainties, correlated between the two channels and develops techniques for a future top quark mass measurement simultaneously in all decay channels. Measurements of the W boson mass and the top quark mass provide a constraint on the mass of the yet unobserved Higgs boson. The Higgs boson mass implied by measurement presented here is higher than Higgs boson mass implied by previously published, most precise CDF measurements of the top quark mass in lepton + jets and dilepton channels separately.

Fedorko, Wojciech T.; /Chicago U.

2008-09-01T23:59:59.000Z

64

Measurement of the Electric Charge of the Top Quark in $\\boldsymbol{t\\bar{t}}$ Events  

E-Print Network (OSTI)

We present a measurement of the electric charge of top quarks using $t\\bar{t}$ events produced in $p\\bar{p}$ collisions at the Tevatron. The analysis is based on fully reconstructed $t\\bar{t}$ pairs in lepton+jets final states. Using data corresponding to 5.3 $\\rm fb^{-1}$ of integrated luminosity, we exclude the hypothesis that the top quark has a charge of $Q=-4/3\\,e$ at a significance greater than 5 standard deviations. We also place an upper limit of 0.46 on the fraction of such quarks that can be present in an admixture with the standard model top quarks ($Q=+2/3\\,e$) at a 95\\% confidence level.

D0 Collaboration

2014-09-25T23:59:59.000Z

65

Top-quark mass measurement using events with missing transverse energy and jets at CDF  

SciTech Connect

We present a measurement of the top-quark mass with tt? events using a data sample corresponding to an integrated luminosity of 5.7 fb -1 of pp? collisions at the Fermilab Tevatron with ?s = 1.96 TeV and collected by the CDF II Detector. We select events having no identified charged leptons, large missing transverse energy, and four, five, or six jets with at least one jet containing a secondary vertex consistent with the decay of a b quark. This analysis considers events from the semileptonic tt? decay channel, including events that contain tau leptons, which are usually not included in the top-quark mass measurements. The measurement uses as kinematic variables the invariant mass of two jets consistent with the mass of the W boson, and the invariant masses of two different three-jet combinations. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of Mtop = 172.3 ± 2.4 (stat) ± 1.0 (syst) GeV/c2.

Aaltonen, T; Alvarez Gonzalez, B; Amerio, S; Anastassov, A; Amidei, D; Antos, J; Annovi, A

2013-07-01T23:59:59.000Z

66

Finding the Charge of the top quark in the Dilepton Channel  

E-Print Network (OSTI)

There is a question about the identity of the top quark. Is it the top quark of the Standard Model (SM) with electric charge 2/3 or is it an exotic quark with charge -4/3? An exotic quark has been proposed by D. Chang et al.\\cite{hep-ph/9810531, hep-ph/9805273}. This analysis will use the standard CDF run II dilepton sample. The key ingredients of this analysis are the correct pairing of the lepton and b-jet, the determination of the charge of the b-jet. The analysis proceeds by using a binomial distribution and is formulated so that rejecting one hypothesis means support for the other hypothesis.

Beretvas, A; Chen, Y C; Gunay, Z; Sorin, V; Tollefson, K; Bednar, P; Tokar, S; Boisvert, V; Hopkins, W; McFarland, K

2007-01-01T23:59:59.000Z

67

Precise measurement of the top-quark mass from lepton+jets events at D0  

SciTech Connect

We report a measurement of the mass of the top quark in lepton+jets final states of pp&3772; ? tt? data corresponding to 2.6 fb-1 of integrated luminosity collected at the D0 experiment at the Fermilab Tevatron Collider. Using a matrix element method, we combine an in situ jet energy calibration with the standard jet energy scale derived in studies of ? + jet and dijet events and employ a novel flavor-dependent jet response correction to measure a top-quark mass of mt = 176.01 ± 1.64 GeV. Combining this result with a previous result obtained on an independent data set, we measure a top-quark mass of mt = 174.94 ± 1.49 GeV for a total integrated luminosity of 3.6 fb-1.

Abazov, Victor Mukhamedovich [Dubna, JINR; Abbott, Braden Keim [Oklahoma U.; Acharya, Bannanje Sripath [Tata Inst.; Adams, Mark Raymond [Illinois U., Chicago; Adams, Todd [Florida State U.; Alexeev, Guennadi D [Dubna, JINR; Alkhazov, Georgiy D [St. Petersburg, INP; Alton, Andrew K [Michigan U.; Augustana Coll., Sioux Falls; Alverson, George O [Northeastern U.; Alves, Gilvan Augusto [Rio de Janeiro, CBPF; Ancu, Lucian Stefan [Nijmegen U.; Fermilab

2011-08-09T23:59:59.000Z

68

Precise measurement of the top-quark mass from lepton+jets events at D0  

We report a measurement of the mass of the top quark in lepton+jets final states of pp&3772; ? tt? data corresponding to 2.6 fb-1 of integrated luminosity collected at the D0 experiment at the Fermilab Tevatron Collider. Using a matrix element method, we combine an in situ jet energy calibration with the standard jet energy scale derived in studies of ? + jet and dijet events and employ a novel flavor-dependent jet response correction to measure a top-quark mass of mt = 176.01 ± 1.64 GeV. Combining this result with a previous result obtained on an independent data set, we measure a top-quark mass of mt = 174.94 ± 1.49 GeV for a total integrated luminosity of 3.6 fb-1.

Abazov, Victor Mukhamedovich [Dubna, JINR; Abbott, Braden Keim [Oklahoma U.; Acharya, Bannanje Sripath [Tata Inst.; Adams, Mark Raymond [Illinois U., Chicago; Adams, Todd [Florida State U.; Alexeev, Guennadi D [Dubna, JINR; Alkhazov, Georgiy D [St. Petersburg, INP; Alton, Andrew K [Michigan U.; Augustana Coll., Sioux Falls; Alverson, George O [Northeastern U.; Alves, Gilvan Augusto [Rio de Janeiro, CBPF; Ancu, Lucian Stefan [Nijmegen U.; Fermilab

2011-08-09T23:59:59.000Z

69

Measurement of the top quark mass in lepton+jets events with secondary vertex tagging  

SciTech Connect

A measurement of the top quark mass with the matrix element method in the lepton + jets final state in D0 Run II is presented. Events with single isolated energetic charged lepton (electron or muon), exactly four calorimeter jets, and significant missing transverse energy are selected. Probabilities used to discriminate between signal and background are assumed to be proportional to differential cross-sections, calculated using event kinematics and folding in object resolutions and parton distribution functions. The event likelihoods constructed using these probabilities are varied with the top quark mass, m{sub t}, and the jet energy scale, JES, to give the smallest possible combined statistical + JES uncertainty.

Harrington, Robert Duane; /Northeastern U.

2007-02-01T23:59:59.000Z

70

Measurement of the Top Quark Mass in the All-Hadronic Mode at CDF  

SciTech Connect

A measurement of the top quark mass (M{sub top}) in the all-hadronic decay channel is presented. It uses 5.8 fb{sup -1} of p{bar p} data collected with the CDF II detector at the Fermilab Tevatron Collider. Events with six to eight jets are selected by a neural network algorithm and by the requirement that at least one of the jets is tagged as a b quark jet. The measurement is performed with a likelihood fit technique, which simultaneously determines M{sub top} and the jet energy scale (JES) calibration. The fit yields a value of M{sub top} = 172.5 {+-} 1.4 (stat) {+-} 1.0 (JES) {+-} 1.1 (syst) GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U.; Artikov, A.; /Dubna, JINR /Texas A-M

2011-12-01T23:59:59.000Z

71

Higgs boson production in association with top quarks in the POWHEG BOX  

E-Print Network (OSTI)

We present results from the analytic calculation of top+antitop+Higgs hadronic production at Next-to-Leading Order in QCD interfaced with parton-shower Monte Carlo event generators in the POWHEG BOX framework. We consider kinematic distributions of the top quark and Higgs boson at the 8 TeV Large Hadron Collider and study the theoretical uncertainties due to specific choices of renormalization/factorization scales and parton-showering algorithms, namely PYTHIA and HERWIG. The importance of spin-correlations in the production and decay stages of a top/antitop quark is discussed on the example of kinematic distributions of leptons originating from the top/antitop decays. The corresponding code is now part of the public release of the POWHEG BOX.

Hartanto, Heribertus B; Reina, Laura; Wackeroth, Doreen

2015-01-01T23:59:59.000Z

72

Virtual corrections to Higgs boson pair production in the large top quark mass limit  

Science Journals Connector (OSTI)

Abstract We calculate the three-loop matching coefficient C H H , required for a consistent description of Higgs boson pair production in gluon fusion through next-to-next-to-leading order QCD in the heavy top quark approximation. We also compute the g g ? H H amplitude in m t ? ? approximation in the full theory and show its consistency with an earlier computation in heavy-top effective theory.

Jonathan Grigo; Kirill Melnikov; Matthias Steinhauser

2014-01-01T23:59:59.000Z

73

Weak interaction corrections to hadronic top quark pair production: contributions from quark-gluon and $b \\bar b$ induced reactions  

E-Print Network (OSTI)

As an addendum to our previous evaluation of the weak-interaction corrections to hadronic top-quark pair production we determine the leading weak-interaction contributions due to the subprocesses $b {\\bar b} \\to t {\\bar t}$ and $g q ({\\bar q}) \\to t {\\bar t} q ({\\bar q})$. For several distributions in $t {\\bar t}$ production at the LHC we find that these contributions are non-negligible as compared to the weak corrections from the other partonic subprocesses.

Werner Bernreuther; Michael Fuecker; Zong-Guo Si

2008-04-08T23:59:59.000Z

74

Observation of s-Channel Production of Single Top Quarks at the Tevatron  

E-Print Network (OSTI)

We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of ...

Aaltonen, T.

75

Observation of single top quark production and measurement of |Vtb| with CDF  

E-Print Network (OSTI)

We report the observation of electroweak single top quark production in 3.2??fb-1 [fb superscript -1] of pp? collision data collected by the Collider Detector at Fermilab at ?s=1.96??TeV [square root of s=1.96 TeV]. Candidate ...

Bauer, Gerry P.

76

Simona Rolli, Fermilab W&C Recent results on top quark,  

E-Print Network (OSTI)

4/27/04 Simona Rolli, Fermilab W&C seminar 1 Recent results on top quark, electroweak and new;4/27/04 Simona Rolli, Fermilab W&C seminar 2 Introduction Exciting time now at CDF ! frenzy activity in physics datasets Common identification/reconstruction cuts #12;4/27/04 Simona Rolli, Fermilab W&C seminar 3 Outline

Fermilab

77

Search for the associated production of the Higgs boson with a top-quark pair  

E-Print Network (OSTI)

A search for the standard model Higgs boson produced in association with a top-quark pair (tt¯H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?1 and 19.7 fb?1 collected in pp ...

CMS Collaboration

78

Diphoton decay of the Higgs boson and new bound states of top and anti-top quarks  

E-Print Network (OSTI)

We consider the constraints, provided by the LHC results on Higgs boson decay into 2 photons and its production via gluon fusion, on the previously proposed Standard Model (SM) strongly bound state $S$ of 6 top quarks and 6 anti-top quarks. A correlation is predicted between the ratios $\\kappa_{\\gamma}$ and $\\kappa_g$ of the Higgs diphoton decay and gluon production amplitudes respectively to their SM values. We estimate the contribution to these amplitudes from one loop diagrams involving the 12 quark bound state $S$ and related excited states using an atomic physics based model. We find two regions of parameter space consistent with the ATLAS and CMS data on ($\\kappa_{\\gamma}$, $\\kappa_g$) at the 3 sigma level: a region close to the SM values ($\\kappa_{\\gamma}=1$, $\\kappa_g =1$) with the mass of the bound state $m_S > 400$ GeV and a region with ($\\kappa_{\\gamma} \\sim 3/2$, $\\kappa_g \\sim -3/4$) corresponding to a bound state mass of $m_S \\sim 220$ GeV.

Froggatt, C D; Laperashvili, L V; Nielsen, H B

2015-01-01T23:59:59.000Z

79

Early physics with top quarks at the LHC  

E-Print Network (OSTI)

The ATLAS and CMS experiments are now in their final installation phase and will be soon ready to study the physics of proton-proton collisions at the Large Hadron Collider. The LHC, by producing 2 $t\\bar{t}$ events per second, will provide more than 8 million top events a year at start-up. In this paper, particular emphasis is given to the $t\\bar{t}$ physics studies that can be performed at the beginning of the LHC running, with a limited amount of integrated luminosity ($\\le$10 fb$^{-1}$).

Pamela Ferrari

2007-05-21T23:59:59.000Z

80

ATLAS sensitivity to Wtb anomalous couplings in top quark decays  

E-Print Network (OSTI)

We study the sensitivity of the ATLAS experiment to Wtb anomalous couplings in top pair production with semileptonic decay, pp -> t tbar -> W+ b W- bbar, with one of the W bosons decaying leptonically and the other hadronically. Several observables are examined, including the W helicity fractions and new quantities recently introduced, such as the ratios of helicity fractions and some angular asymmetries defined in the W rest frame. The dependence on anomalous couplings of all these observables has been previously obtained. In this work we show that some of the new observables also have smaller systematic uncertainties than the helicity fractions, with a dependence on anomalous couplings similar or stronger than for helicity fractions. Consequently, their measurement can significantly improve the limits on anomalous couplings. Moreover, the most sensitive measurements can be combined. In this case, the precision achieved in the determination of Wtb anomalous couplings can be of a few percent in the semileptonic channel alone.

J. A. Aguilar-Saavedra; J. Carvalho; N. Castro; A. Onofre; F. Veloso

2007-12-17T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Top quark pair production cross section using the ATLAS detector at the LHC  

E-Print Network (OSTI)

Measurements of the inclusive top quark pair production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented. The measurements are performed requiring one or two electrons or muons in the final state. Various experimental techniques are compared. The most accurate result in obtained requiring opposite sign electrons and muons, achieves a precision of a few percent, and is in good agreement with a recent NNLO+NNLL QCD calculation. In addition, a di erential measurement of the top transverse momentum and kinematic properties of the top pair system are presented. This measurement requires one electron or muon in the final state and probes our understanding of top pair production in the TeV regime and is compared to recent Monte Carlo generators and theory calculations.

Theveneaux-Pelzer, Timothee; The ATLAS collaboration

2014-01-01T23:59:59.000Z

82

Independent measurement of the top quark mass and the light- and bottom-jet energy scales at hadron colliders  

E-Print Network (OSTI)

A method for the simultaneous determination of the energy scales for b-quark jets and light jets, the jet energy resolution, and the top quark mass at hadron colliders is presented. The method exploits the unique kinematics of events with top-antitop pair production, where one of the top quarks involves a leptonic and one a hadronic W boson decay. The paper shows a feasibility study of how this simultaneous measurement can be performed at the upcoming LHC experiments ATLAS and CMS.

Frank Fiedler

2007-06-12T23:59:59.000Z

83

Precision Measurement of the Mass of the Top Quark in p anti-p Collisions  

SciTech Connect

We report a measurement of the mass of the top quark (m{sub top}) in p{bar p} collisions at a center of mass energy of 1.96 TeV. The analysis is based on p{bar p}{yields}t{bar t}{yields} lepton+jets data recorded with the D0 detector at the Fermilab Tevatron Collider. Events were preselected in the e+jets (913 events/pb of data) and in the {mu}+jets (871 events/pb of data) channels. These were analyzed through a comparison of the matrix element for the production and decay of the t{bar t} states with data, using a likelihood method and 'tagged' b quarks from the t {yields} Wb decays.

Garcia, Carlos A.; /Rochester U.; ,

2007-01-01T23:59:59.000Z

84

Search for H ? ?? produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector  

E-Print Network (OSTI)

A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states ...

Taylor, Frank E.

85

Measurement of the top quark mass in final states with two leptons  

Science Journals Connector (OSTI)

We present measurements of the top quark mass (mt) in tt¯ candidate events with two final state leptons using 1??fb-1 of data collected by the D0 experiment. Our data sample is selected by requiring two fully identified leptons or by relaxing one lepton requirement to an isolated track if at least one jet is tagged as a b jet. The top quark mass is extracted after reconstructing the event kinematics under the tt¯ hypothesis using two methods. In the first method, we integrate over expected neutrino rapidity distributions, and in the second we calculate a weight for the possible top quark masses based on the observed particle momenta and the known parton distribution functions. We analyze 83 candidate events in the data and obtain mt=176.2±4.8(stat)±2.1(sys)??GeV and mt=173.2±4.9(stat)±2.0(sys)??GeV for the two methods, respectively. Accounting for correlations between the two methods, we combine the measurements to obtain mt=174.7±4.4(stat)±2.0(sys)??GeV.

V. M. Abazov et al. (The D0 Collaboration)

2009-11-20T23:59:59.000Z

86

A measurement of the top quark mass with a matrix element method  

SciTech Connect

The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb{sup -1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t{bar t} and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb{sup -1} dataset they extract a top quark mass of 172.0 {+-} 2.6(stat) {+-} 3.3(syst) GeV/c{sup 2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c{sup 2} for m{sub t} = 178 GTeV/c{sup 2} and 3.1 GeV/c{sup 2} for m{sub t} = 172.5 GeV/c{sup 2}. The systematic error is dominated by the uncertainty of the jet energy scale.

Gibson, Adam Paul; /UC, Berkeley

2006-12-01T23:59:59.000Z

87

Study on the top quark pair production mechanism in 1.96 TeV proton-antiproton collisions  

SciTech Connect

The study of the top quark pair production mechanism in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV is described. The main subjects are the measurements of the top quark pair production cross section, the top quark mass and a search for a new particle decaying to the top quark pair. The analyses are based on 1.9 fb{sup -1} of data collected by the Collider Detector at Fermilab (CDF) Run II experiment between March 2002 and May 2007, using the lepton+jets events. The measured top quark pair production cross section is 8.2 {+-} 0.5 (stat.) {+-} 0.8 (syst.) {+-} 0.5 (lum.) pb, which is slightly higher than the standard model prediction at the top mass of 175 GeV/c{sup 2}. The top quark mass is an important parameter in the standard model, and also in the experimental studies. The measured top quark mass if 171.6 {+-} 2.0 (stat.) {+-} 1.3(syst.) GeV/c{sup 2}. Finally, they report on a search for a new gauge boson decaying to t{bar t}, which interferes with the standard model gluon in the q{bar q} {yields} t{bar t} production process. They call such a hypothetical particle a 'Massive Gluon'. The observed t{bar t} invariant mass distribution is consistent with the standard model expectations, and also the measured massive gluon coupling strength with quarks is consistent within a statistical fluctuation of the standard model expectation in the wide range of the massive gluon masses and widths. They set the upper and lower limits on the coupling strength of the massive gluon.

Naganoma, Junji; /Waseda U.

2008-03-01T23:59:59.000Z

88

Perspectives on top quark physics after Run I of the LHC: sqrt(s)=13 TeV and beyond  

E-Print Network (OSTI)

A summary of the on-going preparations from the ATLAS and CMS collaborations to perform top quark physics in Run II of the LHC and at the HL-LHC is given. To maintain the current level of precision and profit from the high-luminosity scenario expected in the next runs of the LHC, several new reconstruction techniques and detector upgrades are foreseen. The prospects for precise measurements and possible discovery stories for new physics with top quarks are summarized.

Pedro Silva

2014-11-25T23:59:59.000Z

89

Measurement of the Top-Quark Mass in the All-Hadronic Channel using the full CDF data set  

E-Print Network (OSTI)

The top-quark mass M_top is measured using top quark-antiquark pairs produced in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV and decaying into a fully hadronic final state. The full data set collected with the CDFII detector at the Fermilab Tevatron Collider, corresponding to an integrated luminosity of 9.3 fb-1, is used. Events are selected that have six to eight jets, at least one of which is identified as having originated from a b quark. In addition, a multivariate algorithm, containing multiple kinematic variables as inputs, is used to discriminate signal events from background events due to QCD multijet production. Templates for the reconstructed top-quark mass are combined in a likelihood fit to measure M_top with a simultaneous calibration of the jet-energy scale. A value of M_top = 175.07+- 1.19(stat)+1.55-1.58(syst) GeV/c^2 is obtained for the top-quark mass.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; S. Grinstein; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; M. Martínez; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; N. Ranjan; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu

2014-10-08T23:59:59.000Z

90

Measurement of the top quark mass in topologies enhanced with single top quarks produced in the $t$-channel at $\\sqrt{s}=8\\,\\mathrm{TeV}$ using the ATLAS experiment  

E-Print Network (OSTI)

This article presents a measurement of the top quark mass in topologies enhanced with single top quarks produced in the $t$-channel produced via weak interactions. The dataset was collected at a centre-of-mass energy of $\\sqrt{s}=8\\,\\mathrm{TeV}$ with the ATLAS detector at the LHC and corresponds to an integrated luminosity of $20.3\\,\\mathrm{fb^{-1}}$. To determine the top quark mass a template method is used based on the distribution of the invariant mass of the lepton and the $b$-tagged jet as estimator. The result of the measurement is $m_{\\mathrm{top}} = 172.2 \\pm 0.7 {\\mathrm{(stat.)}} \\pm 2.0 {\\mathrm{(syst.)}}\\,\\mathrm{GeV}$.

Esch, Hendrik; The ATLAS collaboration

2014-01-01T23:59:59.000Z

91

Measurement of the top quark mass in topologies enhanced with single top quarks produced in the $t$-channel at $\\sqrt{s}=8\\,\\mathrm{TeV}$ using the ATLAS experiment  

E-Print Network (OSTI)

A measurement of the top quark mass in topologies enhanced with single top quarks produced in the $t$-channel produced via weak interactions is presented. The dataset was collected at a centre-of-mass energy of $\\sqrt{s}=8\\,\\mathrm{TeV}$ with the ATLAS detector at the LHC and corresponds to an integrated luminosity of $20.3\\,\\mathrm{fb^{-1}}$. To determine the top quark mass a template method is used based on the distribution of the invariant mass of the lepton and the $b$-tagged jet as estimator. The result of the measurement is $m_{\\mathrm{top}} = 172.2 \\pm 0.7 {\\mathrm{(stat.)}} \\pm 2.0 {\\mathrm{(syst.)}}\\,\\mathrm{GeV}$.

Esch, Hendrik

2014-01-01T23:59:59.000Z

92

Renormalization group-induced phenomena of top pairs from four-quark effective operators  

E-Print Network (OSTI)

We study the renormalization group(RG) evolution of four-quark operators that contribute to the top pair production. In particular, we focus on the cases in which certain observables are \\emph{first} induced from the one-loop RG while being absent at tree-level. From the operator mixing pattern, we classify all such RG-induced phenomena and underlying models that can induce them. We then calculate the full one-loop QCD RG evolution as the leading estimator of the effects and address the question of which RG-induced phenomena have largest and observable effects. The answer is related to the color structure of QCD. The studied topics include the RG-induction of top asymmetries, polarizations and polarization mixings as well as issues arising at this order. The RG-induction of top asymmetries is further compared with the generation of asymmetries from QCD and QED at one-loop order. We finally discuss the validity of using the RG as the proxy of one-loop effects on the top pair production. As an aside, we clarify the often-studied relations between top pair observables.

Sunghoon Jung; P. Ko; Yeo Woong Yoon; Chaehyun Yu

2014-06-18T23:59:59.000Z

93

CDF measurement of the top quark mass in the lepton + jets channel using the multivariate template method  

SciTech Connect

The authors measure the mass of the top quark using 162 pb{sup -1} of data collected by the CDF experiment at FNAL in Run II. The decay chain t{bar t} {yields} bq{bar q}{bar b}lv is studied using a novel technique called the Multivariate Template Method (MTM). Using this technique they obtain a result of M{sub top} = 179.6{sub -6.3}{sup +6.4} {+-} 6.8 GeV/c{sup 2} for the top quark.

Freeman, John; /Fermilab

2004-12-01T23:59:59.000Z

94

Top-quark mass predictions from W,Z masses and Z partial widths  

Science Journals Connector (OSTI)

We use recent measurements of the W- and Z-boson masses and the leptonic, hadronic, and total Z widths to constrain the top-quark mass in the standard model, including full radiative corrections. From a maximum-likelihood analysis we find the most likely value of mt to be 151 GeV and we obtain the bound mt?200 GeV at 95% C.L. based on the central measured value of the Z mass assuming a Higgs-boson mass of 100 GeV and ?s(MZ2)=0.12.

V. Barger; J. L. Hewett; T. G. Rizzo

1990-09-10T23:59:59.000Z

95

The Higgs boson and Top quark masses as tests of Electroweak Vacuum Stability  

E-Print Network (OSTI)

The measurements of the Higgs boson and top quark masses can be used to extrapolate the Standard Model Higgs potential at energies up to the Planck scale. Adopting a NNLO renormalization procedure, we: i) find that electroweak vacuum stability is at present allowed, discuss the associated theoretical and experimental errors and the prospects for its future tests; ii) determine the boundary conditions allowing for the existence of a shallow false minimum slightly below the Planck scale, which is a stable configuration that might have been relevant for primordial inflation; iii) derive a conservative upper bound on type I seesaw right-handed neutrino masses, following from the requirement of electroweak vacuum stability.

Masina, Isabella

2013-01-01T23:59:59.000Z

96

Higgs boson and Top quark masses as tests of Electroweak Vacuum Stability  

E-Print Network (OSTI)

The measurements of the Higgs boson and top quark masses can be used to extrapolate the Standard Model Higgs potential at energies up to the Planck scale. Adopting a NNLO renormalization procedure, we: i) find that electroweak vacuum stability is at present allowed, discuss the associated theoretical and experimental errors and the prospects for its future tests; ii) determine the boundary conditions allowing for the existence of a shallow false minimum slightly below the Planck scale, which is a stable configuration that might have been relevant for primordial inflation; iii) derive a conservative upper bound on type I seesaw right-handed neutrino masses, following from the requirement of electroweak vacuum stability.

Isabella Masina

2012-09-03T23:59:59.000Z

97

Supersymmetric Electroweak Corrections to Single Top Quark Production at the Fermilab Tevatron  

E-Print Network (OSTI)

We have calculated the $O(\\alpha_{ew} M_t^2/M_W^2)$ supersymmetric electroweak corrections to single top quark production via $q\\bar q' \\to t\\bar b$ at the Fermilab Tevatron in the minimal supersymmetric model. The supersymmetric electroweak corrections to the cross section are a few percent for $tan \\beta> 1$, and can exceed 10% for $tan\\beta<1$. The combined effects of SUSY electroweak corrections and the Yukawa corrections can exceed 10% for favorable parameter values, which might be observable at a high-luminosity Tevatron.

Chong Sheng Li; Robert J. Oakes; Jin Min Yang

1996-11-27T23:59:59.000Z

98

DZero (D0) Experiment Results for Top Quark Physics from the Fermilab Tevatron  

DOE Data Explorer (OSTI)

The D0 (DZero) Experiment is a worldwide collaboration of scientists conducting research on the fundamental nature of matter. The experiment is located at the Tevatron Collider, Fermilab. The research is focused on precise studies of interactions of protons and antiprotons and involves an intense search for subatomic clues that reveal the character of the building blocks of the universe. This web page provides access to Run II research results of the Top Quark Physics group, including preliminary, submitted, and published results. Figures and data plots are found in the directories with their respective papers.

99

Searching the Inclusive Lepton + Photon + Missing E(T) + b-quark Signature for Radiative Top Quark Decay and Non-Standard-Model Processes  

SciTech Connect

In a search for new phenomena in a signature suppressed in the standard model of elementary particles (SM), we compare the inclusive production of events containing a lepton ({ell}), a photon ({gamma}), significant transverse momentum imbalance (E{sub T}), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at {radical}s = 1.96 TeV corresponding to 1.9 fb{sup -1} of integrated luminosity taken with the CDF detector at the Fermilab Tevatron. We find 28 {ell}{gamma}bE{sub T} events versus an expectation of 31.0{sub -3.5}{sup +4.1} events. If we further require events to contain at least three jets and large total transverse energy, simulations predict that the largest SM source is top-quark pair production with an additional radiated photon, t{bar t} + {gamma}. In the data we observe 16 t{bar t}{gamma} candidate events versus an expectation from non-top-quark SM sources of 11.2{sub -2.1}{sup +2.3}. Assuming the difference between the observed number and the predicted non-top-quark total is due to SM top quark production, we estimate the t{bar t} cross section to be 0.15 {+-} 0.08 pb.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, Dante E.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, Alberto; /Frascati; Antos, Jaroslav; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2009-06-01T23:59:59.000Z

100

Renormalization group-induced phenomena of top pairs from four-quark effective operators  

E-Print Network (OSTI)

We study the renormalization group(RG) evolution of four-quark operators that contribute to the top pair production. In particular, we focus on the cases in which certain observables are first induced from the one-loop RG while being absent at tree-level. From the operator mixing pattern, we classify all such RG-induced phenomena and underlying models that can induce them. We then calculate the full one-loop QCD RG evolution as the leading estimator of the effects and address the question of which RG-induced phenomena have largest and observable effects. The answer is related to the color structure of QCD. The studied topics include the RG-induction of top asymmetries, polarizations and polarization mixings as well as issues arising at this order. The RG-induction of top asymmetries is further compared with the generation of asymmetries from QCD and QED at one-loop order. We finally discuss the validity of using the RG as the proxy of one-loop effects on the top pair production. As an aside, we clarify the of...

Jung, Sunghoon; Yoon, Yeo Woong; Yu, Chaehyun

2014-01-01T23:59:59.000Z

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101

Probing the flavor violating scalar top quark signal at the LHC  

Science Journals Connector (OSTI)

The Large Hadron Collider (LHC) has completed its run at 8 TeV with the experiments ATLAS and CMS having collected about 25??fb?1 of data each. Discovery of a light Higgs boson coupled with lack of evidence for supersymmetry at the LHC so far, has motivated studies of supersymmetry in the context of naturalness with the principal focus being the third generation squarks. In this work, we analyze the prospects of the flavor violating decay mode t˜1?c?10 at 8 and 13 TeV center-of-mass energy at the LHC. This channel is also relevant in the dark matter context for the stop-coannihilation scenario, where the relic density depends on the mass difference between the lighter stop quark (t˜1) and the lightest neutralino (?10) states. This channel is extremely challenging to probe, especially for situations when the mass difference between the lighter stop quark and the lightest neutralino is small. Using certain kinematical properties of signal events we find that the level of backgrounds can be reduced substantially. We find that the prospect for this channel is limited due to the low production cross section for top squarks and limited luminosity at 8 TeV, but at the 13 TeV LHC with 100??fb?1 luminosity, it is possible to probe top squarks with masses up to ?450??GeV. We also discuss how the sensitivity could be significantly improved by tagging charm jets.

Genevieve Belanger; Diptimoy Ghosh; Rohini Godbole; Monoranjan Guchait; Dipan Sengupta

2014-01-06T23:59:59.000Z

102

Search for Pair Production of Supersymmetric Top Quarks in Dilepton Events at the Tevatron  

SciTech Connect

We search for pair production of the supersymmetric partner of the top quark, the stop quark {tilde t}{sub 1}, decaying to a b-quark and a chargino {tilde {chi}}{sub 1}{sup {+-}} with a subsequent decay into a neutralino {tilde {chi}}{sub 1}{sup 0}, lepton {ell}, and neutrino {nu}. Using 2.7 fb{sup -1} of {radical}s = 1.96 TeV p{bar p} collision data collected by the CDF II experiment, we reconstruct the mass of candidate stop events and fit the observed mass spectrum to a combination of standard model processes and stop signal. No evidence of {tilde t}{sub 1}{tilde {bar 1}}{sub 1} production is found, therefore we set 95% C.L. limits on the masses of the stop and the neutralino for several values of the chargino mass and the branching ratio {Beta} ({tilde {chi}}{sub 1}{sup {+-}} {yields} {tilde {chi}}{sub 1}{sup 0}{ell}{sup {+-}}{nu}).

Johnson, William Casey; /UC, Davis

2010-05-01T23:59:59.000Z

103

Measurement of the top quark mass and top-antitop production cross section from dilepton events at the Collider Detector at Fermilab  

E-Print Network (OSTI)

We present an analysis of dilepton events originating from top-antitop production in proton-antiproton collisions at sqrt{s}=1.8 TeV at the Fermilab Tevatron Collider. The sample corresponds to an integrated luminosity of 109+-7 pb^{-1}. We observe 9 candidate events, with an estimated background of 2.4+-0.5 events. We determine the mass of the top quark to be M_top = 161+-17(stat.)+-10(syst.) GeV/c^2. In addition we measure a top-antitop production cross section of 8.2+4.4-3.4 pb (where M_top = 175 GeV/c^2 has been assumed for the acceptance estimate).

CDF collaboration

1998-02-18T23:59:59.000Z

104

Measurement of the top quark mass and pp-bar -->tt-bar cross section in the all-hadronic mode with the CDF II detector  

E-Print Network (OSTI)

We present a measurement of the top quark mass and of the top-antitop (tt? ) pair production cross section using pp? data collected with the CDF II detector at the Tevatron Collider at the Fermi National Accelerator ...

Paus, Christoph M. E.

105

Search for pair production of scalar top quarks decaying to a tau lepton and a b quark in 1.96-tev ppbar collisions  

E-Print Network (OSTI)

I present the results of a search for pair production of scalar top quarks (~t1) in an R-parity violating supersymmetric scenario using 322 pb_1 of pp collisions at ps = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. I assume each...

Khotilovich, Vadim Gennadyevich

2009-05-15T23:59:59.000Z

106

Search for the associated production of the Higgs boson with a top-quark pair  

E-Print Network (OSTI)

A search for the standard model Higgs boson produced in association with a top-quark pair (t tbar H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 inverse femtobarns and 19.7 inverse femtobarns collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H to hadrons, H to photons, and H to leptons. The results are characterized by an observed t tbar H signal strength relative to the standard model cross section, mu = sigma/sigma[SM], under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is mu = 2.8 +/- 1.0 for a Higgs boson mass of 125.6 GeV.

CMS Collaboration

2014-09-18T23:59:59.000Z

107

Search for scalar top quark production in p[bar over p] collisions at ?s = 1.96 TeV  

E-Print Network (OSTI)

We report on a search for the supersymmetric partner of the top quark (scalar top) decaying into a charm quark and a neutralino in p[¯ over p] collisions at ?s = 1.96 TeV. The data sample, collected by the CDF II detector ...

Gomez-Ceballos, Guillelmo

108

Production of single top-quark final states at the LHC from supersymmetric FCNC interactions  

E-Print Network (OSTI)

We discuss the production of single top-quark final states by direct supersymmetric flavor-changing interactions at the LHC. The total cross section pp(gg)->t\\bar{c}+\\bar{t}c is computed at the 1-loop order within the unconstrained MSSM. We prove that SUSY-QCD effects may furnish sizeable production rates amounting up to barely 10^5 t\\bar{c}(c\\bar{t}) events per 100 fb^{-1} of integrated luminosity, in full compliance with the stringent low-energy constraints from b->s gamma. Furthermore, we show that the cooperative SUSY-EW effects can be sizeable on their own, regardless of the SUSY-QCD contribution, with maximum production rates of the order of 10^3 events per 100 fb^{-1}. Owing to the fact that FCNC production of electrically neutral heavy-quark pairs is virtually absent within the SM, we conclude that the observation of such pp(gg)->t\\bar{c}+\\bar{t}c processes at the LHC could lead to evidence of new physics - of likely supersymmetric nature.

David Lopez-Val; Jaume Guasch; Joan Sola

2008-01-16T23:59:59.000Z

109

Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method  

SciTech Connect

The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /CSIC, Catalunya; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2008-12-01T23:59:59.000Z

110

Exclusion of exotic top-like quarks with -4/3 electric charge using jet-charge tagging in single-lepton ttbar events at CDF  

E-Print Network (OSTI)

We report on a measurement of the top-quark electric charge in ttbar events in which one W boson originating from the top-quark pair decays into leptons and the other into hadrons. The event sample was collected by the CDF II detector in sqrt(s)=1.96 TeV proton-antiproton collisions and corresponds to 5.6 fb^(-1). We find the data to be consistent with the standard model and exclude the existence of an exotic quark with -4/3 electric charge and mass of the conventional top quark at the 99% confidence level.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; V. Boisvert; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; M. A. Ciocci; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. De Barbaro; L. Demortier; M. Deninno; M. d'Errico; F. Devoto; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; R. Eusebi; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; S. Grinstein; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. J. Kim; Y. K. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; M. Martínez; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; K. S. McFarland; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; A. Pranko; F. Prokoshin; F. Ptohos; G. Punzi; N. Ranjan; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; P. Sinervo; K. Sliwa; J. R. Smith; F. D. Snider; H. Song; V. Sorin; M. Stancari; R. St. Denis; B. Stelzer; O. Stelzer-Chilton; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; A. Warburton; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang

2014-10-09T23:59:59.000Z

111

Observation of Top Quark Production in [¯ over p]p Collisions with the Collider Detector at Fermilab  

E-Print Network (OSTI)

We establish the existence of the top quark using a 67pb[superscript ?1] data sample of [¯ over p]p collisions at ?s = 1.8TeV collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those ...

Bauer, Gerry P.

112

Measurement of the Inclusive Leptonic Asymmetry in Top-Quark Pairs that Decay to Two Charged Leptons at CDF  

SciTech Connect

We measure the inclusive forward-backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton-antiproton collisions, and decaying to final states that contain two charged leptons (electrons or muons), using data collected with the Collider Detector at Fermilab.

