Clement, Christian
2011-01-01T23:59:59.000Z
Apokalyptik gelten kann, so tritt eine tiefgreifende innereund Natürlichen hinter sich und tritt in eine Sphäre des
Wissenschaftliches Netzwerk Sozialfrsorge und Gesundheit in Ost-und Sdosteuropa
Schubart, Christoph
, Forschungsassistentin Universität Wien / Österreich und Oberassistentin Andrássy Universität Budapest / Ungarn · Dr
Musik mit Bremstrommel und Mnzen im Klavier Gttingen. Pfeifgerusche, das
Wardetzky, Max
(,,Heul doch") und James Brown, Björn hört Apollo 3, und Jasmin und Svenja haben ein Faible für Lady Gaga. bar Lafee und Lady Gaga Svenja Björn Jasmin G
TUM Berufungs-und Karrieresystem
Heiz, Ulrich
folgende Statut zum QualitÃ¤tsmanagement des neu- en TUM Berufungs- und Karrieresystems tritt mit Wirkung
8 2. Helium und Tritium in der Geosphre 2. Helium und Tritium in der Geosphre
Aeschbach-Hertig, Werner
8 2. Helium und Tritium in der Geosphäre 2. Helium und Tritium in der Geosphäre 2.1. Spezielle Einheiten und Konstanten An dieser Stelle sollen die speziellen für Helium und Tritium verwendeten Einheiten definiert und dazugehörige Umrechnungen angegeben werden. Die Wahl der Werte einiger für Helium und Tritium
Institut fr Medizinische Mikrobiologie, Virologie und Hygiene
Lübeck, Universität zu
Institut für Medizinische Mikrobiologie, Virologie und Hygiene Forschungsgruppe Virologie Das Institut für Medizinische Mikrobiologie, Virologie und Hygiene an den Universitätskliniken Hamburg
MHH Forschungsbericht 2004582 Abteilung Medizinische Mikrobiologie und
Manstein, Dietmar J.
-Wirtsinteraktionen in den Modellsystemen der chronischen Helicobacter pylori- und Helicobacter hepaticus-Infektion. Prof. Dr
BERATER UND UNTERSCHRIFTSBEFUGTE ANERKENNUNG (BZGL. PRAKTIKUMSVEREINBARUNG)
Schüler, Axel
-Siegmund Institut für Psychologie Prof. Dr. Evelin Witruk CHEMIE UND MINERALOGIE Prof. Dr. Reinhard Denecke denecke
Paderborn, Universität
Universität Paderborn Leistungselektronik und Elektrische Antriebstechnik, Prof. Dr. Joachim Böcker -1- Mechatronik und elektrische Antriebe A Beispiele für mechatronische Systeme #12;Universität Paderborn Leistungselektronik und Elektrische Antriebstechnik, Prof. Dr. Joachim Böcker -2- Nicht
Knuth, T
2000-01-01T23:59:59.000Z
Auslegung, Entwicklung und Inbetriebnahme eines longitudinalen und transversalen Feedbacksystems zur Dämpfung gekoppelter Teilchenpaket-Instabilitäten im BESSY-II-Speicherring
Putty und clay Funktionen in Produktion und Finanzen Eine Einfhrung in die Makro-konophysik
Mimkes, Jürgen
Putty und clay Funktionen in Produktion und Finanzen Eine Einführung in die Makro Funktionen als putty oder clay. Putty bedeutet Kitt, der erst weich ist und dann fest wird. Eine putty Jahresende (ex post) ist es fixiert. Clay bedeutet Ton. Eine (gebrannte) Tonschale ist anfangs fest und auch
Villafranca Die Kabinete und die Revolutionen.
Prodinger, Helmut
bucklige Bursche, und lobte mich, daß ich Soldat werden wollte. Er sagte, den Soldaten allein gehöre die
Erich W. Varnes
2008-10-20T23:59:59.000Z
A review is presented of the current experimental status of the top quark sector of the standard model. The measurements summarized include searches for electroweak single top production, the latest results on the ttbar production cross section, and searches for new physics in top quark production and decay. In addition, the recent measurement of the top quark mass to a precision of 0.7% is highlighted
Quark Condensates: Flavour Dependence
R. Williams; C. S. Fischer; M. R. Pennington
2007-03-23T23:59:59.000Z
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.
Eric Laenen
2008-09-18T23:59:59.000Z
I review how the top quark is embedded in the Standard Model and some its proposed extensions, and how it manifests itself in various hadron collider signals.
Christian Schwanenberger
2010-04-28T23:59:59.000Z
Highlights of top quark physics presented at the 2009 Europhysics Conference on High Energy Physics from 16-22 July 2009 in Krakow, Poland, are reviewed.
Georg Faustus – Leben und Legende
Baron, Frank
2009-01-01T23:59:59.000Z
. T h e p u b lis h er v er si o n is a va ila b le o n it s si te . [This document contains the author’s accepted manuscript, in both German and English. For the publisher’s version, see the link in the header of this document.] Paper... begann sein Studium 1483 an der Universität Heidelberg und erlangte rasch akademische Grade als Bakkalaureus 1484 und als Magister der Philosophie 1487. Im Alter von 21 Jahren, dem Mindestalter für den Magisterabschluss, vollbrachte er eine für seine...
Quantum chromodynamics quark benzene
Jialun Ping; Chengrong Deng; Fan Wang; T. Goldman
2007-11-28T23:59:59.000Z
A six-quark state with the benzene-like structure is proposed and studied based on color string model. The calculation with the quadratic confinement show that such structure has the lowest energy among the various hidden color six-quark structures proposed so far. Its possible effect on $NN$ scattering is discussed.
Quark Number Susceptibility with Finite Quark Mass in Holographic QCD
Kyung-il Kim; Youngman Kim; Shingo Takeuchi; Takuya Tsukioka
2011-10-31T23:59:59.000Z
We study the effect of a finite quark mass on the quark number susceptibility in the framework of holographic QCD. We work in a bottom-up model with a deformed AdS black hole and D3/D7 model to calculate the quark number susceptibility at finite temperature with/without a finite quark chemical potential. As expected the finite quark mass suppresses the quark number susceptibility. We find that at high temperatures $T\\ge 600$ MeV the quark number susceptibility of light quarks and heavy quarks are almost equal in the bottom-up model. This indicates that the heavy quark like charm contribution to thermodynamics of a QCD-like system may start to become significant at temperatures $T\\sim 600$ MeV. In D3/D7 model, we focus on the competition between the quark chemical potential, which enhances the quark number susceptibility, and the quark mass that suppresses the susceptibility. We observe that depending on the relative values of the quark mass and the quark chemical potential, the quark number susceptibility shows a diverging or converging behavior. We also calculate the chiral susceptibility in D3/D7 model to support the observation made with the quark number susceptibility.
Peters, Yvonne
2011-12-01T23:59:59.000Z
Since its discovery in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, the top quark has undergone intensive studies. Besides the Tevatron experiments, with the start of the LHC in 2010 a top quark factory started its operation. It is now possible to measure top quark properties simultaneously at four different experiments, namely ATLAS and CMS at LHC and CDF and D0 at Tevatron. Having collected thousands of top quarks each, several top quark properties have been measured precisely, while others are being measured for the first time. In this article, recent measurements of top quark properties from ATLAS, CDF, CMS and D0 are presented, using up to 5.4 fb{sup -1} of integrated luminosity at the Tevatron and 1.1 fb{sup -1} at the LHC. In particular, measurements of the top quark mass, mass difference, foward backward charge asymmetry, t{bar t} spin correlations, the ratio of branching fractions, W helicity, anomalous couplings, color flow and the search for flavor changing neutral currents are discussed.
Yvonne Peters; for the Atlas Collaboration; CDF Collaboration; CMS Collaboration; D0 Collaboration
2011-12-02T23:59:59.000Z
Since its discovery in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, the top quark has undergone intensive studies. Besides the Tevatron experiments, with the start of the LHC in 2010 a top quark factory started its operation. It is now possible to measure top quark properties simultaneously at four different experiments, namely ATLAS and CMS at LHC and CDF and D0 at Tevatron. Having collected thousands of top quarks each, several top quark properties have been measured precisely, while others are being measured for the first time. In this article, recent measurements of top quark properties from ATLAS, CDF, CMS and D0 are presented, using up to 5.4 fb-1 of integrated luminosity at the Tevatron and 1.1 fb^-1 at the LHC. In particular, measurements of the top quark mass, mass difference, forward backward charge asymmetry, tt - spin correlations, the ratio of branching fractions, W helicity, anomalous couplings, color flow and the search for flavor changing neutral currents are discussed.
Institut fr Energie-und Automatisierungstechnik FG Elektronische Mess-und Diagnosetechnik
Wichmann, Felix
,,Thermoeletrische Generatoren 2020" (TEG 2020) wird die Entwicklung modularer, leistungsstarker und flexibel einsetzbarer thermoelektrischer Genera- toren (TEG) zur elektrischen Rückgewinnung in Verbrennungsmaschinen und -anlagen angestrebt. Bei TEG handelt es sich um die direkte Wandlung von thermischer in elektrischer
Institut fr Energie-und Automatisierungstechnik FG Elektronische Mess-und Diagnosetechnik
Wichmann, Felix
- Foschungsprojekt ,,Thermoeletrische Generatoren 2020" (TEG 2020) wird die Entwicklung modularer, leistungsstarker und flexibel einsetzbarer thermoelektrischer Genera- toren (TEG) zur elektrischen Rückgewinnung in Verbrennungsmaschinen und -anlagen angestrebt. Bei TEG handelt es sich um die direkte Wandlung von thermischer
Efe Yazgan; for the CMS Collaboration
2014-09-12T23:59:59.000Z
Measurements involving top quarks provide important tests of QCD. A selected set of top quark measurements in CMS including the strong coupling constant, top quark pole mass, constraints on parton distribution functions, top quark pair differential cross sections, ttbar+0 and >0 jet events, top quark mass studied using various kinematic variables in different phase-space regions, and alternative top quark mass measurements is presented. The evolution of expected uncertainties in future LHC runs for the standard and alternative top quark mass measurements is also presented.
Hammerton, James
Unternehmen und Social Media wie passt das zusammen? Dr. Alexander Stocker, Key Researcher, DIGITAL Institut für Informations und Kommunikationstechnologien, JOANNEUM RESEARCH. DI Harald Mayer, Head of Intelligent Information Systems Group, DIGITAL Institut für Informations und
aus naturwissenschaften und: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Speziell werden vier Probleme behandelt. Zur Vorbereitung auf (more) Richstein, Jrg 1999-01-01 12 Geschichte und transtextuelle Anspielungen auf Mythen und kanonisierte...
Tony M. Liss
2012-12-03T23:59:59.000Z
I review the latest results on properties of the top quark from the Tevatron and the LHC, including results measured in $t\\bar{t}$ and single-top events on the mass, width, couplings, and spin correlations.
Hill, Christopher S.; /UC, Santa Barbara
2004-12-01T23:59:59.000Z
The top quark, with its extraordinarily large mass (nearly that of a gold atom), plays a significant role in the phenomenology of EWSB in the Standard Model. In particular, the top quark mass when combined with the W mass constrains the mass of the as yet unobserved Higgs boson. Thus, a precise determination of the mass of the top quark is a principal goal of the CDF and D0 experiments. With the data collected thus far in Runs 1 and 2 of the Tevatron, CDF and D0 have measured the top quark mass in both the lepton+jets and dilepton decay channels using a variety of complementary experimental techniques. The author presents an overview of the most recent of the measurements.
Heidi Schellman and Ann Heinson
2009-03-12T23:59:59.000Z
Fermilab researchers Heidi Schellman and Ann Heinson take a whimsical look at the recent announcement of the discovery of the single top quark, by Fermilab's CDF and DZero experiments.
Tobias Bolch Rezenter Gletscherschwund und Klimawandel
Bolch, Tobias
Tobias Bolch Rezenter Gletscherschwund und Klimawandel im nördlichen Tien Shan (Kasachstan/Kyrgyzstan). Sie befinden sich im kontinentalen Bereich des südlichen Ka- sachstans an der Grenze zu Kyrgyzstan
Physics with boosted top quarks
Elin Bergeaas Kuutmann
2014-08-29T23:59:59.000Z
The production at the LHC of boosted top quarks (top quarks with a transverse momentum that greatly exceeds their rest mass) is a promising process to search for phenomena beyond the Standard Model. In this contribution several examples are discussed of new techniques to reconstruct and identify (tag) the collimated decay topology of the boosted hadronic decays of top quarks. Boosted top reconstruction techniques have been utilized in searches for new physical phenomena. An overview is given of searches by ATLAS, CDF and CMS for heavy new particles decaying into a top and an anti-top quark, vector-like quarks and supersymmetric partners to the top quark.
MENTORING-PROGRAMM STUDIERENDE UND ALUMNI
Heermann, Dieter W.
MENTORING-PROGRAMM STUDIERENDE UND ALUMNI ZUKUNFT GEMEINSAM GESTALTEN Sie suchen Unterstützung bei? Dann machen Sie mit beim Mentoring- Programm für Studierende und Ehemalige der Universität Heidelberg. So einfach funktioniert's: 1. Registrieren Sie sich kostenlos bei HAI. 2. Als Mentor: Erstellen Sie
Fakultat fur Mathematik und Physik Institut fur Algebra, Zahlentheorie
Bessenrodt, Christine
und Lineal in die Sprache der Algebra ¨ubersetzen und algebraische Methoden zu ihrer BeantwortungFakult¨at f¨ur Mathematik und Physik Institut f¨ur Algebra, Zahlentheorie und Diskrete Mathematik Prof. Dr. C. Bessenrodt Wintersemester 2011/12 Algebra I (4V+2¨U) Eine beispielorientierte Einf
Messdatenerfassung und Kommunikation im MICRO GRID eines industriellen Produktionsstandortes
Paderborn, Universität
Energiespeicher und eine ,,POWER TO GAS" -Anlage kompensiert werden. Die intelligente Koordination von Erzeugungs
1 Veranderungen der Ener-gieerzeugung und -verteilung
Appelrath, Hans-Jürgen
Energien wie Windkraft-, Solar, Wasser, Biogas- und Geothermieanlagen. Zum anderen wurde nicht zuletzt
Friedemann Mattern / Marc Langheinrich Eingebettete, vernetzte und autonom
autarke, aber drahtlos miteinander kommunizierende Computer in Dinge und Le- bensrÃ¤ume integriert werden
Particle-in-Cell Simulation von Elektronenstrahlen und Laserpulsen in
Kull, Hans-Jörg
, · meiner Freundin Evelin für das Korrekturlesen, · und ganz besonders meinen Eltern für die Ermöglichung
Dariusz Miskowiec
2007-07-06T23:59:59.000Z
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.
Paul B. Mackenzie
1992-12-14T23:59:59.000Z
Lattice calculations of heavy quark systems provide very good measures of the lattice spacing, a key element in recent determinations of the strong coupling constant using lattice methods. They also provide excellent testing grounds for lattice methods in general. I review recent phenomenological and technical developments in this field.
Lehrstuhl und Versuchsanstalt fr Wasserbau und Wasserwirtschaft der Technischen Universitt Mnchen
Cengarle, MarÃa Victoria
Â Schadensanalyse und Sanierungskonzept Herr Karl-Heinz StraÃ?er, Fa. E.ON Kraftwerke GmbH, Landshut Hinweis
Institut fr Energie-und Automatisierungstechnik FG Elektronische Mess-und Diagnosetechnik
Wichmann, Felix
BMBF-Forschungsprojektes ,,Thermoelektrische Generatoren 2020" (TEG 2020) unter Berücksichti- gung Anbindung zwischen einzelnen TEG und dem Bordnetz werden DC/DC-Wandler eingesetzt, welche jeweils statisch
The Multimedia Project Quarked!
Bean, Alice
2011-01-01T23:59:59.000Z
Can exposure to fundamental ideas about the nature of matter help motivate children in math and science and support the development of their understanding of these ideas later? Physicists, designers, and museum educators at the University of Kansas created the Quarked!(tm) Adventures in the subatomic Universe project to provide an opportunity for youth to explore the subatomic world in a fun and user friendly way. The project components include a website (located at http://www.quarked.org) and hands-on education programs. These are described and assessment results are presented. Questions addressed include the following. Can you engage elementary and middle school aged children with concepts related to particle physics? Can young children make sense of something they can't directly see? Do teachers think the material is relevant to their students?
Bergische Universitat Wuppertal Fachbereich Mathematik und Naturwissenschaften
Â¨ur Angewandte Mathematik und Numerische Mathematik Preprint BUW-AMNA 06/03 Cathrin van Emmerich Modelling correlation as a stochastic process Cathrin van Emmerich Department of Mathematics, University of Wuppertal
Bergische Universitat Wuppertal Fachbereich Mathematik und Naturwissenschaften
Â¨ur Angewandte Mathematik und Numerische Mathematik Preprint BUW-AMNA 07/02 Cathrin van Emmerich Stochastic Mean;Stochastic Mean Reversion in the Large Homogenous Portfolio Model Cathrin van Emmerich Department
Santopinto, E
2015-01-01T23:59:59.000Z
In this contribution, we briefly discuss the results for charmonium and bottomonium spectra with self-energy corrections in the unquenched quark model, due to the coupling to the meson-meson continuum. The UQM formalism can be extended to include also the effects of hybrid mesons, i.e. hybrid loops. Finally, we discuss the results of a calculation of hybrid mesons spectrum in Coulomb Gauge QCD.
E. Santopinto; J. Ferretti
2015-03-10T23:59:59.000Z
In this contribution, we briefly discuss the results for charmonium and bottomonium spectra with self-energy corrections in the unquenched quark model, due to the coupling to the meson-meson continuum. The UQM formalism can be extended to include also the effects of hybrid mesons, i.e. hybrid loops. Finally, we discuss the results of a calculation of hybrid mesons spectrum in Coulomb Gauge QCD.
Top quark pair production and top quark properties at CDF
Chang-Seong Moon
2014-11-01T23:59:59.000Z
We present the most recent measurements of top quark pairs production and top quark properties in proton-antiproton collisions with center-of-mass energy of 1.96 TeV using CDF II detector at the Tevatron. The combination of top pair production cross section measurements and the direct measurement of top quark width are reported. The test of Standard Model predictions for top quark decaying into $b$-quarks, performed by measuring the ratio $R$ between the top quark branching fraction to $b$-quark and the branching fraction to any type of down quark is shown. The extraction of the CKM matrix element $|V_{tb}|$ from the ratio $R$ is discussed. We also present the latest measurements on the forward-backward asymmetry ($A_{FB}$) in top anti-top quark production. With the full CDF Run II data set, the measurements are performed in top anti-top decaying to final states that contain one or two charged leptons (electrons or muons). In addition, we combine the results of the leptonic forward-backward asymmetry in $t\\bar t$ system between the two final states. All the results show deviations from the next-to-leading order (NLO) standard model (SM) calculation.
Boehringer, Hans
LMU SS09: Galaxien und Galaxienhaufen im Universum The integral constraint (I) 8 (r)measured = (r)true LMU SS09: Galaxien und Galaxienhaufen im Universum Agenda · The correlation function Measurement function and the power spectrum of the density fluctuations · Higher order statistics · Baryonic acoustic
Karolos Potamianos
2011-12-01T23:59:59.000Z
We present the recent results of top-quark physics using up to 6 fb$^{-1}$ 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
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.
Bachelor-, Master-und Doktorandenseminar des Instituts fr Informatik
Zachmann, Gabriel
wird. Die Wahl fällt dabei auf die Integration von CMMI-DEV und ITIL bzw. ITIL Service Design. Zur Schnittstellenbereiche vorgestellt, an denen sich Prozessgebiete von CMMI-DEV und ITIL Service Design berühren. Daraufhin
Organigramm 12 Organe der Stiftung und weitere Gremien 13
Nationale und Internationale Zusammenarbeit 19 5 #12;6 #12;Vorwort Vorwort Das Deutsche Elektronen-Synchrotron sich BESSY, das Max-Born-Institut Berlin und die TU-Darmstadt an PITZ. Vom 15.01. bis zum 17
analyse und modellierung: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
und Komponenten der Zentrosomenaktivitt (more) Oates, Jennifer 2013-01-01 114 AVIONIK AUTOMOTIVE RAUMFAHRT ENERGIESYSTEME PRODUKTION UND LOGISTIK WEHRTECHNIK S Y S T E M S E N...
Heavy Quark production at HERA and Heavy Quark contributions
Detlef Bartsch, University of Bonn on behalf of the ZEUS and H1 Collaborations Â· Introduction Â· Heavy 1500 0 100 200 300 400 electrons positrons low E HERA-1 HERA-2 Detlef Bartsch Heavy Quark production Detlef Bartsch Heavy Quark production at HERA, Feb. 23rd 2008 3 #12;pQCD approximations Massive scheme
Aspekte der Paranoia in utopischer Literatur und Film
Schuetze, Andre
2013-01-01T23:59:59.000Z
aus fast unsichtbar, ein Soldat. Man konnte zwar mit demund Hofpage, Opfer und Soldat im Dreißigjährigen Krieg,
Charm Quark Energy Loss in QCD Matter
W. C. Xiang; H. T. Ding; D. C. Zhou; D. Rohrich
2005-07-13T23:59:59.000Z
The energy loss of heavy quarks in a quark-gluon plasma of finite size is studied within the light-cone integral approach. A simple analytical formulation of the radiative energy loss of heavy quarks is derived. This provides a convenient way to quantitatively estimate the quark energy loss. Our results show that if the energy of a heavy quark is much larger than its mass, the radiative energy loss approaches the radiative energy loss of light quarks.
Sudan und Sd-Sudan. Vom Konflikt zur Kooperation?
Koenig, Friederike - Fachbereich 2 Biologie
Sudan und Süd-Sudan. Vom Konflikt zur Kooperation? Professor Dr. Karl Wohlmuth (Fachbereich aktuellen Konflikte zwischen dem Sudan und dem Süd-Sudan haben, wie die Konflikte innerhalb der beiden internationalen Grenze zwischen Sudan und Süd-Sudan mobilisiert werden können. Schon vor der Unabhängigkeit des
L. Cerrito
2004-07-16T23:59:59.000Z
Preliminary results on the measurement of the top quark mass at the Tevatron Collider are presented. In the dilepton decay channel, the CDF Collaboration measures m{sub t} = 175.0{sub -16.9}{sup +17.4}(stat.){+-}8.4(syst.) GeV/c{sup 2}, using a sample of {approx} 126 pb{sup -1} of proton-antiproton collision data at {radical}s = 1.96 TeV (Run II). In the lepton plus jets channel, the CDF Collaboration measures 177.5{sub -9.4}{sup +12.7}(stat.) {+-} 7.1(syst.) GeV/c{sup 2}, using a sample of {approx} 102 pb{sup -1} at {radical}s = 1.96 TeV. The D0 Collaboration has newly applied a likelihood technique to improve the analysis of {approx} 125 pb{sup -1} of proton-antiproton collisions at {radical}s = 1.8 TeV (Run I), with the result: m{sub t} = 180.1 {+-} 3.6(stat.) {+-}3.9(syst.) GeV/c{sup 2}. The latter is combined with all the measurements based on the data collected in Run I to yield the most recent and comprehensive experimental determination of the top quark mass: m{sub t} = 178.0 {+-} 2.7(stat.) {+-} 3.3(syst.) GeV/c{sup 2}.
Quarks with Integer Electric Charge
J. LaChapelle
2015-01-26T23:59:59.000Z
Within the context of the Standard Model, quarks are placed in a $(\\mathbf{3},\\mathbf{2})\\oplus (\\mathbf{3},\\bar{\\mathbf{2}})$ matter field representation of $U_{EW}(2)$. Although the quarks carry unit intrinsic electric charge in this construction, anomaly cancellation constrains the Lagrangian in such a way that the quarks' associated currents couple to the photon with the usual 2/3 and 1/3 fractional electric charge associated with conventional quarks. The resulting model is identical to the Standard Model in the $SU_C(3)$ sector: However, in the $U_{EW}(2)$ sector it is similar but not necessarily equivalent. Off hand, the model appears to be phenomenologically equivalent to the conventional quark model in the electroweak sector for experimental conditions that preclude observation of individual constituent currents. On the other hand, it is conceivable that detailed analyses for electroweak reactions may reveal discrepancies with the Standard Model in high energy and/or large momentum transfer reactions. The possibility of quarks with integer electric charge strongly suggests the notion that leptons and quarks are merely different manifestations of the same underlying field. A speculative model is proposed in which a phase transition is assumed to occur between $SU_C(3)\\otimes U_{EM}(1)$ and $U_{EM}(1)$ regimes. This immediately; explains the equality of lepton/quark generations and lepton/hadron electric charge, relates neutrino oscillations to quark flavor mixing, reduces the free parameters of the Standard Model, and renders the issue of quark confinement moot.
Relation between quark-antiquark potential and quark-antiquark free energy in hadronic matter
Zhen-Yu Shen; Xiao-Ming Xu
2014-06-19T23:59:59.000Z
We study the relation between the quark-antiquark potential and the quark-antiquark free energy in hadronic matter. While a temperature is over the critical temperature, the potential of a heavy quark and a heavy antiquark almost equals the free energy, otherwise the quark-antiquark potential is substantially larger than the quark-antiquark free energy. While a temperature is below the critical temperature, the quark-antiquark free energy can be taken as the quark-antiquark potential.
Mock, A
1997-01-01T23:59:59.000Z
Produktion von geladenen Pionen und Kaonen, Protonen, Antiprotonen und $\\phi$-Mesonen in ultrarelativistischen Blei-Blei-Stossen bei 158 GeV pro Nukleon
Quark Potential in a Quark-Meson Plasma
Chengfu Mu; Pengfei Zhuang
2008-03-05T23:59:59.000Z
We investigate quark potential by considering meson exchanges in the two flavor Nambu--Jona-Lasinio model at finite temperature and density. There are two kinds of oscillations in the chiral restoration phase, one is the Friedel oscillation due to the sharp quark Fermi surface at high density, and the other is the Yukawa oscillation driven by the complex meson poles at high temperature. The quark-meson plasma is strongly coupled in the temperature region $1\\le T/T_c \\lesssim 3$ with $T_c$ being the critical temperature of chiral phase transition. The maximum coupling in this region is located at the critical point.
On quark-lepton complementarity
F. Gonzalez-Canales; A. Mondragon
2006-06-16T23:59:59.000Z
Recent measurements of the neutrino solar mixing angle and the Cabibbo angle satisfy the empirical relation theta_{sol} + theta_{C} ~ 45^{o}. This relation suggests the existence of a correlation between the mixing matrices of leptons and quarks, the so called quark-lepton complementarity. Here, we examine the possibility that this correlation originates in the strong hierarchy in the mass spectra of quarks and charged leptons, and the seesaw mechanism that gives mass to the Majorana neutrinos. In a unified treatment of quarks and leptons in which the mass matrices of all fermions have a similar Fritzsch texture, we calculate the mixing matrices V_{CKM} and U_{MNSP} as functions of quark and lepton masses and only two free parameters, in very good agreement with the latest experimental values on masses and mixings. Three essential ingredients to explain the quark-lepton complementarity relation are identified: the strong hierarchy in the mass spectra of quarks and charged leptons, the normal seesaw mechanism and the assumption of maximal CP violation in the lepton sector.
On quark-lepton complementarity
Gonzalez Canales, F.; Mondragon, A. [Instituto de Fisica, UNAM, 04510, Mexico D.F. (Mexico)
2006-09-25T23:59:59.000Z
Recent measurements of the neutrino solar mixing angle and the Cabibbo angle satisfy the empirical relation {theta}{sub sol} + {theta}{sub C} {approx_equal} ({pi}/4). This relation suggests the existence of a correlation between the mixing matrices of leptons and quarks, the so called quark-lepton complementarity. Here, we examine the possibility that this correlation originates in the strong hierarchy in the mass spectra of quarks and charged leptons, and the seesaw mechanism that gives mass to the Majorana neutrinos. In a unified treatment of quarks and leptons in which the mass matrices of all fermions have a similar Fritzsch texture, we calculate the mixing matrices VCKM and UMNSP as functions of quark and lepton masses and only two free parameters, in very good agreement with the latest experimental values on masses and mixings. Three essential ingredients to explain the quark-lepton complementarity relation are identified: the strong hierarchy in the mass spectra of quarks and charged leptons, the normal seesaw mechanism and the assumption of maximal CP violation in the lepton sector.
Shear Viscosity of Quark Matter
W. M. Alberico; S. Chiacchiera; H. Hansen; A. Molinari; M. Nardi
2007-07-30T23:59:59.000Z
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.
Wicke, Daniel; /Wuppertal U., Dept. Math.