Aaltonen, Timo Antero; et al.,

2014-07-23T23:59:59.000Z

113

QCD Corrections to Flavor Changing Neutral Coupling Mediated Rare Top Quark Decays  

E-Print Network (OSTI)

Recently we have presented an analysis of flavor changing neutral coupling mediated radiative top quark decays at next-to-leading order in QCD. In the present paper we provide the details of the calculation of QCD corrections to t-> q gamma and t-> q Z decays within the effective theory approach including operator mixing. In particular, we calculate virtual matrix element corrections and the corresponding bremsstrahlung contributions. In the case of t-> q gamma we study the effects of kinematic cuts on the extracted branching ratios. Analytical formulae are given at all stages of the calculation. We find that the t-> q gamma decay can be used to probe also the effective operators mediating t-> q g processes, since these can naturally contribute 10% or more to the radiative decay, given typical experimental cuts on the decay kinematics at hadron colliders. Conversely, we argue that any positive experimental signal of the t-> q g process would indicate a natural lower bound on t-> q gamma decay rate.

Jure Drobnak; Svjetlana Fajfer; Jernej F. Kamenik

2010-07-15T23:59:59.000Z

114

Combination of CDF and D0 measurements of the $W$ boson helicity in top quark decays  

SciTech Connect

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7-5.4 fb{sup -1} of p{bar p} collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f{sub 0}) and right-handed (f{sub +}) helicities, we find f{sub 0} = 0.722 {+-} 0.081 [{+-} 0.062 (stat.) {+-} 0.052 (syst.)] and f{sub +} = -0.033 {+-} 0.046 [{+-} 0.034 (stat.) {+-} 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f{sub 0} = 0.682 {+-} 0.057 [{+-} 0.035 (stat.) {+-} 0.046 (syst.)] and f{sub +} = ?0.015 {+-} 0.035 [{+-} 0.018 (stat.) {+-} 0.030 (syst.)]. The results are consistent with standard model expectations.

Aaltonen, T.; /Helsinki Inst. of Phys.; Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, G.; /St. Petersburg, INP; Alton, A.; /Augustana Coll., Sioux Falls /Michigan U.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Alverson, G.; /Northeastern U. /INFN, Padua

2012-02-01T23:59:59.000Z

115

Search for top-quark production via flavor-changing neutral currents in W+1 jet events at CDF  

SciTech Connect

We report on the first search for top-quark production via flavor-changing neutral-current (FCNC) interactions in the non-standard-model process u(c)+g {yields} t using p{bar p} collision data collected by the CDF II detector. The data set corresponds to an integrated luminosity of 2.2 fb{sup -1}. The candidate events feature the signature of semileptonic top-quark decays and are classified as signal-like or background-like by an artificial neural network trained on simulated events. The observed discriminant distribution is in good agreement with the one predicted by the standard model and provides no evidence for FCNC top-quark production, resulting in a Bayesian upper limit on the production cross section {sigma}(u(c)+g {yields} t) < 1.8 pb at the 95% confidence level. Using theoretical predictions we convert the cross-section limit to upper limits on FCNC branching ratios: {Beta}(t {yields} u + g) < 3.9 x 10{sup -4} and {Beta}(t {yields} c + g) < 5.7 x 10{sup -3}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /CSIC, Catalunya; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2008-12-01T23:59:59.000Z

116

Measurement of the Single Top Quark Production Cross Section and |Vtb| in Events with One Charged Lepton, Large Missing Transverse Energy, and Jets at CDF  

E-Print Network (OSTI)

We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of \\sqrt{s} = 1.96 TeV using a data set corresponding to 7.5 fb-1 of integrated luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process t \\to Wb \\to l{\

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu; I. Yu; A. M. Zanetti; Y. Zeng; C. Zhou; S. Zucchelli

2014-07-15T23:59:59.000Z

117

Measurement of the Single Top Quark Production Cross Section and |Vtb| in Events with One Charged Lepton, Large Missing Transverse Energy, and Jets at CDF  

E-Print Network (OSTI)

We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of \\sqrt{s} = 1.96 TeV using a data set corresponding to 7.5 fb-1 of integrated luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process t \\to Wb \\to l{\

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; D. Hirschbuehl; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu; I. Yu; A. M. Zanetti; Y. Zeng; C. Zhou; S. Zucchelli

2015-01-25T23:59:59.000Z

118

Top-quark production in proton-nucleus and nucleus-nucleus collisions at LHC energies and beyond  

E-Print Network (OSTI)

Single and pair top-quark production in proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions at the CERN Large Hadron Collider (LHC) and future circular collider (FCC) energies, are studied with next-to-leading-order perturbative QCD calculations including nuclear parton distribution functions. At the LHC, the pair-production cross sections amount to sigma(t-tbar) = 3.4 mub in Pb-Pb at sqrt(s) = 5.5 TeV, and sigma(t-tbar) = 60 nb in p-Pb at sqrt(s) = 8.8 TeV. At the FCC energies of sqrt(s) = 39 and 63 TeV, the same cross sections are factors of 90 and 55 times larger respectively. In the leptonic final-state t-tbar --> W+b W-bbar --> b bbar l+l- nu+nu-, after typical acceptance and efficiency cuts, one expects about 90 and 300 top-quarks per nominal LHC-year and 4.7 10^4 and 10^5 per FCC-year in Pb-Pb and p-Pb collisions respectively. The total t-tbar cross sections, dominated by gluon fusion processes, are enhanced by 3--8% in nuclear compared to p-p collisions due to an overall net gluon antishadowing, although different regions of their differential distributions are depleted due to shadowing or EMC-effect corrections. The rapidity distributions of the decay leptons in t-tbar processes can be used to reduce the uncertainty on the Pb gluon density at high virtualities by up to 30% at the LHC (full heavy-ion programme), and by 70% per FCC-year. The cross sections for single-top production in electroweak processes are also computed, yielding about a factor of 30 smaller number of measurable top-quarks after cuts, per system and per year.

David d'Enterria; Krisztian Krajczar; Hannu Paukkunen

2015-01-23T23:59:59.000Z

119

Search for pair production of scalar top quarks decaying to a tau lepton and a b quark in 1.96 TeV ppbar collisions  

SciTech Connect

I present the results of a search for pair production of scalar top quarks ({tilde t}{sub 1}) in an R-parity violating supersymmetric scenario using 322 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. I assume each {tilde t}{sub 1} decays into a {tau} lepton and a b quark, with branching ratio {beta}, and search for final states containing either an electron or a muon from a leptonic {tau} decay, a hadronically decaying {tau} lepton, and two or more jets. Two candidate events pass my final selection criteria, consistent with the expectation from standard model processes. I present upper limits on the cross section times branching ratio squared {sigma}({tilde t}{sub 1}{bar {tilde t}}{sub 1}) x {beta}{sup 2} as a function of the stop mass m({tilde t}{sub 1}). Assuming {beta} = 1, I set a 95% confidence level limit m({tilde t}{sub 1}) > 153 GeV=c{sup 2}. These limits are also fully applicable to the case of a pair produced third generation scalar leptoquark that decays into a {tau} lepton and a b quark.

Khotilovich, Vadim, G.; /Texas A-M

2008-05-01T23:59:59.000Z

120

Top-quark production in proton-nucleus and nucleus-nucleus collisions at LHC energies and beyond  

E-Print Network (OSTI)

Single and pair top-quark production in proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions at the CERN Large Hadron Collider (LHC) and future circular collider (FCC) energies, are studied with next-to-leading-order perturbative QCD calculations including nuclear parton distribution functions. At the LHC, the pair-production cross sections amount to sigma(t-tbar) = 3.4 mub in Pb-Pb at sqrt(s) = 5.5 TeV, and sigma(t-tbar) = 60 nb in p-Pb at sqrt(s) = 8.8 TeV. At the FCC energies of sqrt(s) = 39 and 63 TeV, the same cross sections are factors of 90 and 55 times larger respectively. In the leptonic final-state t-tbar --> W+b W-bbar --> b bbar l+l- nu+nu-, after typical acceptance and efficiency cuts, one expects about 90 and 300 top-quarks per nominal LHC-year and 4.7 10^4 and 10^5 per FCC-year in Pb-Pb and p-Pb collisions respectively. The total t-tbar cross sections, dominated by gluon fusion processes, are enhanced by 3--8% in nuclear compared to p-p collisions due to an overall net gluon antishadowing, altho...

d'Enterria, David; Paukkunen, Hannu

2015-01-01T23:59:59.000Z

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121

Search for single top quark production in pbar p collisions at sqrt{s}=1.96 TeV in the missing transverse energy plus jets topology  

SciTech Connect

We report a search for single top quark production with the CDF II detector using 2.1 fb{sup -1} of integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV. The data selected consist of events characterized by large energy imbalance in the transverse plane and hadronic jets, and no identified electrons and muons, so the sample is enriched in W {yields} {tau}{nu} decays. In order to suppress backgrounds, additional kinematic and topological requirements are imposed through a neural network, and at least one of the jets must be identified as a b quark jet. We measure an excess of signal-like events in agreement with the standard model prediction, but inconsistent with a model without single top quark production by 2.1 standard deviations ({sigma}), with a median expected sensitivity of 1.4 {sigma}. Assuming a top quark mass of 175 GeV/c{sup 2} and ascribing the excess to single top quark production, the cross section is measured to be 4.9{sub -2.2}{sup +2.5} (stat+syst) pb, consistent with measurements performed in independent datasets and with the standard model prediction.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2010-01-01T23:59:59.000Z

122

Measurement of the Top Quark Mass using Dilepton Events and a Neutrino Weighting Algorithm with the D0 Experiment at the Tevatron (Run II)  

SciTech Connect

Elementary particle physics raises questions that are several thousand years old. What are the fundamental components of matter and how do they interact? These questions are linked to the question of what happened in the very first moments after the creation of the universe. Modern physics systematically tests nature to find answers to these and other fundamental questions. Precise theories are developed that describe various phenomena and at the same time are reduced to a few basic principals of nature. Simplification and reduction have always been guiding concepts of physics. The interplay between experimental data and theoretical descriptions led to the Standard Model of elementary particle physics. It summarizes the laws of nature and is one of most precise descriptions of nature achieved by mankind. Despite the great success of the Standard Model it is not the ultimate theory of everything. Models beyond the Standard Model try to unify all interactions in one grand unified theory. The number of free parameters is attempted to be reduced. Gravity is attempted to be incorporated. Extensions to the Standard Model like supersymmetry address the so-called hierarchy problem. Precision measurements are the key for searches of new particles and new physics. A powerful tool of experimental particle physics are particle accelerators. They provide tests of the Standard Model at smallest scales. New particles are produced and their properties are investigated. In 1995 the heaviest known elementary particle, called top quark, has been discovered at Fermilab. It differs from all other lighter quarks due to the high mass and very short lifetime. This makes the top quark special and an interesting object to be studied. A rich program of top physics at Fermilab investigates whether the top quark is really the particle as described by the Standard Model. The top quark mass is a free parameter of the theory that has been measured precisely. This thesis presents a precise measurement of the top quark mass by the D0 experiment at Fermilab in the dilepton final states. The comparison of the measured top quark masses in different final states allows an important consistency check of the Standard Model. Inconsistent results would be a clear hint of a misinterpretation of the analyzed data set. With the exception of the Higgs boson, all particles predicted by the Standard Model have been found. The search for the Higgs boson is one of the main focuses in high energy physics. The theory section will discuss the close relationship between the physics of the Higgs boson and the top quark.

Meyer, Joerg; /Bonn U.

2007-01-01T23:59:59.000Z

123

Search for Top-Quark Production via Flavor-Changing Neutral Currents in W+1 Jet Events at CDF  

SciTech Connect

We report on a search for the non-standard-model process u(c)+g{yields}t using pp collision data collected by the Collider Detector at Fermilab II detector corresponding to 2.2 fb{sup -1}. The candidate events are classified as signal-like or backgroundlike by an artificial neural network. The observed discriminant distribution yields no evidence for flavor-changing neutral current top-quark production, resulting in an upper limit on the production cross section {sigma}(u(c)+g{yields}t)<1.8 pb at the 95% C.L. Using theoretical predictions we convert the cross section limit to upper limits on flavor-changing neutral current branching ratios: B(t{yields}u+g)<3.9x10{sup -4} and B(t{yields}c+g)<5.7x10{sup -3}.

Aaltonen, T.; Maki, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; Remortel, N. van [Division of High Energy Physics, Department of Physics, University of Helsinki and Helsinki Institute of Physics, FIN-00014, Helsinki (Finland); Adelman, J.; Brubaker, E.; Fedorko, W. T.; Grosso-Pilcher, C.; Kim, Y. K.; Krop, D.; Kwang, S.; Lee, H. S.; Paramonov, A. A.; Schmidt, M. A.; Shiraishi, S.; Shochet, M.; Wilbur, S. [Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)] (and others)

2009-04-17T23:59:59.000Z

124

Measurement of the W boson helicity in top quark decays using 5.4??fb-1 of pp¯ collision data  

Science Journals Connector (OSTI)

We present a measurement of the helicity of the W boson produced in top quark decays using tt¯ decays in the ?+jets and dilepton final states selected from a sample of 5.4??fb-1 of collisions recorded using the D0 detector at the Fermilab Tevatron pp¯ collider. We measure the fractions of longitudinal and right-handed W bosons to be f0=0.669±0.102[±0.078(stat.)±0.065(syst.)] and f+=0.023±0.053[±0.041(stat.)±0.034(syst.)], respectively. This result is consistent at the 98% level with the standard model. A measurement with f0 fixed to the value from the standard model yields f+=0.010±0.037[±0.022(stat.)±0.030(syst.).].

V. M. Abazov et al. (D0 Collaboration)

2011-02-18T23:59:59.000Z

125

Multivariate methods and the search for single top-quark production in association with a $W$ boson in ATLAS  

E-Print Network (OSTI)

This thesis describes three machine learning algorithms that can be used for physics analyses. The first is a density estimator that was derived from the Green’s function identity of the Laplace operator and is capable of tagging data samples according to the signal purity. This latter task can also be performed with regression methods, and such an algorithm was implemented based on fast multi-dimensional polynomial regression. The accuracy was improved with a decision tree using smooth boundaries. Both methods apply rigorous checks against overtraining to make sure the results are drawn from statistically significant features. These two methods were applied in the search for the single top-quark production with a $W$ boson. Their separation power differ highly in favour for the regression method, mainly because it can exploit the extra information available during training. The third method is an unsupervised learning algorithm that offers finding an optimal coordinate system for a sample in the sense of m...

Kovesarki, Peter; Dingfelder, Jochen

126

Resummed corrections to the ?parameter due to a finite width of the top quark  

E-Print Network (OSTI)

We perform an all-order calculation of the \\rho parameter in a simplified framework, where the top propagator can be calculated exactly. Special emphasis is placed on the question of gauge invariance and the treatment of non-perturbative cut-off effects.

D. Bettinelli; J. J. van der Bij

2010-09-27T23:59:59.000Z

127

Quark Interactions  

NLE Websites -- All DOE Office Websites (Extended Search)

Interacciones del quark Interacciones del quark Volver Principal ESTOY PERDIDO!!! Los quarks tienen carga eléctrica, por lo que sufren interacciones electromagnéticas. Los quarks tienen carga de color, de modo que sufren las interacciones fuertes. Las interacciones fuertes causan que los quarks se combinen formando hadrones. Las interacciones fuertes residuales mantienen a los hadrones juntos, para formar núcleos. Los diferentes tipos de quark (u, d, c, ...) se denominan sabores. El sabor sólo se altera por medio de interacciones debiles cargadas. Por ejemplo: Todos los quarks del lado izquierdo también aparecen del lado derecho . Sin embargo, cuando un quark emite un bosón ( virtual) W+ o W-, debe cambiar su carga eléctrica y, por lo tanto, su sabor. El proceso débil predominante es el que involucra transiciones entre quarks de la misma

128

Measurement of the Top Quark Mass and ppbar -> ttbar Cross Section in the All-Hadronic Mode with the CDFII Detector  

SciTech Connect

We present a measurement of the top quark mass and of the top-antitop pair production cross section using p{bar p} data collected with the CDF II detector at the Tevatron Collider at the Fermi National Accelerator Laboratory and corresponding to an integrated luminosity of 2.9 fb{sup -1}. We select events with six or more jets satisfying a number of kinematical requirements imposed by means of a neural network algorithm. At least one of these jets must originate from a b quark, as identified by the reconstruction of a secondary vertex inside the jet. The mass measurement is based on a likelihood fit incorporating reconstructed mass distributions representative of signal and background, where the absolute jet energy scale (JES) is measured simultaneously with the top quark mass. The measurement yields a value of 174.8 {+-} 2.4(stat+JES){sub -1.0}{sup +1.2}(syst)GeV/c{sup 2}, where the uncertainty from the absolute jet energy scale is evaluated together with the statistical uncertainty. The procedure measures also the amount of signal from which we derive a cross section, {sigma}{sub t{bar t}} = 7.2 {+-} 0.5(stat) {+-} 1.0(syst) {+-} 0.4(lum) pb, for the measured values of top quark mass and JES.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2010-02-01T23:59:59.000Z

129

A Measurement of the mass of the Top Quark in the di-lepton channels using the D0 Detector at Fermilab  

SciTech Connect

This dissertation describes a measurement of the mass of the top quark using events consistent with the hypothesis t{bar t} {yields} bW{sup +} {bar b}W{sup -} {yields} bl{sup +}{nu}{bar b}l{sup -}{bar {nu}}, where (l=e,{mu}). The events are obtained from nearly 230 pb{sup -1} of p{bar p} collision data collected by the D0 experiment between 2002 and 2004 during Run II. In this decay channel two neutrinos remain undetected. Extraction of the mass of the top quark by kinematic reconstruction is not possible because the event is under-constrained. Therefore, a dynamical likelihood method is developed to obtain the mass of the top quark. The mass of top quark obtained from the candidate events selected in the di-electron channel and the e{mu} channel is: 154.1 {sup +14.2}{sub -12.8}(stat.) {+-}6.6 (syst.) GeV.

Fatakia, Sarosh Noshir; /Boston U.; ,

2005-01-01T23:59:59.000Z

130

Search for charged Higgs bosons in decays of top quarks in p anti-p collisions at s**(1/2) = 1.96 TeV  

SciTech Connect

We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2}, assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0. The upper limits on {Beta}(t {yields} H{sup +}b) can also be used as model-independent limits on the decay branching ratio of top quarks to generic scalar charged bosons beyond the standard model.

Aaltonen, T.; /Helsinki U. /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /Padua U. /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2009-07-01T23:59:59.000Z

131

Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector  

SciTech Connect

A measurement of the top-quark mass is presented using Tevatron data from proton-antiproton collisions at center-of-mass energy ?s = 1.96 TeV collected with the CDF II detector. Events are selected from a sample of candidates for production of tt? pairs that decay into the lepton+jets channel. The top-quark mass is measured with an unbinned maximum likelihood method where the event probability density functions are calculated using signal and background matrix elements, as well as a set of parameterized jet-to-parton transfer functions. The likelihood function is maximized with respect to the top-quark mass, the signal fraction in the sample, and a correction to the jet energy scale (JES) calibration of the calorimeter jets. The simultaneous measurement of the JES correction ({Delta}{sub JES}) amounts to an additional in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using the data sample of 578 lepton+jets candidate events, corresponding to 3.2 fb-1 of integrated luminosity, the top-quark mass is measured to be mt = 172.4± 1.4 (stat + ?JES) ± 1.3 (syst) GeV/c2.

Aaltonen, T [Helsinki Inst. of Phys.; Alvarez Gonzalez, B [Oviedo U., Cantabria Inst. of Phys.; Amerio, S [INFN, Padua; Amidei, D [Michigan U.; Anastassov, A [Northwestern U.; Annovi, A [Frascati

2011-10-14T23:59:59.000Z

132

Measurement of the Single Top Quark Production Cross Section and |V[subscript tb]| in Events with One Charged Lepton, Large Missing Transverse Energy, and Jets at CDF  

E-Print Network (OSTI)

We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of ?s = 1.96??TeV using a data set corresponding to 7.5??fb[superscript -1] of integrated luminosity collected ...

Aaltonen, T.

133

Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector  

A measurement of the top-quark mass is presented using Tevatron data from proton-antiproton collisions at center-of-mass energy ?s = 1.96 TeV collected with the CDF II detector. Events are selected from a sample of candidates for production of tt? pairs that decay into the lepton+jets channel. The top-quark mass is measured with an unbinned maximum likelihood method where the event probability density functions are calculated using signal and background matrix elements, as well as a set of parameterized jet-to-parton transfer functions. The likelihood function is maximized with respect to the top-quark mass, the signal fraction in the sample, and a correction to the jet energy scale (JES) calibration of the calorimeter jets. The simultaneous measurement of the JES correction ({Delta}{sub JES}) amounts to an additional in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using the data sample of 578 lepton+jets candidate events, corresponding to 3.2 fb-1 of integrated luminosity, the top-quark mass is measured to be mt = 172.4± 1.4 (stat + ?JES) ± 1.3 (syst) GeV/c2.

Aaltonen, T [Helsinki Inst. of Phys.; Alvarez Gonzalez, B [Oviedo U., Cantabria Inst. of Phys.; Amerio, S [INFN, Padua; Amidei, D [Michigan U.; Anastassov, A [Northwestern U.; Annovi, A [Frascati

2011-10-14T23:59:59.000Z

134

Search for standard model production of four top quarks in the lepton + jets channel in pp collisions at ?s = 8 TeV  

E-Print Network (OSTI)

A search is presented for standard model (SM) production of four top quarks (tt¯tt¯) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fb[superscript ?1] recorded at a ...

CMS Collaboration

135

Search for V+A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96-TeV  

SciTech Connect

The authors report an upper limit on the fraction of V + A current, f{sub V+A}, in top quark decays, using approximately 700 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t {yields} wb {yields} {ell}vb (where {ell} = e or {mu}), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. They determine f{sub V+A} = -0.06 {+-} 0.25 given a top quark mass of 175 GeV/c{sup 2}. They set an upper limit on f{sub V+A} of 0.29 at the 95% confidence level, which represents an improvement by a factor of two on the previous best direct limit.

Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Taiwan, Inst. Phys.

2006-08-01T23:59:59.000Z

136

Search for V + A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96 TeV  

SciTech Connect

The authors report an upper limit on the fraction of V + A current, f{sub V+A}, in top quark decays, using approximately 700 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t {yields} Wb {yields} {ell}{nu}b (where {ell} = e or {mu}), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. They determine f{sub V+A} = -0.06 {+-} 0.25 given a top quark mass of 175 GeV/c{sup 2}. They set an upper limit on f{sub V+A} of 0.29 at the 95% confidence level, which represents an improvement by a factor of two on the previous best direct limit.

Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; Antos, J.; Aoki, M.; Apollinari, G.; Arguin, J.-F.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Azfar, F.; Azzi-Bacchetta, P.

2006-09-01T23:59:59.000Z

137

Measurement of the front back asymmetry in top-antitop quark pairs produced in proton-antiproton collisions at center of mass energy = 1.96 TeV  

SciTech Connect

Quarks, along with leptons and force carrying particles, are predicted by the Standard Model to be the fundamental constituents of nature. In distinction from the leptons, the quarks interact strongly through the chromodynamic force and are bound together within the hadrons. The familiar proton and neutron are bound states of the light ''up'' and ''down'' quarks. The most massive quark by far, the ''top'' quark, was discovered by the CDF and D0 experiments in March, 1995. The new quark was observed in p{bar p} collisions at 1.8 TeV at the Fermilab Tevatron. The mass of the top quark was measured to be 176 {+-} 13 GeV/c{sup 2} and the cross section 6.8{sub -2.4}{sup +3.6} pb. It is the Q = 2/3, T{sub 3} = +1/2 member of the third generation weak-isospin doublet along with the bottom quark. The top quark is the final Standard Model quark to be discovered. Along with whatever is responsible for electroweak symmetry breaking, top quark physics is considered one of the least understood sectors of the Standard Model and represents a front line of our understanding of particle physics. Currently, the only direct measurements of top quark properties come from the CDF and D0 experiments observing p{bar p} collisions at the Tevatron. Top quark production at the Tevatron is almost exclusively by quark-antiquark annihilation, q{bar q} {yields} t{bar t} (85%), and gluon fusion, gg {yields} t{bar t} (15%), mediated by the strong force. The theoretical cross-section for this process is {sigma}{sub t{bar t}} = 6.7 {+-} 0.8 pb for m{sub t} = 175 GeV/c{sup 2}. Top quarks can also be produced at the Tevatron via q{bar b}{prime} {yields} tb and qg {yields} q{prime}tb through the weak interaction. The cross section for these processes is lower (3pb) and the signal is much more difficult to isolate as backgrounds are much higher. The top quark is predicted to decay almost exclusively into a W-boson and a bottom quark (t {yields} Wb). The total decay width t {yields} Wb is {Lambda} = 1.50 GeV. This corresponds to an incredibly short lifetime of 0.5 x 10{sup -24} seconds. This happens so quickly that hadronization and bound states do not take place, which leads to the interesting consequence that the top quark spin information is passed to the decay products.

Schwarz, Thomas A.; /Michigan U.

2006-01-01T23:59:59.000Z

138

Evidence for electroweak top quark production in proton-antiproton collisions at s**(1/2) = 1.96 TeV  

SciTech Connect

We present the first evidence for electroweak single top quark production using nearly 1 fb{sup -1} of Tevatron Run II data at {radical}s = 1.96 TeV. We select single-top-like data events in the lepton+jets decay channel and separate them from backgrounds using the matrix element analysis method. This technique uses leading order matrix elements to compute an event probability for both signal and background hypotheses. Using the expected signal acceptance, background, and observed data we measure the single top quark cross section: {sigma}(p{bar p} {yields} tb + tqb + X) = 4.6{sub -1.5}{sup +}1.8 pb. The probability for the background to have fluctuated up to give at least the cross section measured in this analysis is 0.21%, which corresponds to a Gaussian equivalent significance of 2.9{sigma}.

Gadfort, Thomas; /Washington U., Seattle

2007-04-01T23:59:59.000Z

139

Search for a Heavy Top-Like Quark in $p\\bar{p}$ Collisions at ${\\surd}s = 1.96$~TeV  

SciTech Connect

We present the results of a search for pair production of a heavy top-like (t') quark decaying to W q final states using data corresponding to an integrated luminosity of 5.6 fb{sup -1} collected by the CDF II detector in p{anti p} collisions at {radical}{ovr s} = 1.96 TeV. We perform parallel searches for t' {yields} W b and t' {yields} W q (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t' quark mass, we set upper limits on the t'{anti t}' production cross section and exclude a standard model fourth-generation t' quark decaying to W b (W q) with mass below 358 (340) GeV/c{sup 2} at 95% CL.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Apresyan, A.; /Purdue U.; Arisawa, T.; /Waseda U. /Dubna, JINR

2011-07-01T23:59:59.000Z

140

Single top-quark production by strong and electroweak supersymmetric flavor-changing interactions at the LHC  

E-Print Network (OSTI)

(Abridged) We report on a complete study of the single top-quark production by direct supersymmetric flavor-changing neutral-current (FCNC) processes at the LHC. The total cross section for pp(gg)->t\\bar{c}+\\bar{t}c is computed at the 1-loop order within the unconstrained Minimal Supersymmetric Standard Model (MSSM). The present study extends the results of the supersymmetric strong effects (SUSY-QCD), which were advanced by some of us in a previous work, and includes the computation of the full supersymmetric electroweak corrections (SUSY-EW). Our analysis of pp(gg)->t\\bar{c}+\\bar{t}c in the MSSM has been performed in correspondence with the stringent low-energy constraints from b->s gamma. In the most favorable scenarios, the SUSY-QCD contribution can give rise to production rates of around 10^5 events per 100 fb^{-1} of integrated luminosity. Furthermore, we show that there exist regions of the MSSM parameter space where the SUSY-EW correction becomes sizeable. In the SUSY-EW favored regions, one obtains lower, but still appreciable, event production rates that can reach the 10^3 level for the same range of integrated luminosity. We study also the possible reduction in the maximum event rate obtained from the full MSSM contribution if we additionally include the constraints from B^0_s-\\bar{B}^0_s. In view of the fact that the FCNC production of heavy quark pairs of different flavors is extremely suppressed in the SM, the detection of a significant number of these events could lead to evidence of new physics -- of likely supersymmetric origin.

David Lopez-Val; Jaume Guasch; Joan Sola

2007-12-10T23:59:59.000Z

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141

Search for a heavy particle decaying to a top quark and a light quark in $p\\bar{p}$ collisions at $\\sqrt{s}=1.96$ TeV  

SciTech Connect

We present a search for a new heavy particle M produced in association with a top quark, p{bar p} {yields} t(M {yields} {bar t}q) or p{bar p} {yields} {bar t}({bar M} {yields} t{bar q}), where q stands for up quarks and down quarks. Such a particle may explain the recent anomalous measurements of top-quark forward-backward asymmetry. If the light-flavor quark (q) is reconstructed as a jet (j), this gives a {bar t}+j or t+j resonance in t{bar t}+jet events, a previously unexplored experimental signature. In a sample of events with exactly one lepton, missing transverse momentum and at least five jets, corresponding to an integrated luminosity of 8.7 fb{sup -1} collected by the CDF II detector, we find the data to be consistent with the standard model. We set cross-section upper limits on the production (p{bar p} {yields} Mt or {bar M} {bar t}) at 95% confidence level from 0.61 pb to 0.02 pb for M masses ranging from 200 GeV/c{sup 2} to 800 GeV/c{sup 2}, respectively.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Yale U.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U. /Dubna, JINR

2012-03-01T23:59:59.000Z

142

Measurement of the Top Quark Mass with the Dynamical Likelihood Method using Lepton plus Jets Events with b-tags in ppbar Collisions at s**(1/2) = 1.96 TeV  

E-Print Network (OSTI)

This report describes a measurement of the top quark mass, M_{top}, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/anti-top pairs in protons and anti-protons collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318 pb^{-1}. We use the top/anti-top candidates in the ``lepton+jets'' decay channel, requiring at least one jet identified as a b quark by finding a displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of M_{top} per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 top quark candidates observed in the data, with 9.2 events expected from background, we measure the top quark mass to be 173.2 +2.6/-2.4 (stat.) +/- 3.2 (syst.) GeV/c^2, or 173.2 +4.1/-4.0 GeV/c^2.

CDF Collaboration

2005-12-05T23:59:59.000Z

143

Measurement of the inclusive leptonic asymmetry in top-quark pairs that decay to two charged leptons at CDF  

E-Print Network (OSTI)

We measure the inclusive forward-backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton-antiproton collisions, and decaying to final states that contain two charged leptons (electrons or muons), using data collected with the Collider Detector at Fermilab. With an integrated luminosity of 9.1 $\\rm{fb}^{-1}$, the leptonic forward-backward asymmetry, $A_{\\text{FB}}^{\\ell}$, is measured to be $0.072 \\pm 0.060$ and the leptonic pair forward-backward asymmetry, $A_{\\text{FB}}^{\\ell\\ell}$, is measured to be $0.076 \\pm 0.082$, compared with the standard model predictions of $A_{\\text{FB}}^{\\ell} = 0.038 \\pm 0.003$ and $A_{\\text{FB}}^{\\ell\\ell} = 0.048 \\pm 0.004$, respectively. Additionally, we combine the $A_{\\text{FB}}^{\\ell}$ result with a previous determination from a final state with a single lepton and hadronic jets and obtain $A_{\\text{FB}}^{\\ell} = 0.090^{+0.028}_{-0.026}$.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; S. Grinstein; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; M. Martínez; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; N. Ranjan; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu

2014-04-14T23:59:59.000Z

144

Top Physics at LHC  

E-Print Network (OSTI)

The Large Hadron Collider (LHC) will provide a huge amount of top-antitop events, making the LHC a top quark factory, producing 1 tt pair per second at a luminosity of 10^33cm-2s-1. A large top quark sample will be available from the start of LHC and will play an important role in commissioning the CMS and ATLAS detectors. An overview of the top quark measurements during the first data-taking period is given.

M. Vander Donckt; for the CMS; ATLAS Collaborations

2008-05-21T23:59:59.000Z

145

Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at sqrt[s]=7??TeV  

SciTech Connect

Electroweak production of the top quark is measured in pp collisions at sqrt(s) = 7 TeV, using a dataset collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 inverse picobarns. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top quark production. The combined measurement of the cross section is 83.6 +/- 29.8 (stat.+syst.) +/- 3.3 (lumi.) pb, consistent with the standard model expectation.

Chatrchyan, Serguei; et al.

2011-08-01T23:59:59.000Z

146

Evidence for $s$-channel Single-Top-Quark Production in Events with one Charged Lepton and two Jets at CDF  

E-Print Network (OSTI)

We report evidence for $s$-channel single-top-quark production in proton-antiproton collisions at center-of-mass energy $\\sqrt{s}= 1.96 \\mathrm{TeV}$ using a data set that corresponds to an integrated luminosity of $9.4 \\mathrm{fb}^{-1}$ collected by the Collider Detector at Fermilab. We select events consistent with the $s$-channel process including two jets and one leptonically decaying $W$ boson. The observed significance is $3.8$ standard deviations with respect to the background-only prediction. Assuming a top-quark mass of $172.5 \\mathrm{GeV}/c^2$, we measure the $s$-channel cross section to be $1.41^{+0.44}_{-0.42} \\mathrm{pb}$.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; S. Grinstein; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; M. Martínez; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; N. Ranjan; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu

2014-04-21T23:59:59.000Z

147

Studies of high-transverse momentum jet substructure and top quarks produced in 1.96 TeV proton-antiproton collisions  

E-Print Network (OSTI)

Results of a study of the substructure of the highest transverse momentum (pT) jets observed by the CDF collaboration are presented. Events containing at least one jet with pT > 400 GeV/c in a sample corresponding to an integrated luminosity of 5.95 inverse fb, collected in 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron collider, are selected. A study of the jet mass, angularity, and planar-flow distributions is presented, and the measurements are compared with predictions of perturbative quantum chromodynamics. A search for boosted top-quark production is also described, leading to a 95% confidence level upper limit of 38 fb on the production cross section of top quarks with pT > 400 GeV/c.

T. Aaltonen; R. Alon; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; M. Deninno; M. D'Errico; F. Devoto; A. Di Canto; B. Di Ruzza; J. R. Dittmann; S. Donati; M. D'Onofrio; M. Dorigo; A. Driutti; E. Duchovni; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernandez Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. Gonzalez Lopez; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. H. Kim; S. B. Kim; Y. J. Kim; Y. K. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhn; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; D. Lucchesi; A. Luc; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; L. Marchese; F. Margaroli; P. Marino; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; G. Perez; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; A. Pranko; F. Prokoshin; F. Ptohos; G. Punzi; I. Redondo Fernandez; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; P. Sinervo; K. Sliwa; J. R. Smith; F. D. Snider; H. Song; V. Sorin; R. St. Denis; M. Stancari; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vazquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizan; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu; I. Yu; A. M. Zanetti; Y. Zeng; C. Zhou; S. Zucchelli

2014-07-13T23:59:59.000Z

148

arXiv:0802.2965v1[hep-ex]21Feb2008 Single Top Quark Production at the Fermilab Tevatron Collider  

E-Print Network (OSTI)

arXiv:0802.2965v1[hep-ex]21Feb2008 Single Top Quark Production at the Fermilab Tevatron Collider at the Fermilab Tevatron Collider are s-channel, which involve the exchange of a time-like W boson, and t be created in association with an an on-shell W boson, but this process is negligible at the Fermilab

California at Santa Cruz, University of

149

Search for charged Higgs bosons in decays of top quarks in proton - antiproton collisions at s**(1/2) = 1.96 TeV  

SciTech Connect

In this dissertation we report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample with an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays; hence 95% C.L. upper limits on the branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2} assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0 and {Beta}(t {yields} Wb)+{Beta}(t {yields} H{sup +}b) = 1.0. The upper limits on {Beta}(t {yields} H{sup +}b) are also used as model independent limits on the decay branching ratio of top quarks to any charged scalar bosons beyond the standard model.

Yu, Geum Bong; /Rochester U.

2009-08-01T23:59:59.000Z

150

Search for s-channel single top-quark production in proton-proton collisions at $\\sqrt{s}$=8 TeV with the ATLAS detector  

E-Print Network (OSTI)

This Letter presents a search at the LHC for s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of 8 TeV. The analyzed data set was recorded by the ATLAS detector and corresponds to an integrated luminosity of 20.3 fb$^{-1}$. Selected events contain one charged lepton, large missing transverse momentum and exactly two b-tagged jets. A multivariate event classifier based on boosted decision trees is developed to discriminate s-channel single top-quark events from the main background contributions. The signal extraction is based on a binned maximum-likelihood fit of the output classifier distribution. The analysis leads to an upper limit on the s-channel single top-quark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of $\\sigma_s$=5.0$\\pm$4.3 pb, consistent with the Standard Model expectation.