2009-08-01T23:59:59.000Z
The aim of particle physics is the understanding of elementary particles and their interactions. The current theory of elementary particle physics, the Standard Model, contains twelve different types of fermions which (neglecting gravity) interact through the gauge bosons of three forces. In addition a scalar particle, the Higgs boson, is needed for theoretical consistency. These few building blocks explain all experimental results found in the context of particle physics, so far. Nevertheless, it is believed that the Standard Model is only an approximation to a more complete theory. First of all the fourth known force, gravity, has withstood all attempts to be included until now. Furthermore, the Standard Model describes several features of the elementary particles like the existence of three families of fermions or the quantisation of charges, but does not explain these properties from underlying principles. Finally, the lightness of the Higgs boson needed to explain the symmetry breaking is difficult to maintain in the presence of expected corrections from gravity at high scales. This is the so called hierarchy problem. In addition astrophysical results indicate that the universe consists only to a very small fraction of matter described by the Standard Model. Large fractions of dark energy and dark matter are needed to describe the observations. Both do not have any correspondence in the Standard Model. Also the very small asymmetry between matter and anti-matter that results in the observed universe built of matter (and not of anti-matter) cannot be explained until now. It is thus an important task of experimental particle physics to test the predictions of the Standard Model to the best possible accuracy and to search for deviations pointing to necessary extensions or modifications of our current theoretical understanding. The top quark was predicted to exist by the Standard Model as the partner of the bottom quark. It was first observed in 1995 by the Tevatron experiments CDF and D0 and was the last of the quarks to be discovered. As the partner of the bottom quark the top quark is expected to have quantum numbers identical to that of the other known up-type quarks. Only the mass is a free parameter. We now know that it is more than 30 times heavier than the next heaviest quark, the bottom quark. Thus, within the Standard Model all production and decay properties are fully defined. Having the complete set of quarks further allows to verify constraints that the Standard Model puts on the sum of all quarks or particles. This alone is reason enough to experimentally study the top quark properties. The high value of the top quark mass and its closeness to the electroweak scale has inspired people to speculate that the top quark could have a special role in the electroweak symmetry breaking. Confirming the expected properties of the top quark experimentally establishes the top quark as we expect it to be. Any deviation from the expectations gives hints to new physics that may help to solve the outstanding questions. In this review the recent results on top quark properties obtained by the Tevatron experiments CDF and D0 are summarized. At the advent of the LHC special emphasis is given to the basic measurement methods and the dominating systematic uncertainties. After a short introduction to the Standard Model and the experimental environment in the remainder of this chapter, Chapter 2 describes the current status of top quark mass measurements. Then measurments of interaction properties are described in Chapter 3. Finally, Chapter 4 deals with analyses that consider hypothetical particles beyond the Standard Model in the observed events.
Top quark studies at hadron colliders
Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)
1997-01-01T23:59:59.000Z
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.
Top Quark Production at the Tevatron Collider
Liang Li
2011-07-21T23:59:59.000Z
Top quark physics has been a rich testing ground for the standard model since the top quark discovery in 1995. The large mass of top quark suggests that it could play a special role in searches for new phenomena. In this paper I provide an overview of recent top quark production cross section measurements from both CDF and D0 collaborations and also some new physics searches done in the top quark sector.
Top Quark Production at the Tevatron Collider
Li, Liang; /UC, Riverside
2011-07-01T23:59:59.000Z
Top quark physics has been a rich testing ground for the standard model since the top quark discovery in 1995. The large mass of top quark suggests that it could play a special role in searches for new phenomena. In this paper I provide an overview of recent top quark production cross section measurements from both CDF and D0 collaborations and also some new physics searches done in the top quark sector.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kong, Kyoungchui; Lee, Hye-Sung; Park, Myeonhun
2014-04-01T23:59:59.000Z
We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 ? deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t ? b W + Z's. This is the same as the dominant topmore »quark decay (t ? b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.« less
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kong, Kyoungchui [Kansas; Lee, Hye-Sung [W&M, JLAB; Park, Myeonhun [Tokyo
2014-04-01T23:59:59.000Z
We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 ? deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t ? b W + Z's. This is the same as the dominant top quark decay (t ? b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.
Fakultt fr Mathematik und Informatik Abteilung Didaktik
Knüpfer, Christian
nichteuklidischen Räumen sowie zur Lehrerbildung, wobei Ungarn aus DDR-Perspektive, wie Prof. Böhm betonte, als Problemlösen auf dem Gebiet der Stochastik unter besonderer Berücksichtigung der neuen Abiturprüfung in Ungarn Problemlösen durch Modellieren Im Vortrag wird der Stochastikunterricht in Ungarn durch konkrete Probleme und
PHILOSOPHIE Geschichte und Klassische Texte der Philosophie
Pfeifer, Holger
24 / 251 Grundfragen der Ethik (EPG I) Dr. Hans-Klaus Keul, UniversitÃ¤t Ulm Seminar, Di 17 /104 Religion und Evolution. Ende oder Wende, Anpassung oder Paradigmenwechsel? Prof. Dr. Roman Bauer Schule (EPG II) Dr. Gisela Badura-Lotter, Dr. Christiane Imhoff, Dr. Hans-Klaus Keul Kompaktseminar, Fr
George Hesekiel Faust und Don Juan
Wagner, Stephan
einige dunkle Gestalten schlafen- der Sclaven und tritt hochaufathmend hinaus in die #12;-- 2 -- kÃ¼hle funkelt, tritt Don Ju- an aus der Verandah zurÃ¼ck in sein Haus, er erreicht sein Zimmer, er lÃ¶scht seine
Bergische Universitat Wuppertal Fachbereich Mathematik und Naturwissenschaften
Â¨ur Angewandte Mathematik und Numerische Mathematik Preprint BUW-AMNA 07/01 Roland Pulch and Cathrin van Emmerich://www.math.uni-wuppertal.de/org/Num/ #12;Polynomial Chaos for Simulating Random Volatilities Roland Pulch and Cathrin van Emmerich
Resonance recombination model and quark distribution functions in the quark-gluon plasma
Ravagli, L.; van Hees, H.; Rapp, Ralf.
2009-01-01T23:59:59.000Z
observed constituent quark number scaling (CQNS) at the Relativistic Heavy Ion Collider (RHIC). To address this problem we combine our earlier developed quark recombination model with quark phase-space distributions computed from relativistic Langevin...
A. W. Jung
2014-10-14T23:59:59.000Z
Recent measurements of top-quark properties at the LHC and the Tevatron are presented. Most recent measurements of the top quark mass have been carried out by CMS using $19.7/$fb of $\\sqrt{s} = 8$ TeV data including the study of the dependence on event kinematics. ATLAS uses the full Run I data at $\\sqrt{s} = 7$ TeV for a "3D" measurement that significantly reduces systematic uncertainties. D0 employs the full Run II data using the matrix element method to measure the top quark mass with significantly reduced systematic uncertainties. Many different measurements of the top quark exist to date and the most precise ones per decay channel per experiment have been combined into the first world combination with a relative precision of 0.44%. Latest updates of measurements of production asymmetries include the measurement of the \\ttbar production asymmetry by D0 employing the full Run II data set, by CMS and ATLAS (including the polarization of the top quark) employing both the full data set at $\\sqrt{s} = 7$ TeV. CMS uses the full $\\sqrt{s} = 8$ TeV data to measure the top quark polarization in single top production, the ratio ${\\cal R}$ of the branching fractions ${\\cal B}(t \\rightarrow Wb) / {\\cal B}(t \\rightarrow Wq)$ and to search for flavor changing neutral currents. The results from all these measurements agree well with their respective Standard Model expectation.
Reggelin, Michael
Team MINT: Fachteam Mathematik, Informatik, Natur- und Ingenieurwissenschaften Stadtmitte Team Human: Fachteam Humanwissenschaften Team GeWiss: Fachteam Gesellschafts- und Geschichtswissenschaften Team Zentr. Info: Team Zentrale Information, P icht und elektronisches Publizieren Team ReWir: Fachteam
Entel, P.
Computersimulationen martensitischer Phasen¨uberg¨ange in Eisen-Nickel- und Nickel Molekulardynamik-Simulationen der martensitischen Umwandlungen in Eisen-Nickel- und Nickel Anpassung parametrisierter Funktionen an experimentelle Daten von Eisen, Nickel, Aluminium und NiAl gewonnen
Tomography of the Quark-Gluon-Plasma by Charm Quarks
Song, Taesoo; Cabrera, Daniel; Torres-Rincon, Juan M; Tolos, Laura; Cassing, Wolfgang; Bratkovskaya, Elena
2015-01-01T23:59:59.000Z
We study charm production in ultra-relativistic heavy-ion collisions by using the Parton-Hadron-String Dynamics (PHSD) transport approach. The initial charm quarks are produced by the Pythia event generator tuned to fit the transverse momentum spectrum and rapidity distribution of charm quarks from Fixed-Order Next-to-Leading Logarithm (FONLL) calculations. The produced charm quarks scatter in the quark-gluon plasma (QGP) with the off-shell partons whose masses and widths are given by the Dynamical Quasi-Particle Model (DQPM) which reproduces the lattice QCD equation-of-state in thermal equilibrium. The relevant cross section are calculated in a consistent way by employing the effective propagators and couplings from the DQPM. Close to the critical energy density of the phase transition, the charm quarks are hadronized into $D$ mesons through coalescence and/or fragmentation depending on transverse momentum. The hadronized $D$ mesons then interact with the various hadrons in the hadronic phase with cross sect...
Paderborn, Universität
,,POWER TO GAS" -Anlage kompensiert werden. Die intelligente Koordination von Erzeugungs- und Regelverhalten der Solar- Wechselrichter, des Batteriespeichers und der POWER TO GAS Einheit in einer
Quarks and Antiquarks in Nuclei
Jason R. Smith
2005-08-19T23:59:59.000Z
The Chiral Quark-Soliton model provides the quark and antiquark substructure of the nucleon, which is embedded in nuclear matter. This provides a new way to asses the effects of the nuclear medium on the nucleon. We calculate nuclear binding and saturation, describe the European Muon Collaboration (EMC) effect consistently with Drell-Yan experiments, and predict modifications to the polarized parton distributions. We also calculate the electromagnetic form factors of a bound proton, and find significant modifications of the electromagnetic form factors in the nuclear environment. In every case, the properties of the sea of quark-antiquark pairs in the nucleon are very important, and serve to mitigate the valence quark effect. The changes in the sea quarks when the nucleon is immersed in the nuclear medium are the primary mode by which consistency is maintained with experimental constraints (Drell-Yan data, magnetic moment), while still maintaining a significant effect needed to explain the deep inelastic scattering and polarization transfer data.
aufbau und inbetriebnahme: Topics by E-print Network
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mit hoher Genauigkeit vermessen. Hierzu war die przise berwachung (more) Greiner, Daniel Bernd 2013-01-01 37 AUFBAU UND UNTERSUCHUNG VON SCHICHTSYSTEMEN AUS AMPHIPHILEN...
aufbau und erprobung: Topics by E-print Network
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mit hoher Genauigkeit vermessen. Hierzu war die przise berwachung (more) Greiner, Daniel Bernd 2013-01-01 36 AUFBAU UND UNTERSUCHUNG VON SCHICHTSYSTEMEN AUS AMPHIPHILEN...
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mit hoher Genauigkeit vermessen. Hierzu war die przise berwachung (more) Greiner, Daniel Bernd 2013-01-01 43 AUFBAU UND UNTERSUCHUNG VON SCHICHTSYSTEMEN AUS AMPHIPHILEN...
aktueller stand und: Topics by E-print Network
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(rechts), begr?ten gemeinsam mit Kanzler Dr. Markus- tt Bayreuth, Dr. Markus Zanner, den doppelten Abiturjahrgang, der aktuell an den Universitten und Ullmann, G....
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Verbindungen mit Lithium 18 2.1.3 Elektrolyte Hoffmann, Rolf 5 Wachstum und Realstruktur von epitaktischen (Al,Ga)N-Schichten. Open Access...
als geschichtliches und: Topics by E-print Network
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Verbindungen mit Lithium 18 2.1.3 Elektrolyte Hoffmann, Rolf 5 Wachstum und Realstruktur von epitaktischen (Al,Ga)N-Schichten. Open Access...
aus leichtwasserreaktoren und: Topics by E-print Network
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 428 Physiologische, chemotaxonomische und molekularbiologische...
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 427 Physiologische, chemotaxonomische und molekularbiologische...
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 432 Physiologische, chemotaxonomische und molekularbiologische...
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 427 Physiologische, chemotaxonomische und molekularbiologische...
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 444 Physiologische, chemotaxonomische und molekularbiologische...
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 434 Physiologische, chemotaxonomische und molekularbiologische...
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ihre 1572 erschien ein neuer Stern am Himmel - eine Supernova. Der dnische Astronom Tycho Brahe war einer 427 Physiologische, chemotaxonomische und molekularbiologische...
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auf den Bewegungsumfang der Halswirbelsule und die elektrische Aktivitt des SPC (Musculus semispinalis capitis) (more) Pogrzeba, Miriam Ruth 2009-01-01 2 Der...
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auf den Bewegungsumfang der Halswirbelsule und die elektrische Aktivitt des SPC (Musculus semispinalis capitis) (more) Pogrzeba, Miriam Ruth 2009-01-01 2 Der...
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Page Topic Index 81 Aktuelle nationale und internationale Anwendungsbeispiele aus dem Car-Sharing. Open Access Theses and Dissertations Summary: ??Die vorliegende Arbeit gibt...
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Lydia 2014-01-01 7 Aktuelle nationale und internationale Anwendungsbeispiele aus dem Car-Sharing. Open Access Theses and Dissertations Summary: ??Die vorliegende Arbeit gibt...
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Felizitas 2010-01-01 53 Aktuelle nationale und internationale Anwendungsbeispiele aus dem Car-Sharing. Open Access Theses and Dissertations Summary: ??Die vorliegende Arbeit gibt...
Thermalization of heavy quarks in the quark-gluon plasma
van Hees, H.; Rapp, Ralf.
2005-01-01T23:59:59.000Z
the kinetic equilibration of c quarks as compared to using perturbative interactions. We also comment on consequences for D-meson observables in ultrarelativistic heavy-ion collisions. DOI: 10.1103/PhysRevC.71.034907 PACS number(s): 12.38.Mh, 24.85.+p, 25... of individual c quarks in the QGP will reflect themselves in transverse- momentum (pT -) spectra of open charm hadrons (D mesons) [4?7], most notably their elliptic flow, v2(pT ), in semicentral collisions [8,9]. Preliminary experimental results from...
Cédric Lorcé
2014-09-16T23:59:59.000Z
The proton spin puzzle issue focused the attention on the parton spin and orbital angular momentum contributions to the proton spin. However, a complete characterization of the proton spin structure requires also the knowledge of the parton spin-orbit correlation. We showed that this quantity can be expressed in terms of moments of measurable parton distributions. Using the available phenomenological information about the valence quarks, we concluded that this correlation is negative, meaning that the valence quark spin and kinetic orbital angular momentum are, in average, opposite. The quark spin-orbit correlation can also be expressed more intuitively in terms of relativistic phase-space distributions, which can be seen as the mother distributions of the standard generalized and transverse-momentum dependent parton distributions. We present here for the first time some examples of the general multipole decomposition of these phase-space distributions.
Quark stars: their influence on Astroparticle Physics
Sanjay K. Ghosh
2008-08-12T23:59:59.000Z
We discuss some of the recent developments in the quark star physics along with the consequences of possible hadron to quark phase transition at high density scenario of neutron stars and their implications on the Astroparticle Physics.
Top Quark Production at the LHC
Francesco Spanò; for the ATLAS; CMS collaborations
2011-12-16T23:59:59.000Z
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.
Werner Bernreuther
2008-05-09T23:59:59.000Z
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.
Quark masses: An environmental impact statement
Kimchi, Itamar
We investigate worlds that lie on a slice through the parameter space of the standard model over which quark masses vary. We allow as many as three quarks to participate in nuclei, while fixing the mass of the electron and ...
Villafranca Die Kabinete und die Revolutionen.
Prodinger, Helmut
TheiÃ? an ihrer Verbindung mit dem KÃ¶rÃ¶s gefÃ¼hrt haben, in denen die Revolu- tion Ungarns sich entspann bereits in einem frÃ¼heren Bande erwÃ¤hnt, und wie der wilde Racen- krieg in Ungarn selbst schon seit dem. Noch ehe das Jahr zu Ende, rÃ¼ckte die Kaiserliche Armee unter WindischgrÃ¤tz in Ungarn ein. Rasch
Top Quark: discovery, present and future Galtieri, The Top Quark, PDG 50th
Galtieri, Lina
1 Top Quark: discovery, present and future Galtieri, The Top Quark, PDG 50th Anniversary. September 23-2006 #12;Chasing the Top Quark 2 Gell-Mann, Zweig uds quarks postulated ('64) GIM mechanism at FNAL 1984 PDG partial listing top should exist Searches at Tristan, PETRA, SPPS, SLC : top not found
Valence Quarks Polarization from COMPASS
A. Korzenev
2007-04-26T23:59:59.000Z
A first evaluation of the polarized valence quark distribution $\\Delta u_v(x)+\\Delta d_v(x)$ from the COMPASS experiment (CERN/SPS) is presented. The data were collected by COMPASS in the years 2002--2004 using a 160 GeV polarized muon beam scattered off a large polarized $^6$LiD target and cover the range $1< Q^2 < 100$ GeV$^2$ and $0.006
Equilibration in Quark Gluon Plasma
Santosh K Das; Jan-e Alam; Payal Mohanty
2009-12-21T23:59:59.000Z
The hydrodynamic expansion rate of quark gluon plasma (QGP) is evaluated and compared with the scattering rate of quarks and gluons within the system. Partonic scattering rates evaluated within the ambit of perturbative Quantum Choromodynamics (pQCD) are found to be smaller than the expansion rate evaluated with ideal equation of state (EoS) for the QGP. This indicate that during the space-time evolution the system remains out of equilibrium. Enhancement of pQCD cross sections and a more realistic EoS keep the partons closer to the equilibrium.
Spontaneously broken quark helicity symmetry
Dalley, Simon [Department of Physics, University of Wales Swansea, Singleton Park, Swansea SA2 8PP (United Kingdom); McCartor, Gary [Department of Physics, SMU Dallas, TX 75275 (United States)]. E-mail: mccartor@mail.physics.smu.edu
2006-02-15T23:59:59.000Z
We discuss the origin of chiral-symmetry breaking in the light-cone representation of QCD. In particular, we show how quark helicity symmetry is spontaneously broken in SU (N) gauge theory with massless quarks if that theory has a condensate of fermion light-cone zero modes. The symmetry breaking appears as induced interactions in an effective light-cone Hamiltonian equation based on a trivial vacuum. The induced interaction is crucial for generating a splitting between pseudoscalar and vector meson masses, which we illustrate with spectrum calculations in some 1 + 1-dimensional reduced models of gauge theory.
Top quark Physics at the Tevatron
Yvonne Peters; for the CDF; D0 Collaborations
2012-01-06T23:59:59.000Z
When the heaviest elementary particle known today, the top quark, was discovered in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, a large program to study this particle in details has started. In this article, an overview of the status of top quark physics at the Tevatron is presented. In particular, recent results on top quark production, properties and searches using top quarks are discussed.
Quark condensates and the deconfinement transition
Christian S. Fischer; Jens A. Mueller
2009-08-18T23:59:59.000Z
In this talk we present results on the chiral and the deconfinement transition of quenched QCD from Dyson-Schwinger equations. We determine the ordinary quark condensate signaling the chiral transition and the dual quark condensate signaling the deconfinement transition from the Landau gauge quark propagator evaluated at generalized boundary conditions. We find only slightly different transition temperatures at finite quark masses, whereas the transition temperatures coincide in the chiral limit.
Chaotic dynamics in quark-gluon cascade
A. T. Temiraliev
2011-06-23T23:59:59.000Z
A map to the quark-gluon cascade on the basis of nonlinearity in the quark and gluon distributions in hadrons is proposed. Calculations of the quarks trajectories have shown the presence of the chaotic dynamics as a consequence of bifurcations.
Exotic hybrid mesons with light quarks
Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs. M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; Bob Sugar; Doug Toussaint; Matt Wingate
1996-07-12T23:59:59.000Z
Hybrid mesons, made from a quark, an antiquark and gluons, can have quantum numbers inaccessible to conventional quark-antiquark states. Confirmation of such states would give information on the role of "dynamical" color in low energy QCD. We present preliminary results for hybrid meson masses using light Wilson valence quarks.
Quark model calculation of the EMC effect
Benesh, C.J.; Goldman, T.; Stephenson, G.J. Jr. [Los Alamos National Laboratory, NM (United States)
1993-10-01T23:59:59.000Z
Using a potential model, we calculate quark distributions for a six-quark quasi-deuteron, including the effects of the Pauli Principle and quark tunneling between nuclei. Using a phenomenological sea distribution, the EMC ratio is calculated and found to be in qualitative agreement with experiment.
Technische Universitt Berlin Institut fr Luft-und Raumfahrt
Berlin,Technische Universität
.-Nr.: ... Modellierung und Zuverlässigkeitsanalyse einer Flugsteuerung mit Modelica Die Bordsysteme moderner-orientierten Modellierungssprache Modelica vorgesehen. Als Beispiel ist in der Abbildung die Nicksteuerung des Airbus A320 Zuverlässigkeitsanalyse. 2. Einarbeitung in die Modellierung und Simulation mit Modelica/Dymola. 3. Erstellen von
Regelsysteme 1 10. Tutorial LQ Regulator und Kalman Filter
Lygeros, John
Regelsysteme 1 10. Tutorial LQ Regulator und Kalman Filter Dave Ochsenbein Institut f¨ur Automatik ETH Z¨urich HS 2013 Dave Ochsenbein Regelsysteme 1 HS 2013 #12;10. Tutorial LQ Regulator und Kalman Filter Gliederung 10.1. Varia 10.2. LQ-Regulator 10.3. Kalman-Bucy Filter 10.4. Eigenschaften des
Diss. ETH Nr. 10714 Helium und Tritium als Tracer fr
Aeschbach-Hertig, Werner
Diss. ETH Nr. 10714 Helium und Tritium als Tracer für physikalische Prozesse in Seen ABHANDLUNG zur Zürich 1994 #12;Kurzfassung ix Kurzfassung Der radioaktive Zerfall von 3H (Tritium) zu 3He mit einer Fluide aus dem Erdinnern. Helium und Tritium werden massenspektrometrisch analysiert. Im Rahmen dieser Ar
Direktion des Innern Amt fr Wald und Wild
Wehrli, Bernhard
Direktion des Innern Amt fÃ¼r Wald und Wild Veranstaltungsreihe Forum Wild "Projet Lac Zugersee" Im Zug Aabachstrasse 5, Zug Veranstaltungsreihe Forum Wild "Projet Lac Zugersee" Im August 2013 hat ein, Zug Direktion des Innern Amt fÃ¼r Wald und Wild #12;
A relativistic constituent quark model
Schlumpf, F.
1993-08-01T23:59:59.000Z
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.
Nr. 314 / 2012 // 5. Dez. 2012 Imperien diesseits und jenseits des Atlantiks
Ullmann, G. Matthias
, Großbritannien, Frankreich, Schweden, Polen, Ungarn und Deutschland für die Teilnahme an der Konfe- renz zu
Nr. 05 | 25.04.2012 THE LARGER PICTURE | NEWSLETTER INTERNATIONAL UND INTERKULTURELL
Hinrichs, Klaus
Finnland, Ungarn und der Schweiz erwartet. ,,Wir wollen mit der Konferenz einen länderüber- greifenden
Uni internationalU-Mail 1/07 Regensburger Universittszeitung 5 Das Thema ,,Verantwortung und Eliten"
Schubart, Christoph
, Tschechien und Ungarn offen. Über 40 Jahresstipendiaten aus diesen Ländern trafen sich Ende November
Gesellschaft der Freunde und Frderer der Universitt zu Lbeck e. V., Sektion Alumni
Lübeck, Universität zu
Illig Protokoll: Frau Gabriele Zillmer TOP 1 Begrüßung Der 1. Vorsitzende begrüßt die Anwesenden und
R. Y. Peters
2014-08-10T23:59:59.000Z
Years after its discovery in 1995 by CDF and D0, the top quark still undergoes intense investigations at the Tevatron. Using up to the full Run~II data sample, new measurements of top quark production and properties by the D0 Collaboration are presented. In particular, the first observation of single top quark s-channel production, the measurement of differential ttbar distributions, forward-backward ttbar asymmetry, a new measurement of the top quark mass, and a measurement of the top quark charge are discussed.
Top-Quark Physics Results From LHC
Luca Fiorini
2012-01-30T23:59:59.000Z
The top-quark is a fundamental element of the physics program at the Large Hadron Collider (LHC). We review the current status of the top-quark measurements performed by ATLAS and CMS experiments in pp collisions at sqrt(s)=7 TeV by presenting the recent results of the top-quark production rates, top mass measurements and additional top quark properties. We will also describe the recent searches for physics beyond the Standard Model in the top-quark sector.
Top Quark Physics at the Tevatron
Frederic Deliot; Douglas Glenzinski
2011-10-10T23:59:59.000Z
We review the field of top-quark physics with an emphasis on experimental techniques. The role of the top quark in the Standard Model of particle physics is summarized and the basic phenomenology of top-quark production and decay is introduced. We discuss how contributions from physics beyond the Standard Model could affect top-quark properties or event samples. The many measurements made at the Fermilab Tevatron, which test the Standard Model predictions or probe for direct evidence of new physics using the top-quark event samples, are reviewed here.
Quark hadronization probed by K(0) mesons
Baringer, Philip S.
1990-04-01T23:59:59.000Z
are well understood in the context of QCD. A quark-antiquark pair with large virtuality (or qz) evolves through a parton shower of quarks and gluons of decreas- ing virtuality. So long as the parton virtuality is large, a, is small and the perturbative... /CP) is given in Fig. 7(a) for tracks opposite the D' tag. These tracks come from the fragmentation of a known 14.5-GeV c (or c) 200 (a)Vebber 4. 1 —c quark events Lund 6.3 — c quark events R(Ko/Charged) opposite D tag 100 (b) WEBBER 4.1: u quark...
Steinhoff, Heinz-Jürgen
System SAP Business Objects als einziges BI-System eingesetzt werden. Der Flughafen arbeitet mit dem ERP-System Controlling wurde das System SAP Business Objects angeschafft, in welches bereits die relevanten Daten aus der1 Projektangebote für das IS-Project (WS 2013/2014 und SS 2014) Fachgebiet Unternehmensrechnung und
Top quark physics in hadron collisions
Wolfgang Wagner
2007-08-03T23:59:59.000Z
The top quark is the heaviest elementary particle observed to date. Its large mass makes the top quark an ideal laboratory to test predictions of perturbation theory concerning heavy quark production at hadron colliders. The top quark is also a powerful probe for new phenomena beyond the Standard Model of particle physics. In addition, the top quark mass is a crucial parameter for scrutinizing the Standard Model in electroweak precision tests and for predicting the mass of the yet unobserved Higgs boson. Ten years after the discovery of the top quark at the Fermilab Tevatron top quark physics has entered an era where detailed measurements of top quark properties are undertaken. In this review article an introduction to the phenomenology of top quark production in hadron collisions is given, the lessons learned in Tevatron Run I are summarized, and first Run II results are discussed. A brief outlook to the possibilities of top quark research a the Large Hadron Collider, currently under construction at CERN, is included.
Light quark masses using domain wall fermions
Tom Blum; Amarjit Soni; Matthew Wingate
1998-09-10T23:59:59.000Z
We compute the one-loop self-energy correction to the massive domain wall quark propagator. Combining this calculation with simulations at several gauge couplings, we estimate the strange quark mass in the continuum limit. The perturbative one-loop mass renormalization is comparable to that for Wilson quarks and considerably smaller than that for Kogut-Susskind quarks. Also, scaling violations appear mild in comparison to other errors at present. Given their good chiral behavior and these features, domain wall quarks are attractive for evaluating the light quark masses. Our preliminary quenched result is m_s(2 GeV) = 82(15) MeV in the ${\\bar{MS}}$ scheme.
Röder, Beate
dissertation-hu und dissonline, Version 6.1 (25.2.2013) Dissertationen und Habilitationsschriften mit Microsoft Word Leitfaden zu den Dokumentvorlagen »dissertation-hu« »dissonline« Version 6.1 (25.2.2013) gefördert Dokumentvorlagen dissertation-hu und dissonline, Version 6.1 (25.2.2013) Impressum Herausgegeben durch: Humboldt
Single top quark production at D0
Reinhard Schwienhorst; for the D0 collaboration
2011-09-13T23:59:59.000Z
Updates of electroweak single top quark production measurements by the D0 collaboration are presented using 5.4fb^-1 of proton-antiproton collision data from the Tevatron at Fermilab. Measurements of the t-channel, s-channel and combined single top quark production cross section are presented, including an updated lower limit on the CKM matrix element |V_tb|. Also reported are results from searches for gluon-quark flavor-changing neutral currents and W' boson production.