ATLAS Collaboration

2015-02-12T23:59:59.000Z

151

Measurement of the Top Quark Mass at D0 Run II with the Matrix Element Method in the Lepton+Jets Final State  

SciTech Connect

The mass of the top quark is a fundamental parameter of the Standard Model. Its precise knowledge yields valuable insights into unresolved phenomena in and beyond the Standard Model. A measurement of the top quark mass with the matrix element method in the lepton+jets final state in D0 Run II is presented. Events are selected requiring an isolated energetic charged lepton (electron or muon), significant missing transverse energy, and exactly four calorimeter jets. For each event, the probabilities to originate from the signal and background processes are calculated based on the measured kinematics, the object resolutions and the respective matrix elements. The jet energy scale is known to be the dominant source of systematic uncertainty. The reference scale for the mass measurement is derived from Monte Carlo events. The matrix element likelihood is defined as a function of both, m{sub top} and jet energy scale JES, where the latter represents a scale factor with respect to the reference scale. The top mass is obtained from a two-dimensional correlated fit, and the likelihood yields both the statistical and jet energy scale uncertainty. Using a dataset of 320 pb{sup -1} of D0 Run II data, the mass of the top quark is measured to be: m{sub top}{sup {ell}+jets} = 169.5 {+-} 4.4(stat. + JES){sub -1.6}{sup +1.7}(syst.) GeV; m{sub top}{sup e+jets} = 168.8 {+-} 6.0(stat. + JES){sub -1.9}{sup +1.9}(syst.) GeV; m{sub top}{sup {mu}+jets} = 172.3 {+-} 9.6(stat.+JES){sub -3.3}{sup +3.4}(syst.) GeV. The jet energy scale measurement in the {ell}+jets sample yields JES = 1.034 {+-} 0.034, suggesting good consistency of the data with the simulation. The measurement forecasts significant improvements to the total top mass uncertainty during Run II before the startup of the LHC, as the data sample will grow by a factor of ten and D0's tracking capabilities will be employed in jet energy reconstruction and flavor identification.

Schieferdecker, Philipp; /Munich U.; ,

2005-08-01T23:59:59.000Z

152

Kinematic evidence for top quark pair production in W+multijet events in pp¯ collisions at ?s =1.8 TeV  

Science Journals Connector (OSTI)

We present a study of W+multijet events that compares the kinematics of the observed events with expectations from direct QCD W+jet production and from production and decay of top quark pairs. The data were collected in the 1992–93 run with the Collider Detector at Fermilab (CDF) from 19.3 pb-1 of proton-antiproton collisions at ?s =1.8 TeV. A W+?2 jet sample and a W+?3 jet sample are selected with the requirement that at least the two or three jets have energy transverse with respect to the beam axis in excess of 20 GeV. The jet energy distributions for the W+?2 jet sample agree well with the predictions of direct QCD W production. From the W+?3 jet events, a ‘‘signal sample’’ with an improved ratio of tt¯ to QCD produced W events is selected by requiring each jet to be emitted centrally in the event center of mass frame. This sample contains 14 events with unusually hard jet ET distributions not well described by expectations for jets from direct QCD W production and other background processes. Using expected jet ET distributions, a relative likelihood is defined and used to determine if an event is more consistent with the decay of tt¯ pairs, with Mtop=170 GeV/c2, than with direct QCD W production. Eight of the 14 signal sample events are found to be more consistent with top-quark than direct QCD W production, while only 1.7 such top-quark–like events are expected in the absence of tt¯.The probability that the observation is due to an upward fluctuation of the number of background events is found to be 0.8%. The robustness of the result was tested by varying the cuts defining the signal sample, and the largest probability for such a fluctuation found was 1.9%. Good agreement in the jet spectra is obtained if jet production from tt¯ pair decays is included. For those events kinematically more consistent with tt¯ we find evidence for a b-quark content in their jets to the extent expected from top quark decay, and larger than expected for background processes. For events with four or more jets, the discrepancy with the predicted jet distributions from direct QCD W production, and the associated excess of b-quark content, is more pronounced.

F. Abe et al.

1995-05-01T23:59:59.000Z

153

Top Physics at ATLAS  

E-Print Network (OSTI)

The Large Hadron Collider LHC is a top quark factory: due to its high design luminosity, LHC will produce about 200 millions of top quarks per year of operation. The large amount of data will allow to study with great precision the properties of the top quark, most notably cross-section, mass and spin. The Top Physics Working Group has been set up at the ATLAS experiment, to evaluate the precision reach of physics measurements in the top sector, and to study the systematic effects of the ATLAS detector on such measurements. This reports give an overview of the main activities of the ATLAS Top Physics Working Group in 2004.

Marcello Barisonzi

2005-08-02T23:59:59.000Z

154

Top-Quark Mass Data and the Sum of Quasi-Degenerate Neutrino Masses (One small electroweak-bound e-parameter organizes elementary particle 3-flavor phenomenology)  

E-Print Network (OSTI)

The absolute neutrino masses and type of neutrino mass hierarchy are among the main problems in neutrino physics. Top-quark mass is another topical problem in particle physics. These problems extend the old puzzle of electron-muon mass ratio close to the fine structure constant, which is still not solved by known theory. Here I continue the search for a general flavor pattern that may incorporate these problems. Relations between neutrino/electron and electron/top-quark pole mass ratios are obtained from supposition that realistic elementary particle dimensionless bare flavor quantities are small deviated (measured by universal parameter e) from the values of a stated flavor pattern (at e=0) and experimental data hints. With the world average t-quark mass data the sum of QD-neutrino masses is estimated (0.50 +- 0.003)eV in agreement with cosmological constraints and known QD-neutrino mass estimations from experimental data on neutrino oscillation mass-squared differences.

E. M. Lipmanov

2008-10-01T23:59:59.000Z

155

Top Physics at the LHC  

E-Print Network (OSTI)

The LHC will be a top quark factory. In this note, the central role of the top quark for LHC physics will be discussed, and an overview will be given of the studies of top quark properties in preparation, with an emphasis on the systematic uncertainties that will dominate most measurements.

P. de Jong

2009-02-27T23:59:59.000Z

156

Measurement of the W-boson helicity in top-quark decays from tt-bar production in lepton+jets events in pp collisions at s?=7 TeV  

E-Print Network (OSTI)

as the combined secondary-vertex (CSV) algorithm [26], is used to separate jets originating from light quarks (or gluons) and heavy quarks, i.e. charm or bottom quarks. Jets are first divided into cat- egories according to the probability of reconstructing a... measured value from the CSV tagger discriminant (see section 4). Since the top-quark and W-boson reconstructed masses are dominated by experimental resolu- tion effects, the parameters ?mt,t and ?M lep, hadW in eq. (5.1) are approximated as Gaussian widths...

Baringer, Philip S.; Bean, Alice; Benelli, Gabriele; Kenny, R. P. III; Murray, Michael J.; Noonan, Danny; Sanders, Stephen J.; Stringer, Robert W.; Wood, Jeffrey Scott; Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.

2013-10-24T23:59:59.000Z

157

Funny Quarks  

NLE Websites -- All DOE Office Websites (Extended Search)

graciosos quarks graciosos quarks Volver Principal ESTOY PERDIDO!!! Un poco de la historia del quark: En 1964 Murray Gell-Mann y George Zweig sugirieron que cientos de las partículas conocidas hasta el momento, podrían ser explicadas como una combinación de sólo 3 partículas fundamentales. Gell-Mann eligió el nombre caprichoso de "quarks" para estos constituyentes. Esta palabra aparece en la frase "three quarks for Muster Mark" en la novela de James Joyce, Finnegan's Wake. La parte revolucionaria de la idea era que ellos debieron asignarle a los quarks cargas eléctricas de 2/3 y -1/3 (en unidades de la carga del protón): nunca habían sido observadas cargas como esas. Primero los quarks fueron considerados como un truco matemático, pero los experimentos

158

CP violating anomalous top-quark coupling in p$\\bar{p}$ collision at $\\sqrt{s}=1.96$ TeV  

SciTech Connect

We conduct the first study of the T-odd correlations in tt events produced in p{bar p} collision at the Fermilab Tevatron collider that can be used to search for CP violation. We select events which have lepton+jets final states to identify t{bar t} events and measure counting asymmetries of several physics observables. Based on the result, we search the top quark anomalous couplings at the production vertex at the Tevatron. In addition, Geant4 development, photon identification, the discrimination of a single photon and a photon doublet from {pi}{sup 0} decay are discussed in this thesis.

Lee, Sehwook; /Iowa State U.

2011-04-01T23:59:59.000Z

159

Search for invisible particles produced in association with single-top-quarks in proton-proton collisions at $\\sqrt{s}$ = 8 TeV with the ATLAS detector  

E-Print Network (OSTI)

A search for the production of single-top-quarks in association with missing energy is performed in proton--proton collisions at a centre-of-mass energy of $\\sqrt{s}$ = 8 TeV with the ATLAS experiment at the Large Hadron Collider using data collected in 2012, corresponding to an integrated luminosity of 20.3 fb$^{-1}$. In this search, the $W$ boson from the top quark is required to decay into an electron or a muon and a neutrino. No deviation from the Standard Model prediction is observed, and upper limits are set on the production cross-section for resonant and non-resonant production of an invisible exotic state in association with a right-handed top quark. In the case of resonant production, for a spin-$0$ resonance with a mass of 500 GeV, an effective coupling strength above 0.15 is excluded at 95% confidence level for the top quark and an invisible spin-$1/2$ state with mass between 0 GeV and 100 GeV. In the case of non-resonant production, an effective coupling strength above 0.2 is excluded at 95% confidence level for the top quark and an invisible spin-$1$ state with mass between 0 GeV and 657 GeV.

ATLAS Collaboration

2014-10-20T23:59:59.000Z

160

Search for Scalar Top Quark Pair-Production in Scenario with Violated R-parity in ppbar Collisions at sqrt(s)=1.96 TeV  

SciTech Connect

A search for the pair production of supersymmetric partner of the top quark in scenario with R-parity violation is presented. The quantum number called R-parity distinguishes particles in standard model from supersymmetric particles. A scalar top quark (stop) is assumed to decay only via R{sub p}-violating supersymmetric coupling into tau lepton and b-quark. To collect events with multiple taus, a new special tau trigger (the lepton plus track trigger) is installed in Run II experiment of the Collider Detector at Fermilab (CDF). The goal of the lepton plus track trigger is to collect generic dilepton ({ell}{ell}, {ell}{tau}, {tau}{tau}) events with lower p{sub T} threshold (8 GeV/c) and without prescale even at high luminosity. The Z {yields} {tau}{tau} event, where one {tau}-lepton decays leptonically and the other hadronically, is a good benchmark to calibrate the lepton plus track trigger and {tau} identification. The data sample of 72 pb{sup -1}, collected using the electron plus track trigger, contains clear a {tau} signal from Z {yields} {tau}{tau} events. The data used in stop search correspond to 200 pb{sup -1}. The lower stop mass bound of 134 GeV/c{sup 2} at a 95% confidence level is obtained. This limit is also directly applicable to the case of the third generation scalar leptoquark (LQ{sub 3}) assuming a 100% branching for the LQ{sub 3} {yields} {tau}b decay mode.

Ogawa, Takashi; /Waseda U.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


161

Top Physics at CDF  

SciTech Connect

We present the recent results of top-quark physics using up to 6 fb{sup -1} of p{bar p} collisions at a center of mass energy of {radical}s = 1.96 TeV analyzed by the CDF collaboration. Thanks to this large data sample, precision top quark measurements are now a reality at the Tevatron. Further, several new physics signals could appear in this large dataset. We will present the latest measurements of top quark intrinsic properties as well as direct searches for new physics in the top sector.

Moon, Chang-Seong

2011-06-01T23:59:59.000Z

162

Search for a Very Light CP-Odd Higgs Boson in Top Quark Decays from pp? Collisions at ?s = 1.96 TeV  

We present the results of a search for a very light CP-odd Higgs boson a10 originating from top quark decays t?H±b ? W±(*)a10b, and subsequently decaying into ?+?-. Using a data sample corresponding to an integrated luminosity of 2.7 fb-1 collected by the CDF II detector in pp? collisions at 1.96 TeV, we perform a search for events containing a lepton, three or more jets, and an additional isolated track with transverse momentum in the range 3 to 20 GeV/c. Observed events are consistent with background sources, and 95% C.L. limits are set on the branching ratio of t?H±b for various masses of H± and a10.

Aaltonen, T [Helsinki Inst. of Phys.; Gonzalez, B Alvarez [Oviedo U.; Cantabria Inst. of Phys.; Amerio, S [INFN, Padua; Amidei, D [Michigan U.; Anastassov, A [Northwestern U.; Annovi, A [Frascati; Antos, J [Comenius U.; Apollinari, G [Fermilab; Appel, J A [Fermilab; Apresyan, A [Purdue U.; Arisawa, T [Waseda U.; Dubna, JINR

2011-07-11T23:59:59.000Z

163

Search for the Standard Model Higgs boson production in association with top quarks in pp collisions at 8 TeV with the ATLAS detector  

E-Print Network (OSTI)

The search for the production of the Higgs boson associated with a pair of top quarks in the ATLAS experiment is presented. It focuses on Higgs bosons decaying to $b\\bar{b}$ and events containing two leptons (electrons and/or muons). It uses 20.3 fb$^{-1}$ of $pp$ collision data at $\\sqrt{s}$ = 8 TeV collected with the ATLAS detector at the LHC in 2012. No significant excess of events is found and the 95% CL observed (expected) limit is 7.0xSM (4.3xSM). After combining with the single lepton final state an observed (expected) limit of 4.1xSM (2.6xSM) with a best fit of $\\mu=1.7\\pm1.4$ is obtained.

Moreno Llacer, Maria

2014-01-01T23:59:59.000Z

164

Top Physics at the LHC  

E-Print Network (OSTI)

Top quark physics will be a prominent topic in Standard Model physics at the LHC. The enormous amount of top quarks expected to be produced will allow to perform a wide range of precision measurements. An overview of the planned top physics programme of the ATLAS and CMS experiments at the LHC is given.

Christian Weiser

2005-06-10T23:59:59.000Z

165

Measurement of the top quark mass with the dynamical likelihood method using lepton plus jets events with b-tags in pp¯ collisions at s=1.96??TeV  

Science Journals Connector (OSTI)

This paper describes a measurement of the top quark mass, Mtop, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/antitop (tt¯) pairs in pp¯ collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318??pb-1. We use the tt¯ candidates in the “lepton+jets” decay channel, requiring at least one jet identified as a b quark by finding a displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of Mtop per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 tt¯ candidates observed in the data, with 9.2 events expected from background, we measure the top quark mass to be 173.2+2.6-2.4(stat.)±3.2(syst.)??GeV/c2, or 173.2+4.1-4.0??GeV/c2.

A. Abulencia et al. (CDF Collaboration)

2006-05-10T23:59:59.000Z

166

Search for single top quark production in pp[over-bar] collisions at [sqrt]s=1.96??TeV in the missing transverse energy plus jets topology  

E-Print Network (OSTI)

We report a search for single top quark production with the CDF II detector using 2.1??fb[superscript -1] of integrated luminosity of p[over-bar p] collisions at [sqrt]s=1.96??TeV. The data selected consist of events ...

Paus, Christoph M. E.

167

Model-independent measurement of $\\boldsymbol{t}$-channel single top quark production in $\\boldsymbol{p\\bar{p}}$ collisions at $\\boldsymbol{\\sqrt{s}=1.96}$ TeV  

SciTech Connect

We present a model-independent measurement of t-channel electroweak production of single top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. Using 5.4 fb{sup -1} of integrated luminosity collected by the D0 detector at the Fermilab Tevatron Collider, and selecting events containing an isolated electron or muon, missing transverse energy and one or two jets originating from the fragmentation of b quarks, we measure a cross section {sigma}(p{bar p} {yields} tqb + X) = 2.90 {+-} 0.59 (stat + syst) pb for a top quark mass of 172.5 GeV. The probability of the background to fluctuate and produce a signal as large as the one observed is 1.6 x 10{sup -8}, corresponding to a significance of 5.5 standard deviations.

Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Alves, Gilvan Augusto; /Rio de Janeiro, CBPF; Ancu, Lucian Stefan; /Nijmegen U. /Fermilab

2011-05-01T23:59:59.000Z

168

Mesure de la section efficace de production de paires de quarks top dans l'etat final di-electron avec les donnees collectees par l'experience D0 au RunIIa  

SciTech Connect

The top quark has been discovered in 1995 by CDF and D0 collaborations in proton-antiproton collisions at the Tevatron. The amount of data recorded by both experiments makes it possible to accurately measure the properties of this very massive quark. This thesis is devoted to the measurement of the top pair production cross-section via the strong interaction, in a final state composed of two electrons, two particle jets and missing transverse energy. It is based on a 1 fb{sup -1} data set collected by the D0 experiment between 2002 and 2006. The reconstruction and identification of electrons and jets is of major importance in this analysis, and have been studied in events where a Z boson is produced together with one or more jets. The Z+jets process is indeed the dominant physics background to top pair production in the dielectron final state. The primary goal of this cross-section measurement is to verify Standard Model predictions. In this document, this result is also interpreted to indirectly extract the top quark mass. Moreover, the cross-section measurement is sensitive to new physics such as the existence of a charged Higgs boson. The selection established for the cross-section analysis has been used to search for a H{sup +} boson lighter than the top quark, where the latter can decay into a W{sup +} or H{sup +} boson and a b quark. The model that has been studied makes the assumption that the H{sup +} boson can only decay into a tau lepton and a neutrino.

Martin Dit Latour, Bertrand; /LPSC, Grenoble

2008-09-01T23:59:59.000Z

169

Top Mass and Properties  

E-Print Network (OSTI)

The top quark was discovered in 1995. The top quark mass is now well measured at the Tevatron, with uncertainty getting below 1% of the top mass. The world average from last year was 170.9 $\\pm$ 1.8 GeV/$c^2$. The new CDF measurement is 172 $\\pm$ 1.2 (stat) $\\pm$ 1.5 (sys) GeV/$c^2$, and D0 will soon present a new measurement. The top quark mass is an important parameter in the Standard Model, and should be measured as precisely as possible. To learn more about the top quark observed and study possible new physics, other properties also should be measured. At the Tevatron, the charge of the top quark can be measured directly. Examples of other properties studied and reported in this presentation are W helicity, top decay branching ratio to b ($R_b$), searches for $t \\to H b$ and for flavor changing neutral current (FCNC). The results are all consistent with the Standard Model within current statistics. With significantly more data being collected at the Tevatron, precision measurements of the top properties are just starting.

Yen-Chu Chen

2008-05-15T23:59:59.000Z

170

Next-to-leading order QCD corrections to the top quark associated with $?$ production via model-independent flavor-changing neutral-current couplings at hadron colliders  

E-Print Network (OSTI)

We present the complete next-to-leading order (NLO) QCD corrections to the top quark associated with $\\gamma$ production induced by model-independent $tq\\gamma$ and $tqg$ flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the $tq\\gamma$ and $tqg$ FCNC couplings for this process. Our results show that, for the $tq\\gamma$ couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the $tq\\gamma$, $tqg$ FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the $tu\\gamma$ and $tug$ FCNC couplings, and by about the 80% for the $tc\\gamma$ and $tcg$ FCNC couplings at the LHC, respectively. Moreover, the NLO corrections reduce the dependence of the total cross section on the renormalization and factorization scale significantly. We also evaluate the NLO corrections for several important kinematic distributions.

Yue Zhang; Bo Hua Li; Chong Sheng Li; Jun Gao; Hua Xing Zhu

2011-01-27T23:59:59.000Z

171

Search for a Very Light CP-Odd Higgs Boson in Top Quark Decays from pp? Collisions at ?s = 1.96 TeV  

SciTech Connect

We present the results of a search for a very light CP-odd Higgs boson a10 originating from top quark decays t?H±b ? W±(*)a10b, and subsequently decaying into ?+?-. Using a data sample corresponding to an integrated luminosity of 2.7 fb-1 collected by the CDF II detector in pp? collisions at 1.96 TeV, we perform a search for events containing a lepton, three or more jets, and an additional isolated track with transverse momentum in the range 3 to 20 GeV/c. Observed events are consistent with background sources, and 95% C.L. limits are set on the branching ratio of t?H±b for various masses of H± and a10.

Aaltonen, T [Helsinki Inst. of Phys.; Gonzalez, B Alvarez [Oviedo U.; Cantabria Inst. of Phys.; Amerio, S [INFN, Padua; Amidei, D [Michigan U.; Anastassov, A [Northwestern U.; Annovi, A [Frascati; Antos, J [Comenius U.; Apollinari, G [Fermilab; Appel, J A [Fermilab; Apresyan, A [Purdue U.; Arisawa, T [Waseda U.; Dubna, JINR

2011-07-11T23:59:59.000Z

172

Measurement of associated production of vector bosons and top quark-antiquark pairs in pp collisions at ?s=7??TeV  

The first measurement of vector-boson production associated with a top quark-antiquark pair in proton-proton collisions at ?s=7??TeV is presented. The results are based on a data set corresponding to an integrated luminosity of 5.0??fb?1 , recorded by the CMS detector at the LHC in 2011. The measurement is performed in two independent channels through a trilepton analysis of tt¯Z events and a same-sign dilepton analysis of tt¯V (V=W or Z ) events. In the trilepton channel a direct measurement of the tt¯Z cross section ?tt¯Z =0.28+0.14?0.11 ?(stat)+0.06?0.03 ?(syst)??pb is obtained. In the dilepton channel a measurement of the tt¯V cross section yields ?tt¯V =0.43+0.17?0.15 ?(stat)+0.09?0.07 ?(syst)??pb . These measurements have a significance, respectively, of 3.3 and 3.0 standard deviations from the background hypotheses and are compatible, within uncertainties, with the corresponding next-to-leading order predictions of 0.137+0.012?0.016 and 0.306+0.031?0.053??pb .

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rabady, D.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D’Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins Junior, M.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Malek, M.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, Q.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Carrillo Montoya, C. A.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Mekterovic, D.; Morovic, S.; Tikvica, L.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Kuotb Awad, A. M.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Murumaa, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Florent, A.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Brochet, S.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Autermann, C.

2013-04-01T23:59:59.000Z

173

Search for the Standard Model Higgs boson produced in association with top quarks in pp collisions at ?s=8 TeV with the ATLAS detector  

E-Print Network (OSTI)

A search for the Standard Model Higgs boson produced in association with a pair of top quarks, t\\overline{t}H, is presented. The analysis uses 20.3 fb^{-1} of pp collision data at \\sqrt{s} = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H\\to~b\\overline{b} decay mode and uses events containing one or two leptons (electrons or/and muons). The Higgs boson is assumed to have a mass of 125 GeV. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities. A multivariate technique is used to discriminate between signal and background events, which are dominated by t\\overline{t}+jets production. No significant excess of events above the background expectation is found and an observed (expected) 95% confidence-level limit of 4.1 (2.6) times the Standard Model cross section is obtained.

Moreno Llácer, M; The ATLAS collaboration

2014-01-01T23:59:59.000Z

174

Measurement of \\boldmath $R = {\\mathcal{B}\\left(t \\rightarrow Wb \\right)/\\mathcal{B}\\left(t \\rightarrow Wq \\right)} $ in Top--Quark--Pair Decays using Dilepton Events and the Full CDF Run II Data Set  

E-Print Network (OSTI)

We present a measurement of the ratio of the top-quark branching fractions $R=\\mathcal{B}(t\\rightarrow Wb)/\\mathcal{B}(t\\rightarrow $ $q$ represents quarks of flavors $b$, $s$, or $d$, in the final state, in events with two charged leptons, missing transverse energy and at least two jets. The measurement uses $\\sqrt{s}$ = 1.96 TeV proton--antiproton collision data corresponding to an integrated luminosity of 8.7 fb$^{-1}$ and collected with the Collider Detector at Fermilab during Run II of the Tevatron. We measure $R=0.87 \\pm 0.07$ (stat+syst), and extract the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element, $\\left|V_{tb}\\right| = 0.93 \\pm 0.04$ (stat+syst) assuming three generations of quarks. Under these assumptions, a lower limit of $|V_{tb}|>0.85$ at 95% credibility level is set.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; S. Grinstein; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; M. Martínez; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; G. Piacentino; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; N. Ranjan; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu

2014-04-13T23:59:59.000Z

175

Updated Measurement of the Single Top Quark Production Cross Section and $V{tb}$ in the Missing Transverse Energy Plus Jets Topology in $p\\bar{p}$ Collisions at $\\sqrt{s} = 1.96$ TeV  

E-Print Network (OSTI)

An updated measurement of the single top quark production cross section is presented using the full data set collected by the Collider Detector at Fermilab (CDF) and corresponding to 9.5 fb${}^{-1}$ of integrated luminosity from proton-antiproton collisions at 1.96 TeV center-of-mass energy. The events selected contain an imbalance in the total transverse energy, jets identified as originating from $b$ quarks, and no identified leptons. The sum of the $s$- and $t$-channel single top quark cross sections is measured to be $3.53_{-1.16}^{+1.25}$ pb and a lower limit on $V_{tb}$ of 0.63 is obtained at the 95% credibility level. These measurements are combined with previously reported CDF results obtained from events with an imbalance in total transverse energy, jets identified as originating from $b$ quarks, and exactly one identified lepton. The combined cross section is measured to be $3.02_{-0.48}^{+0.49}$ pb and a lower limit on $V{tb}$ of 0.84 is obtained at the 95% credibility level.

CDF Collaboration; T. Aaltonen; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. A. Appel; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; B. Auerbach; A. Aurisano; F. Azfar; W. Badgett; T. Bae; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; M. Bauce; F. Bedeschi; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; K. R. Bland; B. Blumenfeld; A. Bocci; A. Bodek; D. Bortoletto; J. Boudreau; A. Boveia; L. Brigliadori; C. Bromberg; E. Brucken; J. Budagov; H. S. Budd; K. Burkett; G. Busetto; P. Bussey; P. Butti; A. Buzatu; A. Calamba; S. Camarda; M. Campanelli; F. Canelli; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; A. Cerri; L. Cerrito; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; K. Cho; D. Chokheli; A. Clark; C. Clarke; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; M. Cremonesi; D. Cruz; J. Cuevas; R. Culbertson; N. d'Ascenzo; M. Datta; P. de Barbaro; L. Demortier; L. Marchese; M. Deninno; F. Devoto; M. D'Errico; A. Di Canto; B. Di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; M. Dorigo; A. Driutti; K. Ebina; R. Edgar; A. Elagin; R. Erbacher; S. Errede; B. Esham; S. Farrington; J. P. Fernández Ramos; R. Field; G. Flanagan; R. Forrest; M. Franklin; J. C. Freeman; H. Frisch; Y. Funakoshi; C. Galloni; A. F. Garfinkel; P. Garosi; H. Gerberich; E. Gerchtein; S. Giagu; V. Giakoumopoulou; K. Gibson; C. M. Ginsburg; N. Giokaris; P. Giromini; V. Glagolev; D. Glenzinski; M. Gold; D. Goldin; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González López; I. Gorelov; A. T. Goshaw; K. Goulianos; E. Gramellini; C. Grosso-Pilcher; R. C. Group; J. Guimaraes da Costa; S. R. Hahn; J. Y. Han; F. Happacher; K. Hara; M. Hare; R. F. Harr; T. Harrington-Taber; K. Hatakeyama; C. Hays; J. Heinrich; M. Herndon; A. Hocker; Z. Hong; W. Hopkins; S. Hou; R. E. Hughes; U. Husemann; M. Hussein; J. Huston; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; S. Jindariani; M. Jones; K. K. Joo; S. Y. Jun; T. R. Junk; M. Kambeitz; T. Kamon; P. E. Karchin; A. Kasmi; Y. Kato; W. Ketchum; J. Keung; B. Kilminster; D. H. Kim; H. S. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; Y. J. Kim; N. Kimura; M. Kirby; K. Knoepfel; K. Kondo; D. J. Kong; J. Konigsberg; A. V. Kotwal; M. Kreps; J. Kroll; M. Kruse; T. Kuhr; M. Kurata; A. T. Laasanen; S. Lammel; M. Lancaster; K. Lannon; G. Latino; H. S. Lee; J. S. Lee; S. Leo; S. Leone; J. D. Lewis; A. Limosani; E. Lipeles; A. Lister; H. Liu; Q. Liu; T. Liu; S. Lockwitz; A. Loginov; A. Lucà; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; R. Madrak; P. Maestro; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; P. Marino; K. Matera; M. E. Mattson; A. Mazzacane; P. Mazzanti; R. McNulty; A. Mehta; P. Mehtala; C. Mesropian; T. Miao; D. Mietlicki; A. Mitra; H. Miyake; S. Moed; N. Moggi; C. S. Moon; R. Moore; M. J. Morello; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; I. Nakano; A. Napier; J. Nett; C. Neu; T. Nigmanov; L. Nodulman; S. Y. Noh; O. Norniella; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; L. Ortolan; C. Pagliarone; E. Palencia; P. Palni; V. Papadimitriou; W. Parker; G. Pauletta; M. Paulini; C. Paus; T. J. Phillips; E. Pianori; J. Pilot; K. Pitts; C. Plager; L. Pondrom; S. Poprocki; K. Potamianos; F. Prokoshin; A. Pranko; F. Ptohos; G. Punzi; I. Redondo Fernández; P. Renton; M. Rescigno; F. Rimondi; L. Ristori; A. Robson; T. Rodriguez; S. Rolli; M. Ronzani; R. Roser; J. L. Rosner; F. Ruffini; A. Ruiz; J. Russ; V. Rusu; W. K. Sakumoto; Y. Sakurai; L. Santi; K. Sato; V. Saveliev; A. Savoy-Navarro; P. Schlabach; E. E. Schmidt; T. Schwarz; L. Scodellaro; F. Scuri; S. Seidel; Y. Seiya; A. Semenov; F. Sforza; S. Z. Shalhout; T. Shears; P. F. Shepard; M. Shimojima; M. Shochet; I. Shreyber-Tecker; A. Simonenko; K. Sliwa; J. R. Smith; F. D. Snider; V. Sorin; H. Song; M. Stancari; R. St. Denis; D. Stentz; J. Strologas; Y. Sudo; A. Sukhanov; I. Suslov; K. Takemasa; Y. Takeuchi; J. Tang; M. Tecchio; P. K. Teng; J. Thom; E. Thomson; V. Thukral; D. Toback; S. Tokar; K. Tollefson; T. Tomura; D. Tonelli; S. Torre; D. Torretta; P. Totaro; M. Trovato; F. Ukegawa; S. Uozumi; F. Vázquez; G. Velev; C. Vellidis; C. Vernieri; M. Vidal; R. Vilar; J. Vizán; M. Vogel; G. Volpi; P. Wagner; R. Wallny; S. M. Wang; D. Waters; W. C. Wester III; D. Whiteson; A. B. Wicklund; S. Wilbur; H. H. Williams; J. S. Wilson; P. Wilson; B. L. Winer; P. Wittich; S. Wolbers; H. Wolfe; T. Wright; X. Wu; Z. Wu; K. Yamamoto; D. Yamato; T. Yang; U. K. Yang; Y. C. Yang; W. -M. Yao; G. P. Yeh; K. Yi; J. Yoh; K. Yorita; T. Yoshida; G. B. Yu; I. Yu; A. M. Zanetti; Y. Zeng; C. Zhou; S. Zucchelli

2014-10-21T23:59:59.000Z

176

Determination of the top-quark pole mass and strong coupling constant from the t t-bar production cross section in pp collisions at sqrt(s) = 7 TeV  

E-Print Network (OSTI)

The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, mtpole, or the strong coupling constant, alphaS. With the parton distribution function set NNPDF2.3, a pole mass of 176.7 +3.0 -2.8 GeV is obtained when constraining alphaS at the scale of the Z boson mass, mZ, to the current world average. Alternatively, by constraining mtpole to the latest average from direct mass measurements, a value of alphaS(mZ) = 0.1151 +0.0028 -0.0027 is extracted. This is the first determination of alphaS using events from top-quark production.

CMS Collaboration

2014-08-20T23:59:59.000Z

177

CDF Top Physics  

DOE R&D Accomplishments (OSTI)

The authors present the latest results about top physics obtained by the CDF experiment at the Fermilab Tevatron collider. The data sample used for these analysis (about 110 pb{sup{minus}1}) represents almost the entire statistics collected by CDF during four years (1992--95) of data taking. This large data size has allowed detailed studies of top production and decay properties. The results discussed here include the determination of the top quark mass, the measurement of the production cross section, the study of the kinematics of the top events and a look at top decays.

Tartarelli, G. F.; CDF Collaboration

1996-05-00T23:59:59.000Z

178

Search for the standard model Higgs boson produced in association with a top-quark pair in pp collisions at the LHC  

E-Print Network (OSTI)

a pseudorapidity in the range |?| CSV) algorithm [42]. This algorithm combines information about the impact parameter of tracks and reconstructed secondary... vertices within the jets in a multivariate algorithm designed to separate jets containing the decay products of bottom-flavored hadrons from jets originating from charm quarks, light quarks, or gluons. The CSV algorithm provides a continuous output...

Baringer, Philip S.; Bean, Alice; Benelli, Gabriele; Kenny, R. P. III; Murray, Michael J.; Noonan, Danny; Sanders, Stephen J.; Stringer, Robert W.; Wood, Jeffrey Scott; Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö , J.; Fabjan, C.

2013-05-28T23:59:59.000Z

179

Top partner probes of extended Higgs sectors  

E-Print Network (OSTI)

Natural theories of the weak scale often include fermionic partners of the top quark. If the electroweak symmetry breaking sector contains scalars beyond a single Higgs doublet, then top partners can have sizable branching ...

Kearney, John

180

Heavy flavour physics from top to bottom  

SciTech Connect

We review the status of heavy flavour physics at the Fermilab Tevatron collider by summarizing recent top quark and B physics results from CDF and D0. In particular we discuss the measurement of the top quark mass and top production cross section as well as B meson lifetimes and time dependent B{bar B} mixing results. An outlook of perspectives for top and B physics in Run II starting in 1999 is also given. 38 refs., 23 figs., 8 tabs.

Paulini, M. [Lawrence Berkeley National Lab., CA (United States); CDF and D0 Collaborations

1997-01-01T23:59:59.000Z

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181

Search for Production of Heavy Particles Decaying to Top Quarks and Invisible Particles in $p\\bar{p}$ collisions at $\\sqrt{s}=1.96$ TeV  

SciTech Connect

We present a search for a new particle T{prime} decaying to a top-quark via T{prime} {yields} t + X, where X is an invisible particle. In a data sample with 4.8 fb{sup -1} of integrated luminosity collected by the CDF II detector at Fermilab in p{bar p} collisions with {radical}s = 1.96 TeV, we search for pair production of T0 in the lepton+jets channel, p{bar p} {yields} t{bar t} + XX {yields} {ell}{nu}bqq{prime}b + XX. We interpret our results primarily in terms of a model where T{prime} are exotic fourth generation quarks and X are dark matter particles. The data are consistent with standard model expectations, and we set 95% confidence level limits on the generic production of T{prime}{bar T}{prime} {yields} t{bar t} + XX. We apply these limits to the dark matter model and exclude the fourth generation exotic quarks T{prime} at 95% confidence level up to m{sub T{prime}} = 360 GeV/c{sup 2} for m{sub x} {<=} 100 GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Apresyan, A.; /Purdue U.; Arisawa, T.; /Waseda U. /Dubna, JINR

2011-03-01T23:59:59.000Z

182

Measurement of the top-antitop quark pair differential cross section with respect to the invariant mass of the pair in proton-antiproton collisions at a center of mass energy of 1.96 TeV  

SciTech Connect

I present a measurement of the t{bar t} differential cross section, d{sigma}/dM{sub t{bar t}}, in p{bar p} collisions at {radical}s = 1.96 TeV using 2.7 fb{sup -1} of CDF II data. I find that d{sigma}/dM{sub t{bar t}} is consistent with the Standard Model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions. I set limits on the ratio {kappa}/M{sub Pl} in the Randall-Sundrum model by looking for Kaluza Klein gravitons which decay to top quarks. I find {kappa}/M{sub Pl} > 0.16 at the 95% confidence level.

Bridgeman, Alice; /Illinois U., Urbana

2008-10-01T23:59:59.000Z

183

Single Top production at LHC  

E-Print Network (OSTI)

The Production of single top quarks at LHC provides an ideal framework to investigate the properties of electroweak interaction, in particular of the {\\it tWb} coupling. Moreover, single top is a powerful mean to identify physics beyond the standard model. All three different production mechanisms of single top are expected to be observed at LHC. Recent studies from ATLAS and CMS are presented.

M. Mohammadi Najafabadi

2006-05-12T23:59:59.000Z

184

Searches for new physics in top decays at the LHC  

E-Print Network (OSTI)

The search for new physics in top quark decays at the LHC is reviewed in this paper. Results from ATLAS and CMS experiments on top quark decays within the Standard Model are presented together with the measurements of the W boson polarizations and the study of the structure of the Wtb vertex. As a natural step forward, the experimental status on measurements sensitive to top quark couplings to gauge bosons (\\gamma, Z, W and H) is reviewed as well as possible top quark decays Beyond the Standard Model (MSSM and FCNC).

A. Onofre

2012-12-31T23:59:59.000Z

185

TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS  

SciTech Connect

This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of ? s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of ? s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

Jabeen, Shabnam

2013-10-20T23:59:59.000Z

186

Top condensation as a motivated explanation of the top forward-backward asymmetry  

E-Print Network (OSTI)

Models of top condensation can provide both a compelling solution to the hierarchy problem as well as an explanation of why the top-quark mass is large. The spectrum of such models, in particular topcolor-assisted technicolor, includes top-pions, top-rhos and the top-Higgs, all of which can easily have large top-charm or top-up couplings. Large top-up couplings in particular would lead to a top forward-backward asymmetry through $t$-channel exchange, easily consistent with the Tevatron measurements. Intriguingly, there is destructive interference between the top-mesons and the standard model which conspire to make the overall top pair production rate consistent with the standard model. The rate for same-sign top production is also small due to destructive interference between the neutral top-pion and the top-Higgs. Flavor physics is under control because new physics is mostly confined to the top quark. In this way, top condensation can explain the asymmetry and be consistent with all experimental bounds. There are many additional signatures of topcolor with large tu mixing, such as top(s)+jet(s) events, in which a top and a jet reconstruct a resonance mass, which make these models easily testable at the LHC.

Yanou Cui; Zhenyu Han; Matthew D. Schwartz

2011-06-15T23:59:59.000Z

187

Searches for new physics in top events at the Tevatron  

SciTech Connect

During the past years the CDF and D0 detectors have collected large amounts of data obtaining a relatively pure sample of pair-produced top quarks and a well understood sample containing singly-produced top quarks. These samples have been used for the precise measurement of the top quark properties, and have set stringent limits on new physics in the top sample. This reports presents the latest results from the CDF and D0 collaborations on the search for new physics within the top sample using an integrated data sample of up to 3.6 fb{sup -1}.

Eusebi, Ricardo; collaboration, CDF; collaboration, D0

2009-05-01T23:59:59.000Z

188

Electroweak Corrections to the Top Quark Decay  

E-Print Network (OSTI)

We have calculated the one-loop electroweak corrections to the decay t-> bW+, including the counterterm for the CKM matrix elements V(tb). Previous calculations used an incorrect delta V(tb) that led to a gauge dependent amplitude. However, since the contribution stemming from delta V(tb) is small, those calculations only underestimate the width by roughly one part in 10^5.

S. M. Oliveira; L. Bruecher; R. Santos; A. Barroso

2001-01-18T23:59:59.000Z

189

Top quark physics expectations at the LHC  

E-Print Network (OSTI)

physics expectations at the LHC Andrei Gaponenko, on behalfbe produced copiously at the LHC. This will make possiblepurpose detectors at the LHC, which will provide proton-

Gaponenko, Andrei; ATLAS Collaboration; CMS Collaboration

2008-01-01T23:59:59.000Z

190

Probing top-Z dipole moments at the LHC and ILC  

E-Print Network (OSTI)

We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirect constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. We find that LHC experiments will soon be able to probe weak dipole moments for the first time.

Raoul Röntsch; Markus Schulze

2015-01-23T23:59:59.000Z

191

Probing top-Z dipole moments at the LHC and ILC  

E-Print Network (OSTI)

We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirect constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. We find that LHC experiments will soon be able to probe weak dipole moments for the first time.

Röntsch, Raoul

2015-01-01T23:59:59.000Z

192

Quark Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Quark Quark Matter in Neutron Stars Prashanth Jaikumar Argonne National Laboratory, (PHY) September 7th, 2006 . - p.1/29 Outline * Neutron stars: observations by a theorist . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) * Is quark matter inside neutron stars ruled out? . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) * Is quark matter inside neutron stars ruled out? ------------------------ * Strange Quark stars: Features and "Findings" . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) * Is quark matter inside neutron stars ruled out? ------------------------

193

Measurement of the Top Quark Pair Production Cross Section in pp Collisions at a Center-of-Mass Energy of 7 TeV with the CMS Experiment at the LHC  

E-Print Network (OSTI)

its position in the ECAL bore in the experimental cavern aton top of a HCAL wedge in the experimental cavern atHCAL wedges in the experimental cavern as shown in Fig. C.1.

Jeng, Geng-yuan

2011-01-01T23:59:59.000Z

194

Remarks on quark-quark and quark-antiquark potentials  

Science Journals Connector (OSTI)

The quark-quark potential in antisymmetrical color states and the quark-antiquark potential in color-singlet states are given to the fourth order in perturbative quantum chromodynamics. We have also corrected an error involving the charge conjugation of color matrices in our recent derivation of the quark-antiquark potential for arbitrary color states.

Suraj N. Gupta and Stanley F. Radford

1982-06-15T23:59:59.000Z

195

Building a Better Boosted Top Tagger  

E-Print Network (OSTI)

Distinguishing hadronically decaying boosted top quarks from massive QCD jets is an important challenge at the Large Hadron Collider. In this paper we use the power counting method to study jet substructure observables designed for top tagging, and gain insight into their performance. We introduce a powerful new family of discriminants formed from the energy correlation functions which outperform the widely used N-subjettiness. These observables take a highly non-trivial form, demonstrating the importance of a systematic approach to their construction.

Andrew J. Larkoski; Ian Moult; Duff Neill

2014-11-03T23:59:59.000Z

196

Single top measurements and the $|V_{\\rm tb}|$ extraction at the LHC  

E-Print Network (OSTI)

The CMS and ATLAS experiments have performed detailed studies on the electroweakly produced top quarks at the LHC. These studies range from accurate measurements of the cross section and $|V_{\\rm tb}|$ in different production modes to search for new interactions in the $\\rm tWb$ vertex. Moreover, different properties of the top quark are precisely measured in this context. All measurements are consistent with the standard model and no sign of new physics is observed.

Jafari, Abideh

2014-01-01T23:59:59.000Z

197

Playing Tag with ANN: Boosted Top Identification with Pattern Recognition  

E-Print Network (OSTI)

Many searches for physics beyond the Standard Model at the Large Hadron Collider (LHC) rely on top tagging algorithms, which discriminate between boosted hadronic top quarks and the much more common jets initiated by light quarks and gluons. We note that the hadronic calorimeter (HCAL) effectively takes a "digital image" of each jet, with pixel intensities given by energy deposits in individual HCAL cells. Viewed in this way, top tagging becomes a canonical pattern recognition problem. With this motivation, we present a novel top tagging algorithm based on an Artificial Neural Network (ANN), one of the most popular approaches to pattern recognition. The ANN is trained on a large sample of boosted tops and light quark/gluon jets, and is then applied to independent test samples. The ANN tagger demonstrated excellent performance in a Monte Carlo study: for example, for jets with p_T in the 1100-1200 GeV range, 60% top-tag efficiency can be achieved with a 4% mis-tag rate. We discuss the physical features of the ...

Almeida, Leandro G; Cliche, Mathieu; Lee, Seung J; Perelstein, Maxim

2015-01-01T23:59:59.000Z

198

Model-Independent Production of a Top-Philic Resonance at the LHC  

E-Print Network (OSTI)

We investigate the collider phenomenology of a color-singlet vector resonance, which couples to the heaviest quarks, the top quarks, but very weakly to the rest of the fermions in the Standard Model. We find that the dominant production of such a resonance does not appear at the tree level -- it rather occurs at the one-loop level in association with an extra jet. Signatures like t anti-t plus jets readily emerge as a result of the subsequent decay of the resonance into a pair of top quarks. Without the additional jet, the resonance can still be produced off-shell, which gives a sizeable contribution at low masses. The lower top quark multiplicity of the loop induced resonance production facilitates its reconstruction as compared to the tree level production that gives rise to more exotic signatures involving three or even four top quarks in the final state. For all these cases, we discuss the constraints on the resonance production stemming from recent experimental measurements in the top quark sector. We find that the top-philic vector resonance remains largely unconstrained for the majority of the parameter space, although this will be scrutinized closely in the Run 2 phase of the LHC.

Nicolas Greiner; Kyoungchul Kong; Jong-Chul Park; Seong Chan Park; Jan-Christopher Winter

2014-10-22T23:59:59.000Z

199

Top-mass measurements from D0  

SciTech Connect

We present three recent analyses (Abstracts 169, 170 and 174) of the mass of the top quark (M{sub t}) using top-antitop candidate events collected by the D0 experiment at the Fermilab Tevatron Collider: (i) a 3.6 events/fb sample of data in the lepton+jets channel analyzed to extract a precision value of M{sub t} using the 'Matrix-Element' (ME) method, wherein each event probability is calculated from the differential production cross section as a function of M{sub t} and the overall jet energy scale, with the latter constrained by the two jets from W decay into q{prime}{bar q}, (ii) a first measurement of the mass difference between top and antitop quarks as a check of CPT invariance in the quark sector, also based on the ME method in lepton+jets channels, and corresponding to a 1 event/fb data sample, and (iii) measurements of M{sub t} in dilepton final states (updated to 3.6 events/fb), based on 'matrix' weighting, 'neutrino' weighting and the ME method, which rely, respectively, on the likelihood of observing the events in data for a range of assumed M{sub t} values, distributions generated from event weights that compare calculated and reconstructed missing transverse energies, and event probabilities based on the leading-order differential cross section as a function of assumed M{sub t}. In addition, we provide a combination of recent top-mass measurements from D0.

Ferbel, T.; /Rochester U. /Maryland U.

2009-01-01T23:59:59.000Z

200

Top Science of 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

RAPTOR telescope witnesses black hole birth science-innovationassetsimagesicon-science.jpg Top Science of 2013 Our strong interdisciplinary teaming and unique research...

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Top Science of 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

firsts pave way for greener, faster supercomputing science-innovationassetsimagesicon-science.jpg Top Science of 2013 Our strong interdisciplinary teaming and unique...

202

Effects of R-parity violating supersymmetry in top pair production at linear colliders with polarized beams  

E-Print Network (OSTI)

In the minimal supersymmetric standard model with R-parity violation, the lepton number violating top quark interactions can contribute to the top pair production at a linear collider via tree-level u-channel squark exchange diagrams. We calculate such contributions and find that in the allowed range of these R-violating couplings, the top pair production rate as well as the top quark polarization and the forward-backward asymmetry can be significantly altered. By comparing the unpolarized beams with the polarized beams, we find that the polarized beams are more powerful in probing such new physics.

Xuelei Wang; Jitao Li; Suzhen Liu

2006-11-06T23:59:59.000Z

203

Top physics at CDF  

SciTech Connect

We report on top physics results using a 100 pb{sup -1} data sample of p{bar p} collisions at {radical}s = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). We have identified top signals in a variety of decay channels, and used these channels to extract a measurement of the top mass and production cross section. A subset of the data (67 pb{sup -1}) is used to determine M{sub top} = 176 {+-} 8(stat) {+-} 10(syst) and {sigma}(tt) = 7.6 {sub -2.0}{sup +2.4} pb. We present studies of the kinematics of t{bar t} events and extract the first direct measurement of V{sub tb}. Finally, we indicate prospects for future study of top physics at the Tevatron.

Hughes, R.E. [Univ. of Rochester, NY (United States)

1997-01-01T23:59:59.000Z

204

Using jet mass to discover vector quarks at the CERN LHC  

Science Journals Connector (OSTI)

We illustrate the utility of jet-mass distributions as probes of new physics at the LHC, focusing on a heavy vector-quark doublet that mixes with the top as a concrete example. For 1 TeV vector-quark masses, we find that signals with greater than 5? significance can be achieved after 100??fb-1. More generally, jet-mass distributions have the potential to provide signals for heavy states that produce highly boosted weak gauge bosons and/or top quarks.

Witold Skiba and David Tucker-Smith

2007-06-14T23:59:59.000Z

205

Quark Condensates: Flavour Dependence  

E-Print Network (OSTI)

We determine the q-bar q condensate for quark masses from zero up to that of the strange quark within a phenomenologically successful modelling of continuum QCD by solving the quark Schwinger-Dyson equation. The existence of multiple solutions to this equation is the key to an accurate and reliable extraction of this condensate using the operator product expansion. We explain why alternative definitions fail to give the physical condensate.

R. Williams; C. S. Fischer; M. R. Pennington

2007-03-23T23:59:59.000Z

206

quark-web.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

FREE FREE QUARK SEARCHES The basis for much of the theory of particle scattering and hadron spectroscopy is the construction of the hadrons from a set of fractionally charged constituents (quarks). A central but unproven hypothesis of this theory, Quantum Chromodynamics, is that quarks cannot be observed as free particles but are confined to mesons and baryons. Experiments show that it is at best difficult to "unglue" quarks. Accelerator searches at increasing energies have pro- duced no evidence for free quarks, while only a few cosmic-ray and matter searches have produced uncorroborated events. This compilation is only a guide to the literature, since the quoted experimental limits are often only indicative. Reviews can be found in Refs. 1-4. References 1. M.L. Perl, E.R. Lee, and D. Lomba, Mod. Phys. Lett. A19, 2595 (2004). 2. P.F. Smith, Ann. Rev. Nucl. and Part. Sci. 39,

207

Experimental results on $t\\bar{t}+W/Z/\\gamma$ and SM top couplings from the Tevatron and the LHC  

E-Print Network (OSTI)

(Proceedings of TOP2014 Conference) Experimental results from the CDF and D0 Collaborations at the Tevatron and the ATLAS and CMS Collaborations at the LHC on the processes related to probing top quark couplings are presented. Evidence of both $t\\bar{t}Z$ and $t\\bar{t}W$ processes is reported. All measurements are in agreement with the SM expectations.

Vazquez Schroeder, Tamara; The ATLAS collaboration

2014-01-01T23:59:59.000Z

208

Questions and Answers - What kinds of quarks are protons and neutrons made  

NLE Websites -- All DOE Office Websites (Extended Search)

How many quarks are inprotons and neutrons? How many quarks are in<br>protons and neutrons? Previous Question (How many quarks are in protons and neutrons?) Questions and Answers Main Index Next Question (What is the charge of an up quark and of down quark?) What is the charge of an up quarkand of down quark? What kinds of quarks are protons and neutrons made of? What was the old name for the Top and Bottom quark? Protons are made of two Up and one Down quark. The neutron is made of two Down and one Up quark. The Up quarks have a 2/3 positive charge and the Down has a 1/3 negative charge. Fractional charges are a pretty funny concept, but remember we (humans) made up the unit of charge that a proton has, so its very possible that there could be a smaller division of charge. If you add those charges you will see that sum is positive one for the

209

Top Ten Lists  

NLE Websites -- All DOE Office Websites (Extended Search)

Fueleconomy Top Ten Fueleconomy Top Ten EPA Rated - 2014 EPA Rated - All Years Shared Estimates - All Years Misconceptions Fueleconomy.gov's Top Ten EPA-Rated Fuel Sippers (2014) Include all-electric and plug-in hybrid vehicles? Yes No Vehicles are ranked by their combined rating (weighted by 55% city and 45% highway). In the event of a tie, multiple vehicles may share the same ranking. Electric vehicles are measured in Miles Per Gallon equivalent (MPGe) where 33.7 kW-hrs = 1 gallon of gasoline. 1. 2014 Chevrolet Spark EV 2014 Chevrolet Spark EV Combined 119 City 128/Highway 109 All-electric, Auto (A1) 2. 2014 Honda Fit EV 2014 Honda Fit EV Combined 118 City 132/Highway 105 All-electric, Auto (A1) 3. 2014 Fiat 500e 2014 Fiat 500e Combined 116 City 122/Highway 108 All-electric, Auto (A1)

210

Multiple Rankine topping cycles  

SciTech Connect

The efficiency of a Rankine cycle is primarily determined by the temperatures of heat addition and rejection. However, no working fluid has been identified which will operate in a Rankine cycle over an extremely wide temperature range. Multiple Rankine topping cycles offer a technique for achieving high thermal efficiencies in power plants by allowing the use of several working fluids. This paper gives a history of Rankine topping cycles, presents an analysis for the calculation of the overall efficiency of a three-module multiple Rankine cycle, and presents results from a case study for a sodium-mercury-water cycle.

McWhirter, J.D. [Argonne National Lab., Idaho Falls, ID (United States). Engineering Div.]|[Idaho State Univ., Pocatello, ID (United States). Coll. of Engineering

1995-07-01T23:59:59.000Z

211

quarks-web.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

and and 2013 update for the 2014 edition (URL: http://pdg.lbl.gov) December 18, 2013 12:00 - 2- the introduction of a dimensionful scale parameter µ. The mass parameters in the QCD Lagrangian Eq. (1) depend on the renor- malization scheme used to define the theory, and also on the scale parameter µ. The most commonly used renormalization scheme for QCD perturbation theory is the MS scheme. The QCD Lagrangian has a chiral symmetry in the limit that the quark masses vanish. This symmetry is spontaneously broken by dynamical chiral symmetry breaking, and explicitly broken by the quark masses. The nonperturbative scale of dynamical chiral symmetry breaking, Λ χ , is around 1 GeV [2]. It is conventional to call quarks heavy if m > Λ χ , so that explicit chiral symmetry breaking dominates (c, b, and t quarks are heavy), and light if m < Λ χ , so that spontaneous chiral symmetry breaking

212

Anatomy of Coannihilation with a Scalar Top Partner  

E-Print Network (OSTI)

We investigate a simplified model of dark matter where a Majorana fermion $\\chi$ coannihilates with a colored scalar top partner $\\tilde{t}$. We explore the cosmological history, with particular emphasis on the most relevant low-energy parameters: the mass splitting between the dark matter and the coannihilator, and the Yukawa coupling $y_\\chi$ that connects these fields to the Standard Model top quarks. We also allow a free quartic coupling $\\lambda_h$ between a pair of Higgs bosons and $\\tilde{t}$ pairs. We pay special attention to the case where the values take on those expected where $\\tilde{t}$ corresponds to the superpartner of the right-handed top, and $\\chi$ is a bino. Direct detection, indirect detection, and colliders are complementary probes of this simple model.

Ibarra, A; Shah, N R; Vogl, S

2015-01-01T23:59:59.000Z

213

Top Jets at the LHC  

E-Print Network (OSTI)

Physics Signatures at the LHC,” talk presented at the 2007Top Jets at the LHC Leandro G. Almeida, Seung J. Lee, GiladSEPT-DPP Top Jets at the LHC Leandro G. Almeida a , Seung J.

Almeida, L.G.

2009-01-01T23:59:59.000Z

214

Building America 2013 Top Innovations  

Energy.gov (U.S. Department of Energy (DOE))

This page provides a listing of and links to 2013 Top Innovations coming out of the Building America program.

215

Reconstruction of stop quark mass at the LHC  

Science Journals Connector (OSTI)

The cascade mass reconstruction approach was applied to simulated production of the lightest stop quark at the LHC in the cascade decay g˜?t˜1t??˜20tt??˜R?tt??˜10??tt with top quarks decaying into hadrons. The stop quark mass was reconstructed assuming that the masses of gluino, slepton, and the two lightest neutralinos were reconstructed in advance. A data sample set for the SU3 model point containing 400 k supersymmetry events was generated which corresponded to an integrated luminosity of about 20??fb-1 at 14 TeV. These events were passed through the AcerDET detector simulator, which parametrized the response of a generic LHC detector. The mass of the t˜1 was reconstructed with a precision of about 10%.

Diego Casadei; Rostislav Konoplich; Rashid Djilkibaev

2010-10-15T23:59:59.000Z

216

Detecting heavy quarks  

SciTech Connect

In this exercise we examine the performance of a detector specifically configured to tag heavy quark (HQ) jets through direct observations of D-meson decays with a high resolution vertex detector. To optimize the performance of such a detector, we assume the small diamond beam crossing configuration as described in the 1978 ISABELLE proposal, giving a luminosity of 10/sup 32/ cm/sup -2/ sec/sup -1/. Because of the very large backgrounds from light quark (LQ) jets, most triggering schemes at this luminosity require high P/sub perpendicular to/ leptons and inevitably give missing neutrinos. If alternative triggering schemes could be found, then one can hope to find and calculate the mass of objects decaying to heavy quarks. A scheme using the high resolution detector will also be discussed in detail. The study was carried out with events generated by the ISAJET Monte Carlo and a computer simulation of the described detector system. (WHK)

Benenson, G.; Chau, L.L.; Ludlam, T.; Paige, F.E.; Platner, E.D.; Protopopescu, S.D.; Rehak, P.

1983-01-01T23:59:59.000Z

217

Search for pair production of third-generation scalar leptoquarks and top squarks in proton-proton collisions at sqrt(s) = 8 TeV  

E-Print Network (OSTI)

A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.7 inverse femtobarns, collected with the CMS detector at the LHC with sqrt(s) = 8 TeV. The number of observed events is found to be in agreement with the expected standard model background. Third-generation scalar leptoquarks with masses below 740 GeV are excluded at 95% confidence level, assuming a 100% branching fraction for the leptoquark decay to a tau lepton and a bottom quark. In addition, this mass limit applies directly to top squarks decaying via an R-parity violating coupling lambda'[333]. The search also considers a similar signature from top squarks undergoing a chargino-mediated decay involving the R-parity violating coupling lambda'[3jk]. Each top squark decays to a tau lepton, a bottom quark, and two light quarks. Top squarks in this model with masses below 580 GeV are excluded at 95% confidence level. The constraint on the leptoquark mass is the most stringent to date, and this is the first search for top squarks decaying via lambda'[3jk].

CMS Collaboration

2014-08-04T23:59:59.000Z

218

Quark-gluon plasma paradox  

E-Print Network (OSTI)

Based on simple physics arguments it is shown that the concept of quark-gluon plasma, a state of matter consisting of uncorrelated quarks, antiquarks, and gluons, has a fundamental problem.

Dariusz Miskowiec

2007-07-06T23:59:59.000Z

219

Computing Z_top  

E-Print Network (OSTI)

This is the text of my habilitation thesis defended at the \\'Ecole Normale Sup\\'erieure. The topological string presents an arena in which many features of string theory proper, such as the interplay between worldsheet and target space descriptions or open-closed duality, can be distilled into computational techniques which yield results beyond perturbation theory. In this thesis, I will summarize my research activity in this area. The presentation is organized around computations of the topological string partition function Z_top based on various perspectives on the topological string.

Amir-Kian Kashani-Poor

2014-08-06T23:59:59.000Z

220

A handbook of vector-like quarks: mixing and single production  

E-Print Network (OSTI)

We obtain constraints on the mixing of vector-like quarks coupling predominantly to the third generation. We consider all (seven) possible types of vector-like quarks, individually. The constraints are derived from oblique corrections and Z -> b bbar measurements at LEP and SLC. We investigate the implications of these constraints on LHC phenomenology, concerning the decays of the heavy quarks and their single production. We also explore indirect effects of heavy quark mixing in top and bottom couplings. The most remarkable of these effects is the possibility of explaining the anomalous forward-backward asymmetry in Z -> b bbar at LEP, with a hypercharge -5/6 doublet. We also study the impact of the new quarks on single Higgs production at the LHC and Higgs decay.

Aguilar-Saavedra, J A; Heinemeyer, S; Perez-Victoria, M

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

A handbook of vector-like quarks: mixing and single production  

E-Print Network (OSTI)

We obtain constraints on the mixing of vector-like quarks coupling predominantly to the third generation. We consider all (seven) relevant types of vector-like quarks, individually. The constraints are derived from oblique corrections and Z -> b bbar measurements at LEP and SLC. We investigate the implications of these constraints on LHC phenomenology, concerning the decays of the heavy quarks and their single production. We also explore indirect effects of heavy quark mixing in top and bottom couplings. A remarkable effect is the possibility of explaining the anomalous forward-backward asymmetry in Z -> b bbar at LEP, with a hypercharge -5/6 doublet. We also study the impact of the new quarks on single Higgs production at the LHC and Higgs decay.

J. A. Aguilar-Saavedra; R. Benbrik; S. Heinemeyer; M. Perez-Victoria

2013-06-03T23:59:59.000Z

222

Top Science of 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

Space probes predict hazards to protect spacecraft Space probes predict hazards to protect spacecraft /science-innovation/_assets/images/icon-science.jpg Top Science of 2013 Our strong interdisciplinary teaming and unique research facilities allow us to develop solutions to complex problems, and to support partners and collaborators, all with the goal of strengthening national security and making a safer world. Space probes predict hazards to protect spacecraft placeholder Researchers think they've solved a 50-year-old space mystery about how electrons within the Van Allen radiation belts that surround our planet can become energetic enough to cripple orbiting satellites. With data collected by space-probe instruments, they discovered how electromagnetic radio waves cause electrons in these belts to greatly

223

Top Science of 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

RAPTOR telescope witnesses black hole birth RAPTOR telescope witnesses black hole birth /science-innovation/_assets/images/icon-science.jpg Top Science of 2013 Our strong interdisciplinary teaming and unique research facilities allow us to develop solutions to complex problems, and to support partners and collaborators, all with the goal of strengthening national security and making a safer world. RAPTOR telescope witnesses black hole birth placeholder The first "thinking telescope" RAPTOR found the birth of big black holes, possibly the most powerful events since the big bang. This robotic array screens 100 million objects and runs real-time analysis-autonomously alerting us when there's a discovery or a threat. In 2006, RAPTOR was the first of its kind to make a discovery: the birth of

224

QuarkNet  

NLE Websites -- All DOE Office Websites (Extended Search)

QuarkNet: The science connection you've been waiting for! QuarkNet: The science connection you've been waiting for! The Opportunity: "Your program rejuvenates my soul. It connects me with a cadre of intelligent and excited educators. It reinvigorates my teaching and provides me avenues to extend and enliven the projects that I can offer my students. Without the Quarknet program I am sure that I would have left teaching years ago." The Players: High school students, teachers and physicsts working together on physics research projects exploring the hidden nature of matter, energy, space and time. The Questions: What are the origins of mass? Can the basic forces of nature be unified? How did the universe begin? How will it evolve? LHC & Fermilab Links For Teachers For Students CERN Homepage ATLAS Experiment

225

Top mass measurements at the Tevatron run II  

SciTech Connect

The latest top quark mass measurements by the CDF and D0 experiments are presented here. The mass has been determined in the dilepton (t{bar t} {yields} e{mu}, ee, {mu}{mu} + jets + E{sub T}) and lepton plus jets (t{bar t} {yields} e or {mu} + jets + E{sub T}) final states. The most accurate single result from lepton plus jets channel is 173.5{sub -3.6}{sup +3.7}(stat. + Jet Energy Scale Systematic) {+-} 1.3(syst.) GeV/c{sup 2}, which is better than the combined CDF and D0 Run I average. A preliminary and unofficial average of the best experimental Run II results gives M{sub top} = 172.7 {+-} 3.5 GeV/c{sup 2}.

Velev, Gueorgui V.; /Fermilab

2005-10-01T23:59:59.000Z

226

Techniques for the Top Squark Search at the Fermilab Tevatron  

E-Print Network (OSTI)

This dissertation addresses the question of how to detect light top squarks at the upgraded Fermilab Tevatron collider. After a brief introduction to supersymmetry, the basic phenomenology of the light stop is reviewed and the current experimental situation is surveyed. The analysis presented here is based on collider event simulations. The main decay modes accessible to the Tevatron are studied, feasible discovery channels are identified, and recipes for experimental analysis are proposed. It is found that stops with masses up to the top quark mass are liable to detection under these schemes with the data from a few years' running at the upgraded Tevatron. With such an extended run, significant portions of parameter space may be probed.

John Sender

2000-10-04T23:59:59.000Z

227

Holographic Accelerated Heavy Quark-Anti-Quark Pair  

E-Print Network (OSTI)

The problem of a heavy quark-anti-quark pair which have constant eternal acceleration in opposite directions in the vacuum of deconfined maximally supersymmetric Yang-Mills theory is studied both in perturbation theory and at strong coupling using AdS/CFT. Perturbation theory is summed to obtain what is conjectured to be an exact result. It is shown to agree with a particular prescription for computing the disc amplitude in the string theory dual and it yields a value $s=\\sqrt{\\lambda}$ for the entanglement entropy of the quark and anti-quark.

Veronika E. Hubeny; Gordon W. Semenoff

2014-10-05T23:59:59.000Z

228

Exploiting Third Generation Quarks for New Physics Discoveries at the Energy Frontier  

SciTech Connect

The K-State group's effort is top quark physics and searches for beyond-standard-model physics in t{anti #22;}t final states. The KSU team performed the most precise measurement of the t#22;{anti t} cross section in the lepton + jets channel, and for the first time excluded the fourth generation of the standard model in the perturbative regime.

Ivanov, Andrew G. [KSU] (ORCID:0000000292705643)

2013-10-15T23:59:59.000Z

229

E-Print Network 3.0 - al noreste del Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

two types of Summary: Ruz-Morales Jess Garca-Hernndez Regin Marina Noreste, PEMEX Exploracin y Produccin, Ciudad del... with the classic Ir anomaly at its top...

230

Limiting Factors for Convective Cloud Top Height in the Tropics  

NLE Websites -- All DOE Office Websites (Extended Search)

Limiting Factors for Convective Cloud Top Limiting Factors for Convective Cloud Top Height in the Tropics M. P. Jensen and A. D. Del Genio National Aeronautics and Space Administration Goddard Institute for Space Studies Columbia University New York, New York Introduction Populations of tropical convective clouds are mainly comprised of three types: shallow trade cumulus, mid-level cumulus congestus and deep convective clouds (Johnson et al. 1999). Each of these cloud types has different impacts on the local radiation and water budgets. For climate model applications it is therefore important to understand the factors which determine the type of convective cloud that will occur. In this study, we concentrate on describing the factors that limit the cloud-top heights of mid-

231

Cold quark matter in compact stars  

SciTech Connect

We used an equation of state for the cold quark matter to the study of properties of quark stars. We also discuss the absolute stability of quark matter and compute the mass-radius relation for self-bound stars.

Franzon, B.; Fogaca, D. A.; Navarra, F. S. [Instituto de Fisica, Universidade de Sao Paulo Rua do Matao, Travessa R, 187, 05508-090 Sao Paulo, SP (Brazil); Horvath, J. E. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao, 1226, 05508-090, Sao Paulo, SP (Brazil)

2013-03-25T23:59:59.000Z

232

Invisible Higgs in weak bosons associative production with heavy quarks at LHC: probing mass and width  

E-Print Network (OSTI)

New physics coupled to the Higgs boson may hide it in the standard decay channels to be investigated at LHC. We consider the models where new invisible dominant decay modes of the Higgs boson are responsible for this hiding. We propose to study at LHC the weak boson production associated with heavy quarks: our analysis revealed that boson pair invariant mass distribution is sensitive to both mass and width of the invisible Higgs boson, if it is not too far from the weak boson pair threshold. We present tree-level results for the most relevant cases of top quarks and of bottom quarks in Standard Model extensions with large $b$-quark Yukawa coupling. We argue that QCD corrections do not spoil these results allowing for unambiguous extraction of the Higgs boson mass and width from the analysis of large enough amount of data.

E. E. Boos; S. V. Demidov; D. S. Gorbunov

2010-10-26T23:59:59.000Z

233

ARM - Measurement - Cloud top height  

NLE Websites -- All DOE Office Websites (Extended Search)

to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud top height For a given cloud or cloud layer, the highest level of the atmosphere where...

234

Smoke busters WIN TOp HONOURS  

E-Print Network (OSTI)

Smoke busters WIN TOp HONOURS Re-brand continues INE|SPRING2010|UNIVERSITYOFWATERLOOMAGAZINE|SPRING2010|UNIVERSITYOFWATERL RSITYOFWATERLOOMAGAZINE|SPRING2010|UNIVERSITYOFWATERLOOMAGAZINE|SPRING2010|UNIVERSITYOFWATERLOOMAGAZINE|SPRING2010 RING2010|UNIVERSITYOFWATERLOOMAGAZINE|SPRING2010|UNIVERSITYOFWATERLOOMAGAZINE|SPRING

Waterloo, University of

235

Experimental results on $t\\bar{t}+W/Z/\\gamma$ and SM top couplings from the Tevatron and the LHC  

E-Print Network (OSTI)

Experimental results from the CDF and D0 Collaborations at the Tevatron and the ATLAS and CMS Collaborations at the LHC on the processes related to probing top quark couplings are presented. Evidence of both $t\\bar{t}Z$ and $t\\bar{t}W$ processes is reported. All measurements are in agreement with the SM expectations.

Schröder, Tamara Vázquez; CMS,

2014-01-01T23:59:59.000Z

236

Active QuarkNet Centers  

NLE Websites -- All DOE Office Websites (Extended Search)

Active QuarkNet Centers Active QuarkNet Centers       QuarkNet Home - Information - Calendar - Contacts - Projects - Forms: EoI - Teachers Centers on a Google Map @ the PTEC website Mentor List Sorted by: Last Name Institution Name First Year in Program Argonne National Laboratory - On sabbatical Black Hills State University Brown, Northeastern & Brandeis Universities Brookhaven National Laboratory, Columbia & Stony Brook Universities Chicago State University Colorado State University Fermilab & University of Chicago Florida Institute of Technology Florida International University Florida State University Hampton, George Mason, William & Mary Universities Idaho State University Indiana University - On sabbatical Johns Hopkins University

237

Shear Viscosity of Quark Matter  

E-Print Network (OSTI)

We consider the shear viscosity of a system of quarks and its ratio to the entropy density above the critical temperature for deconfinement. Both quantities are derived and computed for different modeling of the quark self-energy, also allowing for a temperature dependence of the effective mass and width. The behaviour of the viscosity and the entropy density is argued in terms of the strength of the coupling and of the main characteristics of the quark self-energy. A comparison with existing results is also discussed.

W. M. Alberico; S. Chiacchiera; H. Hansen; A. Molinari; M. Nardi

2007-07-30T23:59:59.000Z

238

Dissipative force on an external quark in heavy quark cloud  

E-Print Network (OSTI)

Within the finite temperature N = 4 strongly coupled super Yang- Mills, we compute the dissipative force on an external quark in the presence of evenly distributed heavy quark cloud. This is computed holographically by constructing the corresponding gravity dual. We study the behaviour of this force as a function of the cloud density. Along the way we also analyze the stability of the gravity dual for vector and tensor perturbations.

Shankhadeep Chakrabortty

2011-10-01T23:59:59.000Z

239

Heavy quarks in the jet calculus  

Science Journals Connector (OSTI)

In this paper we explore a method for treating heavy quarks such as c and b quarks within the jet calculus. These quarks are differentiated from the more common u, d, and s quarks by the requirement that the gluons never branch into heavy-quark pairs during the jet development. We compute and discuss the charmed-quark "propagators"; the x distribution of colorless clusters containing a charmed quark, a noncharmed antiquark, and gluons; and the mass distribution of the parent partons giving rise to these colorless clusters.

L. M. Jones

1983-07-01T23:59:59.000Z

240

Los Alamos National Laboratory top  

NLE Websites -- All DOE Office Websites (Extended Search)

top top science news of 2012 December 20, 2012 Scientific advances that caught the world's interest LOS ALAMOS, NEW MEXICO, December 20, 2012-In 2012 Los Alamos National Laboratory made its scientific mark in a wide variety of areas, and the stories that caught the public's attention and that of the science community reflect those broad capabilities. Top science stories for the year traveled from the canyons of Mars to the high desert forests of New Mexico, from cosmic particles to the structure of proteins and enzymes. Computer models of wildfires, and nuclear magnetic resonance signatures of plutonium, it all was fascinating for those following Los Alamos' science news. - 2 - Mars Science Laboratory Curiosity rover and ChemCam 2:12 ChemCam rock laser for the Mars Science Laboratory

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

MTS Table Top Load frame  

NLE Websites -- All DOE Office Websites (Extended Search)

MTS Table Top Load frame MTS Table Top Load frame The Non-destructive Evaluation group operates an MTS Table Top Load frame for ultimate strength and life cycle testing of various ceramic, ceramic-matrix (FGI), carbon, carbon fiber, cermet (CMC) and metal alloy engineering samples. The load frame is a servo-hydraulic type designed to function in a closed loop configuration under computer control. The system can perform non-cyclic, tension, compression and flexure testing and cyclic fatigue tests. The system is comprised of two parts: * The Load Frame and * The Control System. Load Frame The Load Frame (figure 1) is a cross-head assembly which includes a single moving grip, a stationary grip and LVDT position sensor. It can generate up to 25 kN (5.5 kip) of force in the sample under test and can

242

SRNL Microspheres Win Top Honors  

NLE Websites -- All DOE Office Websites (Extended Search)

Microspheres Microspheres Win Top Honors AIKEN, S.C. (July 16, 2012) - Savannah River National Laboratory (SRNL) captured top honors at a symposium spotlighting some of the most innovative research being conducted by the researchers supporting the U.S. Department of Energy's National Nuclear Security Administration (NNSA) . Dr. George Wicks of SRNL was presented the top "Award of Excellence" for the poster presen- tation on SRNL's porous-walled hollow glass microspheres at the NNSA Laboratory Directed Research and Development (LDRD) Symposium on Discovery and Innovation for National Security. The poster described how development of the microspheres began with funding from the Savannah River Site Plant-Directed Research and Development (PDRD) program, which funds

243

Top 10 Energy Efficiency Opportunities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Top 10 Energy Efficiency Top 10 Energy Efficiency Opportunities Federal Utility Partnership Working Group San Francisco, 5/22/2013 Siva Sethuraman Customer Energy Solutions PG&E 2 Whole Building A comprehensive, performance-based approach to achieving 15+% energy savings in existing commercial buildings - quantification of energy use baselines and estimate savings at the whole building level leveraging the power of interval meter data. Behavioral Operational Retrofit Types of Energy Savings * Simplified, integrated offering * Bigger incentives tied to performance * Flexibility to pursue a range of measures overtime * Transparent and credible bill savings Baseline Analytics, Examples 3 Small Commercial EMS * Energy management system (EMS) products that offer integrated

244

Physics of the Charm Quark  

SciTech Connect

This is a brief summary about the development of the charm quark physics in the area of experimental physics. The summary is centered in what is done by mexican physicists, particularly in the E791 and the FOCUS Experiment at FERMILAB. FOCUS (or E831) was designed to detect states of matter combining one or more charm quarks with light quarks (strange, up, down). The experiment created 10 times as many such particles as in previous experiments and investigated several topics on charm physics including high precision studies of charm semileptonic decays, studies of hadronic charm decays (branching ratios and Daltiz analyses), lifetime measurements of all charm particles, searches for mixing, CP/CPT violation, rare and forbidden decays, spectroscopy of excited charm mesons and baryons, charm production asymmetry measurements, light quark diffractive studies, QCD studies using charm pair events and searches for and upper limits on: charm pentaquarks, double charm baryons, DSJ(2632)

Carrillo Moreno, Salvador [Universidad Iberoamericana (Mexico); Vazquez Valencia, Elsa Fabiola [CINVESTAV (Mexico); Universidad Iberoamericana (Mexico)

2006-09-25T23:59:59.000Z

245

Symmetries of Quarks and Leptons  

Science Journals Connector (OSTI)

The course is divided in four Chapters corresponding to three lectures. After an introductory first chapter, the second deals with the symmetries of strong interactions from a quark point of view. We shall dis...