Quark Nuggets as Baryonic Dark Matter
Jan-e Alam; Sibaji Raha; Bikash Sinha
1997-04-23T23:59:59.000Z
The cosmic first order phase transition from quarks to hadrons, occurring a few microseconds after the Big Bang, would lead to the formation of quark nuggets which would be stable on a cosmological time scale, if the associated baryon number is larger than a critical value. We examine the possibility that these surviving quark nuggets may not only be viable candidates for cold dark matter but even close the universe.
Top Quark Physics at the CDF Experiment
Bernd Stelzer; for the CDF Collaboration
2010-07-21T23:59:59.000Z
Fermilab's Tevatron accelerator is recently performing at record luminosities that enables a program systematically addressing the physics of top quarks. The CDF collaboration has analyzed up to 5/fb of proton anti-proton collisions from the Tevatron at a center of mass energy of 1.96 TeV. The large datasets available allow to push top quark measurements to higher and higher precision and have lead to the recent observation of electroweak single top quark production at the Tevatron. This article reviews recent results on top quark physics from the CDF experiment.
Single Top Quarks at the Tevatron
A. P. Heinson
2008-09-05T23:59:59.000Z
After many years searching for electroweak production of top quarks, the Tevatron collider experiments have now moved from obtaining first evidence for single top quark production to an impressive array of measurements that test the standard model in several directions. This paper describes measurements of the single top quark cross sections, limits set on the CKM matrix element |Vtb|, searches for production of single top quarks produced via flavor-changing neutral currents and from heavy W-prime and H+ boson resonances, and studies of anomalous Wtb couplings. It concludes with projections for future expected significance as the analyzed datasets grow.
Jet substructures of boosted polarized top quarks
Yoshio Kitadono; Hsiang-nan Li
2014-09-05T23:59:59.000Z
We study jet substructures of a boosted polarized top quark, which undergoes the semileptonic decay $t\\to b\\ell\
Top Quark Production Asymmetries AFBt and AFBl
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Berger, Edmond L.; Cao, Qing-Hong; Chen, Chuan-Ren; Yu, Jiang-Hao; Zhang, Hao
2012-02-01T23:59:59.000Z
A large forward-backward asymmetry is seen in both the top quark rapidity distribution AFBt and in the rapidity distribution of charged leptons AFBl from top quarks produced at the Tevatron. We study the kinematic and dynamic aspects of the relationship of the two observables arising from the spin correlation between the charged lepton and the top quark with different polarization states. We emphasize the value of both measurements, and we conclude that a new physics model which produces more right-handed than left-handed top quarks is favored by the present data.
Collisional energy loss of heavy quarks
Alex Meistrenko; Andre Peshier; Jan Uphoff; Carsten Greiner
2013-04-13T23:59:59.000Z
We develop a transport approach for heavy quarks in a quark-gluon plasma, which is based on improved binary collision rates taking into account quantum statistics, the running of the QCD coupling and an effective screening mass adjusted to hard-thermal loop calculations. We quantify the effects of in-medium collisions by calculating the heavy flavor nuclear modification factor and the elliptic flow for RHIC energies, which are comparable to radiative effects. We also derive an analytic formula for the mean collisional energy loss of an energetic heavy quark in a streaming quark gluon plasma.
Thermalization of heavy quarks in the quark-gluon plasma
van Hees, H.; Rapp, Ralf.
2005-01-01T23:59:59.000Z
the BNL Relativistic Heavy-Ion Collider (RHIC) indicate the possibility that the D-meson v2 could be similar in magnitude to the one of light hadrons [10,11]. Since the c quark is rather heavy, this would be quite remarkable and could provide important... temperature) has been suggested as a mechanism to enhance partonic cross sections [12?14] to facilitate rapid thermalization of the bulk matter at RHIC as required in hy- drodynamical models. The notion of charmonium resonances in the QGP [15,16] has been...
Name: Nicole Immig Habilitationsthema: Das Trken-und Osmanenbild in
Knüpfer, Christian
/Athen, Forschungsaufenthalt am Centre of Asia-Minor- Studies/Athen und am Institute of Balkan Studies/Thessaloniki 2005 Nafoeg and their Architectural Legacy in Arta and Thessaly, Konferenz Balkan Worlds (Thessaloniki, 5.-7. Okt. 2012
FTD/am; Quelle: MPI fr Dynamik und Selbstorganisation Pennsylvania
Amaral, Luis A.N.
Arkansas Pennsylvania New Mexico Kalifornien Bis hierher und nicht weiter Mobilitätsgrenzen in den USA medizini- sche Anwendungen entwickelt, der die Positronenemissionstomografie (PET) mit der Detektionsempfindlichkeit der PET verbunden werden. Bislang können allerdings nur kleine Labor- tiere untersucht werden. FTD
Nr. 316 / 2012 // 10. Dezember 2012 Volksbanken und Raiffeisenbanken in
Ullmann, G. Matthias
unterstÃ¼tzen traditionell die UniversitÃ¤t Bayreuth Bildunterschrift: von links: Dr. Markus Zanner, Kanzler der Zanner, dankend entgegennahm, kommt dem Lehrstuhl fÃ¼r BWL I (Finanzwirtschaft und Bankbetriebslehre
Lehrstuhl fur Steuerungs-und Regelungstechnik Technische Universitat Munchen
Kuehnlenz, Kolja
and stimulating working environment. It was a great experience to get this generous freedom for research also to Florian Soldner at BMW AG and to Dr.-Ing. Patrick Kuhl and Michael Gr¨af at BMW Forschung und
Top quark mass and properties at the Tevatron
J. -F. Arguin; for the CDF; D0 Collaborations
2005-07-29T23:59:59.000Z
We present recent analyses of top quark properties performed at Run II of the Tevatron. Measurements of the top quark mass, branching ratios and W boson helicity inside top quark decays are covered.
Leibniz Universitat Hannover Fakultat fur Mathematik und Physik
Holm, Thorsten
Algebra II Sommersemester 2011 ¨Ubungsblatt 1 Aufgabe 1: (a) Zeigen Sie: F¨ur alle a, b Q gilt Q( a, b gleichseitiges Dreieck mit Fl¨acheninhalt 1 ist mit Zirkel und Lineal konstruierbar (aus M = {(0, 0), (1, 0)}). (e) Sei a C, so dass a(a2 + 4a - 4) = -1. Dann ist a mit Zirkel und Lineal konstruierbar (aus M
Quark Masses: An Environmental Impact Statement
Robert L. Jaffe; Alejandro Jenkins; Itamar Kimchi
2009-04-03T23:59:59.000Z
We investigate worlds that lie on a slice through the parameter space of the Standard Model over which quark masses vary. We allow as many as three quarks to participate in nuclei, while fixing the mass of the electron and the average mass of the lightest baryon flavor multiplet. We classify as "congenial" worlds that satisfy the environmental constraint that the quark masses allow for stable nuclei with charges one, six, and eight, making organic chemistry possible. Whether a congenial world actually produces observers depends on a multitude of historical contingencies, beginning with primordial nucleosynthesis, which we do not explore. Such constraints may be independently superimposed on our results. Environmental constraints such as the ones we study may be combined with information about the a priori distribution of quark masses over the landscape of possible universes to determine whether the measured values of the quark masses are determined environmentally, but our analysis is independent of such an anthropic approach. We estimate baryon masses as functions of quark masses and nuclear masses as functions of baryon masses. We check for the stability of nuclei against fission, strong particle emission, and weak nucleon emission. For two light quarks with charges 2/3 and -1/3, we find a band of congeniality roughly 29 MeV wide in their mass difference. We also find another, less robust region of congeniality with one light, charge -1/3 quark, and two heavier, approximately degenerate charge -1/3 and 2/3 quarks. No other assignment of light quark charges yields congenial worlds with two baryons participating in nuclei. We identify and discuss the region in quark-mass space where nuclei would be made from three or more baryon species.
Relation between quark-antiquark potential and quark-antiquark free energy in hadronic matter
Zhen-Yu Shen; Xiao-Ming Xu
2015-07-07T23:59:59.000Z
In the high-temperature quark-gluon plasma and its subsequent hadronic matter created in a high-energy nucleus-nucleus collision, the quark-antiquark potential depends on the temperature. The temperature-dependent potential is expected to be derived from the free energy obtained in lattice gauge theory calculations. This requires one to study the relation between the quark-antiquark potential and the quark-antiquark free energy. When the system's temperature is above the critical temperature, the potential of a heavy quark and a heavy antiquark almost equals the free energy, but the potential of a light quark and a light antiquark, of a heavy quark and a light antiquark and of a light quark and a heavy antiquark is substantially larger than the free energy. When the system's temperature is below the critical temperature, the quark-antiquark free energy can be taken as the quark-antiquark potential. This allows one to apply the quark-antiquark free energy to study hadron properties and hadron-hadron reactions in hadronic matter.
Friction Coefficient for Quarks in Supergravity Duals
E. Antonyan
2006-11-22T23:59:59.000Z
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.
Top quark physics expectations at the LHC
Andrei Gaponenko; for the ATLAS Collaboration; for the CMS Collaboration
2008-10-22T23:59:59.000Z
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.
Heavy quark thermodynamics in full QCD
Konstantin Petrov; RBC-Bielefeld Collaboration
2007-01-22T23:59:59.000Z
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.
Light-Quark Decays in Heavy Hadrons
Faller, Sven
2015-01-01T23:59:59.000Z
We consider weak decays of heavy hadrons (bottom and charmed) where the heavy quark acts as a spectator. Theses decays are heavily phase-space suppressed but may become experimentally accessible in the near future. These decays are interesting as a QCD laboratory to study the behaviour of the light quarks in the colour-background field of the heavy spectator.
Static quark free energies at finite temperature
Z. Fodor; A. Jakovac; S. D. Katz; K. K. Szabo
2007-10-22T23:59:59.000Z
We determine the static quark free energies around the transition temperature using 2+1 flavors of staggered fermions. Simulations are carried out on N_t=4,6,8 and 10 lattices using physical quark masses. The free energies extracted from Polyakov-loop correlators are extrapolated to the continuum limit.
The Chandrasekhar limit for quark stars
Shibaji Banerjee; Sanjay K. Ghosh; Sibaji Raha
2000-01-14T23:59:59.000Z
The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant.
Review of Top Quark Physics Results
Kehoe, R.; Narain, M.; Kumar, A.; ,
2007-12-01T23:59:59.000Z
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.
Recent advances in heavy quark theory
Wise, M. [California Institute of Technology, Pasadena, CA (United States)
1997-01-01T23:59:59.000Z
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.
Tevatron Top-Quark Combinations and World Top-Quark Mass Combination
Reinhild Yvonne Peters; on behalf of the ATLAS; CDF; CMS; D0 collaborations
2014-11-04T23:59:59.000Z
Almost 20 years after its discovery, the top quark is still an interesting particle, undergoing precise investigation of its properties. For many years, the Tevatron proton antiproton collider at Fermilab was the only place to study top quarks in detail, while with the recent start of the LHC proton proton collider a top quark factory has opened. An important ingredient for the full understanding of the top quark is the combination of measurements from the individual experiments. In particular, the Tevaton combinations of single top-quark cross sections, the ttbar production cross section, the W helicity in top-quark decays as well as the Tevatron and the world combination of the top-quark mass are discussed.
Static quark free energies at finite temperature with two flavors of improved Wilson quarks
Y. Maezawa; S. Ejiri; T. Hatsuda; N. Ishii; N. Ukita; S. Aoki; K. Kanaya
2006-10-02T23:59:59.000Z
Polyakov loop correlations at finite temperature in two-flavor QCD are studied in lattice simulations with the RG-improved gluon action and the clover-improved Wilson quark action. From the simulations on a $16^3 \\times 4$ lattice, we extract the free energies, the effective running coupling $g_{\\rm eff}(T)$ and the Debye screening mass $m_D(T)$ for various color channels of heavy quark--quark and quark--anti-quark pairs above the critical temperature. The free energies are well approximated by the screened Coulomb form with the appropriate Casimir factors. The magnitude and the temperature dependence of the Debye mass are compared to those of the next-to-leading order thermal perturbation theory and to a phenomenological formula given in terms of $g_{\\rm eff}(T)$. Also we made a comparison between our results with the Wilson quark and those with the staggered quark previously reported.
M. Bishai
2002-12-13T23:59:59.000Z
Heavy quark production cross-sections, correlations and polarizations have been measured at the Collider Detector at Fermilab (CDF) using 118 pb{sup -1} of data collected from the 1992 to 1995 Run I of the Fermilab Tevatron. There is still disagreement between theoretical predictions of bottom and charm hadro-production cross-sections and the Run I results. The observed transverse momentum spectrum of the prompt J/{psi} production polarization is still not understood. Run II of the Tevatron began in July of 2001 and the CDF Run II detector [11] has collected 70 pb{sup -1} of physics quality data since January 2002. Large statistics of onia states have been collected. Exclusive B meson decay modes have been reconstructed and the SVT level 2 displaced track trigger has produced large samples of D mesons. The prompt charm and b {yields} cX fractions in both charmonium and D meson samples have been measured. Run II is now poised to greatly enhance the knowledge of heavy quark production dynamics well beyond the reach of the Run I detector.
Hard quark-quark scattering with exclusive reactions
Barton, D.S.; Bunce, G.M.; Carroll, A.S.; Makdisi, Y.I.; Baller, B.; Blazey, G.C.; Courant, H.; Heller, K.J.; Heppelmann, S.; Marshak, M.L.
1984-07-19T23:59:59.000Z
We have begun a program designed to study hard quark-quark scattering with exclusive reactions, focusing on quasi-elastic two-body reactions with all possible quark flavor exchanges. Examples are ..pi../sup -/p ..-->.. ..pi../sup -/p, rho/sup -/p, ..pi../sup +/..delta../sup -/, K/sup +/..sigma../sup -/, or K..lambda... Of the two-body exclusives, only elastic scattering had been measured at such large t previous to our experiment. By comparing the relative importance of different final states, the energy dependence of the production ratios of these states, the prominence of resonances such as rho/sup -/ over background in this region, and measuring polarizations where accessible, we have collected a large body of data on hard scattering in a completely new domain. Previously, essential all short distance QCD tests have been for inclusive processes. We have taken data with both negative and positive incident beam at 10 GeV/c on a hydrogen target and will present the first results, for ..pi../sup -/p ..-->.. ..pi../sup -/p and rho/sup -/p at THETA/sub cm/ = 90/sup 0/, -t = 9 GeV/sup 2//c/sup 2/. The apparatus consists of a magnetic spectrometer, with Cerenkov particle identification, which selects stable charged particles (protons in this case) at high momentum near 90/sup 0/ in the center-of-mass. A large aperture array of PWCs observes the recoil particle or charged decay products. Cross sections are extremely low, approximately a 1 nb/(GeV/c)/sup 2/ for elastic scattering. We will report on a sample of more than 1000 ..pi../sup -/p elastic events, and on rho/sup -/p, where the rho/sup -/ decay distribution was observed. We find a surprisingly large rho/sup -/p cross section in this large momentum transfer region, with rho/sup -/p about half the elastic cross section, and a striking spin alignment of the rho/sup -/.
The QCD spectrum with three quark flavors
Claude Bernard; Tom Burch; Thomas A. DeGrand; Saumen Datta; Carleton DeTar; Steven Gottlieb; Urs M. Heller; Kostas Orginos; Robert Sugar; Doug Toussaint
2001-05-29T23:59:59.000Z
We present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks - two light and one strange, and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge action and an improved Kogut-Susskind quark action. The lattice spacings, and hence also the physical volumes, were tuned to be the same in all the runs to better expose differences due to flavor number. Lattice spacings were tuned using the static quark potential, so as a byproduct we obtain updated results for the effect of sea quarks on the static quark potential. We find indications that the full QCD meson spectrum is in better agreement with experiment than the quenched spectrum. For the 0++ (a0) meson we see a coupling to two pseudoscalar mesons, or a meson decay on the lattice.
Quarks and gluons in hadrons and nuclei
Close, F.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))
1989-12-01T23:59:59.000Z
These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. This lecture discusses the distribution functions of quarks and gluons in nucleons and nuclei, and how knowledge of these is necessary before some quark-gluon plasma searches can be analyzed. 56 refs., 2 figs.
Kaczmarek, O
2005-01-01T23:59:59.000Z
We analyze the change in free energy, internal energy and entropy due to the presence of a heavy quark anti-quark pair in a QCD heat bath. The internal energies and entropies are introduced as intensive observables calculated through thermal derivatives of the QCD partition function containing additional static color sources. The quark anti-quark internal energy and, in particular, the entropy clearly signal the phase change from quark confinement below and deconfinement above the transition and both observables are introduced such that they survive the continuum limit. The intermediate and large distance behavior of the energies reflect string breaking and color screening phenomena. This is used to characterize the energies which are needed to dissolve heavy quarkonium states in a thermal medium. Our discussion supports recent findings which suggest that parts of the quarkonium systems may survive the phase transition and dissolve only at higher temperatures.
Starzinger, Jakob
2005-01-01T23:59:59.000Z
Syrakus im Jahre 1802. Mein Sommer 1805. Herausgegeben vonnach Syrakus und Mein Sommer 1805. Wien 2005 (im Druck).nach Syrakus und Mein Sommer 1805. Wien 2005 (im Druck).
I II. MUSICA PRO PACE 1999: Das >Junge Frankreich< und die
Steinhoff, Heinz-Jürgen
Kriegsniederlage 1940: André Jolivets »Les Trois Complaintes du Soldat« und Olivier Messiaens »Quatuor pour la Fin und Empfindungen der folgenden beiden Monate haben sich in Jolivets Les Trois Complaintes du Soldat
Fakultt fr Wirtschafts-und Sozialwissenschaften Alfred Weber-Institut fr Wirtschaftswissenschaften
Heermann, Dieter W.
FakultÃ¤t fÃ¼r Wirtschafts- und Sozialwissenschaften Alfred Weber-Institut fÃ¼r Abschlussarbeit". Hiermit lÃ¤dt das Studierenden- und Alumni Netzwerk des Alfred-Weber Instituts fÃ¼r
Quo vadis universitas? Kritische Beitrge zur Idee und Zukunft der Universitt
ZÃ¼rich, UniversitÃ¤t
Vorwort Vor zehn Jahren erfasste eine Reformwelle die Institutionen der Ã¶ffentlichen Verwaltung: NPM und fÃ¼r die Uni- versitÃ¤t. Nicht wenige kommunale und staatliche Verwaltungen haben ihre NPM
Mühlemann, Oliver
Wiederholungsprüfungen Termine fürs HS 2013 und FS 2014 (im KSL unter Leistungskontrolle 2. Termin erfasst) Bachelor Chemie Bachelor Biochemie Grundstudium Pharmazie Master Chemie und Molekulare Biochemie (Büro S170) für Veranstaltungen aus der Biochemie (°), falls Sie einen Termin abmachen möchten
Gesellschaft der Freunde und Frderer der Universitt zu Lbeck e. V., Sektion Alumni
Lübeck, Universität zu
Gabriele Zillmer TOP 1 Begrüßung Der 1. Vorsitzende begrüßt die Anwesenden und dankt allen für ihr Kommen
HUNTING THE QUARK GLUON PLASMA.
LUDLAM, T.; ARONSON, S.
2005-04-11T23:59:59.000Z
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.
Energie-und Leistungsbilanzierung im MICRO GRID eines industriellen Produktionsstandortes mit
Paderborn, Universität
an das lokale MICRO GRID angeschlossenen elektrischen Energiespeicher und eine ,,POWER TO GAS" -Anlage ermöglichen. Aufgabe: Um einen effizienten Einsatz des BHKW's, des Speichers und der POWER TO GAS Einheit zu Konzeptes zum wirtschaftlich effizienten Einsatz des BHKW's, des Speichers und der POWER TO GAS Einheit 6
PD Dr. Martin Stetter, Siemens AG 1 Statistische und neuronale Lernverfahren
Popeea, Corneliu - Chair for Foundations of Software Reliability and Theoretical Computer Science
PD Dr. Martin Stetter, Siemens AG 1 Statistische und neuronale Lernverfahren Martin Stetter SS 2003, Siemens AG 2 Behandelte Themen 0. ,,Motivation": Lernen in Statistik und Biologie 1-Regression 4. Bayes-Belief-Netze Statistische und neuronale Lernverfahren #12;PD Dr. Martin Stetter, Siemens AG
Andrzejak, Artur
Zielsetzungen und Rahmenbedingungen für die Gewährung des Siemens-ZIB-Doktorandenstipendiums (inklusive Anlage) Die Firma Siemens AG und das KonradZuseZentrum für Informationstechnik Berlin (ZIB. Verantwortlich für die Vergabe des SiemensZIBDoktorandenstipendiums und für die Betreuung der Doktoranden sind
PD Dr. Martin Stetter, Siemens AG 1 Statistische und neuronale Lernverfahren
Popeea, Corneliu - Chair for Foundations of Software Reliability and Theoretical Computer Science
PD Dr. Martin Stetter, Siemens AG 1 Statistische und neuronale Lernverfahren Martin Stetter WS 03, Siemens AG 2 Behandelte Themen 0. ,,Motivation": Lernen in Statistik und Biologie 1-Regression 4. Bayes-Belief-Netze Statistische und neuronale Lernverfahren #12;PD Dr. Martin Stetter, Siemens AG
Universitt Hannover Club Apollo 13 Institut fr Photogrammetrie und GeoInformation Januar 2006
Nejdl, Wolfgang
Universität Hannover Club Apollo 13 Institut für Photogrammetrie und GeoInformation Januar 2006 Club Apollo 13 Seite 1 - Aufgabe Club Apollo 13: Luftbildphotogrammetrie und automatische darstellen. #12;Universität Hannover Club Apollo 13 Institut für Photogrammetrie und GeoInformation Januar
Messner, R. [Stanford Univ., CA (United States)
1997-01-01T23:59:59.000Z
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.
Top Quark Pair Production in Early CMS Data
Kao, Shih-Chuan
2011-01-01T23:59:59.000Z
23 2.13 top decay . . . . . . . . . . . . .of the Top Quark . . . . . . . . . . . . . . . . . . . . .20 Top Production in Hadron
Top Quark Physics at the ILC: Methods and Meanings
Zack Sullivan
2009-03-06T23:59:59.000Z
The physics case for studying top-quark physics at the International Linear Collider is well established. This summary places in context the top-quark physics goals, examines the current state-of-the art in understanding of the top-quark mass, and identifies some areas in which the study of the top-quark mass enhances our understanding of new techniques.
Singlet Free Energies of a Static Quark-Antiquark Pair
Konstantin Petrov
2004-09-01T23:59:59.000Z
We study the singlet part of the free energy of a static quark anti-quark pair at finite temperature in three flavor QCD with degenerate quark masses using $N_{\\tau}=4$ and 6 lattices with Asqtad staggered fermion action. We look at thermodynamics of the system around phase transition and study its scaling with lattice spacing and quark masses.
Newtonian gravity, red shift, confinement, asymptotic freedom and quarks oscillations
G. Quznetsov
2008-10-18T23:59:59.000Z
Quarks oscillations give the Newtonian gravity law, the red shift, the confinement and the asymptotic freedom.
Discovery of single top quark production
Gillberg, Dag
2009-05-01T23:59:59.000Z
The top quark is by far the heaviest known fundamental particle with a mass nearing that of a gold atom. Because of this strikingly high mass, the top quark has several unique properties and might play an important role in electroweak symmetry breaking - the mechanism that gives all elementary particles mass. Creating top quarks requires access to very high energy collisions, and at present only the Tevatron collider at Fermilab is capable of reaching these energies. Until now, top quarks have only been observed produced in pairs via the strong interaction. At hadron colliders, it should also be possible to produce single top quarks via the electroweak interaction. Studies of single top quark production provide opportunities to measure the top quark spin, how top quarks mix with other quarks, and to look for new physics beyond the standard model. Because of these interesting properties, scientists have been looking for single top quarks for more than 15 years. This thesis presents the first discovery of single top quark production. An analysis is performed using 2.3 fb{sup -1} of data recorded by the D0 detector at the Fermilab Tevatron Collider at centre-of-mass energy {radical}s = 1.96 TeV. Boosted decision trees are used to isolate the single top signal from background, and the single top cross section is measured to be {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.74{sub -0.74}{sup +0.95} pb. Using the same analysis, a measurement of the amplitude of the CKM matrix element V{sub tb}, governing how top and b quarks mix, is also performed. The measurement yields: |V{sub tb}|f{sub 1}{sup L}| = 1.05{sub -0.12}{sup +0.13}, where f{sub 1}{sup L} is the left-handed Wtb coupling. The separation of signal from background is improved by combining the boosted decision trees with two other multivariate techniques. A new cross section measurement is performed, and the significance for the excess over the predicted background exceeds 5 standard deviations.
Top Quark Forward-Backward Asymmetry
Kingman Cheung; Wai-Yee Keung; Tzu-Chiang Yuan
2009-11-17T23:59:59.000Z
The recent forward-backward asymmetry recorded by the CDF Collaboration for the top and anti-top quark pair production indicates more than $2\\sigma$ deviation from the Standard Model prediction, while its total production cross section remains consistent. We propose a $W'$ boson that couples to down and top quarks. We identify the parameter space that can give rise a large enough forward-backward asymmetry without producing too many top and anti-top quark pairs. Other models presented erstwhile in the literature that can produce such effects are also discussed.
Top quark properties from the Tevatron
Klute, Markus; /MIT, LNS
2006-05-01T23:59:59.000Z
This report describes latest measurements and studies of top quark properties from the Tevatron in Run II with an integrated luminosity of up to 750 pb{sup -1}. Due to its large mass of about 172 GeV/c{sup 2}, the top quark provides a unique environment for tests of the Standard Model and is believed to yield sensitivity to new physics beyond the Standard Model. With data samples of close to 1 fb{sup -1} the CDF and D0 collaborations at the Tevatron enter a new area of precision top quark measurements.
A. M. Green; C. Michael; J. E. Paton
1992-09-15T23:59:59.000Z
Four-quark potentials for $SU(2)$ are evaluated in the static limit with the quenched approximation -- using a lattice of $16^3\\times 32$ and $\\beta=2.4$. The four quarks are restricted to the corners of rectangles with sides upto seven lattice spacings long. The results are analysed in terms of a strategy based on interquark two-body potentials -- as advocated earlier by the authors. This shows that a standard two-body approach overestimates the four-quark binding energy by upto a factor of about three for the largest rectangles.
Hadron structure with light dynamical quarks
LHPC Collaboration; Robert G. Edwards; George Taminga Fleming; Philipp Hagler; John W. Negele; Kostas Orginos; Andrew V. Pochinsky; Dru B. Renner; David G. Richards; Wolfram Schroers
2005-09-30T23:59:59.000Z
Generalized parton distributions encompass a wealth of information concerning the three-dimensional quark and gluon structure of the nucleon, and thus provide an ideal focus for the study of hadron structure using lattice QCD. The special limits corresponding to form factors and parton distributions are well explored experimentally, providing clear tests of lattice calculations, and the lack of experimental data for more general cases provides opportunities for genuine predictions and for guiding experiment. We present results from hybrid calculations with improved staggered (Asqtad) sea quarks and domain wall valence quarks at pion masses down to 350 MeV.
Quarks and gluons in hadrons and nuclei
Close, F.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))
1989-01-01T23:59:59.000Z
These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. 38 refs.
Berlin,Technische UniversitÃ¤t
das unbemannte fliegende System IFSys Mila, Joan Singla 04/13 A. KÃ¶the2 MA Autonomous Flight Control Unmanned Aerial Vehicle (UAV) ALEXIS Â Konzept und erste Realisierung KÃ¶the, Alexander 04/12 A. SchÃ¶nfeld2
Heavy Quark Anti-Quark Free Energy and the Renormalized Polyakov Loop
Kaczmarek, O; Petreczky, P; Zantow, F
2002-01-01T23:59:59.000Z
We calculate the colour averaged and colour singlet free energies of static quark anti-quark sources placed in a thermal gluonic heat bath. We discuss the renormalization of these free energies using the short distance properties of the zero temperature heavy quark potential. This leads to the definition of the renormalized Polyakov loop as an order parameter for the deconfinement phase transition of the SU(3) gauge theory which is well behaved in the continuum limit.
Recent Results of Top Quark Physics from the Tevatron
R. Y. Peters; on behalf of the D0; CDF collaborations
2015-07-09T23:59:59.000Z
Twenty years after its discovery in 1995 by the CDF and D0 collaborations at the Tevatron proton-antiproton collider at Fermilab, the top quark still undergoes intensive studies at the Tevatron and the LHC at CERN. In this article, recent top quark physics results from CDF and D0 are reported. In particular, measurements of single top quark and double top quark production, the ttbar forward-backward asymmetry and the top quark mass are discussed.