F. Gürsey

1979-01-01T23:59:59.000Z

246

Experimental Discrimination between Charge 2e/3 Top Quark and Charge 4e/3 Exotic Quark Production Scenarios  

E-Print Network (OSTI)

. Gavrilov,37 A. Gay,19 P. Gay,13 D. Gele´,19 R. Gelhaus,49 C. E. Gerber,52 Y. Gershtein,50 D. Gillberg,5 G. Ginther,72 N. Gollub,41 B. Go´mez,8 A. Goussiou,56 P. D. Grannis,73 H. Greenlee,51 Z. D. Greenwood,61 E. M. Gregores,4 G. Grenier,20 Ph. Gris,13 J.... Hoeneisen,12 H. Hoeth,26 M. Hohlfeld,16 S. J. Hong,31 R. Hooper,78 P. Houben,34 Y. Hu,73 Z. Hubacek,10 V. Hynek,9 I. Iashvili,70 R. Illingworth,51 A. S. Ito,51 S. Jabeen,63 M. Jaffre´,16 S. Jain,76 K. Jakobs,23 C. Jarvis,62 A. Jenkins,44 R. Jesik,44 K. Johns...

Baringer, Philip S.; Bean, Alice; Coppage, Don; Gardner, J.; Hensel, Carsten; Moulik, Tania; Wilson, Graham Wallace; Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.

2007-01-22T23:59:59.000Z

247

Quark condensate for various heavy flavors  

E-Print Network (OSTI)

The quark condensate is calculated within the world-line effective-action formalism, by using for the Wilson loop an ansatz provided by the stochastic vacuum model. Starting with the relation between the quark and the gluon condensates in the heavy-quark limit, we diminish the current quark mass down to the value of the inverse vacuum correlation length, finding in this way a 64%-decrease in the absolute value of the quark condensate. In particular, we find that the conventional formula for the heavy-quark condensate cannot be applied to the c-quark, and that the corrections to this formula can reach 23% even in the case of the b-quark. We also demonstrate that, for an exponential parametrization of the two-point correlation function of gluonic field strengths, the quark condensate does not depend on the non-confining non-perturbative interactions of the stochastic background Yang-Mills fields.

Dmitri Antonov; Jose Emilio F. T. Ribeiro

2012-10-04T23:59:59.000Z

248

New results on CLEO`s heavy quarks - bottom and charm  

SciTech Connect

While the top quark is confined to virtual reality for CLEO, the increased luminosity of the Cornell Electron Storage Ring (CESR) and the improved photon detection capabilities of the CLEO`s {open_quotes}heavy{close_quotes} quarks - bottom and charm. I will describe new results in the B meson sector including the first observation of exclusive b {yields} ulv decays, upper limits on gluonic penguin decay rates, and precise measurements of semileptonic and hadronic b {yields} c branching fractions. The charmed hadron results that are discussed include the observation of isospin violation in D{sub s}*{sup +} decays, an update on measurements of the D{sub s}{sup +} decay constant, and the observation of a new excited {Xi}{sub c} charmed baryon. These measurements have had a large impact on our understanding of heavy quark physics.

Menary, S. [Univ. of California, Santa Barbara, CA (United States)

1997-01-01T23:59:59.000Z

249

Building Technologies Office: Top Innovations 2012  

NLE Websites -- All DOE Office Websites (Extended Search)

Top Innovations 2012 to Top Innovations 2012 to someone by E-mail Share Building Technologies Office: Top Innovations 2012 on Facebook Tweet about Building Technologies Office: Top Innovations 2012 on Twitter Bookmark Building Technologies Office: Top Innovations 2012 on Google Bookmark Building Technologies Office: Top Innovations 2012 on Delicious Rank Building Technologies Office: Top Innovations 2012 on Digg Find More places to share Building Technologies Office: Top Innovations 2012 on AddThis.com... About Take Action to Save Energy Partner With DOE Activities Solar Decathlon Building America Research Innovations Research Tools Building Science Education Climate-Specific Guidance Solution Center Partnerships Meetings Publications Home Energy Score Home Performance with ENERGY STAR Better Buildings Neighborhood Program

250

Modeling and control of top tensioned risers  

E-Print Network (OSTI)

1 Modeling and control of top tensioned risers Anne Marthine Rustad Department of Marine Technology increasing platform size · Constant high top tension is expensive and could result in wear and tear

Nørvåg, Kjetil

251

Heavy quarks in effective field theories  

E-Print Network (OSTI)

Heavy quark physics serves as a probe to understand QCD, measure standard model parameters, and look for signs of new physics. We study several aspects of heavy quark systems in an effective field theory framework, including ...

Jain, Ambar

2009-01-01T23:59:59.000Z

252

Quarks in the looking glass | Jefferson Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Quarks in the looking glass Jefferson Lab's Experimental Hall A The electron-quark scattering experiment was carried out in Jefferson Lab's Experimental Hall A. In this view from...

253

QuarkNet at Work  

NLE Websites -- All DOE Office Websites (Extended Search)

QuarkNet at Work Information for Active Mentors & Teachers     QuarkNet Home - Information - Calendar - Contacts - Projects - Forms: EoI - Teachers Information Active Centers Calendar Contacts Expectations: for Teachers, for Mentors Information on Other Funding Sources Program Overview Support: for Teachers, for Centers Staff Job Description Activities Essential Practices - Teaching with Inquiry (word.doc) Classroom Activities e-Labs: CMS - Cosmic Ray Boot Camp Project Activities Databases: Data Entry (password only) 2012 Center Reporting Resources Important Findings from Previous Years Mentor Tips Associate Teacher Institute Toolkit Print Bibliography - Online Resources Imaging Detector Principles of Professionalism for Science Educators - NSTA position

254

Flavordynamics of quarks and leptons  

Science Journals Connector (OSTI)

The present theory of flavordynamics is discussed. After giving a general introduction into the field we describe the gauge theory framework and the spontaneous symmetry breaking. Several examples of spontaneously broken theories are studied. We describe the standard theory of leptons and quarks. A special emphasis is given to a discussion of the weak decays of strange and charmed particles. Furthermore the neutral current interaction is studied. We discuss the sequential flavordynamics of leptons and quarks, concentrating on the six flavor scheme, and speculations about extended schemes of flavordynamics. The report concludes with a description of weak interactions at very high energies (production and decays of W, Z or Higgs bosons etc.).

H. Fritzsch; P. Minkowski

1981-01-01T23:59:59.000Z

255

Top Hat Pressure System Hyperbaric Test Analysis | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Top Hat Pressure System Hyperbaric Test Analysis Top Hat Pressure System Hyperbaric Test Analysis This file contains data from pressure measurements inside Top Hat 4....

256

A relativistic constituent quark model  

SciTech Connect

We investigate the predictive power of a relativistic quark model formulated on the light-front. The nucleon electromagnetic form factors, the semileptonic weak decays of the hyperons and the magnetic moments of both baryon octet and decuplet are calculated and found to be in excellent agreement with experiment.

Schlumpf, F.

1993-08-01T23:59:59.000Z

257

Quark confinement mechanism for baryons  

E-Print Network (OSTI)

The confinement mechanism proposed earlier and then successfully applied to meson spectroscopy by the author is extended over baryons. For this aim the wave functions of baryons are built as tensorial products of those corresponding to the 2-body problem underlying the confinement mechanism of two quarks. This allows one to obtain the Hamiltonian of the quark interactions in a baryon and, accordingly, the possible energy spectrum of the latter. Also one may construct the electric and magnetic form factors of baryon in a natural way which entails the expressions for the root-mean-square radius and anomalous magnetic moment. To ullustrate the formalism in the given Chapter for the sake of simplicity only symmetrical baryons (i.e., composed from three quarks of the same flavours) $\\Delta^{++}$, $\\Delta^{-}$, $\\Omega^-$ are considered. For them the masses, the root-mean-square radii and anomalous magnetic moments are expressed in an explicit analytical form through the parameters of the confining SU(3)-gluonic field among quarks and that enables one to get a number of numerical estimates for the mentioned parameters from experimental data. We also discuss chiral limit for the baryons under consideration and estimate the purely gluonic contribution to their masses. Further the problem of masses in particle physics is shortly discussed within the framework of the given approach. Finally, a few remarks are made about the so-called Yang-Mills Millennium problem and a possible way for proving it is outlined.

Yu. P. Goncharov

2013-12-14T23:59:59.000Z

258

MHD Integrated Topping Cycle Project  

SciTech Connect

This eighteenth quarterly technical progress report of the MHD Integrated Topping cycle Project presents the accomplishments during the period November 1, 1991 to January 31, 1992. The precombustor is fully assembled. Manufacturing of all slagging stage components has been completed. All cooling panels were welded in place and the panel/shell gap was filled with RTV. Final combustor assembly is in progress. The low pressure cooling subsystem (LPCS) was delivered to the CDIF. Second stage brazing issues were resolved. The construction of the two anode power cabinets was completed.

Not Available

1992-07-01T23:59:59.000Z

259

Table-top job analysis  

SciTech Connect

The purpose of this Handbook is to establish general training program guidelines for training personnel in developing training for operation, maintenance, and technical support personnel at Department of Energy (DOE) nuclear facilities. TTJA is not the only method of job analysis; however, when conducted properly TTJA can be cost effective, efficient, and self-validating, and represents an effective method of defining job requirements. The table-top job analysis is suggested in the DOE Training Accreditation Program manuals as an acceptable alternative to traditional methods of analyzing job requirements. DOE 5480-20A strongly endorses and recommends it as the preferred method for analyzing jobs for positions addressed by the Order.

Not Available

1994-12-01T23:59:59.000Z

260

Discovering strong top dynamics at the LHC  

Science Journals Connector (OSTI)

We analyze the phenomenology of the top-pion and top-Higgs states in models with strong top dynamics, and translate the present LHC searches for the Standard Model Higgs into bounds on these scalar states. We explore the possibility that the new state at a mass of approximately 125 GeV observed at the LHC is consistent with a neutral pseudoscalar top-pion state. We demonstrate that a neutral pseudoscalar top pion can generate the diphoton signal at the observed rate. However, the region of model parameter space where this is the case does not correspond to classic top-color-assisted technicolor scenarios with degenerate charged and neutral top pions and a top-Higgs mass of order 2mt; rather, additional isospin violation would need to be present and the top dynamics would be more akin to that in top seesaw models. Moreover, the interpretation of the new state as a top pion can be sustained only if the ZZ (four-lepton) and WW (two-lepton plus missing energy) signatures initially observed at the 3? level decline in significance as additional data are accrued.

R. Sekhar Chivukula; Pawin Ittisamai; Elizabeth H. Simmons; Baradhwaj Coleppa; Heather E. Logan; Adam Martin; Jing Ren

2012-11-16T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

MHD Integrated Topping Cycle Project  

SciTech Connect

The overall objective of the project is to design and construct prototypical hardware for an integrated MHD topping cycle, and conduct long duration proof-of-concept tests of integrated system at the US DOE Component Development and Integration Facility in Butte, Montana. The results of the long duration tests will augment the existing engineering design data base on MHD power train reliability, availability, maintainability, and performance, and will serve as a basis for scaling up the topping cycle design to the next level of development, an early commercial scale power plant retrofit. The components of the MHD power train to be designed, fabricated, and tested include: A slagging coal combustor with a rated capacity of 50 MW thermal input, capable of operation with an Eastern (Illinois {number sign}6) or Western (Montana Rosebud) coal, a segmented supersonic nozzle, a supersonic MHD channel capable of generating at least 1.5 MW of electrical power, a segmented supersonic diffuser section to interface the channel with existing facility quench and exhaust systems, a complete set of current control circuits for local diagonal current control along the channel, and a set of current consolidation circuits to interface the channel with the existing facility inverter.

Not Available

1992-01-01T23:59:59.000Z

262

MHD Integrated Topping Cycle Project  

SciTech Connect

The Magnetohydrodynamics (MHD) Integrated Topping Cycle (ITC) Project represents the culmination of the proof-of-concept (POC) development stage in the US Department of Energy (DOE) program to advance MHD technology to early commercial development stage utility power applications. The project is a joint effort, combining the skills of three topping cycle component developers: TRW, Avco/TDS, and Westinghouse. TRW, the prime contractor and system integrator, is responsible for the 50 thermal megawatt (50 MW{sub t}) slagging coal combustion subsystem. Avco/TDS is responsible for the MHD channel subsystem (nozzle, channel, diffuser, and power conditioning circuits), and Westinghouse is responsible for the current consolidation subsystem. The ITC Project will advance the state-of-the-art in MHD power systems with the design, construction, and integrated testing of 50 MW{sub t} power train components which are prototypical of the equipment that will be used in an early commercial scale MHD utility retrofit. Long duration testing of the integrated power train at the Component Development and Integration Facility (CDIF) in Butte, Montana will be performed, so that by the early 1990's, an engineering data base on the reliability, availability, maintainability and performance of the system will be available to allow scaleup of the prototypical designs to the next development level. This Sixteenth Quarterly Technical Progress Report covers the period May 1, 1991 to July 31, 1991.

Not Available

1992-03-01T23:59:59.000Z

263

Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production  

SciTech Connect

We present a new measurement of the inclusive forward-backward t{bar t} production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t{bar t} rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and {bar t}. In the t{bar t} rest frame, the asymmetry is observed to increase with the t{bar t} rapidity difference, {Delta}y, and with the invariant mass M{sub t{bar t}} of the t{bar t} system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large {Delta}y and M{sub t{bar t}}. For M{sub t{bar t}} {ge} 450 GeV/c{sup 2}, the parton-level asymmetry in the t{bar t} rest frame is A{sup t{bar t}} = 0.475 {+-} 0.114 compared to a next-to-leading order QCD prediction of 0.088 {+-} 0.013.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Apresyan, A.; /Purdue U.; Arisawa, T.; /Waseda U. /Dubna, JINR

2011-01-01T23:59:59.000Z

264

Search For Heavy, Neutral Gague Bosons Decaying To Boosted Top Quark Pairs At The LHC  

E-Print Network (OSTI)

pixel layer. For high energy muons the impact parametermatches in the muon chambers or energy depositions in thethe selected muon and the missing trans- verse energy of the

Babb, John

2012-01-01T23:59:59.000Z

265

Measurement of the top quark mass in the lepton+jets channel using the ideogram method  

E-Print Network (OSTI)

in the overall likelihood fit. This paper is organized as follows: Sections II and III describe the D0 Run II detector and the event reconstruc- tion, respectively. Sections IV, V, and VI describe the data and simulation samples used and outline the event selec... in Sec. IX and the systematic uncertainties are discussed in Sec. X. Section XI presents a cross-check of the JES calibration, followed by the con- clusion in Sec. XII. II. THE D0 DETECTOR Run II of the Fermilab Tevatron collider started in 2001 after...

Baringer, Philip S.; Bean, Alice; Hensel, Carsten; Moulik, Tania; Wilson, Graham Wallace; Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.

2007-05-11T23:59:59.000Z

266

Angular correlations of lepton pairs from vector boson and top quark decays in Monte Carlo simulations.  

E-Print Network (OSTI)

) u(k1)(?iFV )?? (VV l ?AV l?5) v(k2) , (2.15) 4 where mV and ?V are the mass and the width of the vector boson respectively, and Mµ is the amplitude for the process a(P1) + b(P2) ?? V (q) +X(x) , (2.16) µ being the Lorentz index associated with V... to thank the CERN TH division for hospitality during the completion of this work. We also would like to thank Fabio Maltoni for his collaboration during early stages of this work, and Chris White for useful discussions. The work of E.L. and P...

Frixione, Stefano; Laenen, Eric; Motylinski, Patrick; Webber, Bryan R

267

MHD Integrated Topping Cycle Project  

SciTech Connect

This seventeenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period August 1, 1991 to October 31, 1991. Manufacturing of the prototypical combustor pressure shell has been completed including leak, proof, and assembly fit checking. Manufacturing of forty-five cooling panels was also completed including leak, proof, and flow testing. All precombustor internal components (combustion can baffle and swirl box) were received and checked, and integration of the components was initiated. A decision was made regarding the primary and backup designs for the 1A4 channel. The assembly of the channel related prototypical hardware continued. The cathode wall electrical wiring is now complete. The mechanical design of the diffuser has been completed.

Not Available

1992-07-01T23:59:59.000Z

268

Top Innovations 2012 | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Top Innovations 2012 Top Innovations 2012 Top Innovations 2012 On this page, you will find Building America's Top Innovations from 1995 through 2012, with links to a profile describing each innovation. Note that some categories may not have a top innovation each year. Flow chart graphic 1. Advanced Technologies and Practices Top Innovations in this category cover research in thermal enclosure improvements, HVAC components, ventilation and other health and safety issues. 1.1 Building Science Solutions Thermal Enclosure: Basement Insulation Systems Advanced Framing Systems and Packages Unvented, Conditioned Attics Unvented, Conditioned Crawlspaces High-R Walls Heating, Ventilation, and Air Conditioning: Integration of HVAC System Design with Simplified Duct Distribution Ducts in Conditioned Space

269

Infrastructure Development- Building America Top Innovations  

Energy.gov (U.S. Department of Energy (DOE))

Top Innovations in this category include research results that have influenced codes and standards and improvements in education and the transaction process.

270

Water Management Guide- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

This Top Innovation highlights the DOE-sponsored Water Management Guide, which has proven to be a highly effective tool for disseminating much needed best practices.

271

Mesa Top Photovoltaic Array (Fact Sheet)  

SciTech Connect

Fact sheet overview of the Mesa Top Photovoltaic Array project implemented by the Department of Energy Golden Office and National Renewable Energy Laboratory.

Not Available

2009-07-01T23:59:59.000Z

272

Ultraviolet photodissociation enhances top?down mass...  

NLE Websites -- All DOE Office Websites (Extended Search)

Ultraviolet photodissociation enhances top-down mass spectrometry as demonstrated on green fluorescent protein variants Xibei Dang 1,2 and Nicolas L. Young 1 1 Ion Cyclotron...

273

Four-quark Bound States in Chiral SU(3) Quark Model  

E-Print Network (OSTI)

The possibility of $QQ\\bar{q}\\bar{q}$ heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where $Q$ is the heavy quark ($c$ or $b$) and $q$ is the light quark ($u$, $d$ or $s$). We obtain a bound state for the $bb\\bar{n}\\bar{n}$ configuration with quantum number $J^{P}=1^{+},I=0$ and for the $cc\\bar{n}\\bar{n}$ ($J^{P}=1^{+},I=0$) configuration which is not bound but slightly above the $D^{*}D^{*}$ threshold (n is $u$ or $d$ quark). Meanwhile, we also conclude that a weakly bound state in $bb\\bar{n}\\bar{n}$ system can also be found without considering the chiral quark interactions between the two light quarks, yet its binding energy is weaker than that with the chiral quark interactions.

M. Zhang; H. X. Zhang; Z. Y. Zhang

2007-11-07T23:59:59.000Z

274

Top 10 Nano & Chem Eng TMVogel, updated Fall 2012 Top 10 Things UCSD Nanoengineering &  

E-Print Network (OSTI)

Top 10 Nano & Chem Eng TMVogel, updated Fall 2012 Top 10 Things UCSD Nanoengineering & Chemical Engineering Researchers Need to Know http://libguides.ucsd.edu/nano http://libguides.ucsd.edu/chemeng http

Hampton, Randy

275

String Junction Model, Cluster Hypothesis, Penta-Quark Baryon and Tetra-Quark Meson  

Science Journals Connector (OSTI)

......and mB 1 GeV is the ordinary light baryon mass. In this paper...non-strange quarks. Mass of such light penta-quark baryons with NJ...O(10) MeV. While mass of light tetra-quark meson with NJ...junction was first written in the Christmas greeting card of Y. Nambu around......

Masahiro Imachi; Shoichiro Otsuki; Fumihiko Toyoda

2008-10-01T23:59:59.000Z

276

MHD Integrated Topping Cycle Project  

SciTech Connect

This fourteenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period November 1, 1990 to January 31, 1991. Testing of the High Pressure Cooling Subsystem electrical isolator was completed. The PEEK material successfully passed the high temperature, high pressure duration tests (50 hours). The Combustion Subsystem drawings were CADAM released. The procurement process is in progress. An equipment specification and RFP were prepared for the new Low Pressure Cooling System (LPCS) and released for quotation. Work has been conducted on confirmation tests leading to final gas-side designs and studies to assist in channel fabrication.The final cathode gas-side design and the proposed gas-side designs of the anode and sidewall are presented. Anode confirmation tests and related analyses of anode wear mechanisms used in the selection of the proposed anode design are presented. Sidewall confirmation tests, which were used to select the proposed gas-side design, were conducted. The design for the full scale CDIF system was completed. A test program was initiated to investigate the practicality of using Avco current controls for current consolidation in the power takeoff (PTO) regions and to determine the cause of past current consolidation failures. Another important activity was the installation of 1A4-style coupons in the 1A1 channel. A description of the coupons and their location with 1A1 channel is presented herein.

Not Available

1992-02-01T23:59:59.000Z

277

Final TOPS Rpt-10pt.PDF  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

TECHNOLOGICAL OPPORTUNITIES TECHNOLOGICAL OPPORTUNITIES TO INCREASE THE PROLIFERATION RESISTANCE OF GLOBAL CIVILIAN NUCLEAR POWER SYSTEMS (TOPS) REPORT BY THE TOPS TASK FORCE OF THE NUCLEAR ENERGY RESEARCH ADVISORY COMMITTEE (NERAC) JANUARY 2001 i TABLE OF CONTENTS INTRODUCTORY NOTE .............................................................................................................iii EXECUTIVE SUMMARY .......................................................................................................ES-1 I. INTRODUCTION ..............................................................................................................1 A. Scope and Purpose ..................................................................................................1 B. The Potential Role of Nuclear Power ......................................................................2

278

Search for a Vectorlike Quark with Charge 2/3 in t+Z Events from pp Collisions at sqrt[s]=7??TeV  

SciTech Connect

A search for pair-produced heavy vector-like charge-2/3 quarks, T, in pp collisions at a center-of-mass energy of 7 TeV, is performed with the CMS detector at the LHC. Events consistent with the flavor-changing-neutral-current decay of a T quark to a top quark and a Z boson are selected by requiring two leptons from the Z-boson decay, as well as an additional isolated charged lepton. In a data sample corresponding to an integrated luminosity of 1.14 inverse femtobarns, the number of observed events is found to be consistent with the standard model background prediction. Assuming a branching fraction of 100% for the decay T to tZ, a T quark with a mass less than 475 GeV/c^2 is excluded at the 95% confidence level.

Chatrchyan, Serguei; et al.

2011-12-01T23:59:59.000Z

279

Heavy Quark Production in ep Collisions  

E-Print Network (OSTI)

Heavy Quark Production in ep Collisions o Introduction o Charm Production o Beauty Production o in ep collisions 23 February 2007 2/17 Heavy Flavor Production Boson-Gluon Fusion, dominant process Hard of the proton: #12;G. Leibenguth, Heavy Quarks Production in ep collisions 23 February 2007 3/17 HERA, Electron

280

Recent advances in heavy quark theory  

SciTech Connect

Some recent developments in heavy quark theory are reviewed. Particular emphasis is given to inclusive weak decays of hadrons containing a b quark. The isospin violating hadronic decay D{sub s}* {yields} D{sub s}{sup pi}{sup 0} is also discussed.

Wise, M. [California Institute of Technology, Pasadena, CA (United States)

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Friction Coefficient for Quarks in Supergravity Duals  

E-Print Network (OSTI)

We study quarks moving in strongly-coupled plasmas that have supergravity duals. We compute the friction coefficient of strings dual to such quarks for general static supergravity backgrounds near the horizon. Our results also show that a previous conjecture on the bound has to be modified and higher friction coefficients can be achieved.

E. Antonyan

2006-11-22T23:59:59.000Z

282

Heavy quark thermodynamics in full QCD  

E-Print Network (OSTI)

We analyze the large-distance behaviour of static quark-anti-quark pair correlations in QCD. The singlet free energy is calculated and the entropy contribution to it is identified allowing us to calculate the excess internal energy. The free energy has a sharp drop in the critical region, leading to sharp peaks in both excess entropy and internal energy.

Konstantin Petrov; RBC-Bielefeld Collaboration

2007-01-22T23:59:59.000Z

283

Excited quark production at the CERN LHC  

Science Journals Connector (OSTI)

We study the production of excited quarks q? of spin-1/2 predicted by composite models. Production rates, signatures, and backgrounds are discussed for the CERN LHC. We estimate the discovery mass reach for the excited quarks decaying to jet+photon.

O. Çak?r and R. Mehdiyev

1999-06-22T23:59:59.000Z

284

Electric top drives gain wide industry acceptance  

SciTech Connect

Since its introduction, the top drive drilling system has gained acceptance as a productive and safe method for drilling oil and gas wells. Originally, the system was used mostly for offshore and higher cost land drilling, and it had to be installed as a permanent installation because of its enormous weight and size. Essentially, a top drive replaces the kelly and rotary table as the means of rotating drillpipe on oil, gas and geothermal rigs and is considered to be 15% to 40% more efficient than a kelly drive. Top drive systems allow the operator to drill and maintain directional orientation for triple stands and provide tripping efficiency because of the ability to ream and circulate with triple stands, to reduce the risk of stuck pipe or lost wells, and to improve well control and pipe handling safety. The paper describes electric top drives with DC motors, top drives with AC motors, top drives with permanent magnet motors, and top drives with permanent magnet brushless synchronous motors.

Riahi, M.L.

1998-05-01T23:59:59.000Z

285

Gamma rays from top-mediated dark matter annihilations  

SciTech Connect

Lines in the energy spectrum of gamma rays are a fascinating experimental signal, which are often considered ''smoking gun'' evidence of dark matter annihilation. The current generation of gamma ray observatories are currently closing in on parameter space of great interest in the context of dark matter which is a thermal relic. We consider theories in which the dark matter's primary connection to the Standard Model is via the top quark, realizing strong gamma ray lines consistent with a thermal relic through the forbidden channel mechanism proposed in the Higgs in Space Model. We consider realistic UV-completions of the Higgs in Space and related theories, and show that a rich structure of observable gamma ray lines is consistent with a thermal relic as well as constraints from dark matter searches and the LHC. Particular attention is paid to the one loop contributions to the continuum gamma rays, which can easily swamp the line signals in some cases, and have been largely overlooked in previous literature.

Jackson, C.B. [University of Texas at Arlington, Arlington, TX 76019 (United States); Servant, Géraldine [CERN Physics Department, Theory Division, CH-1211 Geneva 23 (Switzerland); Shaughnessy, Gabe [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Tait, Tim M.P. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Taoso, Marco, E-mail: geraldine.servant@cern.ch, E-mail: chris@uta.edu, E-mail: gshau@hep.wisc.edu, E-mail: ttait@uci.edu, E-mail: marco.taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

2013-07-01T23:59:59.000Z

286

The Particle Adventure | What holds it together? | Quark confinement  

NLE Websites -- All DOE Office Websites (Extended Search)

Quark confinement Quark confinement Quark confinement Color-charged particles cannot be found individually. For this reason, the color-charged quarks are confined in groups (hadrons) with other quarks. These composites are color neutral. The development of the Standard Model's theory of the strong interactions reflected evidence that quarks combine only into baryons (three quark objects), and mesons (quark-antiquark objects), but not, for example, four-quark objects. Now we understand that only baryons (three different colors) and mesons (color and anticolor) are color-neutral. Particles such as ud or uddd that cannot be combined into color-neutral states are never observed. Color-Force Field The quarks in a given hadron madly exchange gluons. For this reason, physicists talk about the color-force field which consists of the gluons holding the bunch of quarks together.

287

The Particle Adventure | What holds it together? | Quarks emit gluons  

NLE Websites -- All DOE Office Websites (Extended Search)

holds it together? > Quarks emit gluons holds it together? > Quarks emit gluons Quarks emit gluons Color charge is always conserved. When a quark emits or absorbs a gluon, that quark's color must change in order to conserve color charge. For example, suppose a red quark changes into a blue quark and emits a red/antiblue gluon (the image below illustrates antiblue as yellow). The net color is still red. This is because - after the emission of the gluon - the blue color of the quark cancels with the antiblue color of the gluon. The remaining color then is the red color of the gluon. Quarks emit and absorb gluons very frequently within a hadron, so there is no way to observe the color of an individual quark. Within a hadron, though, the color of the two quarks exchanging a gluon will change in a way that keeps the bound system in a color-neutral state.

288

NERSC Supports 2013's Top Breakthroughs  

NLE Websites -- All DOE Office Websites (Extended Search)

Supports 2013's Supports 2013's Top Breakthroughs NERSC Supports Top Breakthroughs of 2013 December 20, 2013 | Tags: Astrophysics, Hopper, PDSF, Physics Linda Vu, +1 510 495 2402, lvu@lbl.gov Research supported by NERSC is being honored by end-of-year reviews in two leading magazines: Physics World and WIRED. The IceCube South Pole Neutrino Observatory was notably named to both lists, being honored as the most important discovery by Physics World. Three of Physics World's top 10 breakthroughs of 2013 went to discoveries that used NERSC resources. In addition to the IceCube South Pole Neutrino Observatory's top honor, "breakthrough of the year," the magazine named the European Space Agency's European Planck space telescope, which revealed new information about the age and composition of the universe; and the South

289

LANL named 2010 top corporate volunteer organization  

NLE Websites -- All DOE Office Websites (Extended Search)

2010 top corporate volunteer organization 2010 top corporate volunteer organization LANL named 2010 top corporate volunteer organization The Laboratory ranked ahead of dozens of other qualifying companies with 10,000 or more employees. May 18, 2011 Building and painting birdhouses with children in Santa Fe Building and painting birdhouses with children in Santa Fe. Contact Steve Sandoval Communicatons Office (505) 665-9206 Email LOS ALAMOS, New Mexico, May 18, 2011-Los Alamos National Laboratory has earned an award as the top corporate volunteer organization among large employers in VolunteerMatch's network of more than 140 leading companies and brands. Debbi Wersonick of Los Alamos National Laboratory's Community Programs Office, coordinator of volunteer programs at the Laboratory, traveled to Chicago to receive the Corporate Volunteer Program of the Year Award, given

290

How to rank the top500 list?  

E-Print Network (OSTI)

HOW TO RANK THE TOP500 LIST? Lin-Wang Wang Computationalone question emerged: how to rank the computers according tothe first 10 computers. Old rank (based on speed) New rank (

Wang, Lin-Wang

2008-01-01T23:59:59.000Z

291

Top Low- or No-Cost Improvements  

Energy.gov (U.S. Department of Energy (DOE))

This presentation describes the top low- or no-cost projects to improve energy efficiency as identified in energy assessments performed by DOE and by the Industrial Assessment Centers.

292

Top ECMs for Labs and Data Centers  

Energy.gov (U.S. Department of Energy (DOE))

Presentation—given at at the Fall 2012 Federal Utility Partnership Working Group (FUPWG) meeting—covers the top energy conservation measures (ECMs) laboratories and data centers can apply for energy efficiency and savings.

293

Diesel prices top $4 per gallon  

U.S. Energy Information Administration (EIA) Indexed Site

Diesel prices top 4 per gallon The U.S. average retail price for on-highway diesel fuel surpassed the four dollar mark for the first time this year. Prices rose to 4.02 a gallon...

294

Enter Keyword(s) Today's Ecology Top  

E-Print Network (OSTI)

Enter Keyword(s) Today's Ecology Top News OMG's Business Ecology Initiative BEI Reaches 250 Member Advertisement Ecology Topics Botany Climate Research Ecology Environment Environmental Microbiology Environmental Monitoring Environmental Research Fisheries Research Marine Biology Meteorology Molecular Ecology

295

JLab Cluster Tops 100 Teraflops | Jefferson Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

JLab Cluster Tops 100 Teraflops NEWPORT NEWS, VA, Oct. 14 - The fastest computer system in Hampton Roads has booted up with more than 100 Teraflops of processing power. Located at...

296

HUNTING THE QUARK GLUON PLASMA.  

SciTech Connect

The U.S. Department of Energy's Relativistic Heavy Ion Collider (RHIC) construction project was completed at BNL in 1999, with the first data-taking runs in the summer of 2000. Since then the early measurements at RHIC have yielded a wealth of data, from four independent detectors, each with its international collaboration of scientists: BRAHMS, PHENIX, PHOBOS, and STAR [1]. For the first time, collisions of heavy nuclei have been carried out at colliding-beam energies that have previously been accessible only for high-energy physics experiments with collisions of ''elementary'' particles such as protons and electrons. It is at these high energies that the predictions of quantum chromodynamics (QCD), the fundamental theory that describes the role of quarks and gluons in nuclear matter, come into play, and new phenomena are sought that may illuminate our view of the basic structure of matter on the sub-atomic scale, with important implications for the origins of matter on the cosmic scale. The RHIC experiments have recorded data from collisions of gold nuclei at the highest energies ever achieved in man-made particle accelerators. These collisions, of which hundreds of millions have now been examined, result in final states of unprecedented complexity, with thousands of produced particles radiating from the nuclear collision. All four of the RHIC experiments have moved quickly to analyze these data, and have begun to understand the phenomena that unfold from the moment of collision as these particles are produced. In order to provide benchmarks of simpler interactions against which to compare the gold-gold collisions, the experiments have gathered comparable samples of data from collisions of a very light nucleus (deuterium) with gold nuclei, as well as proton-proton collisions, all with identical beam energies and experimental apparatus. The early measurements have revealed compelling evidence for the existence of a new form of nuclear matter at extremely high density and temperature--a medium in which the predictions of QCD can be tested, and new phenomena explored, under conditions where the relevant degrees of freedom, over nuclear volumes, are expected to be those of quarks and gluons, rather than of hadrons. This is the realm of the quark gluon plasma, the predicted state of matter whose existence and properties are now being explored by the RHIC experiments.

LUDLAM, T.; ARONSON, S.

2005-04-11T23:59:59.000Z

297

Active QuarkNet Centers  

NLE Websites -- All DOE Office Websites (Extended Search)

first active year) first active year)       QuarkNet Home - Information - Calendar - Contacts - Projects - Forms: EoI - Teachers Institution Contact e-mail Year Brown, Northeastern & Brandeis Universities Richard Dower - rick.dower@roxburylatin.org 1999 Fermilab & University of Chicago Chris Stoughton - stoughto@fnal.gov 1999 Florida State University Horst Wahl - wahl@hep.fsu.edu 1999 Indiana University Rick Van Kooten - rickv@paoli.physics.indiana.edu 1999 University of California - Santa Cruz Steve Ritz - ritz@scipp.ucsc.edu 1999 University of Notre Dame Dan Karmgard - Karmgard.1@nd.edu 1999 University of Oklahoma Michael Strauss - strauss@mail.nhn.ou.edu 1999 University of Rochester Kevin McFarland - ksmcf@pas.rochester.edu 1999

298

Heavy quark physics from SLD  

SciTech Connect

This report covers preliminary measurements from SLD on heavy quark production at the Z{sup 0}, using 150,000 hadronic Z{sup 0} decays accumulated during the 1993-1995 runs. A measurement of R{sub b} with a lifetime double tag is presented. The high electron beam polarization of the SLC is employed in the direct measurement of the parity-violating parameters A{sub b} and A{sub c} by use of the left-right forward-backward asymmetry. The lifetimes of B{sup +} and B{sup 0} mesons have been measured by two analyses. The first identifies semileptonic decays of B mesons with high (p,p{sub t}) leptons; the second analysis isolates a sample of B meson decays with a two-dimensional impact parameter tag and reconstructs the decay length and charge using a topological vertex reconstruction method.

Messner, R. [Stanford Univ., CA (United States)

1997-01-01T23:59:59.000Z

299

Building Technologies Office: Building America's Top Innovations Advance  

NLE Websites -- All DOE Office Websites (Extended Search)

America's Top America's Top Innovations Advance High Performance Homes to someone by E-mail Share Building Technologies Office: Building America's Top Innovations Advance High Performance Homes on Facebook Tweet about Building Technologies Office: Building America's Top Innovations Advance High Performance Homes on Twitter Bookmark Building Technologies Office: Building America's Top Innovations Advance High Performance Homes on Google Bookmark Building Technologies Office: Building America's Top Innovations Advance High Performance Homes on Delicious Rank Building Technologies Office: Building America's Top Innovations Advance High Performance Homes on Digg Find More places to share Building Technologies Office: Building America's Top Innovations Advance High Performance Homes on AddThis.com...

300

Water Management Guide - Building America Top Innovation | Department...  

Energy Savers (EERE)

Water Management Guide - Building America Top Innovation Water Management Guide - Building America Top Innovation Cover of the EEBA Water Management Guide. As energy codes and...

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Tankless Gas Water Heater Performance - Building America Top...  

Energy Savers (EERE)

Tankless Gas Water Heater Performance - Building America Top Innovation Tankless Gas Water Heater Performance - Building America Top Innovation This photo shows a hot water heater...

302

The Business Case for Fuel Cells 2011: Energizing America's Top...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1: Energizing America's Top Companies The Business Case for Fuel Cells 2011: Energizing America's Top Companies This report profiles a select group of nationally recognizable...

303

Next Generation Advanced Framing - Building America Top Innovation...  

Energy Savers (EERE)

Next Generation Advanced Framing - Building America Top Innovation Next Generation Advanced Framing - Building America Top Innovation This photo shows advanced framing on a rim...

304

Five-quark components in baryons  

E-Print Network (OSTI)

Evidence has been accumulating for the existence of significant intrinsic non-perturbative five-quark components in various baryons. The inclusion of the five-quark components gives a natural explanation of the excess of $\\bar d$ over $\\bar u$, significant quark orbital angular momentum in the proton, the problematic mass and decay pattern of the lowest $1/2^-$ baryon nonet, etc.. A breathing mode of $qqq\\leftrightarrow qqqq\\bar q$ is suggested for the lowest $1/2^-$ baryon octet. Evidence of a predicted member of the new scheme, $\\Sigma^*(1/2^-)$ around 1380 MeV, is introduced.

B. S. Zou

2010-01-07T23:59:59.000Z

305

Heavy quark diffusion from the lattice  

SciTech Connect

We study the diffusion of heavy quarks in the quark gluon plasma using the Langevin equations of motion and estimate the contribution of the transport peak to the Euclidean current-current correlator. We show that the Euclidean correlator is remarkably insensitive to the heavy quark diffusion coefficient and give a physical interpretation of this result using the free streaming Boltzmann equation. However if the diffusion coefficient is smaller than {approx}1/({pi}T), as favored by RHIC phenomenology, the transport contribution should be visible in the Euclidean correlator. We outline a procedure to isolate this contribution.

Petreczky, Peter; Teaney, Derek [Nuclear Theory Group, Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); Department of Physics and Astronomy, SUNY at Stony Brook, Stony Brook, New York 11764 (United States)

2006-01-01T23:59:59.000Z

306

Fractional electric charge and quark confinement  

E-Print Network (OSTI)

Owing to their fractional electric charges, quarks are blind to transformations that combine a color center phase with an appropriate electromagnetic one. Such transformations are part of a global $Z_6$-like center symmetry of the Standard Model that is lost when quantum chromodynamics (QCD) is treated as an isolated theory. This symmetry and the corresponding topological defects may be relevant to non-perturbative phenomena such as quark confinement, much like center symmetry and ordinary center vortices are in pure SU($N$) gauge theories. Here we report on our investigations of an analogous symmetry in a 2-color model with dynamical Wilson quarks carrying half-integer electric charge.

Sam R. Edwards; André Sternbeck; Lorenz von Smekal

2012-02-07T23:59:59.000Z

307

Heavy quark production from jet conversions in a quark-gluon plasma  

SciTech Connect

Recently, it has been demonstrated that the chemical composition of jets in heavy ion collisions is significantly altered compared to the jets in the vacuum. This signal can be used to probe the medium formed in nuclear collisions. In this study we investigate the possibility that fast light quarks and gluons can convert to heavy quarks when passing through a quark-gluon plasma. We study the rate of light to heavy jet conversions in a consistent Fokker-Planck framework and investigate their impact on the production of high-p{sub T} charm and bottom quarks at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

Liu, W. [Cyclotron Institute and Physics Department, Texas A and M University, College Station, Texas 77843-3366 (United States); Fries, R. J. [Cyclotron Institute and Physics Department, Texas A and M University, College Station, Texas 77843-3366 (United States); RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2008-09-15T23:59:59.000Z

308

Accelerator probes for new stable quarks  

E-Print Network (OSTI)

The nonbaryonic dark matter of the Universe can consist of new stable double charged particles $O^{--}$, bound with primordial helium in heavy neutral O-helium (OHe)"atoms" by ordinary Coulomb interaction. O-helium dark atoms can play the role of specific nuclear interacting dark matter and provide solution for the puzzles of dark matter searches. The successful development of composite dark matter scenarios appeals to experimental search for the charged constituents of dark atoms. If $O^{--}$ is a "heavy quark cluster" $\\bar U \\bar U \\bar U$, its production at accelerators is virtually impossible and the strategy of heavy quark search is reduced to search for heavy stable hadrons, containing only single heavy quark (or antiquark). Estimates of production cross section of such particles at LHC are presented and the experimental signatures for new stable quarks are outlined.

Konstantin M. Belostky; Maxim Yu. Khlopov; Konstantin I. Shibaev

2011-11-15T23:59:59.000Z

309

Color screening in cold quark matter  

E-Print Network (OSTI)

We compute color screening at finite quark chemical potentials cold quark matter at the one-loop level, comparing the normal, BCS paired U(1)_em, or Higgs, and a singlet phase with color-singlet condensate near the Fermi surface. The latter phase is computed in the example of two-color QCD with a color singlet diquark condensate. In contrast to the normal and Higgs phases, neither electric nor magnetic screening masses appear in the singlet phase. The absence of a magnetic mass, within a perturbative framework, is a consequence of proper treatment of gauge invariance. While at large momenta the gluon self-energies approach those in the normal phase, the medium contributions to the infrared region below a scale of the mass gap are substantially suppressed. Infrared gluons at low quark density in the singlet phase appear protected from medium effects, unless the quark-gluon vertices are significantly enhanced in the infrared.

Kojo, Toru

2014-01-01T23:59:59.000Z

310

Hunting the Quark Gluon Plasma ASSESSMENTS  

NLE Websites -- All DOE Office Websites (Extended Search)

Hunting the Quark Gluon Plasma Hunting the Quark Gluon Plasma ASSESSMENTS BY THE EXPERIMENTAL COLLABORATIONS Relativistic Heavy Ion Collider (RHIC) * Brookhaven National Laboratory, Upton, NY 11974-5000 RESULTS FROM THE FIRST 3 YEARS AT RHIC managed for the U.S. Department of Energy by Brookhaven Science Associates, a company founded by Stony Brook University and Battelle April 18, 2005 BNL -73847-2005 Formal Report

311

Shear viscosity of the quark matter  

E-Print Network (OSTI)

We discuss shear viscosity of the quark matter by using Kubo formula. The shear viscosity is calculated in the framework of the quasi-particle RPA for the Nambu-Jona-Lasinio model. We obtain a formula that the shear viscosity is expressed by the quadratic form of the quark spectral function in the chiral symmetric phase. The magnitude of the shear viscosity is discussed assuming the Breit-Wigner type for the spectral function.

Masaharu Iwasaki; Hiromasa Ohnishi; Takahiko Fukutome

2007-03-26T23:59:59.000Z

312

Magnetism and superconductivity in quark matter  

E-Print Network (OSTI)

Magnetic properties of quark matter and its relation to the microscopic origin of the magnetic field observed in compact stars are studied. Spontaneous spin polarization appears in high-density region due to the Fock exchange term, which may provide a scenario for the behaviors of magnetars. On the other hand, quark matter becomes unstable to form spin density wave in the moderate density region, where restoration of chiral symmetry plays an important role. Coexistence of magnetism and color superconductivity is also discussed.

T. Tatsumi; E. Nakano; K. Nawa

2005-06-01T23:59:59.000Z

313

Search for Pair Production of Third-Generation Leptoquarks and Top Squarks in pp Collisions at ?s=7??TeV  

Results are presented from a search for the pair production of third-generation scalar and vector leptoquarks, as well as for top squarks in R -parity-violating supersymmetric models. In either scenario, the new, heavy particle decays into a ? lepton and a b quark. The search is based on a data sample of pp collisions at ?s =7??TeV , which is collected by the CMS detector at the LHC and corresponds to an integrated luminosity of 4.8??fb?1. The number of observed events is found to be in agreement with the standard model prediction, and exclusion limits on mass parameters are obtained at the 95% confidence level. Vector leptoquarks with masses below 760 GeV are excluded and, if the branching fraction of the scalar leptoquark decay to a ? lepton and a b quark is assumed to be unity, third-generation scalar leptoquarks with masses below 525 GeV are ruled out. Top squarks with masses below 453 GeV are excluded for a typical benchmark scenario, and limits on the coupling between the top squark, ? lepton, and b quark, ? ?333 are obtained. These results are the most stringent for these scenarios to date.

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D’Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Thomas, L.; Vander Marcken, G.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins Junior, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sgandurra, L.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Anagnostou, G.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.; Jussen, R.

2013-02-01T23:59:59.000Z

314

Buried and Encapsulated Ducts- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

This Top Innovation profile highlights Building America research into insulating ductwork that is in unconditioned attics.

315

Furnace Blower Performance Improvements- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

This Top Innovation profile describes Building America research into improving efficiency of furnace fan blowers.

316

Vehicle Technologies Program: Goals, Strategies, and Top Accomplishments (Brochure)  

SciTech Connect

Fact sheet describes the Vehicle Technologies Program and its goals, strategies and top accomplishments.

Not Available

2010-12-01T23:59:59.000Z

317

Category:Top level | Open Energy Information  

Open Energy Info (EERE)

View form View form View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Facebook icon Twitter icon » Category:Top level Jump to: navigation, search This page has been deleted. The deletion and move log for the page are provided below for reference. 16:11, 16 August 2012 Rmckeel (Talk | contribs) deleted page Category:Top level (Mass removal of pages added by Fceeh) There is currently no text in this page. You can search for this page title in other pages, or search the related logs, but you do not have permission to create this page. Subcategories This category has only the following subcategory. H [×] Help‎ 68 pages Retrieved from "http://en.openei.org/wiki/Category:Top_level"

318

Mesa Top Photovoltaic Array, NREL (Fact Sheet)  

NLE Websites -- All DOE Office Websites (Extended Search)

Mesa Top Photovoltaic Array Mesa Top Photovoltaic Array System Specifications System size: 720 kilowatts (kW) DC Characteristics: Single axis tracker photovoltaic, ground mounted Annual output: 1.2 gigawatt hours (GWh) Location: Top of South Table Mountain, Golden, Colorado Start of operation: December 2008 Financial Terms System ownership: SunEdison financed, built, owns, operates and maintains the system Solar Power and Services Agreement (SPSA): SunEdison and the Western Area Power Administration (WAPA) entered into a 20-year SPSA to provide Solar Energy Services to the Department of Energy (DOE) for use at the National Renewable Energy Laboratory (NREL) Cost to DOE/NREL: There are no up-front costs to DOE or NREL * The price per kilowatt hour (kWh) for the power purchased from the

319

Mesa Top Photovoltaic Array, NREL (Fact Sheet)  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Mesa Top Photovoltaic Array Mesa Top Photovoltaic Array System Specifications System size: 720 kilowatts (kW) DC Characteristics: Single axis tracker photovoltaic, ground mounted Annual output: 1.2 gigawatt hours (GWh) Location: Top of South Table Mountain, Golden, Colorado Start of operation: December 2008 Financial Terms System ownership: SunEdison financed, built, owns, operates and maintains the system Solar Power and Services Agreement (SPSA): SunEdison and the Western Area Power Administration (WAPA) entered into a 20-year SPSA to provide Solar Energy Services to the Department of Energy (DOE) for use at the National Renewable Energy Laboratory (NREL) Cost to DOE/NREL: There are no up-front costs to DOE or NREL * The price per kilowatt hour (kWh) for the power purchased from the

320

Drilling of wells with top drive unit  

SciTech Connect

Well drilling apparatus including a top drive drilling assembly having a motor driven stem adapted to be attached to the upper end of a drill string and drive it during a drilling operation, a torque wrench carried by the top drive assembly and movable upwardly and downwardly therewith and operable to break a threated connection between the drill string and the stem, and an elevator carried by and suspended from the top drive assembly and adapted to engage a section of drill pipe beneath the torque wrench in suspending relation. The torque wrench and elevator are preferably retained against rotation with the rotary element which drives the drill string, but may be movable vertically relative to that rotary element and relative to one another in a manner actuating the apparatus between various different operating conditions.

Boyadjieff, G.I.

1984-05-22T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Baryons with strangeness and charm in a quark model with chromodynamics  

Science Journals Connector (OSTI)

The low-lying spectrum of baryons containing a charmed quark and one or two strange quarks is calculated in a a quark model with chromodynamics.

Kim Maltman and Nathan Isgur

1980-10-01T23:59:59.000Z

322

Doe's Race to the top initiative  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Race to the Top Initiative Race to the Top Initiative Recommendations of the EAC Working Group June 5, 2013 EAC Working Group * Chair: Sonny Popowsky * Vice-Chair: Bob Curry * Working Group Members: Ralph Cavanagh, Sue Kelly, Paul Centolella, Dian Grueneich, Val Jensen, Paul Hudson, Phyllis Reha, Ralph Masiello, Mike Weedall RAP Staff - Janine Migden-Ostrander 2 President's State of the Union Message February 12, 2013 "I'm also issuing a new goal for America: Let's cut in half the energy wasted by our homes and businesses over the next 20 years. We'll work

323

Quarkonia and heavy-quark relaxation times in the quark-gluon plasma  

E-Print Network (OSTI)

A thermodynamic T-matrix approach for elastic two-body interactions is employed to calculate spectral functions of open and hidden heavy-quark systems in the quark-gluon plasma. This enables the evaluation of quarkonium bound-state properties...

Riek, F.; Rapp, Ralf.

2010-01-01T23:59:59.000Z

324

Production and FCNC decay of supersymmetric Higgs bosons into heavy quarks in the LHC  

E-Print Network (OSTI)

We analyze the production and subsequent decay of the neutral MSSM Higgs bosons (h = h^0, H^0, A^0) mediated by flavor changing neutral currents (FCNC) in the LHC collider. We have computed the h-production cross-section times the FCNC branching ratio, \\sigma(pp -> h -> qq') = \\sigma(pp -> h) B(h -> qq'), in the LHC focusing on the strongly-interacting FCNC sector. Here qq' is an electrically neutral pair of quarks of different flavors, the dominant modes being those containing a heavy quark: tc or bs. We determine the maximum production rates for each of these modes and identify the relevant regions of the MSSM parameter space, after taking into account the severe restrictions imposed by low energy FCNC processes. The analysis of \\sigma(pp -> h -> qq') singles out regions of the MSSM parameter space different from those obtained by maximizing only the branching ratio, due to non-trivial correlations between the parameters that maximize/minimize each isolated factor. The production rates for the bs channel can be huge for a FCNC process (0.1-1 pb), but its detection can be problematic. The production rates for the tc channel are more modest (10^{-3}-10^{-2} pb), but its detection should be easier due to the clear-cut top quark signature. A few thousand tc events could be collected in the highest luminosity phase of the LHC, with no counterpart in the SM.

Santi Bejar; Jaume Guasch; Joan Sola

2005-10-31T23:59:59.000Z

325

Top-up operation experience at APS.  

SciTech Connect

The Advanced Photon Source (APS) is a 7-OeV, third-generation synchrotrons radiation source. To provide more stable beam for users, in September 1998 we began commissioning a new operating mode called ''top-up.'' In this mode, the beam current does not decay but is maintained at a high level using frequent injection, while photon shutters are open and photon beams are delivered to users. The hardware, software, and safety requirements for top-up will be reported. Safety issues related to injection with open photon shutters are covered in companion papers in this conference. Recent operational experience includes testing aspects of top-up injection and delivering beam to X-ray users for a few hours with fractional current stability of 10{sup {minus}3}. We expect to run several top-up operation shifts in Spring 1999. Issues of importance are orbit and emittance transients during the injection and scheduling of injection pulses for the convenience of users.

Emery, L.

1999-03-31T23:59:59.000Z

326

Heavy quark production in the black hole evaporation at LHC  

SciTech Connect

The understanding of Quantum Chromodynamics (QCD) and Quantum Gravity are currently two of the main open questions in Physics. In order to understand these problems some authors proposed the existence of extra dimensions in the Nature. These extra dimensions would be compacted and not visible on the macroscopic world, but the effects would be manifest in ultrarelativistic colision process. In particular, black holes (BH) could be produced in proton-proton colisions in the Large Hadron Collider (LHC) and in future colliders. The BH is an object characterized by its mass and temperature wich also characterizes the evaporation process. All kind of particle should be produced in this process. Our goal in this contribution is to study the BH production in proton - proton collisions at LHC and its evaporation rate in heavy quarks. We present our estimate considering two scenarios (with and without trapped energy corrections) and compare our predictions with those obtained using perturbative QCD. Our results demonstrate that in both scenarios the charm and bottom production in the BH evaporation are smaller than the QCD prediction at LHC. In contrast, the top production is similar or larger than the QCD prediction, if the trapped energy corrections are disregarded.

Thiel, M.; Goncalves, V. P.; Sauter, W. K. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas (Brazil)

2013-03-25T23:59:59.000Z

327

Building America's Top Innovations Advance High Performance Homes |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

America's Top America's Top Innovations Advance High Performance Homes Building America's Top Innovations Advance High Performance Homes Building America Top Innovations. Recognizing top innovations in building science. Innovations sponsored by the U.S. Department of Energy's (DOE) Building America program and its teams of building science experts continue to have a transforming impact, leading our nation's home building industry to high-performance homes. Building America researchers have worked directly with more than 300 U.S. production home builders and have boosted the performance of more than 42,000 new homes. Learn more about Building America Top Innovations. 2013 Top Innovations New Top Innovations are awarded annually for outstanding Building America research achievements. Learn more about the 2013 Top Innovations recently

328

Questions and Answers - What is the charge of an up quark and the charge of  

NLE Websites -- All DOE Office Websites (Extended Search)

What kinds of quarks are inprotons and neutrons? What kinds of quarks are in<br>protons and neutrons? Previous Question (What kinds of quarks are in protons and neutrons?) Questions and Answers Main Index Next Question (Are quarks confineable for study?) Are quarks confineable for study? What is the charge of an up quark and the charge of a down quark? How many quarks make up a proton and a neutron? Protons and neutrons are each composed of three quarks. Protons are made up of two 'up' quarks and one 'down' quark while neutrons are made up of two 'down' quarks and one 'up' quark. Quarks carry fractional electrical charges. An 'up' quark has a charge of +2/3 and a 'down' quark has a charge of -1/3. Is this consistent with what we know about protons and neutrons? Remember that protons carry an electrical charge of +1 while neutrons carry no electrical charge. We said

329

The NJL Model for Quark Fragmentation Functions  

SciTech Connect

A description of fragmentation functions which satisfy the momentum and isospin sum rules is presented in an effective quark theory. Concentrating on the pion fragmentation function, we first explain the reason why the elementary (lowest order) fragmentation process q ? q? is completely inadequate to describe the empirical data, although the “crossed” process ? ? qq describes the quark distribution functions in the pion reasonably well. Then, taking into account cascade-like processes in a modified jet-model approach, we show that the momentum and isospin sum rules can be satisfied naturally without introducing any ad-hoc parameters. We present numerical results for the Nambu-Jona-Lasinio model in the invariant mass regularization scheme, and compare the results with the empirical parametrizations. We argue that this NJL-jet model provides a very useful framework to calculate the fragmentation functions in an effective chiral quark theory.

T. Ito, W. Bentz, I. Cloet, A W Thomas, K. Yazaki

2009-10-01T23:59:59.000Z

330

Constraints from jet calculus on quark recombination  

Science Journals Connector (OSTI)

Within the quantum-chromodynamic jet-calculus formalism, we deduce an equation describing recombination of quarks and antiquarks into mesons within a quark or gluon jet. This equation relates the recombination function R(x1,x2,x) used in current literature to the fragmentation function for producing that same meson out of the parton initiating the jet. We submit currently used recombination functions to our consistency test, taking as input mainly the u-quark fragmentation "data" into ?+ mesons. The qq¯?? recombination functions popular in the literature are consistent with measured fragmentation functions, but they must be supplemented by other contributions to provide the full Du?+. We also discuss the Q2 dependence of the resulting fragmentation functions.

L. M. Jones; K. E. Lassila; U. Sukhatme; D. Willen

1981-02-01T23:59:59.000Z

331

Essence of the Vacuum Quark Condensate  

SciTech Connect

We show that the chiral-limit vacuum quark condensate is qualitatively equivalent to the pseudoscalar meson leptonic decay constant in the sense that they are both obtained as the chiral-limit value of well-defined gauge-invariant hadron-to-vacuum transition amplitudes that possess a spectral representation in terms of the current-quark mass. Thus, whereas it might sometimes be convenient to imagine otherwise, neither is essentially a constant mass-scale that fills all spacetime. This means, in particular, that the quark condensate can be understood as a property of hadrons themselves, which is expressed, for example, in their Bethe-Salpeter or light-front wavefunctions.

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Roberts, Craig D.; /Argonne, PHY /Peking U.; Shrock, Robert; /YITP, Stony Brook; Tandy, Peter C.; /Kent State U.

2010-08-25T23:59:59.000Z

332

Bulk viscosity in nuclear and quark matter: A short review  

E-Print Network (OSTI)

The history and recent progresses in the study of bulk viscosity in nuclear and quark matter are reviewed. The constraints from baryon number conservation and electric neutrality in quark matter on particle densities and fluid velocity divergences are discussed.

Hui Dong; Nan Su; Qun Wang

2007-02-07T23:59:59.000Z

333

Momentum broadening in weakly coupled quark-gluon plasma  

E-Print Network (OSTI)

We calculate the probability distribution P(k [subscript ?]) for the momentum perpendicular to its original direction of motion that an energetic quark or gluon picks up as it propagates through weakly coupled quark-gluon ...

D'Eramo, F.

334

Phenomenological applications of non-perturbative heavy quark effective theory  

E-Print Network (OSTI)

We briefly review the strategy to perform non-perturbative heavy quark effective theory computations and we specialize to the case of the b quark mass which has recently been computed including the 1/m term.

Mauro Papinutto

2007-10-11T23:59:59.000Z

335

Looking for quark droplets in ultrarelativistic collisions  

Science Journals Connector (OSTI)

Heavy ion collisions at ultrarelativistic energies are expected to provide an environment where quarks and gluons replace hadrons as the appropriate degrees of freedom. As the excited region expands and cools, the transition to the hadronic state might be characterized by phase separation with hadrons being emitted from dense droplets of quark-gluon matter. Here we study four techniques to search for such droplets: rapidity correlations, identical kaon correlations, ? meson production, and proton correlations. We conclude that rapidity correlations are the clearest signal of such fluctuations, and that proton correlations and ? production can also be strongly affected by drop formation.

Scott Pratt

1994-05-01T23:59:59.000Z

336

Down Type Isosinglet Quarks in ATLAS  

E-Print Network (OSTI)

We evaluate the discovery reach of the ATLAS experiment for down type isosinglet quarks, $D$, using both their neutral and charged decay channels, namely the process $pp\\to D\\bar{D}+X$ with subsequent decays resulting in $2\\ell+2j+E^{miss}_{T}$, $3\\ell+2j+E^{miss}_{T}$ and $2\\ell+4j$ final states. The integrated luminosity required for observation of a heavy quark is estimated for a mass range between 600 and 1000 GeV using the combination of results from different search channels.

R. Mehdiyev; A. Siodmok; S. Sultansoy; G. Unel

2007-11-07T23:59:59.000Z

337

Heavy-quark correlations in deep inelastic scattering  

E-Print Network (OSTI)

We discuss results for heavy quark correlations in next-to-leading order QCD in deep inelastic electroproduction.

J. Smith; B. W. Harris

1996-05-20T23:59:59.000Z

338

Cold quark matter, quadratic corrections, and gauge/string duality  

Science Journals Connector (OSTI)

We make an estimate of the quadratic correction in the pressure of cold quark matter using gauge/string duality.

Oleg Andreev

2010-04-05T23:59:59.000Z

339

Top ECMs for Labs and Data Centers  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Top ECMs for Labs and Top ECMs for Labs and Data Centers FUPWG Otto Van Geet, PE October 10, 2012 2 Labs are Energy Hogs! * 3 to 8 times as energy intensive as office buildings Total Site Energy Use Intensity BTU/sf-yr for various laboratories in the Labs21 Benchmarking Database Typical Office Building 3 * Core information resources - Design Guide - Case Studies - Energy Benchmarking - Best Practice Guides - Technical Bulletins * Design process tools - Env. Performance Criteria - Labs21 Process Manual Labs21 Toolkit 4 Six BIG HITS 1. Scrutinize the air changes: Optimize ventilation rates 2. Tame the hoods: Compare exhaust device options 3. Get real with loads: Right-size HVAC systems 4. Just say no to re-heat: Minimize simultaneous heating and cooling 5. Drop the pressure drop:

340

Multiple Rankine topping cycles offer high efficiency  

SciTech Connect

The efficiency of a Rankine cycle is primarily determined by the temperatures of heat addition and heat rejection. However, no working fluid has been identified that will operate in a Rankine cycle over an extremely wide temperature range. Multiple Rankine topping cycles offer a technique for achieving high thermal efficiencies in power plants by allowing the use of several working fluids to span larger temperature ranges.

McWhirter, J.D. [Idaho State Univ., Pocatello, ID (United States)

1997-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Bestimmung des ep{Wirkungsquerschnittes von Beauty-Quarks  

E-Print Network (OSTI)

Bestimmung des ep{Wirkungsquerschnittes von Beauty-Quarks durch ihren semileptonischen Zerfall in Myonen mit dem H1-Detektor bei HERA Determination of the ep Cross Section for Beauty Quarks via werden die sichtbaren ep-Wirkungsquerschnitte fur schwere Quarks in dem kinematischen Bereich Q2

342

Search for heavy quarks decaying into a top quark and a W or Z boson using lepton + jets events in pp collisions at s?=7 TeV  

E-Print Network (OSTI)

. Tuovinen, D. Ungaro, L. Wendland – 14 – J H E P01(2013)154 Lappeenranta University of Technology, Lappeenranta, Finland K. Banzuzi, A. Karjalainen, A. Korpela, T. Tuuva DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France M. Besancon, S. Choudhury, M. Dejardin, D...

Baringer, Philip S.; Bean, Alice; Benelli, Gabriele; Kenny, R. P. III; Murray, Michael J.; Noonan, Danny; Sanders, Stephen J.; Stringer, Robert W.; Tinti, Gemma; Wood, Jeffrey Scott; Zhukova, Victoria; Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.

2013-01-24T23:59:59.000Z

343

Building Technologies Office: Building America's Top Innovations Advance  

NLE Websites -- All DOE Office Websites (Extended Search)

America's Top Innovations Advance High Performance Homes America's Top Innovations Advance High Performance Homes Building America Top Innovations. Recognizing top innovations in building science. Innovations sponsored by the U.S. Department of Energy's (DOE) Building America program and its teams of building science experts continue to have a transforming impact, leading our nation's home building industry to high-performance homes. Building America researchers have worked directly with more than 300 U.S. production home builders and have boosted the performance of more than 42,000 new homes. Learn more about Building America Top Innovations. 2013 Top Innovations New Top Innovations are awarded annually for outstanding Building America research achievements. Learn more about the 2013 Top Innovations recently awarded by selecting a category or award recipient below.

344

Building America Top Innovations 2013 Profile - Zero Energy-Ready...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Top Innovations 2013 Profile - Zero Energy-Ready Single-Family Homes Building America Top Innovations 2013 Profile - Zero Energy-Ready Single-Family Homes Many Building America...

345

NERSC's Hopper is Among World's Top 10 Fastest Computers  

NLE Websites -- All DOE Office Websites (Extended Search)

Hopper Among World's Top 10 Fastest Computers Hopper Among World's Top 10 Fastest Computers One of only 10 Petaflops Systems Worldwide June 17, 2011 | Tags: Hopper, NERSC Linda Vu,...

346

Terascale Optimal PDE Simulations (TOPS) Center  

SciTech Connect

This report covers the period from Oct. 2002 to Sep. 2004 when Old Dominion University (ODU) was the lead institution for the TOPS ISIC, until in Oct. 2004 Columbia University replaced ODU as the lead institution. The TOPS members from ODU focused on various aspects of the linear and nonlinear solver infrastructure required by the partial differential equations simulation codes, working directly with SciDAC teams from the Fusion Energy Sciences program: the Center for Extended agnetohydrodynamic Modeling (CEMM) at Princeton, and with the Center for Magnetic Reconnection Studies (CMRS) at University of New Hampshire. With CEMM we worked with their MHD simulation code, called M3D, which is semi-implicit, requiring linear solves but no onlinear solves. We contributed several improvements to their current semi-implicit code. Among these was the use of multilevel reconditioning, which provides optimal scaling. This was done through the multigrid preconditioner available in Hypre, another major solver package available in TOPS. We also provided them direct solver functionality for their linear solves since they may be required for more accurate solutions in some regimes. With the CMRS group, we implemented a fully implicit parallel magnetic reconnection simulation code, built on top of PETSc. Our first attempt was a Krylov linear iteration (GMRES because of the lack of symmetry), within each nonlinear (Newton) iteration, with optimal multilevel preconditioning, using the geometric multigrid preconditioner from PETSc. However, for reasons that we have not yet fully understood, the multigrid preconditioner fails early in the simulation, breaking the outer Newton iteration. Much better results were obtained after switching from optimal multilevel preconditioning to suboptimal one level preconditioning. Our current code, based on the additive Schwartz preconditioner from in PETSc, with ILU on subdomains, scales reasonably well, while matching the output of the original explicit code. The new Newton-Krylov-Schwarz implicitcode can take time-steps that are hundreds or thousands of times larger than the explicit code. During the three year period of this grant, we published thirteen papers and gave several invited talks at international conferences. Work on these TOPS projects continues with Columbia University as lead until Sep. 2006.

Pothen, Alex

2006-08-23T23:59:59.000Z

347

Heavy quark collisional energy loss in the quark-gluon plasma including finite relaxation time  

E-Print Network (OSTI)

In this paper, we calculate the soft-collisional energy loss of heavy quarks traversing the viscous quark-gluon plasma including the effects of a finite relaxation time $\\tau_\\pi$ on the energy loss. We find that the collisional energy loss depends appreciably on $\\tau_\\pi$ . In particular, for typical values of the viscosity-to-entropy ratio, we show that the energy loss obtained using $\\tau_\\pi$ = 0 can be $\\sim$ 10$\\%$ larger than the one obtained using $\\tau_\\pi$ = 0. Moreover, we find that the energy loss obtained using the kinetic theory expression for $\\tau_\\pi$ is much larger that the one obtained with the $\\tau_\\pi$ derived from the Anti de Sitter/Conformal Field Theory correspondence. Our results may be relevant in the modeling of heavy quark evolution through the quark-gluon plasma.

Mauro Elias; J. Peralta-Ramos; E. Calzetta

2014-04-30T23:59:59.000Z

348

Phase transition from quark-meson coupling hyperonic matter to deconfined quark matter  

SciTech Connect

We investigate the possibility and consequences of phase transitions from an equation of state (EOS) describing nucleons and hyperons interacting via mean fields of {sigma}, {omega}, and {rho} mesons in the recently improved quark-meson coupling (QMC) model to an EOS describing a Fermi gas of quarks in an MIT bag. The transition to a mixed phase of baryons and deconfined quarks, and subsequently to a pure deconfined quark phase, is described using the method of Glendenning. The overall EOS for the three phases is calculated for various scenarios and used to calculate stellar solutions using the Tolman-Oppenheimer-Volkoff equations. The results are compared with recent experimental data, and the validity of each case is discussed with consequences for determining the species content of the interior of neutron stars.

Carroll, J. D.; Leinweber, D. B.; Williams, A. G.; Thomas, A. W. [Centre for the Subatomic Structure of Matter (CSSM), Department of Physics, University of Adelaide, SA 5005 (Australia); Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, Virginia 23606 (United States); College of William and Mary, Williamsburg, Virginia 23187 (United States) and Centre for the Subatomic Structure of Matter (CSSM), Department of Physics, University of Adelaide, SA 5005 (Australia)

2009-04-15T23:59:59.000Z

349

Quark-gluon plasma (Selected Topics)  

SciTech Connect

Introductory lectures to the theory of (strongly interacting) quark-gluon plasma given at the Winter School of Physics of ITEP (Moscow, February 2010). We emphasize theoretical issues highlighted by the discovery of the low viscosity of the plasma. The topics include relativistic hydrodynamics, manifestations of chiral anomaly in hydrodynamics, superfluidity, relativistic superfluid hydrodynamics, effective stringy scalars, holographic models of Yang-Mills theories.

Zakharov, V. I., E-mail: vzakharov@itep.ru [Institute for Theoretical and Experimental Physics (Russian Federation)

2012-09-15T23:59:59.000Z

350

Color screening in cold quark matter  

E-Print Network (OSTI)

We compute---at finite quark chemical potentials---the color screening of cold quark matter at the one-loop level, comparing the normal, BCS-paired U(1)em (or Higgs) phase and a singlet phase with color-singlet condensate near the Fermi surface. The latter phase is computed using the example of two-color QCD with a color-singlet diquark condensate. In contrast to the normal and Higgs phases, neither electric nor magnetic screening masses appear in the singlet phase. The absence of a magnetic mass, within a perturbative framework, is a consequence of the proper treatment of gauge invariance. While at large momenta the gluon self-energies approach those in the normal phase, the medium contributions to the infrared region below a scale of the mass gap are substantially suppressed. Infrared gluons at low quark density in the singlet phase appear protected from medium effects, unless the quark-gluon vertices are significantly enhanced in the infrared.

Toru Kojo; Gordon Baym

2014-04-04T23:59:59.000Z

351

Model study of a quark star  

SciTech Connect

In this paper we apply the equation of state (EOS) of QCD at finite chemical potential and zero temperature proposed in H. S. Zong and W. M. Sun [Int. J. Mod. Phys. A 23, 3591 (2008)] to the study of properties of quark star. This EOS contains only one adjustable parameter m{sub D} which sets the scale of chiral symmetry breaking (in our calculation we have chosen two values of m{sub D}: m{sub D}=244 MeV and m{sub D}=239 MeV, which is fitted from the value of f{sub {pi}} and determined by e{sup +}e{sup -} annihilation experiment, respectively). From this EOS a model of quark star is established by applying the Tolman-Oppenheimer-Volkoff equation under two conditions: with the P({mu}=0) term and without the P({mu}=0) term. Our results show clearly that the P({mu}=0) term is an important quantity in the study of quark star. A comparison between our model and other models of quark star is made. In particular, we have compared our results with the most recent observational data measured using Shapiro delay reported in P. B. Demorest et al.[Nature (London) 467, 1081 (2010)].

Li Hua; Jiang Yu [Department of Physics, Nanjing University, Nanjing 210093 (China); Luo Xinlian [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Zong Hongshi [Department of Physics, Nanjing University, Nanjing 210093 (China); Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing 210093 (China)

2011-01-15T23:59:59.000Z

352

Electroproduction of heavy quarks at NLO  

E-Print Network (OSTI)

A new next-to-leading order Monte Carlo program for the calculation of fully differential heavy quark cross sections in electroproduction is described. A comparison between the theoretical predictions and the latest charm production data from H1 and ZEUS at HERA is presented.

B. W. Harris

1996-08-20T23:59:59.000Z

353

Quark matter and meson properties in a Nonlocal SU(3) chiral quark model at finite temperature  

SciTech Connect

We study the finite temperature behavior of light scalar and pseudoscalar meson properties in the context of a three-flavor nonlocal chiral quark model. The model includes mixing with active strangeness degrees of freedom, and takes care of the effect of gauge interactions by coupling the quarks with a background color field. We analyze the chiral restoration and deconfinement transitions, as well as the temperature dependence of meson masses, mixing angles, and decay constants.

Gomez Dumm, D., E-mail: dumm@fisica.unlp.edu.ar [UNLP, IFLP, Departamento de Fisica (Argentina); Contrera, G. A., E-mail: contrera@tandar.cnea.gov.ar [CONICET (Argentina)

2012-06-15T23:59:59.000Z

354

Fast top-k simple shortest paths discovery in graphs  

Science Journals Connector (OSTI)

With the wide applications of large scale graph data such as social networks, the problem of finding the top-k shortest paths attracts increasing attention. This paper focuses on the discovery of the top-k simple shortest paths (paths without ... Keywords: graphs, shortest path, top-k

Jun Gao; Huida Qiu; Xiao Jiang; Tengjiao Wang; Dongqing Yang

2010-10-01T23:59:59.000Z

355

New Statistical Techniques in the Measurement of the inclusive Top Pair Production Cross Section  

E-Print Network (OSTI)

We present several different types of multivariate statistical techniques used in the measurement of the inclusive top pair production cross section in $p \\bar{p}$-collisions at $\\sqrt{s} = 1.96 \\text{TeV}$ employing the full RunII data ($9.7\\textrm{fb}^{-1}$) collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair decays containing one electron or muon and at least two jets. We proceed various statistical homogeneity tests such as Anderson - Darling, Kolmogorov - Smirnov, and $\\varphi$-divergences tests to determine, which variables have good data-MC agreement, as well as a good separation power. We adjusted all tests for using weighted empirical distribution functions. Further we separate $t\\bar{t}$ signal from the background by the application of Generalized Linear Models, Gaussian Mixture Models), Neural Networks with Switching Units and confront them with familiar methods from ROOT TMVA package such as Boosted Decision Trees, and Multi-layer Per...

Franc, Ji?í; Št?pánek, Michal; K?s, Václav

2014-01-01T23:59:59.000Z

356

Stable quarks of the 4th family?  

E-Print Network (OSTI)

Existence of metastable quarks of new generation can be embedded into phenomenology of heterotic string together with new long range interaction, which only this new generation possesses. We discuss primordial quark production in the early Universe, their successive cosmological evolution and astrophysical effects, as well as possible production in present or future accelerators. In case of a charge symmetry of 4th generation quarks in Universe, they can be stored in neutral mesons, doubly positively charged baryons, while all the doubly negatively charged "baryons" are combined with He-4 into neutral nucleus-size atom-like states. The existence of all these anomalous stable particles may escape present experimental limits, being close to present and future experimental test. Due to the nuclear binding with He-4 primordial lightest baryons of the 4th generation with charge +1 can also escape the experimental upper limits on anomalous isotopes of hydrogen, being compatible with upper limits on anomalous lithium. While 4th quark hadrons are rare, their presence may be nearly detectable in cosmic rays, muon and neutrino fluxes and cosmic electromagnetic spectra. In case of charge asymmetry, a nontrivial solution for the problem of dark matter (DM) can be provided by excessive (meta)stable anti-up quarks of 4th generation, bound with He-4 in specific nuclear-interacting form of dark matter. Such candidate to DM is surprisingly close to Warm Dark Matter by its role in large scale structure formation. It catalyzes primordial heavy element production in Big Bang Nucleosynthesis and new types of nuclear transformations around us.