Quenched hadron spectroscopy with improved staggered quark action
MILC Collaboration; Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs M. Heller; James Hetrick; Craig McNeile; K. Rummukainen; Bob Sugar; Doug Toussaint
1997-12-11T23:59:59.000Z
We investigate light hadron spectroscopy with an improved quenched staggered quark action. We compare the results obtained with an improved gauge plus an improved quark action, an improved gauge plus standard quark action, and the standard gauge plus standard quark action. Most of the improvement in the spectroscopy results is due to the improved gauge sector. However, the improved quark action substantially reduces violations of Lorentz invariance, as evidenced by the meson dispersion relations.
Commissioning ATLAS and CMS with top quarks
B. S. Acharya; F. Cavallari; G. Corcella; R. Di Sipio; G. Petrucciani
2008-05-25T23:59:59.000Z
The large ttbar production cross-section at the LHC suggests the use of top quark decays to calibrate several critical parts of the detectors, such as the trigger system, the jet energy scale and b-tagging.
Kong, Kyoungchul; Lee, Hye-Sung; Park, Myeonghun
2014-04-01T23:59:59.000Z
We suggest top quark decays as a venue to search for light dark force carriers. The top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6sigma deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t-->bW+Z's. This is the same as the dominant top quark decay (t-->bW) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.
Theory of top quark production and decay
Kuehn, J.H. [Universitaet Karlsruhe (Germany)
1997-01-01T23:59:59.000Z
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.
Mass inequality for the quark propagator
Dean Lee; Richard Thomson
2005-06-09T23:59:59.000Z
We show that for any gauge-fixing scheme with positive semi-definite functional integral measure, the inverse correlation length of the quark propagator is bounded below by one-half the pion mass.
Relativistic harmonic oscillator model for quark stars
Vishnu M. Bannur
2008-10-06T23:59:59.000Z
The relativistic harmonic oscillator (RHO) model of hadrons is used to study quark stars. The mass-radius relationship is obtained and compared with bag model of quark star, using Tolman-Oppenheimer-Volkoff equation. In this model, the outward degenerate pressure due to discrete Landau levels and Landau degeneracy balances the inward gravitational pressure. Where as in bag model the degenerate pressure is due to the standard continuum levels which balances the combined inward pressure due to gravitation and bag pressure. So in RHO model, the confinement effect is included in the degenerate pressure. We found a qualitative similarity, but quantitative differences in mass-radius relationship of quark stars in these two models. Masses and radii are relatively larger and the central energy densities, required for stable quark stars, are lower in RHO model than that of bag model.
Evidence for production of single top quarks
Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Simon Fraser U.; Ahn, S.H.; /Korea U., KODEL; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, G.; /St. Petersburg, INP /Michigan U.
2008-03-01T23:59:59.000Z
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p{bar p} 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 datasets. In this analysis, we select events from a 0.9 fb{sup -1} dataset 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 t{bar t} 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 {sigma}(p{bar p} {yields} 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 |V{sub tb}f{sub 1}{sup L}| = 1.31{sub -0.21}{sup +0.25}, where f{sub 1}{sup L} is a generic vector coupling. This model-independent measurement translates into 0.68 < |V{sub tb}| {le} 1 at the 95% C.L. in the standard model.
Single top quark production at the Tevatron
Schwienhorst, Reinhard; /Michigan State U.
2008-05-01T23:59:59.000Z
The Tevatron experiments D0 and CDF have found evidence for single top quark production, based on datasets between 0.9 fb{sup -1} and 2.2 fb{sup -1}. Several different multivariate techniques are used to extract the single top quark signal out of the large backgrounds. The cross section measurements are also used to provide the first direct measurement of the CKM matrix element |V{sub tb}|.
Charmonium with three flavors of synamical quarks
Massimo Di Pierro et al.
2003-12-23T23:59:59.000Z
We present a calculation of the charmonium spectrum with three flavors of dynamical staggered quarks from gauge configurations that were generated by the MILC collaboration. We use the Fermilab action for the valence charm quarks. Our calculation of the spin-averaged 1P-1S and 2S-1S splittings yields a determination of the strong coupling, with {alpha}{sub {ovr MS}}(M{sub Z}) = 0.119(4).
Shear viscosity of the quark matter
Masaharu Iwasaki; Hiromasa Ohnishi; Takahiko Fukutome
2007-05-14T23:59:59.000Z
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.
Running heavy-quark masses in DIS
S. Alekhin; S. -O. Moch
2011-07-03T23:59:59.000Z
We report on determinations of the running mass for charm quarks from deep-inelastic scattering reactions. The method provides complementary information on this fundamental parameter from hadronic processes with space-like kinematics. The obtained values are consistent with but systematically lower than the world average as published by the PDG. We also address the consequences of the running mass scheme for heavy-quark parton distributions in global fits to deep-inelastic scattering data.
Magnetism and superconductivity in quark matter
T. Tatsumi; E. Nakano; K. Nawa
2005-06-01T23:59:59.000Z
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.
Heavy-light quarks interactions in QCD vacuum
Mirzayusuf Musakhanov
2015-03-20T23:59:59.000Z
QCD vacuum instantons induce very strong interactions between light quarks, which generate large dynamical light quark mass M for initially almost massless quarks and can bound these quarks to produce almost massless pions in accordance with the spontaneous breaking of chiral symmetry (S\\chiSB). On the other hand, the QCD vacuum instantons generate heavy-light quark interactions terms, which are responsible for the effects of S\\chiSB in a heavy-light quark system. Summing the re-scattering series that lead to the total light quark propagator and making few further steps, we get the fermionized representation of low-frequencies light quark determinant in the presence of the quark sources, which is relevant for our problems. The next important step in the line of this strategy is to derive the equation and calculate the heavy quark propagator in the instanton media and in the presence of light quarks. This one provide finally the heavy and N_f light quarks interaction term. As an example, we derive heavy quark-light mesons interaction term for the N_f=2 case. If we take the average instanton size \\rho=0.35 fm, and average inter-instanton distance R=0.856 fm from our previous estimates, we obtain at LO on 1/N_c expansion dynamical light quark mass M = 570 MeV and instanton media contribution to heavy quark mass \\Delta M=148 MeV. These factors define the coupling between heavy and light quarks and, certainly, between heavy quarks and light mesons. We will apply this approach to heavy quark and heavy-light quark systems.
Phase transition from hadronic matter to quark matter
P. Wang; A. W. Thomas; A. G. Williams
2007-04-03T23:59:59.000Z
We study the phase transition from nuclear matter to quark matter within the SU(3) quark mean field model and NJL model. The SU(3) quark mean field model is used to give the equation of state for nuclear matter, while the equation of state for color superconducting quark matter is calculated within the NJL model. It is found that at low temperature, the phase transition from nuclear to color superconducting quark matter will take place when the density is of order 2.5$\\rho_0$ - 5$\\rho_0$. At zero density, the quark phase will appear when the temperature is larger than about 148 MeV. The phase transition from nuclear matter to quark matter is always first order, whereas the transition between color superconducting quark matter and normal quark matter is second order.
Production, elliptic flow and energy loss of heavy quarks in the quark-gluon plasma
Jan Uphoff; Oliver Fochler; Zhe Xu; Carsten Greiner
2010-11-10T23:59:59.000Z
Production, elliptic flow and the nuclear modification factor of charm and bottom quarks are studied in central and non-central heavy-ion collisions at RHIC and LHC using the partonic transport model Boltzmann Approach of MultiParton Scatterings (BAMPS). Employing an initial heavy quark yield obtained with PYTHIA the full space-time evolution of charm and bottom quarks in the quark-gluon plasma (QGP) is carried out with BAMPS, taking also secondary production in the QGP into account. Only elastic collisions of heavy quarks with particles from the medium cannot describe the experimentally observed elliptic flow and nuclear modification factor. However, using an improved Debye screening and the running coupling yields a result which is much closer to data.
Diplomanden-und Doktorandenseminar des Instituts fr Informatik
Zachmann, Gabriel
Diplomanden- und Doktorandenseminar des Instituts fÃ¼r Informatik Six Sigma im Im Ã¼blichen Sinne wird Six Sigma insbesondere in Fertigungsindustrien wie zum Beispiel in der ist Six Sigma nicht nur eine Managementstrategie, die sich ausschlieÃ?lich auf die Fertigungsindustrie
STRUKTUR UND HERKUNFT DER WILDBIENEN-POPULATIONEN AUF FELDERN
Paris-Sud XI, Université de
STRUKTUR UND HERKUNFT DER WILDBIENEN-POPULATIONEN AUF FELDERN DER ZOTTELWICKE IN UNGARN. EIN, Budapest / Ungarn 2 SUMMARY STRUCTURE AND ORIGIN OF HAIRY VETCH POLLINATING WILD BEE POPULATIONS IN HUNGARY- wiesen, die in bestimmten Gebieten Ungarns die Zottelwicke bestäuben. Wegen der übergrossen Häufigkeit
Forschung und EU-Hochschulbro, Technologietransfer September 2014
Nejdl, Wolfgang
Nachwuchswissenschaftler/innen 4 1.2. LEIT: Information and communication technologies 4 1.2.1. Öffentliche Konsultation zu Programme Chemical Biology of Native Nucleic Acid Modifications (SPP 1784) 13 4.1.4. Volkswagen.1.8. NIH: Research Grants 16 5. Umweltwissenschaften und Energie 16 5.1.1. EU/KIC InnoEnergy: Call
INSTITUT FR ASIEN-UND AFRIKAWISSENSCHAFTEN ZENTRALASIEN-SEMINAR
Peters, Achim
INSTITUT FÜR ASIEN- UND AFRIKAWISSENSCHAFTEN ZENTRALASIEN-SEMINAR Kyrgyzstan today Youth services for women, migrants and youth in Kyrgyzstan Bolotkan Sydykanov Due to lack of information, education and financial resources, young women in the rural areas of Kyrgyzstan do not properly use health
Macht Musizieren gesund? Zur Herzrate und deren Variabilitt
Widmer, Gerhard
in Sankt Florian im Sommer 2008 in Ã?sterreich wurden die Herzraten von Klaus Laczika (Pianist und Mediziner Nachhinein nur die Herzdaten fÃ¼r die Auswertung verwendet werden. 1.Klaus Laczika, Klavier 2.Kirill Kobatschenko Violine 3.RenÃ© Staar, Violine 4.Arkadij Winokurov, Violine 5.Fritz Bauer, Viola 6.Erich Kaufmann
Bachelor's Thesis Hotfile-und Flaschenhals-Erkennung im
Wardetzky, Max
of those resources is dCache, a mass-storage management system partic- ularly developed for high energy relies on the deployment of efficient and reliable monitoring systems and optimisation techniques. OneBachelor's Thesis Hotfile- und Flaschenhals-Erkennung im dCache-System Hotfile and Bottleneck
Fakultat fur Physik und Astronomie Ruprecht-Karls-Universitat Heidelberg
Aeschbach-Hertig, Werner
wurden Bodenluftmessungen f¨ur die an der Zehrung beteiligten Gase O2, CO2, CH4 und H2S an zwei permanent and H2S involved in oxygen depletion were performed at two permanent sampling sites in Stuttgart process of relative noble gas enrichment in soil air due to the partial removal of gaseous CO2 produced
4. Mit Charakterstarke und Integritat ubernommene Verantwortung im "Dritten Reich"
Alsmeyer, Gerold
Wahlgang (gegen Adolf Hitler und Ernst Th¨almann) erfolgte Wiederwahl er sich sehr stark engagiert hatte am 17. November 1932 zur¨uck. Nach ergebnislosen Verhandlungen mit Hitler wurde Schleicher am 3. De seinem R¨ucken verhandelte je- doch Papen am 22. Januar 1933 im Auftrage Hindenburgs mit Hitler ¨uber
FE-Analysen zur Thermoermdung Test-und Feldzyklen
Berlin,Technische Universität
LIVE AG 1 -AG 2 FE-Analysen zur Thermoermüdung Test- und Feldzyklen R. Dudek, R. Döring, B #12;LIVE different SAC creep laws: Steady State Creep (after Schubert, SAC405 and Röllig/Wiese SAC xx) Creep properties of SAC 407 show much higher creep resistance than SAC xx SAC 305 bulk averaged values
Langevin dynamics and decoherence of heavy quarks at high temperatures
Akamatsu, Yukinao
2015-01-01T23:59:59.000Z
Langevin equation of heavy quarks in high-temperature quark-gluon plasma is derived. The dynamics of heavy quark color is coupled with the phase space dynamics and causes a macroscopic superposition state of heavy quark momentum. Decoherence of the superposition state allows us classical description. The time scale of decoherence gives an appropriate discretization time scale $\\Delta t \\sim \\sqrt{M/\\gamma}$ for the classical Langevin equation, where $M$ is heavy quark mass and $\\gamma$ is heavy quark momentum diffusion constant.
Measurements of top quark properties at the Tevatron collider
Margaroli, Fabrizio
2011-05-01T23:59:59.000Z
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.
Universal Mass Texture, CP violation and Quark-Lepton Complementarity
Canales, F Gonzalez; Barranco, J
2010-01-01T23:59:59.000Z
Recent measurements of the neutrino and quark mixing angles satisfy the empirical relations called quark-lepton complementarity. These empirical relations suggests the existence of a correlation between the mixing matrices of leptons and quarks. In this work, we examine the possibility that this correlation between the mixing angles of quarks and leptons originates in the similar hierarchy of quarks and charged lepton masses and the seesaw mechanism type I, that gives mass to the Majorana neutrinos. We asssume that the similar mass hierarchies of charged lepton and quark masses allows us to represent all the mass matrices of Dirac fermions in terms of a two zeroes Fritzsch texture.
Universal mass matrix for quarks and leptons and CP violation
Barranco, J.; Gonzalez Canales, F.; Mondragon, A. [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Golm (Germany); Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510, Mexico D.F. (Mexico)
2010-10-01T23:59:59.000Z
The measurements of the neutrino and quark mixing angles satisfy the empirical relations called quark-lepton complementarity. These empirical relations suggest the existence of a correlation between the mixing matrices of leptons and quarks. In this work, we examine the possibility that this correlation between the mixing angles of quarks and leptons originates in the similar hierarchy of quarks and charged lepton masses and the seesaw mechanism type I, that gives mass to the Majorana neutrinos. We assume that the similar mass hierarchies of charged lepton and quark masses allows us to represent all the mass matrices of Dirac fermions in terms of a universal form with four texture zeroes.