K. Belotsky; M. Khlopov; K. Shibaev

2008-06-05T23:59:59.000Z

357

Questions and Answers - Are quarks confineable for study?  

NLE Websites -- All DOE Office Websites (Extended Search)

is the charge of an up quarkand of down quark? is the charge of an up quark<br>and of down quark? Previous Question (What is the charge of an up quark and of down quark?) Questions and Answers Main Index Next Question (Is vacuum matter? What are ten things that are not matter? ) Is vacuum matter? What are tenthings that are not matter? Are quarks confineable for study? Quarks we study at Jefferson Lab are confined to each other by nature's laws. We shine our electrons on them to observe their behavior in their confined state. This is not so different from turning on a light to see a gold fish swimming in a glass bowl. Author: Nathan Isgur, Theory Group Leader (Other answers by Nathan Isgur) Related Pages: All About Atoms What is the smallest particle of matter known? Could there be anything smaller inside of an electron or inside of a

358

Tailoring graphene with metals on top  

Science Journals Connector (OSTI)

We study the effects of metallic doping on the electronic properties of graphene using density functional theory in the local density approximation in the presence of a local charging energy. The electronic properties are sensitive to whether graphene is doped with alkali or transition metals. We estimate the charge transfer from a single layer of potassium on top of graphene in terms of the local charging energy of the graphene sheet. The coating of graphene with a nonmagnetic layer of palladium, on the other hand, can lead to a magnetic instability in coated graphene due to the hybridization between the transition metal and the carbon orbitals.

B. Uchoa; C.-Y. Lin; A. H. Castro Neto

2008-01-17T23:59:59.000Z

359

Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten  

NLE Websites -- All DOE Office Websites (Extended Search)

9: June 28, 2010 9: June 28, 2010 Top Ten Misconceptions about Fuel Economy to someone by E-mail Share Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten Misconceptions about Fuel Economy on Facebook Tweet about Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten Misconceptions about Fuel Economy on Twitter Bookmark Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten Misconceptions about Fuel Economy on Google Bookmark Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten Misconceptions about Fuel Economy on Delicious Rank Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten Misconceptions about Fuel Economy on Digg Find More places to share Vehicle Technologies Office: Fact #629: June 28, 2010 Top Ten Misconceptions about Fuel Economy on AddThis.com...

360

Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles  

NLE Websites -- All DOE Office Websites (Extended Search)

1: January 23, 1: January 23, 2012 Top Vehicles around the Globe, 2011 to someone by E-mail Share Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles around the Globe, 2011 on Facebook Tweet about Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles around the Globe, 2011 on Twitter Bookmark Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles around the Globe, 2011 on Google Bookmark Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles around the Globe, 2011 on Delicious Rank Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles around the Globe, 2011 on Digg Find More places to share Vehicle Technologies Office: Fact #711: January 23, 2012 Top Vehicles around the Globe, 2011 on AddThis.com...

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361

Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top  

NLE Websites -- All DOE Office Websites (Extended Search)

3: June 25, 2012 3: June 25, 2012 World's Top Petroleum-Producing Countries to someone by E-mail Share Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top Petroleum-Producing Countries on Facebook Tweet about Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top Petroleum-Producing Countries on Twitter Bookmark Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top Petroleum-Producing Countries on Google Bookmark Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top Petroleum-Producing Countries on Delicious Rank Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top Petroleum-Producing Countries on Digg Find More places to share Vehicle Technologies Office: Fact #733: June 25, 2012 World's Top Petroleum-Producing Countries on AddThis.com...

362

Fuel Cell Technologies Office: America's Next Top Energy Innovator  

NLE Websites -- All DOE Office Websites (Extended Search)

America's Next Top America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies (Text Version) to someone by E-mail Share Fuel Cell Technologies Office: America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies (Text Version) on Facebook Tweet about Fuel Cell Technologies Office: America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies (Text Version) on Twitter Bookmark Fuel Cell Technologies Office: America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies (Text Version) on Google Bookmark Fuel Cell Technologies Office: America's Next Top Energy Innovator Runner-Up Presents Hydrogen Detection Technologies (Text Version) on Delicious Rank Fuel Cell Technologies Office: America's Next Top Energy

363

A measurement of the top pair production cross-section in the dilepton channel using lepton plus track selection  

SciTech Connect

Using 1.1 fb{sup -1} of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, they measure the t{bar t} production cross section in events with two leptons, significant missing transverse energy, and {ge} 2 jets. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t {yields} Wb {yields} {ell}{nu}b, is of particular interest due to its high purity even in the absence of a b jet 'tagging' requirement. Use of an isolated track as the second lepton significant increases the dilepton acceptance, at the price of some increase in background, particular from W + jets events where one of the jets is identified as a lepton. With the amount of data available, it has been possible to improve the estimate of the contribution from that background, reflected in a reduced systematic uncertainty. Assuming a branching ratio of BR(W {yields} {ell}{nu}) = 10.8% and a top mass of m{sub t} = 175 GeV/c{sup 2}, the measured cross-section is {sigma}(p{bar p} {yields} t{bar t}) = 8.3 {+-} 1.3(stat.) {+-} 0.7(syst.) {+-} 0.5(lumi.) pb. The result is consistent with the Standard Model prediction of 6.7{sub -0.9}{sup +0.7} pb and represents a significant improvement in precision over previous results using this selection.

Mills, Corrinne Elaine; /UC, Santa Barbara

2007-06-01T23:59:59.000Z

364

The uncertainties due to quark energy loss on determining nuclear sea quark distribution from nuclear Drell-Yan data  

E-Print Network (OSTI)

By means of two different parametrizations of quark energy loss and the nuclear parton distributions determined only with lepton-nuclear deep inelastic scattering experimental data, a leading order phenomenological analysis is performed on the nuclear Drell-Yan differential cross section ratios as a function of the quark momentum fraction in the beam proton and target nuclei for E772 experimental data. It is shown that there is the quark energy loss effect in nuclear Drell-Yan process apart from the nuclear effects on the parton distribution as in deep inelastic scattering. The uncertainties due to quark energy loss effect is quantified on determining nuclear sea quark distribution by using nuclear Drell-Yan data. It is found that the quark energy loss effect on nuclear Drell-Yan cross section ratios make greater with the increase of quark momentum fraction in the target nuclei. The uncertainties from quark energy loss become bigger as the nucleus A come to be heavier. The Drell-Yan data on proton incident middle and heavy nuclei versus deuterium would result in an overestimate for nuclear modifications on sea quark distribution functions with neglecting the quark energy loss. Our results are hoped to provide good directional information on the magnitude and form of nuclear modifications on sea quark distribution functions by means of the nuclear Drell-Yan experimental data.

C. G. Duan; N. Liu; G. L. Li

2008-11-05T23:59:59.000Z

365

Top quark loop corrections to the decay $H^+ \\to h^0 W^+$ in the Two Higgs Doublet Model  

E-Print Network (OSTI)

We calculate the decay width for the process $H^+ \\to h^0 W^+$ up to order $g^4$ in the framework of the Two Higgs Doublet Model. We argue that for some reasonable choice of the free parameters the contribution from the one-loop graphs can be as large as 40%.

R. Santos; A. Barroso; L. Bruecher

1997-04-28T23:59:59.000Z

366

RHIC | Why Does Quark Matter Matter?  

NLE Websites -- All DOE Office Websites (Extended Search)

Why Does Quark Matter 'Matter'? Why Does Quark Matter 'Matter'? The history of modern technological development can be viewed as a series of investigations, with ever increasing resolution, into the microscopic structure of matter. Since the days of the early Greek philosophers, science has been on a continual quest to find the smallest piece - the most fundamental building block - forming the substance of the universe. STAR researchers During that journey, many beautiful and exotic properties of the subatomic world have been discovered: particles with wave-like properties the ultimate position of which can never be known; "particles" of light that deliver a fixed amount of energy when they strike the atoms of a material's surface; particles in some types of electrical conductors that

367

Secondary Production of Massive Quarks in Thrust  

E-Print Network (OSTI)

We present a factorization framework that takes into account the production of heavy quarks through gluon splitting in the thrust distribution for e+ e- --> hadrons. The explicit factorization theorems and some numerical results are displayed in the dijet region where the kinematic scales are widely separated, which can be extended systematically to the whole spectrum. We account for the necessary two-loop matrix elements, threshold corrections, and include resummation up to N3LL order. We include nonperturbative power corrections through a field theoretical shape function, and remove the O(Lambda_QCD) renormalon in the partonic soft function by appropriate mass-dependent subtractions. Our results hold for any value of the quark mass, from an infinitesimally small (merging to the known massless result) to an infinitely large one (achieving the decoupling limit). This is the first example of an application of a variable flavor number scheme to final state jets.

Andre H. Hoang; Vicent Mateu; Piotr Pietrulewicz

2014-12-22T23:59:59.000Z

368

Quark and Gluon Tagging at the LHC  

Science Journals Connector (OSTI)

Being able to distinguish light-quark jets from gluon jets on an event-by-event basis could significantly enhance the reach for many new physics searches at the Large Hadron Collider. Through an exhaustive search of existing and novel jet substructure observables, we find that a multivariate approach can filter out over 95% of the gluon jets while keeping more than half of the light-quark jets. Moreover, a combination of two simple variables, the charge track multiplicity and the pT-weighted linear radial moment (girth), can achieve similar results. Our study is only Monte Carlo based, so other observables constructed using different jet sizes and parameters are used to highlight areas that deserve further theoretical and experimental scrutiny. Additional information, including distributions of around 10?000 variables, can be found at http://jets.physics.harvard.edu/qvg/.

Jason Gallicchio and Matthew D. Schwartz

2011-10-17T23:59:59.000Z

369

The Bonn nuclear quark model revisited  

SciTech Connect

We present the exact solutions to the equations of the lowest energy states of the colored and color-symmetric sectors of the Bonn quark model, which is SU(3) symmetric and is defined in terms of an effective pairing force with su(4) algebraic structure. We show that the groundstate of the model is not color symmetrical except for a narrow interval in the range of possible quark numbers. We also study the performance of the Glauber coherent state, as well as of superconducting states of the BCS type, with respect to the description, not only of the absolute (colored) groundstate, but also of the minimum energy state of the color-symmetrical sector, finding that it is remarkably good. We use the model to discuss, in a schematic context, some controversial aspects of the conventional treatment of color superconductivity.

Providencia, Constanca [Departamento de Fi sica, Universidade de Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal); Providencia, Joao da [Departamento de Fi sica, Universidade de Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal)], E-mail: providencia@teor.fis.uc.pt; Cordeiro, Flavio [Departamento de Fi sica, Universidade de Coimbra, Rua Larga, P-3004-516 Coimbra (Portugal); Yamamura, Masatoshi [Department of Pure and Applied Physics, Faculty of Engineering Science, Kansai University, Suita 564-8680 (Japan); Tsue, Yasuhiko; Nishiyama, Seiya [Physics Division, Faculty of Science, Kochi University, Kochi 780-8520 (Japan)

2009-08-15T23:59:59.000Z

370

Bottom-quark fragmentation: comparing results from tuned event generators and resummed calculations  

E-Print Network (OSTI)

We study bottom-quark fragmentation in e+e- annihilation, top and Higgs decay H -> b bbar, using Monte Carlo event generators, as well as calculations, based on the formalism of perturbative fragmentation functions, which resum soft- and collinear-radiation effects in the next-to-leading logarithmic approximation. We consider the PYTHIA and HERWIG generators, and implement matrix-element corrections to the parton shower simulation of the H -> b bbar process in HERWIG. We tune the Kartvelishvili, string and cluster models to B-hadron data from LEP and SLD, and present results in both x_B and moment spaces. The B-hadron spectra yielded by HERWIG, PYTHIA and resummed calculations show small discrepancies, which are due to the different approaches and models employed and to the quality of the fits to the e+e- data.

Gennaro Corcella; Volker Drollinger

2005-11-23T23:59:59.000Z

371

The Surface Tension of Magnetized Quark Matter  

E-Print Network (OSTI)

The surface tension of quark matter plays a crucial role for the possibility of quark matter nucleation during the formation of compact stellar objects and also for the existence of a mixed phase within hybrid stars. However, despite its importance, this quantity does not have a well established numerical value. Some early estimates have predicted that, at zero temperature, the value falls within the wide range $\\gamma_0\\approx10-300{\\rm\\ MeV/fm^2}$ but, very recently, different model applications have reduced these numerical values to fall within the range $\\gamma_0\\approx5-30{\\rm\\ MeV/fm^2}$ which would favor the phase conversion process as well as the appearance of a mixed phase in hybrid stars. In magnetars one should also account for the presence of very high magnetic fields which may reach up to about $ eB\\approx 3-30\\, m_\\pi^2$ ($B \\approx 10^{19}-10^{20} \\,G$) at the core of the star so that it may also be important to analyze how the presence of a magnetic field affects the surface tension. With this aim we consider magnetized two flavor quark matter, described by the Nambu--Jona-Lasinio model. We show that although the surface tension oscillates around its B=0 value, when $0 surface tension value drops by about 30% while for $eB \\gtrsim 10\\, m_\\pi^2$ it quickly raises with the field intensity so that the phase conversion and the presence of a mixed phase should be suppressed if extremely high fields are present. We also investigate how thermal effects influence the surface tension for magnetized quark matter.

A. F. Garcia; M. B. Pinto

2013-06-13T23:59:59.000Z

372

Heavy quark masses from Fermilab Fermions  

E-Print Network (OSTI)

Using automated perturbation theory techniques, we have computed the one-loop mass of Fermilab fermions, with an improved gluon action. We will present the results of these calculations, and the resulting predictions for the charm and bottom quark masses in the MSbar scheme. We report mc(mc) = 1:22(9) GeV and mb(mb) = 4:7(4) GeV. In addition we present results for the one-loop coeffcients of the Fermilab action.

Matthew Nobes; Howard Trottier

2005-09-26T23:59:59.000Z

373

Environmental assessment of curly top virus control in California. [Curly Top Virus  

SciTech Connect

Curly top is a viral disease of sugarbeets, tomatoes, melons, peppers, beans, cucumbers, squash, pumpkins, spinach, vineseed and other commercially important crops, including ornamentals. Curly top not only infects commercial crops, but at times devastates backyard vegetable and flower gardens. The only known vector of curly top is Circulifer tenellus, commonly known as the beet leafhopper. Control of the beet leafhopper may take place at various locations throughout the San Joaquin Valley, Salinas Valley, Cuyama Valley, Antelope Valley of northern Los Angeles County, Riverside County and the Imperial Valley (See Maps in Appendix E''), including portions of Merced, Fresno, Kings. Kern, San Luis Obispo, Monterey, San Benito, Santa Barbara, Los Angeles, Riverside and Imperial Counties. The size of the control program is totally dependent on the location, size, nd distribution of the beet leafhopper population. In a year with a low population, only 80,000 acres in western Fresno, Kings, and Kern Counties may require treatment. In a drought year, the treatment required may increase to more than 200,000 acres and include some inter-coastal valleys of Monterey, San Luis Obispo and Santa Barbara Counties. Not all areas require treatment on an annual basis and at no time is the entire area subject to blanket treatment. The Curly Top Virus Control Program (CTVCP) was instrumental in supporting research which developed an antisera allowing the use of Enzyme-Linked Immunosorbent Assay to determine the presence, on a percentage basis, of curly top virus. Thus, the amount of virus found in a given area lends weight to treatment priorities.

Not Available

1991-03-15T23:59:59.000Z

374

Finite top-mass effects in gluon-induced Higgs production with a jet-veto at NNLO  

E-Print Network (OSTI)

Effects from a finite top quark mass on the H+n-jet cross section through gluon fusion are studied for $n=0/n\\ge 1$ at NNLO/NLO QCD. For this purpose, sub-leading terms in $1/m_t$ are calculated. We show that the asymptotic expansion of the jet-vetoed cross section at NNLO is very well behaved and that the heavy-top approximation is valid at the five permille level up to jet-veto cuts of 300 GeV. For the inclusive Higgs+jet rate, we introduce a matching procedure that allows for a reliable prediction of the top-mass effects using the expansion in $1/m_t$. The quality of the effective field theory to evaluate differential K-factors for the distribution of the hardest jet is found to be better than 1-2% as long as the transverse momentum of the jet is integrated out or remains below about 150 GeV.

Neumann, Tobias

2014-01-01T23:59:59.000Z

375

Heavy quarks and long-lived hadrons  

Science Journals Connector (OSTI)

In a recent Letter we reported on some work which led us to suggest the possibility of narrow spikes in the e+e- annihilation cross section into hadrons. In this paper, we discuss the theoretical infrastructure of this work more thoroughly, and improve and extend the calculations and experimental predictions. We examine a colored quark-gluon model of hadronic matter, with color an exact SU(3) gauge symmetry. In addition to the light quarks that make up ordinary hadrons, a heavy quark, such as the charmed c, is included. The narrow resonances recently discovered by the MIT-BNL and SLAC-LBL groups are interpreted as cc¯ bound states (orthocharmonium). In this energy range, the effective coupling has become small according to asymptotic freedom, and many aspects of the bound-state structure can be calculated. The existence of 0- (paracharmonium) states is predicted, and decay widths and mass splittings are estimated. The total e+e- cross section into hadrons is predicted to scale asymptotically, with an approach to scaling from above that can be calculated over a large energy range.

Thomas Appelquist and H. David Politzer

1975-09-01T23:59:59.000Z

376

Quark-Gluon Bags with Surface Tension  

E-Print Network (OSTI)

The temperature and chemical potential dependent surface tension of bags is introduced into the gas of quark-gluon bags model. This resolves a long standing problem of a unified description of the first and second order phase transition with the cross-over. Such an approach is necessary to model the complicated properties of quark-gluon plasma and hadronic matter from the first principles of statistical mechanics. The suggested model has an exact analytical solution and allows one to rigorously study the vicinity of the critical endpoint of the deconfinement phase transition. The existence of higher order phase transitions at the critical endpoint is discussed. In addition, we found that at the curve of a zero surface tension coefficient there must exist the surface induced phase tranition of the 2$^{nd}$ or higher order, which separates the pure quark gluon plasma (QGP) from the cross-over states, that are the mixed states of hadrons and QGP bags. Thus, the present model predicts that the critical endpoint of quantum chromodynamics is the tricritical endpoint.

Kyrill Bugaev

2007-03-20T23:59:59.000Z

377

Domain wall QCD with physical quark masses  

E-Print Network (OSTI)

We present results for several light hadronic quantities ($f_\\pi$, $f_K$, $B_K$, $m_{ud}$, $m_s$, $t_0^{1/2}$, $w_0$) obtained from simulations of 2+1 flavor domain wall lattice QCD with large physical volumes and nearly-physical pion masses at two lattice spacings. We perform a short, O(3)%, extrapolation in pion mass to the physical values by combining our new data in a simultaneous chiral/continuum `global fit' with a number of other ensembles with heavier pion masses. We use the physical values of $m_\\pi$, $m_K$ and $m_\\Omega$ to determine the two quark masses and the scale - all other quantities are outputs from our simulations. We obtain results with sub-percent statistical errors and negligible chiral and finite-volume systematics for these light hadronic quantities, including: $f_\\pi$ = 130.2(9) MeV; $f_K$ = 155.5(8) MeV; the average up/down quark mass and strange quark mass in the $\\overline {\\rm MS}$ scheme at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon mixing parameter, $B_K$, in the RGI scheme, 0.750(15) and the $\\overline{\\rm MS}$ scheme at 3 GeV, 0.530(11).

RBC; UKQCD collaborations; :; T. Blum; P. A. Boyle; N. H. Christ; J. Frison; N. Garron; R. J. Hudspith; T. Izubuchi; T. Janowski; C. Jung; A. Juettner; C. Kelly; R. D. Kenway; C. Lehner; M. Marinkovic; R. D. Mawhinney; G. McGlynn; D. J. Murphy; S. Ohta; A. Portelli; C. T. Sachrajda; A. Soni

2014-11-25T23:59:59.000Z

378

Astrophysical Aspects of Quark-Gluon Plasma  

E-Print Network (OSTI)

This M.Sc. thesis in Engineering Physics is an overview of the present theory of quark-gluon plasma (QGP) as well as an analysis of the stability criterion for possible stable cosmic QGP objects left over from the quark-hadron transition in the early Universe. It covers fundamental ideas of the formation and decay of the plasma, including the standard model, QCD, and the MIT bag model. I discuss the equation of state of a QGP and the possible signatures for a plasma created in heavy-ion collisions. Astrophysical aspects of QGP are put forward, including compact stars and the quark-hadron transition in the early Universe. The possible role of QGP objects as cosmic dark matter is mentioned. The analytic part is an investigation of possible stability among cosmic QGP objects from the early Universe. A model is suggested where a pressure balance makes a QGP stable against gravitational contraction and hadronization. The mass/radius relationship for stability also forbids a direct gravitational collapse. Finally, ...

Enström, D

1998-01-01T23:59:59.000Z

379

Flavor Physics in the Quark Sector  

E-Print Network (OSTI)

One of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor and measurements and theoretical interpretations of their results have advanced tremendously: apart from masses and quantum numbers of flavor particles, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. Till early 1990s observations of CP violation were confined to neutral $K$ mesons, but since then a large number of CP-violating processes have been studied in detail in neutral $B$ mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of $K, D$, and $B$ mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field.

M. Antonelli; D. M. Asner; D. Bauer; T. Becher; M. Beneke; A. J. Bevan; M. Blanke; C. Bloise; M. Bona; A. Bondar; C. Bozzi; J. Brod; A. J. Buras; N. Cabibbo; A. Carbone; G. Cavoto; V. Cirigliano; M. Ciuchini; J. P. Coleman; D. P. Cronin-Hennessy; J. P. Dalseno; C. H. Davies; F. DiLodovico; J. Dingfelder; Z. Dolezal; S. Donati; W. Dungel; U. Egede; G. Eigen; R. Faccini; T. Feldmann; F. Ferroni; J. M. Flynn; E. Franco; M. Fujikawa; I. K. Furic; P. Gambino; E. Gardi; T. J. Gershon; S. Giagu; E. Golowich; T. Goto; C. Greub; C. Grojean; D. Guadagnoli; U. A. Haisch; R. F. Harr; A. H. Hoang; T. Hurth; G. Isidori; D. E. Jaffe; A. Jüttner; S. Jäger; A. Khodjamirian; P. Koppenburg; R. V. Kowalewski; P. Krokovny; A. S. Kronfeld; J. Laiho; G. Lanfranchi; T. E. Latham; J. Libby; A. Limosani; D. Lopes Pegna; C. D. Lu; V. Lubicz; E. Lunghi; V. G. Lüth; K. Maltman; W. J. Marciano; E. C. Martin; G. Martinelli; F. Martinez-Vidal; A. Masiero; V. Mateu; F. Mescia; G. Mohanty; M. Moulson; M. Neubert; H. Neufeld; S. Nishida; N. Offen; M. Palutan; P. Paradisi; Z. Parsa; E. Passemar; M. Patel; B. D. Pecjak; A. A. Petrov; A. Pich; M. Pierini; B. Plaster; A. Powell; S. Prell; J. Rademaker; M. Rescigno; S. Ricciardi; P. Robbe; E. Rodrigues; M. Rotondo; R. Sacco; C. J. Schilling; O. Schneider; E. E. Scholz; B. A. Schumm; C. Schwanda; A. J. Schwartz; B. Sciascia; J. Serrano; J. Shigemitsu; I. J. Shipsey; A. Sibidanov; L. Silvestrini; F. Simonetto; S. Simula; C. Smith; A. Soni; L. Sonnenschein; V. Sordini; M. Sozzi; T. Spadaro; P. Spradlin; A. Stocchi; N. Tantalo; C. Tarantino; A. V. Telnov; D. Tonelli; I. S. Towner; K. Trabelsi; P. Urquijo; R. S. Van de Water; R. J. Van Kooten; J. Virto; G. Volpi; R. Wanke; S. Westhoff; G. Wilkinson; M. Wingate; Y. Xie; J. Zupan

2009-07-29T23:59:59.000Z

380

Gauge bosons and heavy quarks: Proceedings of Summer Institute on Particle Physics  

SciTech Connect

This report contains papers on the following topics: Z decays and tests of the standard model; future possibilities for LEP; studies of the interactions of electroweak gauge bosons; top quark topics; the next linear collider; electroweak processes in hadron colliders; theoretical topics in B-physics; experimental aspects of B-physics; B-factory storage ring design; rare kaon decays; CP violation in K{sup 0} decays at CERN; recent K{sup 0} decay results from Fermilab E-731; results from LEP on heavy quark physics; review of recent results on heavy flavor production; weak matrix elements and the determination of the weak mixing angles; recent results from CLEO I and a glance at CLEO II data; recent results from ARGUS; neutrino lepton physics with the CHARM 2 detector; recent results from the three TRISTAN experiments; baryon number violation at high energy in the standard model: fact or fiction New particle searches at LEP; review of QCD at LEP; electroweak interactions at LEP; recent results on W physics from the UA2 experiment at the CERN {rho}{bar {rho}} collider; B physics at CDF; and review of particle astrophysics.

Hawthorne, J.F. (ed.)

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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381

Top Crop Wind Farm | Open Energy Information  

Open Energy Info (EERE)

Crop Wind Farm Crop Wind Farm Facility Top Crop Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Horizon-EDPR Developer Horizon-EDPR Location Grundy/Livingston/La Salle Counties IL Coordinates 41.159826°, -88.637381° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.159826,"lon":-88.637381,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

382

Top 10 Water Dos and Donts  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

WATER SAVERS WATER SAVERS Francis Wheeler (713) 504-6684 fwheeler@thewater-savers.com Why Worry About Water Humanity's Top Ten Problems for next 50 years 1. ENERGY 2. WATER 3. FOOD 4. ENVIRONMENT 5. POVERTY 6. TERRORISM & WAR 7. DISEASE 8. EDUCATION 9. DEMOCRACY 10. POPULATION 2004 6.5 Billion People 2050 ~ 10 Billion People DON'T DON'T irrigate during or 12 hours before or after a rain event DON'T allow your irrigation systems to go without maintenance DON'T waste mother natures free/provided resources (FRESH CLEAN WATER) DON'T utilize bleeding edge technology that is not proven and/or that is a life cycle cost loser (NO BLACK BOXES) DON'T DON'T Over do it on plumbing retrofits DON'T Forget to do a water balance DON'T Forget to review billing

383

[Place at top of Part I]  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

inserting in the FOA template are in blue. inserting in the FOA template are in blue. [Place at top of Part I - FUNDING OPPORTUNITY DESCRIPTION] Projects under this FOA will be funded, in whole or in part, with funds appropriated by the American Recovery and Reinvestment Act of 2009, Pub. L. 111-5, (Recovery Act or Act). The Recovery Act's purposes are to stimulate the economy and to create and retain jobs. The Act gives preference to activities that can be started and completed expeditiously, including a goal of using at least 50 percent of the funds made available by it for activities that can be initiated not later than June 17, 2009. Accordingly, special consideration will be given to projects that promote and enhance the objectives of the Act, especially job creation, preservation and

384

Jet Dipolarity: Top Tagging with Color Flow  

SciTech Connect

A new jet observable, dipolarity, is introduced that can distinguish whether a pair of subjets arises from a color singlet source. This observable is incorporated into the HEPTopTagger and is shown to improve discrimination between top jets and QCD jets for moderate to high p{sub T}. The impressive resolution of the ATLAS and CMS detectors means that a typical QCD jet at the LHC deposits energy in {Omicron}(10-100) calorimeter cells. Such fine-grained calorimetry allows for jets to be studied in much greater detail than previously, with sophisticated versions of current techniques making it possible to measure more than just the bulk properties of jets (e.g. event jet multiplicities or jet masses). One goal of the LHC is to employ these techniques to extend the amount of information available from each jet, allowing for a broader probe of the properties of QCD. The past several years have seen significant progress in developing such jet substructure techniques. A number of general purpose tools have been developed, including: (i) top-tagging algorithms designed for use at both lower and higher p{sub T} as well as (ii) jet grooming techniques such as filtering, pruning, and trimming, which are designed to improve jet mass resolution. Jet substructure techniques have also been studied in the context of specific particle searches, where they have been shown to substantially extend the reach of traditional search techniques in a wide variety of scenarios, including for example boosted Higgses, neutral spin-one resonances, searches for supersymmetry, and many others. Despite these many successes, however, there is every reason to expect that there remains room for refinement of jet substructure techniques.

Hook, Anson; Jankowiak, Martin; /SLAC /Stanford U., Phys. Dept.; Wacker, Jay G.; /SLAC

2011-08-12T23:59:59.000Z

385

Jet conversions in a quark-gluon plasma  

Science Journals Connector (OSTI)

Quark and gluon jets traversing through a quark-gluon plasma not only lose their energies but also can undergo flavor conversions. The conversion rates via the elastic q(q¯)g?gq(q¯) and the inelastic qq¯?gg scatterings are evaluated in the lowest order in QCD. Including both jet energy loss and conversions in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we have found a net of quark jets to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the p/?+ and p¯/?- ratios at high transverse momentum. However, a much larger net quark-to-gluon jet conversion rate than the one given by the lowest order QCD is needed to account for the observed similar ratios in central Au+Au and p+p collisions at the same energy. Implications of our results are discussed.

W. Liu; C. M. Ko; B. W. Zhang

2007-05-04T23:59:59.000Z

386

LANL announces top 10 science stories of 2009  

NLE Websites -- All DOE Office Websites (Extended Search)

Top 10 science stories of 2009 Top 10 science stories of 2009 LANL announces top 10 science stories of 2009 Top 10 Laboratory science stories of 2009 based on global viewership of online media content and major programmatic milestones. January 8, 2010 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Contact Communications Office

387

The Onset of Quark-Hadron Duality in Pion Electroproduction  

E-Print Network (OSTI)

A large data set of charged-pion electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-to- pion production mechanisms.

T. Navasardyan

2006-08-18T23:59:59.000Z

388

The Onset of Quark-Hadron Duality in Pion Electroproduction  

SciTech Connect

A large data set of charged-pion electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-to- pion production mechanisms.

Tigran Navasardyan; Gary Adams; Abdellah Ahmidouch; Tatiana Angelescu; John Arrington; Razmik Asaturyan; O. Baker; Nawal Benmouna; Crystal Bertoncini; Henk Blok; Werner Boeglin; Peter Bosted; Herbert Breuer; Michael Christy; Simon Connell; Yonggang Cui; Mark Dalton; Samuel Danagoulian; Donal Day; T. Dodario; James Dunne; Dipangkar Dutta; Najib Elkhayari; Rolf Ent; Howard Fenker; Valera Frolov; Liping Gan; David Gaskell; Kawtar Hafidi; Wendy Hinton; Roy Holt; Tanja Horn; Garth Huber; Ed Hungerford; Xiaodong Jiang; Mark Jones; Kyungseon Joo; Narbe Kalantarians; James Kelly; Cynthia Keppel; Edward Kinney; V. Kubarovski; Ya Li; Yongguang Liang; Simona Malace; Pete Markowitz; Erin McGrath; Daniella Mckee; David Meekins; Hamlet Mkrtchyan; Brian Moziak; Gabriel Niculescu; Maria-Ioana Niculescu; Allena Opper; Tanya Ostapenko; Paul Reimer; Joerg Reinhold; Julie Roche; Stephen Rock; Elaine Schulte; Edwin Segbefia; C. Smith; G.R. Smith; Paul Stoler; Vardan Tadevosyan; Liguang Tang; Maurizio Ungaro; Alicia Uzzle; Sandra Vidakovic; Anthony Villano; William Vulcan; Miao Wang; Glen Warren; Frank Wesselmann; Bogdan Wojtsekhowski; Stephen Wood; Chuncheng Xu; Lulin Yuan; Xiaochao Zheng; Hong Guo Zhu

2006-08-29T23:59:59.000Z

389

Covariant nonlocal chiral quark models with separable interactions  

SciTech Connect

We present a comparative analysis of chiral quark models which include nonlocal covariant four-fermion couplings. We consider two alternative ways of introducing the nonlocality, as well as various shapes for the momentum-dependent form factors governing the effective interactions. In all cases we study the behavior of model parameters and analyze numerical results for constituent quark masses and quark propagator poles. Advantages of these covariant nonlocal schemes over instantaneous nonlocal schemes and the standard NJL model are pointed out.

Dumm, D. Gomez [IFLP - Dpto. de Fisica, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina); Grunfeld, A. G. [Physics Department, Comision Nacional de Energia Atomica, Av. Libertador 8250, 1429 Buenos Aires (Argentina); Scoccola, N. N. [CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina); Physics Department, Comision Nacional de Energia Atomica, Av. Libertador 8250, 1429 Buenos Aires (Argentina); Universidad Favaloro, Solis 453, 1078 Buenos Aires (Argentina)

2006-09-01T23:59:59.000Z

390

QCD Thermodynamics with an almost realistic quark mass spectrum  

E-Print Network (OSTI)

We will report on the status of a new large scale calculation of thermodynamic quantities in QCD with light up and down quarks corresponding to an almost physical light quark mass value and a heavier strange quark mass. These calculations are currently being performed on the QCDOC Teraflops computers at BNL. We will present new lattice calculations of the transition temperature and various susceptibilities reflecting properties of the chiral transition. All these quantities are of immediate interest for heavy ion phenomenology.

C. Schmidt

2006-01-25T23:59:59.000Z

391

Decuplet baryon magnetic moments in the chiral quark model  

Science Journals Connector (OSTI)

We present calculations of the decuplet baryon magnetic moments in the chiral quark model. As input we use parameters obtained in qualitatively accurate fits to the octet baryon magnetic moments studied previously. The values found for the magnetic moments of ?++ and ?- are in good agreement with experiments. We finally calculate the total quark spin polarizations of the decuplet baryons and find that they are considerably smaller than what is expected from the non-relativistic quark model.

Johan Linde; Tommy Ohlsson; Håkan Snellman

1998-05-01T23:59:59.000Z

392

Report of the Quark Flavor Physics Working Group  

E-Print Network (OSTI)

This report represents the response of the Intensity Frontier Quark Flavor Physics Working Group to the Snowmass charge. We summarize the current status of quark flavor physics and identify many exciting future opportunities for studying the properties of strange, charm, and bottom quarks. The ability of these studies to reveal the effects of new physics at high mass scales make them an essential ingredient in a well-balanced experimental particle physics program.

Butler, J N; Ritchie, J L; Cirigliano, V; Kettell, S; Briere, R; Petrov, A A; Schwartz, A; Skwarnicki, T; Zupan, J; Christ, N; Sharpe, S R; Van de Water, R S; Altmannshofer, W; Arkani-Hamed, N; Artuso, M; Asner, D M; Bernard, C; Bevan, A J; Blanke, M; Bonvicini, G; Browder, T E; Bryman, D A; Campana, P; Cenci, R; Cline, D; Comfort, J; Cronin-Hennessy, D; Datta, A; Dobbs, S; Duraisamy, M; El-Khadra, A X; Fast, J E; Forty, R; Flood, K T; Gershon, T; Grossman, Y; Hamilton, B; Hill, C T; Hill, R J; Hitlin, D G; Jaffe, D E; Jawahery, A; Jessop, C P; Kagan, A L; Kaplan, D M; Kohl, M; Krizan, P; Kronfeld, A S; Lee, K; Littenberg, L S; MacFarlane, D B; Mackenzie, P B; Meadows, B T; Olsen, J; Papucci, M; Parsa, Z; Paz, G; Perez, G; Piilonen, L E; Pitts, K; Purohit, M V; Quinn, B; Ratcliff, B N; Roberts, D A; Rosner, J L; Rubin, P; Seeman, J; Seth, K K; Schmidt, B; Schopper, A; Sokoloff, M D; Soni, A; Stenson, K; Stone, S; Sundrum, R; Tschirhart, R; Vainshtein, A; Wah, Y W; Wilkinson, G; Wise, M B; Worcester, E; Xu, J; Yamanaka, T

2013-01-01T23:59:59.000Z

393

EM Recovery Act Top Line Messages | Department of Energy  

Energy Savers (EERE)

Recovery Act Top Line Messages - April, 2013 More Documents & Publications Workers at Hanford Site Achieve Recovery Act Legacy Cleanup Goals Ahead of Schedule Audit Report:...

394

Next Generation Advanced Framing- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

Building America researchers garnered a Top Innovation award for research into simple, cost-effective ways to implement advanced framing techniques.

395

Top 5 Maps and Interactive Graphics of 2014  

Energy.gov (U.S. Department of Energy (DOE))

Here are our top five maps and interactive graphics from 2014. Explore space-based solar power, how much energy you consume, energy production and more.

396

Sandia National Laboratories: Optical performance of top-down...  

NLE Websites -- All DOE Office Websites (Extended Search)

and Exhibition (EU PVSC) EC Top Publications Reference Model 5 (RM5): Oscillating Surge Wave Energy Converter Experimental Wave Tank Test for Reference Model 3 Floating- Point...

397

Buried and Encapsulated Ducts - Building America Top Innovation...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Encapsulated Ducts - Building America Top Innovation photo of worker blowing insulation on ducts in an attic. Ductwork installed in unconditioned attics can significantly...

398

High-Efficiency Window Air Conditioners - Building America Top...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Window Air Conditioners - Building America Top Innovation This photo shows a window air conditioning unit in place in a window frame. Window air conditioners are inexpensive,...

399

Top 10 Water Savings Do and Don't  

Energy.gov (U.S. Department of Energy (DOE))

Presentation—given at the Spring 2009 Federal Utility Partnership Working Group (FUPWG) meeting—covers the top ways to conserve water.

400

Building America Solution Center - Building America Top Innovation...  

Energy Savers (EERE)

America Top Innovation SCimagemale.jpg The Building America Solution Center is a Web-based tool connecting users to fast, free, and expert building science and energy...

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Valuing Green in the Appraisal Process- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

This 2014 Top Innovation describes Building America work to pave the way for a Green and Energy Effiiciency Addendum for real estate appraisers.

402

Ex Parte Memorandum on Set Top Boxes and Network Equipment |...  

Energy Savers (EERE)

provides a summary of a May 1, 2012, meeting with DOE officials concerning potential test procedures and energy conservation standards for set-top boxes and network equipment....

403

NSTec tops more than $2 million in contributions to education...  

National Nuclear Security Administration (NNSA)

NSTec tops more than 2 million in contributions to education outreach | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the...

404

Advanced Technologies and Practices- Building America Top Innovations  

Energy.gov (U.S. Department of Energy (DOE))

Top Innovations in this category encompass research in specific technologies and construction practices that improve the building envelope, HVAC components, ventilation, and health and safety issues.

405

Secretary Chu Announces Second Round of "America's Next Top Energy...  

Energy Savers (EERE)

Second Round of "America's Next Top Energy Innovator" on One Year Anniversary of the White House Startup America Initiative Secretary Chu Announces Second Round of "America's...

406

Northwest public utilities, BPA top five-year energy savings...  

NLE Websites -- All DOE Office Websites (Extended Search)

public-utilities-BPA-top-five-year-energy-savings-target Sign In About | Careers | Contact | Investors | bpa.gov Search News & Us Expand News & Us Projects & Initiatives Expand...

407

Effective Guidance and Tools - Building America Top Innovations...  

Energy Savers (EERE)

Quality Management System Guidelines 1995-2012 Top Innovations EEBA Builder's Guides EEBA Water Management Guide Attic Air Sealing Guidelines High-Performance Home Metrics These...

408

Valuing Green in the Appraisal Process - Building America Top...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

America Top Innovation Real estate appraisers have historically faced challenges with green and energy efficient homes, both in identifying comparables and in supporting...

409

Search for Excited Quarks in ep Collisions at HERA  

E-Print Network (OSTI)

A search for excited quarks is performed using the full ep data sample collected by the H1 experiment at HERA, corresponding to a total integrated luminosity of 475 pb^-1. The electroweak decays of excited quarks q* -> q gamma, q* -> q Z and q* -> q W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for first generation excited quark production is found. Mass dependent exclusion limits on q* production cross sections and on the ratio f/Lambda of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited quark searches.

Aaron, F D; Alimujiang, K; Andreev, V; Antunovic, B; Asmone, A; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; de Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; De Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, S; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jemanov, V; Jonsson, L; Jung, Andreas Werner; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Korbel, V; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H U; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naroska, B; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schmitz, C; Schoeffel, L; Schoning, A; Schultz-Coulon, H C; Sefkow, F; Shaw-West, R N; Sheviakov, I; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F; Zus, R; 10.1016/j.physletb.2009.06.044

2009-01-01T23:59:59.000Z

410

Thermodynamics and heavy-quark free energies at finite temperature and density with two flavors of improved Wilson quarks  

E-Print Network (OSTI)

Thermodynamics of two-flavor QCD at finite temperature and density is studied on a $16^3 \\times 4$ lattice, using a renormalization group improved gauge action and the clover improved Wilson quark action. In the simulations along lines of constant $m_{\\rm PS}/m_{\\rm V}$, we calculate the Taylor expansion coefficients of the heavy-quark free energy with respect to the quark chemical potential ($\\mu_q$) up to the second order. By comparing the expansion coefficients of the free energies between quark($Q$)and antiquark($\\bar{Q}$), and between $Q$ and $Q$, we find a characteristic difference at finite $\\mu_q$ due to the first order coefficient of the Taylor expansion. We also calculate the quark number and isospin susceptibilities, and find that the second order coefficient of the quark number susceptibility shows enhancement around the pseudo-critical temperature.

Y. Maezawa; S. Aoki; S. Ejiri; T. Hatsuda; N. Ishii; K. Kanaya; N. Ukita; T. Umeda

2007-10-04T23:59:59.000Z

411

Photon emission from bare quark stars  

E-Print Network (OSTI)

We investigate the photon emission from the electrosphere of a quark star. It is shown that at temperatures T\\sim 0.1-1 MeV the dominating mechanism is the bremsstrahlung due to bending of electron trajectories in the mean Coulomb field of the electrosphere. The radiated energy for this mechanism is much larger than that for the Bethe-Heitler bremsstrahlung. The energy flux from the mean field bremsstrahlung exceeds the one from the tunnel e^{+}e^{-} pair creation as well. We demonstrate that the LPM suppression of the photon emission is negligible.

B. G. Zakharov

2010-08-16T23:59:59.000Z

412

Seismic Search for Strange Quark Nuggets  

E-Print Network (OSTI)

Bounds on masses and abundances of Strange Quark Nuggets (SQNs) are inferred from a seismic search on Earth. Potential SQN bounds from a possible seismic search on the Moon are reviewed and compared with Earth capabilities. Bounds are derived from the data taken by seismometers implanted on the Moon by the Apollo astronauts. We show that the Apollo data implies that the abundance of SQNs in the region of 10 kg to one ton must be at least an order of magnitude less than would saturate the dark matter in the solar neighborhood.

Eugene T. Herrin; Doris C. Rosenbaum; Vigdor L. Teplitz

2005-05-29T23:59:59.000Z

413

Dissipative phenomena in quark-gluon plasmas  

SciTech Connect

Transport coefficients of small-chemical-potential quark-gluon plasmas are estimated and dissipative corrections to the scaling hydrodynamic equations for ultrarelativistic nuclear collisions are studied. The absence of heat-conduction phenomena is clarified. Lower and upper bounds on the shear-viscosity coefficient are derived. QCD phenomenology is used to estimate effects of color-electric and -magnetic shielding, and nonperturbative antiscreening. Bulk viscosity associated with the plasma-to-hadron transition is estimated within the relaxation-time approximation. Finally, effects of dissipative phenomena on the relation between initial energy density and final rapidity density are estimated.

Danielewicz, P.; Gyulassy, M.

1985-01-01T23:59:59.000Z

414

Top 10 Algorithms in Data Mining Xindong Wu ( )  

E-Print Network (OSTI)

Learning Theory. Springer-Verlag New York, Inc. ­ #6. EM: McLachlan, G. and Peel, D. (2000). Finite Mixture of Vermont, USA; #12;2 Top 10 Algorithms in Data Mining: Xindong Wu and Vipin Kumar "Top 10 Algorithms.5: Quinlan, J. R. 1993. C4.5: Programs for Machine Learning. Morgan Kaufmann Publishers Inc. ­ #2. CART: L

Wu, Xindong

415

HumanTop: a multi-object tracking tabletop  

Science Journals Connector (OSTI)

In this paper, a computer vision based interactive multi-touch tabletop system called HumanTop is introduced. HumanTop implements a stereo camera vision subsystem which allows ... Keywords: Camera-projector system, Finger detection, Markerless tracking, Multitouch, Tabletop, Technology enhanced learning

Emilio Soto Candela, Mario Ortega Pérez, Clemente Marín Romero, David C. López, Gustavo Salvador Herranz, Manuel Contero, Mariano Alcañiz Raya

2014-06-01T23:59:59.000Z

416

Compositions of Extended Top-down Tree Transducers  

E-Print Network (OSTI)

initil stte q suh tht q@tA n e rewritten to uF st is shown in PH tht synhronized tree sustitution grmmrsCompositions of Extended Top-down Tree Transducers Andreas Maletti£;1 International Computer of transformations computed by linear extended top-down tree trans- ducers with regular look-ahead is not closed

Reyle, Uwe

417

Separation of strangeness from antistrangeness in the phase transition from quark to hadron matter: Possible formation of strange quark matter in heavy-ion collisions  

Science Journals Connector (OSTI)

We present a mechanism for the separation of strangeness from antistrangeness in the deconfinement transition. For a net strangeness of zero in the total system, the population of s quarks is greatly enriched in the quark-gluon plasma, while the s¯ quarks drift into the hadronic phase. This separation could result in ‘‘strangelet’’ formation, i.e., metastable blobs of strange-quark matter, which could serve as a unique signature for quark-gluon plasma formation in heavy-ion collisions.

Carsten Greiner; Peter Koch; Horst Stöcker

1987-05-04T23:59:59.000Z

418

Dark matter-motivated searches for exotic fourth-generation mirror quarks in Tevatron and early LHC data  

SciTech Connect

We determine the prospects for finding dark matter at the Tevatron and LHC through the production of exotic fourth-generation mirror quarks T{sup '} that decay through T{sup '{yields}}tX, where X is dark matter. The resulting signal of tt+Ee{sub T} has not previously been considered in searches for fourth-generation quarks, but there are both general and specific dark matter motivations for this signal, and with slight modifications, this analysis applies to any scenario where invisible particles are produced in association with top quarks. Current direct and indirect bounds on such exotic quarks restrict their masses to be between 300 and 600 GeV, and the dark matter's mass may be anywhere below m{sub T}{sup '}. We simulate the signal and main backgrounds with MadGraph/MadEvent-Pythia-PGS4. For the Tevatron, we find that an integrated luminosity of 20 fb{sup -1} will allow 3{sigma} discovery up to m{sub T}{sup '}=400 GeV and 95% exclusion up to m{sub T}{sup '}=455 GeV. For the 10 TeV LHC with 300 pb{sup -1}, the discovery and exclusion sensitivities rise to 490 GeV and 600 GeV. These scenarios are therefore among the most promising for dark matter at colliders. Perhaps most interestingly, we find that dark matter models that can explain results from the DAMA, CDMS, and CoGeNT collaborations can be tested with high statistical significance using data already collected at the Tevatron and have extraordinarily promising implications for early runs of the LHC.

Alwall, Johan [Department of Physics and National Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Feng, Jonathan L. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Kumar, Jason [Department of Physics and Astronomy, University of Hawaii, Honolulu, Hawaii 96822 (United States); Su Shufang [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2010-06-01T23:59:59.000Z

419

America's Next Top Energy Innovator Challenge | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Science & Innovation » Innovation » America's Next Top Energy Science & Innovation » Innovation » America's Next Top Energy Innovator » America's Next Top Energy Innovator Challenge America's Next Top Energy Innovator Challenge The America's Next Top Energy Innovator Challenge, a part of the Startup America initiative, made it easier for start-ups to use inventions and technology developed at the U.S. Department of Energy's 17 National Laboratories and the Y-12 National Security Complex. The companies highlighted below signed option agreements allowing them to license valuable, cutting-edge technologies from one of the labs. You can see the winners of the 2012 competition here. We counted your 'likes' and then left it up to the panel of experts to evaluate which three of these companies are selected to attend the 2012

420

Top-secret super-secure vault declassified  

NLE Websites -- All DOE Office Websites (Extended Search)

Top-secret super-secure vault declassified Top-secret super-secure vault declassified Top-secret super-secure vault declassified Located in Los Alamos canyon at Technical Area 41, the Tunnel Vault was built between 1948 and 1949. July 23, 2013 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Contact Kevin Roark Communications Office

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
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421

WIPP Receives Top Safety Award | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Top Safety Award Top Safety Award WIPP Receives Top Safety Award November 9, 2011 - 12:00pm Addthis Media Contact Deb Gill www.wipp.energy.gov 575-234-7270 CARLSBAD, N.M. - The U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) received top accolades from New Mexico's leading mining organizations. The New Mexico Bureau of Mine Safety (BMS) recently recognized URS Washington TRU Solutions (WTS), LLC, the WIPP management and operating contractor, for receiving the New Mexico Mining Association (NMMA) and New Mexico BMS Safe Operator of the Year Award. "I'm pleased to congratulate Washington TRU Solutions and the WIPP workforce for receiving the state's top mine safety award for 23 of the past 25 years," said Ed Ziemianski, Carlsbad Field Office Interim

422

WIPP Receives Top Safety Award | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

WIPP Receives Top Safety Award WIPP Receives Top Safety Award WIPP Receives Top Safety Award November 9, 2011 - 12:00pm Addthis Media Contact Deb Gill www.wipp.energy.gov 575-234-7270 CARLSBAD, N.M. - The U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) received top accolades from New Mexico's leading mining organizations. The New Mexico Bureau of Mine Safety (BMS) recently recognized URS Washington TRU Solutions (WTS), LLC, the WIPP management and operating contractor, for receiving the New Mexico Mining Association (NMMA) and New Mexico BMS Safe Operator of the Year Award. "I'm pleased to congratulate Washington TRU Solutions and the WIPP workforce for receiving the state's top mine safety award for 23 of the past 25 years," said Ed Ziemianski, Carlsbad Field Office Interim

423

Secretary Chu Recognizes America's Next Top Energy Innovators | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Recognizes America's Next Top Energy Innovators Recognizes America's Next Top Energy Innovators Secretary Chu Recognizes America's Next Top Energy Innovators February 27, 2012 - 5:48pm Addthis Andrew Heidloff, representing start-up company Iowa Powder Atomization Technologies, is one of America's Next Top Innovators. Secretary Chu announced the winners of the competition today at the 2012 ARPA-E Energy Innovation Summit. | Photo courtesy of ARPA-e contractor Dave Meyer. Andrew Heidloff, representing start-up company Iowa Powder Atomization Technologies, is one of America's Next Top Innovators. Secretary Chu announced the winners of the competition today at the 2012 ARPA-E Energy Innovation Summit. | Photo courtesy of ARPA-e contractor Dave Meyer. April Saylor April Saylor Former Digital Outreach Strategist, Office of Public Affairs

424

Help Choose America's Next Top Energy Innovator | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Help Choose America's Next Top Energy Innovator Help Choose America's Next Top Energy Innovator Help Choose America's Next Top Energy Innovator January 26, 2012 - 9:00am Addthis The America’s Next Top Energy Innovator Challenge, a part of the Startup America initiative, makes it easier for start-ups to use inventions and technologies developed at the U.S. Department of Energy’s 17 National Laboratories and the Y-12 National Security Complex. | Photo courtesy of National Renewable Energy Laboratory. The America's Next Top Energy Innovator Challenge, a part of the Startup America initiative, makes it easier for start-ups to use inventions and technologies developed at the U.S. Department of Energy's 17 National Laboratories and the Y-12 National Security Complex. | Photo courtesy of National Renewable Energy Laboratory.

425

KCP hosts top STEM educators to develop curriculum | National Nuclear  

National Nuclear Security Administration (NNSA)

hosts top STEM educators to develop curriculum | National Nuclear hosts top STEM educators to develop curriculum | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > NNSA Blog > KCP hosts top STEM educators to develop ... KCP hosts top STEM educators to develop curriculum Posted By Office of Public Affairs NNSA Blog The Kansas City Plant recently hosted top STEM educators from Historically

426

America Chooses the Next Top Energy Innovator | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

America Chooses the Next Top Energy Innovator America Chooses the Next Top Energy Innovator America Chooses the Next Top Energy Innovator February 10, 2012 - 1:00pm Addthis The America’s Next Top Energy Innovator Challenge makes inventions and technologies developed at the U.S. Department of Energy’s 17 National Laboratories and the Y-12 National Security Complex available to innovative startups. | Photo courtesy of Lawrence Berkeley National Laboratory. The America's Next Top Energy Innovator Challenge makes inventions and technologies developed at the U.S. Department of Energy's 17 National Laboratories and the Y-12 National Security Complex available to innovative startups. | Photo courtesy of Lawrence Berkeley National Laboratory. Michael Hess Michael Hess Former Digital Communications Specialist, Office of Public Affairs

427

Screening of quark-monopole in N=4 plasma  

E-Print Network (OSTI)

We study a quark-monopole bound system moving in N=4 SYM plasma with a constant velocity by the AdS/CFT correspondence. The screening length of this system is calculated, and is smaller than that of the quark-antiquark bound state.

Wei-shui Xu; Ding-fang Zeng

2014-09-08T23:59:59.000Z

428

Heavy quark impact factor for the LHC phenomenology  

E-Print Network (OSTI)

We comment on the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic (NLx) accuracy. The result is presented in a form suitable for phenomenological studies such as the calculation of the cross-section for single heavy quark production at the LHC within the kT-factorization scheme.

Grigorios Chachamis; Michal Deak; German Rodrigo

2013-10-29T23:59:59.000Z

429

Diquark condensation effects on hot quark star configurations  

E-Print Network (OSTI)

The equation of state for quark matter is derived for a nonlocal, chiral quark model within the mean field approximation. We investigate the effects of a variation of the form factors of the interaction on the phase diagram of quark matter under the condition of beta-equilibrium and charge neutrality. Special emphasis is on the occurrence of a diquark condensate which signals a phase transition to color superconductivity and its effects on the equation of state. We calculate the quark star configurations by solving the Tolman- Oppenheimer- Volkoff equations and obtain for the transition from a hot, normal quark matter core of a protoneutron star to a cool diquark condensed one a release of binding energy of the order of Delta M c^2 ~ 10^{53} erg. We discuss the claim that this energy could serve as an engine for explosive phenomena.

Blaschke, David B; Grigorian, H

2004-01-01T23:59:59.000Z

430

Alcances Constitucionales del Royalty.  

E-Print Network (OSTI)

??La discusión acerca del royalty al cobre genera distintas sensibilidades, a favor y en contra de este derecho, básicamente por considerarlo, algunos, como un tributo… (more)

Graig Palacios, Claudia

2006-01-01T23:59:59.000Z

431

The influence of quark energy loss on extracting nuclear sea quark distribution from nuclear Drell-Yan experimental data  

E-Print Network (OSTI)

By means of two typical kinds of quark energy loss parametrization and the nuclear parton distributions determined only with lepton-nuclear deep inelastic scattering experimental data, a leading order analysis are performed on the proton-induced Drell-Yan differential cross section ratios of tungsten versus deuterium as a function of the quark momentum fraction in the beam proton and target nuclei. It is found that the theoretical results with quark energy loss are in good agreement with the experimental data. The quark energy loss effect produce approximately 3% to 11% suppression on the Drell-Yan differential cross section ratios $R_{W/D}$ in the range $0.05\\leq x_2\\leq0.3$. The application of nuclear Drell-Yan data with heavy targets is remarkably subject to difficulty in the constraints of the nuclear sea-quark distribution.

Duan Chun-Gui; Liu Na

2008-09-28T23:59:59.000Z

432

modelado y analisis del transporte del herbicida glifosato en una ...  

E-Print Network (OSTI)

(2) Departamento de Ingeniería del Terreno, Universidad Politécnica de Cataluña ... fenómeno dependerá de la composición físico-química del suelo, en

2001-03-12T23:59:59.000Z

433

TopTen Energy Efficient Products Website | Open Energy Information  

Open Energy Info (EERE)

TopTen Energy Efficient Products Website TopTen Energy Efficient Products Website Jump to: navigation, search Tool Summary LAUNCH TOOL Name: TopTen Energy Efficient Products Website Focus Area: Energy Efficiency Topics: Market Analysis Website: www.topten.info/ Equivalent URI: cleanenergysolutions.org/content/topten-energy-efficient-products-webs Language: English Policies: "Deployment Programs,Regulations" is not in the list of possible values (Deployment Programs, Financial Incentives, Regulations) for this property. DeploymentPrograms: Industry Codes & Standards Regulations: Appliance & Equipment Standards and Required Labeling This Web portal intends to: 1) guide consumers to the most energy efficient products in Europe, China, and the United States; 2) provide policy

434

Search for New Physics in Rare Top Decays  

E-Print Network (OSTI)

Top physics provides a fertile ground for new-physics searches. At present, most top observables appear to be in good agreement with the respective Standard Model predictions. However, in the case of decay modes that are suppressed in the Standard Model, new-physics contributions of comparable magnitude may exist and yet go unnoticed because their impact on the total decay width is small. Hence it is interesting to probe rare top decays. This analysis focuses on the decay $t \\to b \\bar b c$. Useful observables are identified and prospects for measuring new-physics parameters are examined.

Pratishruti Saha

2014-11-27T23:59:59.000Z

435

Fluctuating Heavy Quark Energy Loss in Strongly-Coupled Quark-Gluon Plasma  

E-Print Network (OSTI)

Results from an energy loss model that includes thermal fluctuations in the energy loss for heavy quarks in a strongly-coupled plasma are shown to be qualitatively consistent with single particle data from both RHIC and LHC. The model used is the first to properly include the fluctuations in heavy quark energy loss as derived in string theory and that do not obey the usual fluctuation-dissipation relations. These fluctuations are crucial for simultaneously describing both RHIC and LHC data; leading order drag results without fluctuations are falsified by current data. Including the fluctuations is non-trivial and relies on the Wong-Zakai theorem to fix the numerical Langevin implementation. The fluctuations lead to surprising results: B meson anisotropy is similar to that for D mesons at LHC, and the double ratio of D to B meson nuclear modification factors approaches unity more rapidly than even predictions from perturbative energy loss models. It is clear that future work in improving heavy quark energy los...

Horowitz, W A

2015-01-01T23:59:59.000Z

436

Combined search for the quarks of a sequential fourth generation  

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5??fb?1 recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about ±20??GeV . These results significantly reduce the allowed parameter space for a fourth generation of fermions.

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D’Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Thomas, L.; Vander Marcken, G.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins Junior, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Tomei, T.R. Fernandez Perez; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, S.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zhu, B.; Zou, W.; Avila, C.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Khalil, S.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Anagnostou, G.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.; Jussen, R.; Klein, K.

2012-12-01T23:59:59.000Z

437

Combined search for the quarks of a sequential fourth generation  

E-Print Network (OSTI)

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up- and down-type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant CKM matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. This result significantly reduces the allowed parameter space for a fourt...

Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Aguilo, Ernest; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hammer, Josef; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rahbaran, Babak; Rohringer, Christine; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Waltenberger, Wolfgang; Walzel, Gerhard; Widl, Edmund; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Luyckx, Sten; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Staykova, Zlatka; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Michael; Olbrechts, Annik; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hreus, Tomas; Léonard, Alexandre; Marage, Pierre Edouard; Mohammadi, Abdollah; Reis, Thomas; Thomas, Laurent; Vander Marcken, Gil; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Cimmino, Anna; Costantini, Silvia; Garcia, Guillaume; Grunewald, Martin; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Verwilligen, Piet; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Castello, Roberto; Ceard, Ludivine; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Schul, Nicolas; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; De Jesus Damiao, Dilson; Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Custódio, Analu; Da Costa, Eliza Melo; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Oguri, Vitor; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Soares Jorge, Luana; Sznajder, Andre; Souza Dos Anjos, Tiago; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Da Cunha Marinho, Franciole; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vutova, Mariana; Dimitrov, Anton; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xiao, Hong; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Shuang; Guo, Yifei; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Wang, Dayong; Zhang, Linlin; Zhu, Bo; Zou, Wei; Avila, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Luetic, Jelena; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Ellithi Kamel, Ali; Khalil, Shaaban; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Karjalainen, Ahti; Korpela, Arja; Tuuva, Tuure; Besancon, Marc; Choudhury, Somnath

2012-01-01T23:59:59.000Z

438

Four-Quark Hadrons: an Updated Review  

E-Print Network (OSTI)

The past decade witnessed a remarkable proliferation of exotic charmonium-like resonances discovered at accelerators. In particular, the recently observed charged states are clearly not interpretable as q-qbar mesons. Notwithstanding the considerable advances on the experimental side, conflicting theoretical descriptions do not seem to provide a definitive picture about the nature of the so-called XYZ particles. We present here a comprehensive review about this intriguing topic, discussing both those experimental and theoretical aspects which we consider relevant to make further progress in the field. At this state of progress, XYZ phenomenology speaks in favour of the existence of compact four-quark particles (tetraquarks) and we believe that realizing this instructs us in the quest for a firm theoretical framework.

Angelo Esposito; Andrea L. Guerrieri; Fulvio Piccinini; Alessandro Pilloni; Antonio D. Polosa

2014-12-29T23:59:59.000Z

439

Four-Quark Hadrons: an Updated Review  

E-Print Network (OSTI)

The past decade witnessed a remarkable proliferation of exotic charmonium-like resonances discovered at accelerators. In particular, the recently observed charged states are clearly not interpretable as q-qbar mesons. Notwithstanding the considerable advances on the experimental side, conflicting theoretical descriptions do not seem to provide a definitive picture about the nature of the so-called XYZ particles. We present here a comprehensive review about this intriguing topic, discussing both those experimental and theoretical aspects which we consider relevant to make further progress in the field. At this state of progress, XYZ phenomenology speaks in favour of the existence of compact four-quark particles (tetraquarks) and we believe that realizing this instructs us in the quest for a firm theoretical framework.

Esposito, Angelo; Piccinini, Fulvio; Pilloni, Alessandro; Polosa, Antonio D

2014-01-01T23:59:59.000Z

440

Congeniality bounds on quark masses from nucleosynthesis  

Science Journals Connector (OSTI)

The work of Jaffe, Jenkins and Kimchi [Phys. Rev. D 79, 065014 (2009)] is revisited to see if indeed the region of congeniality found in their analysis survives further restrictions from nucleosynthesis. It is observed that much of their congenial region disappears when imposing conditions required to produce the correct and required abundances of the primordial elements as well as ensure that stars can continue to burn hydrogen nuclei to form helium as the first step in forming heavier elements in stellar nucleosynthesis. The remaining region is a very narrow slit reduced in width from around 29 MeV found by Jaffe et al. to only about 2.2 MeV in the difference of the nucleon/quark masses. Further bounds on ?mq/mq seem to reduce even this narrow slit to the physical point itself.

M. Hossain Ali; M. Jakir Hossain; Abdullah Shams Bin Tariq

2013-08-02T23:59:59.000Z

Note: This page contains sample records for the topic "del quark top" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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441

Joint resummation for heavy quark production.  

E-Print Network (OSTI)

ar X iv :h ep -p h/ 05 10 14 9v 1 1 2 O ct 2 00 5 February 2, 2008 4:14 WSPC/INSTRUCTION FILE jr International Journal of Modern Physics A c© World Scientific Publishing Company JOINT RESUMMATION FOR HEAVY QUARK PRODUCTION ANDREA BANFI Cavendish... to corrections O(1/p2T ), the observable may at any order 12 be written in the following factorized form d?AB?Q+X dpT = ? a,b ? 1 0 d?ad?b ?a/A(?a, µ)?b/B(?b, µ) d?ˆab?Q+X dpT (?a, ?b, ?s(µ), pT ) , (1) with d?ˆab?Q+X/dpT the partonic differential cross...

Banfi, Andrea; Laenen, Eric

442

Quark contact interactions at the LHC  

Science Journals Connector (OSTI)

Quark contact interactions are an important signal of new physics. We introduce a model in which the presence of a symmetry protects these new interactions from giving large corrections in flavor changing processes at low energies. This minimal model provides the basic set of operators which must be considered to contribute to the high-energy processes. To discuss their experimental signature in jet pairs produced in proton-proton collisions, we simplify the number of possible operators down to two. We show (for a representative integrated luminosity of 200??pb-1 at s=7??TeV) how the presence of two operators significantly modifies the bound on the characteristic energy scale of the contact interactions, which is obtained by keeping a single operator.

F. Bazzocchi; U. De Sanctis; M. Fabbrichesi; A. Tonero

2012-06-01T23:59:59.000Z

443

The sigma term and the quark number operator in QCD  

E-Print Network (OSTI)

We discuss the relationship of the forward matrix element of the operator $\\bar\\psi\\psi$, related to the so-called sigma term, to the quark number. We show that in the naive quark model in the canonical formalism these quantities coincide in the limit of small average quark momenta. In the QCD parton model defined through light-front quantization this result is preserved at leading perturbative order but it receives radiative corrections. We analyze the theoretical and phenomenological consequences of this result, which provides a bridge between a current algebra quantity, the sigma term, and a deep-inelastic quantity, the parton number.

Mauro Anselmino; Stefano Forte

1993-05-03T23:59:59.000Z

444

Heavy-quark correlations in deep-inelastic electroproduction  

E-Print Network (OSTI)

We have completed the next-to-leading order perturbative QCD corrections to the virtual-photon exclusive differential cross sections for heavy quark production in deep-inelastic electron-proton scattering, i.e. $e + P \\rightarrow Q + \\overline{Q} + X$. Using these results, we have computed distributions which are sensitive to correlations among the heavy quark, the heavy antiquark, and the associated jet. Some predictions for charm and bottom heavy quark production at the electron-proton collider HERA are presented.

B. W. Harris; J. Smith

1995-03-31T23:59:59.000Z

445

Nucleosynthesis in neutron-rich ejecta from quark-novae  

E-Print Network (OSTI)

We explore heavy-element nucleosynthesis by rapid neutron capture (r-process) in the decompressing ejecta from the surface of a neutron star. The decompression is triggered by a violent phase transition to strange quark matter (quark-nova scenario). The presence of neutron-rich large Z nuclei (40,95) solar abundance pattern of r-process elements. We highlight the distinguishing features of quark-novae by contrasting it with conventional nucleosynthetic sites such as type II supernovae and neutron star mergers, especially in the context of heavy-element compositions of extremely metal-deficient stars.

Prashanth Jaikumar; Bradley S. Meyer; Kaori Otsuki; Rachid Ouyed

2006-10-04T23:59:59.000Z

446

NNSA Production Office tops Feds Feed Families campaign goal | National  

NLE Websites -- All DOE Office Websites (Extended Search)

Production Office tops Feds Feed Families campaign goal | National Production Office tops Feds Feed Families campaign goal | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > NNSA Blog > NNSA Production Office tops Feds Feed Families ... NNSA Production Office tops Feds Feed Families campaign goal Posted By Office of Public Affairs Employees of the NNSA Production Office (NPO) have donated 17,348 pounds of

447

The 'America's Next Top Energy Innovator' Challenge Begins Today |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The 'America's Next Top Energy Innovator' Challenge Begins Today The 'America's Next Top Energy Innovator' Challenge Begins Today The 'America's Next Top Energy Innovator' Challenge Begins Today May 2, 2011 - 12:02pm Addthis Lasers used for photovoltaic research in one of SERI's PV labs. | Photo courtesy of the National Renewable Energy Laboratory Lasers used for photovoltaic research in one of SERI's PV labs. | Photo courtesy of the National Renewable Energy Laboratory Ginny Simmons Ginny Simmons Former Managing Editor for Energy.gov, Office of Public Affairs What does this mean for me? The Energy Department's 17 national laboratories currently hold more than 15,000 patents. As part of 'America's Next Top Energy Innovator' challenge, companies can obtain up to three patents from a single lab for $1,000. In a year, the Energy Department will showcase the start-up

448

Military students access top R&D  

NLE Websites -- All DOE Office Websites (Extended Search)

Military students access top R&D Military students access top R&D Military students access top R&D Cadets and midshipmen spend summer expanding their scientific knowledge at world-class Los Alamos facilities August 27, 2013 Military students access top R&D Micah Dose, a midshipman at the U.S. Naval Academy and a SARA intern in the Laboratory's ARIES program, peers inside the glovebox where plutonium pits are dis-assembled at Los Alamos. ARIES is the only program in the nation that disassembles and destroys surplus plutonium pits. The pits are transformed into plutonium oxide powder suitable for being made into fuel for civilian nuclear reactors. "There are a lot of summer training programs out there, but most are class-like," said U.S. Air Force cadet Dale Becker, mentored by the Physics

449

PPPL earns top EPA award | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

PPPL earns top EPA award By Jeanne Jackson DeVoe March 14, 2013 Tweet Widget Google Plus One Share on Facebook The demolition and sale of the C-Site motor generators yielded over 4...

450

Ducts in Conditioned Space - Building America Top Innovation...  

Energy Savers (EERE)

moving ductwork into conditioned space in the hot-dry climate zone saved 8% to 15% on air-conditioning costs for homeowners. For this Top Innovation profile, Building America...

451

High-Efficiency Window Air Conditioners- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

This Top Innovation profile highlights research into making window air conditioners much more energy efficient, and recommendations for homeowners about how to improve the operating efficiency of their units.

452

HVAC Cabinet Air Leakage Test Method- Building America Top Innovation  

Energy.gov (U.S. Department of Energy (DOE))

This 2014 Top Innovation describes Building America research that resulted in the development of an ASHRAE standard and standardized testing method for testing the air leakage of HVAC air handlers and furnace cabinets.

453

NREL: News Feature - Solar System Tops Off Efficient NREL Building  

NLE Websites -- All DOE Office Websites (Extended Search)

Solar System Tops Off Efficient NREL Building September 29, 2010 Photo of the sun reflecting off of a solar panel on a roof. Enlarge image More than 1,800 solar panels are being...

454

New Physics in Top Events at the LHC  

Science Journals Connector (OSTI)

It is widely believed now that new physics beyond the Standard Model (SM) will appear at the electroweak scale. In almost all models of electroweak symmetry breaking, top either couples strongly to new particl...

Marina Cobal-Grassmann

2007-01-01T23:59:59.000Z

455

CDF/TOP/DOC/6548 Version 1.1  

E-Print Network (OSTI)

, muons and the amount of missing transverse energy. In order to pick up certain calorimeter and tracking T electron and muon data sam- ples which will be used for Top group analysis results for Summer 2003-cdf.fnal.gov/internal/physics/top/topdata/newtopdata.html 1 Introduction The Level 3 trigger data-sets for high p T electrons and muons have identi#12;ers

456

Measurement of the top - anti-top Production Cross Section at s**(/1/2) = 1.96-TeV in the e + jets Final State of proton anti-proton Collisions at the Tevatron  

SciTech Connect

We discuss the measurement of the cross section for t{bar t} production in p{bar p} collisions at {radical}s = 1.96 TeV in e+jets final states observed at the D0 experiment at the Fermilab Tevatron. Our result is based on data collected from the June 2002 to September 2003 period of Run II of the p{bar p} Collider. In the Standard Model, the top quark is expected to decay mainly into a W boson and a b quark. The W boson can decay subsequently into a lepton and its neutrino or a q{bar q} quark-antiquark pair. In this thesis, we focus on the e{sup +} {nu}{sub e} or e{sup -} {bar {nu}}{sub e} decays of one of the W bosons and the q{bar q} decays of the other W boson in t{bar t} final states. The b, q and q' quarks appear as jets of particles in the detector, thereby defining the e+jets final state. We present two methods used for performing this measurement. The first method is based on a Random Grid Search (RGS) that minimizes the uncertainty on the extracted cross section. The variables used in the search take advantage of differences between expected background and signal processes to obtain the yield of t{bar t} events. The second method uses a Neural Network (NN) procedure that discriminates signal from background through the application of a NN trained on simulated t{bar t} signal and W+jets background events. The preliminary results presented in this thesis for inclusive t{bar t} production are {sigma}{sub p{bar p} {yields} t{bar t} + x} of 7.9{sub -2.4}{sup +2.6}(stat) {sub -2.3}{sup +2.2}(syst) {+-} 0.5 (L) pb for the NN analysis, where the uncertainties correspond to contributions from statistical and systematic sources and from the uncertainty on luminosity. Our measurements are consistent with each other, and are within error of the value of 6.77 {+-} 0.42 pb expected in the Standard Model.

Cho, DooKee; /Rochester U.; ,

2005-02-01T23:59:59.000Z

457

The Particle Adventure | What is the world made of? | The naming of quarks  

NLE Websites -- All DOE Office Websites (Extended Search)

The naming of quarks The naming of quarks The naming of quarks The naming of quarks... ...began when, in 1964, Murray Gell-Mann and George Zweig suggested that hundreds of the particles known at the time could be explained as combinations of just three fundamental particles. Gell-Mann chose the name "quarks," pronounced "kworks," for these three particles, a nonsense word used by James Joyce in the novel Finnegan's Wake: "Three quarks for Muster Mark!" In order to make their calculations work, the quarks had to be assigned fractional electrical charges of 2/3 and -1/3. Such charges had never been observed before. Quarks are never observed by themselves, and so initially these quarks were regarded as mathematical fiction. Experiments have since convinced physicists that not only do quarks exist, but there are six of them, not three.

458

Quarkonium mass splittings with Fermilab heavy quarks and 2+1 flavors of improved staggered sea quarks  

E-Print Network (OSTI)

We present results from an ongoing lattice study of the lowest lying charmonium and bottomonium level splittings using the Fermilab heavy quark formalism. Our objective is to test the performance of this action on MILC-collaboration ensembles of (2+1) flavors of light improved staggered (asqtad) quarks. Measurements are done on 16 ensembles with degenerate up and down quarks of various masses, thus permitting a chiral extrapolation, and over lattice spacings ranging from 0.09 fm to 0.18 fm, thus permitting study of lattice-spacing dependence. We examine combinations of the mass splittings that are sensitive to components of the effective quarkonium potential.

T. Burch; C. E. DeTar; M. Di Pierro; A. X. El-Khadra; Steven Gottlieb; A. S. Kronfeld; L. Levkova; P. B. Mackenzie; J. Simone

2009-11-02T23:59:59.000Z

459

Reading Comprehension - Looking for Quarks Inside the Atom  

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Looking for Quarks Inside the Atom Looking for Quarks Inside the Atom In the late 1960's, three scientists ran some accelerator experiments to study the nucleus at the _________ outside edge center perimeter of the atom. They ran the experiments because they wanted to know more about the structure of the _________ nucleus accelerator electromagnet spectrometer . They found that the protons and neutrons in the nucleus are made of quarks. The discovery of _________ alpha quarks nuclei electron raised new questions about the nucleus. The three scientists are Richard Taylor, Henry Kendall and Jerome Friedman. They did their experiments from 1967 to 1973 in California at the Stanford Linear Accelerator Center, called SLAC for short. These scientists won the 1990 Nobel Prize in Physics, one of the world's greatest honors for