Color superconductivity and dense quark matter
Massimo Mannarelli
2008-12-26T23:59:59.000Z
The properties of cold and dense quark matter have been the subject of extensive investigation, especially in the last decade. Unfortunately, we still lack of a complete understanding of the properties of matter in these conditions. One possibility is that quark matter is in a color superconducting phase which is characterized by the formation of a diquark condensate. We review some of the basic concepts of color superconductivity and some of the aspects of this phase of matter which are relevant for compact stars. Since quarks have color, flavor as well as spin degrees of freedom many different color superconducting phases can be realized. At asymptotic densities QCD predicts that the color flavor locked phase is favored. At lower densities where the QCD coupling constant is large, perturbative methods cannot be applied and one has to rely on some effective model, eventually trying to constrain such a model with experimental observations. The picture is complicated by the requirement that matter in the interior of compact stars is in weak equilibrium and neutral. These conditions and the (possible) large value of the strange quark mass conspire to separate the Fermi momenta of quarks with different flavors, rendering homogenous superconducting phases unstable. One of the aims of this presentation is to introduce non-experts in the field to some of the basic ideas of color superconductivity and to some of its open problems.
Reyle, Uwe
Die Civil Academy ist ein gemeinsames Programm von BBE und BP Europa SE. Träger und Veranstalter der Civil Academy ist die BBE Geschäftsstelle gemeinnützige GmbH. Ausschreibung der 18. Civil Academy Civil Academy Gutes auch gut tun! Du willst mit einer kreativen Idee die Welt zum Besseren verändern
Heavy quarks in deeply virtual Compton scattering
Jens D. Noritzsch
2003-12-11T23:59:59.000Z
A detailed study of the heavy quark h=c,b,... contributions to deeply virtual Compton scattering is performed at both the amplitude and the cross section level, and their phenomenological relevance is discussed. For this purpose I calculate the lowest order off-forward photon-gluon scattering amplitude with a massive quark loop and the corresponding hard scattering coefficients. In a first numerical analysis these fixed order perturbation theory results are compared with the conventional intrinsic "massless" parton approach considering generalized parton distributions for the heavy quarks. The differences between these two prescriptions can be quite significant, especially at small skewedness where the massless approach largely overestimates the deeply virtual Compton scattering cross section.
Lattice QCD Thermodynamics with Physical Quark Masses
R. A. Soltz; C. DeTar; F. Karsch; Swagato Mukherjee; P. Vranas
2015-02-08T23:59:59.000Z
Over the past few years new physics methods and algorithms as well as the latest supercomputers have enabled the study of the QCD thermodynamic phase transition using lattice gauge theory numerical simulations with unprecedented control over systematic errors. This is largely a consequence of the ability to perform continuum extrapolations with physical quark masses. Here we review recent progress in lattice QCD thermodynamics, focussing mainly on results that benefit from the use of physical quark masses: the crossover temperature, the equation of state, and fluctuations of the quark number susceptibilities. In addition, we place a special emphasis on calculations that are directly relevant to the study of relativistic heavy ion collisions at RHIC and the LHC.
The heavy top quark and supersymmetry
Hall, L.J. [Lawrence Berkeley Lab., CA (United States); [Univ. of California, Berkeley, CA (United States)
1997-01-01T23:59:59.000Z
Three aspects of supersymmetric theories are discussed: electroweak symmetry breaking, the issues of flavor, and gauge unification. The heavy top quark plays an important, sometimes dominant, role in each case. Additional symmetries lead to extensions of the Standard Model which can provide an understanding for many of the outstanding problems of particle physics. A broken supersymmetric extension of spacetime allows electroweak symmetry breaking to follow from the dynamics of the heavy top quark; an extension of isospin provides a constrained framework for understanding the pattern of quark and lepton masses; and a grand unified extension of the Standard Model gauge group provides an elegant understanding of the gauge quantum numbers of the components of a generation. Experimental signatures for each of these additional symmetries are discussed.
Short distance physics with heavy quark potentials
Zantow, F; Karsch, Frithjof; Petreczky, P
2002-01-01T23:59:59.000Z
We present lattice studies of heavy quark potentials in the quenched approximation of QCD at finite temperatures. Both, the color singlet and color averaged potentials are calculated. While the potentials are well known at large distances, we give a detailed analysis of their short distance behavior (from 0.015 fm to 1 fm) near the critical temperature. At these distances we expect that the T-dependent potentials go over into the zero temperature potential. Indeed, we find evidences that the temperature influence gets suppressed and the potentials starts to become a unique function of the underlying distance scale. We use this feature to normalize the heavy quark potentials at short distances and extract the free energy of the quark system in a gluonic heat bath.
Dressed Quark Mass Dependence of Pion and Kaon Form Factors
Y. Ninomiya; W. Bentz; I. C. Cloët
2015-01-27T23:59:59.000Z
The structure of hadrons is described well by the Nambu--Jona-Lasinio (NJL) model, which is a chiral effective quark theory of QCD. In this work we explore the electromagnetic structure of the pion and kaon using the three-flavor NJL model, including effects of confinement and a pion cloud at the quark level. In the calculation there is only one free parameter, which we take as the dressed light quark ($u$ and $d$) mass. In the regime where the dressed light quark mass is approximately $0.25\\,$GeV, we find that the calculated values of the kaon decay constant, current quark masses, and quark condensates are consistent with experiment and QCD based analyses. We also investigate the dressed light quark mass dependence of the pion and kaon electromagnetic form factors, where comparison with empirical data and QCD predictions also favors a dressed light quark mass near $0.25\\,$GeV.
Bulk viscosity in nuclear and quark matter: A short review
Hui Dong; Nan Su; Qun Wang
2007-03-05T23:59:59.000Z
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.
Effect of thermalized charm on heavy quark energy loss
Souvik Priyam Adhya; Mahatsab Mandal; Sreemoyee Sarkar; Pradip K. Roy; Sukalyan Chattopadhyay
2014-08-28T23:59:59.000Z
The recent experimental results on the flow of $J/\\psi$ at LHC show that ample amount of charm quarks is present in the quark gluon plasma and probably they are thermalized. In the current study we investigate the effect of thermalized charm quarks on the heavy quark energy loss to leading order in the QCD coupling constant. It is seen that the energy loss of charm quark increases considerably due to the inclusion of thermal charm quarks. Running coupling has also been implemented to study heavy quark energy loss and we find substantial increase in the heavy quark energy loss due to heavy-heavy scattering at higher temperature to be realized at LHC energies.
Joint resummation for heavy quark production.
Banfi, Andrea; Laenen, Eric
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... hadroproduction, at next-to-leading logarithmic accuracy. We exhibit their dependence on the production channel and the color configurations, and compare these distributions to eachother and to NLO. Keywords: Resummation; heavy quark production. 1. Joint threshold...
Top Quark Mass Measurements at the Tevatron
Zhenyu Ye; for CDF; D0 collaborations
2011-07-22T23:59:59.000Z
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 $\\sqrt{s}=1.96$ 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.
Top Quark Mass Measurements at the Tevatron
Ye, Zhenyu; /Fermilab
2011-07-01T23:59:59.000Z
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.
Quark mass thresholds in QCD thermodynamics
M. Laine; Y. Schroder
2006-05-05T23:59:59.000Z
We discuss radiative corrections to how quark mass thresholds are crossed, as a function of the temperature, in basic thermodynamic observables such as the pressure, the energy and entropy densities, and the heat capacity of high temperature QCD. The indication from leading order that the charm quark plays a visible role at surprisingly low temperatures, is confirmed. We also sketch a way to obtain phenomenological estimates relevant for generic expansion rate computations at temperatures between the QCD and electroweak scales, pointing out where improvements over the current knowledge are particularly welcome.
Quark and Gluon Condensates in Isospin Matter
Lianyi He; Yin Jiang; Pengfei Zhuang
2009-05-03T23:59:59.000Z
Applying the Hellmann-Feynman theorem to a charged pion gas, the quark and gluon condensates at low isospin density are determined by precise pion properties. At intermediate density around $ f_\\pi^2m_\\pi$, from both the estimation for the dilute pion gas and the calculation with Nambu--Jona-Lasinio model, the quark condensate is strongly and monotonously suppressed, while the gluon condensate is enhanced and can be larger than its vacuum value. This unusual behavior of the gluon condensate is universal for Bose condensed matter of mesons. Our results can be tested by lattice calculations at finite isospin density.
New lattice action for heavy quarks
Oktay, Mehmet B.; Kronfeld, Andreas S. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States) and School of Mathematics, Trinity College, Dublin 2 (Ireland); Theoretical Physics Department, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)
2008-07-01T23:59:59.000Z
We extend the Fermilab method for heavy quarks to include interactions of dimensions 6 and 7 in the action. There are, in general, many new interactions, but we carry out the calculations needed to match the lattice action to continuum QCD at the tree level, finding six nonzero couplings. Using the heavy-quark theory of cutoff effects, we estimate how large the remaining discretization errors are. We find that our tree-level matching, augmented with one-loop matching of the dimension-5 interactions, can bring these errors below 1%, at currently available lattice spacings.
Correlations of chiral condensates and quark number densities with static quark sources
Kay Huebner
2007-09-10T23:59:59.000Z
We investigate correlation functions of the Polyakov loop and static meson/diquark systems with the chiral condensate and the quark number density at finite temperature. In particular the latter observable can give insight in the mechanism of screening and string breaking at finite temperature. We use for our analysis gauge field configurations generated in 2+1 flavor QCD with an improved staggered fermion action with almost physical light quark masses and a physical value of the strange quark mass on lattices with temporal extent Nt=4 and 6.
Review of recent top-quark LHC combinations
Giorgio Cortiana; on behalf of the ATLAS; CMS collaborations within the TOPLHCWG
2014-11-27T23:59:59.000Z
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.
Light quark spectrum with improved gauge and fermion actions
MILC Collaboration; Claude Bernard; Tom DeGrand; Carleton DeTar; Steven Gottlieb; Urs M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; Bob Sugar; Doug Toussaint; Matthew Wingate
1997-11-08T23:59:59.000Z
We report on a study of the light quark spectrum using an improved gauge action and both Kogut-Susskind and Naik quark actions. We have studied six different lattice spacings, corresponding to plaquette couplings ranging from 6.8 to 7.9, with five to six quark masses per coupling. We compare the two quark actions in terms of the spectrum and restoration of flavor symmetry. We also compare these results with those from the conventional action.
Systems of two heavy quarks with effective field theories
Nora Brambilla
2006-09-22T23:59:59.000Z
I discuss results and applications of QCD nonrelativistic effective field theories for systems with two heavy quarks.
TOP QUARK PHYSICS AT THE NLC CARL R. SCHMIDT
Schmidt, Carl
TOP QUARK PHYSICS AT THE NLC CARL R. SCHMIDT Santa Cruz Institute for Particle Physics University) is an excellent tool for studying the properties of the top quark. In this talk I review some of the theory of top, is an ideal tool for studying the properties of the top quark. The event environment in e + e \\Gamma
Heavy quark collisional energy loss in the quark-gluon plasma including finite relaxation time
Mauro Elias; J. Peralta-Ramos; E. Calzetta
2014-07-12T23:59:59.000Z
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.
Resonance recombination model and quark distribution functions in the quark-gluon plasma
Ravagli, L.; van Hees, H.; Rapp, Ralf.
2009-01-01T23:59:59.000Z
We investigate the consequences of space-momentum correlations in quark phase-space distributions for coalescence processes at the hadronization transition. Thus far it has been proved difficult to reconcile such correlations with the empirically...
Strange quark momentum fraction from overlap fermion
Mingyang Sun; Yi-Bo Yang; Keh-Fei Liu; Ming Gong
2015-03-10T23:59:59.000Z
We present a calculation of $_s$ for the strange quark in the nucleon. We also report the ratio of the strange $$ to that of $u/d$ in the disconnected insertion which will be useful in constraining the global fit of parton distribution functions at small $x$. We adopt overlap fermion action on $2 + 1$ flavor domain-wall fermion configurations on the $24^3 \\times 64$ lattice with a light sea quark mass which corresponds to $m_{\\pi}=330$ MeV. Smeared grid $Z_3$ sources are deployed to calculate the nucleon propagator with low-mode substitution. Even-odd grid sources and time-dilution technique with stochastic noises are used to calculate the high mode contribution to the quark loop. Low mode averaging (LMA) for the quark loop is applied to reduce the statistical error of the disconnected insertion calculation. We find the ratio $_s/_{u/d}^{\\mathrm{DI}}= 0.78(3)$ in this study.
Strange quark momentum fraction from overlap fermion
Sun, Mingyang; Liu, Keh-Fei; Gong, Ming
2015-01-01T23:59:59.000Z
We present a calculation of $\\langle x \\rangle_s$ for the strange quark in the nucleon. We also report the ratio of the strange $\\langle x \\rangle$ to that of $u/d$ in the disconnected insertion which will be useful in constraining the global fit of parton distribution functions at small $x$. We adopt overlap fermion action on $2 + 1$ flavor domain-wall fermion configurations on the $24^3 \\times 64$ lattice with a light sea quark mass which corresponds to $m_{\\pi}=330$ MeV. Smeared grid $Z_3$ sources are deployed to calculate the nucleon propagator with low-mode substitution. Even-odd grid sources and time-dilution technique with stochastic noises are used to calculate the high mode contribution to the quark loop. Low mode averaging (LMA) for the quark loop is applied to reduce the statistical error of the disconnected insertion calculation. We find the ratio $\\langle x \\rangle_s/\\langle x \\rangle_{u/d}^{\\mathrm{DI}}= 0.78(3)$ in this study.
Strange Quark Matter and Compact Stars
Fridolin Weber
2004-09-27T23:59:59.000Z
Astrophysicists distinguish between three different types of compact stars. These are white dwarfs, neutron stars, and black holes. The former contain matter in one of the densest forms found in the Universe which, together with the unprecedented progress in observational astronomy, make such stars superb astrophysical laboratories for a broad range of most striking physical phenomena. These range from nuclear processes on the stellar surface to processes in electron degenerate matter at subnuclear densities to boson condensates and the existence of new states of baryonic matter--like color superconducting quark matter--at supernuclear densities. More than that, according to the strange matter hypothesis strange quark matter could be more stable than nuclear matter, in which case neutron stars should be largely composed of pure quark matter possibly enveloped in thin nuclear crusts. Another remarkable implication of the hypothesis is the possible existence of a new class of white dwarfs. This article aims at giving an overview of all these striking physical possibilities, with an emphasis on the astrophysical phenomenology of strange quark matter. Possible observational signatures associated with the theoretically proposed states of matter inside compact stars are discussed as well. They will provide most valuable information about the phase diagram of superdense nuclear matter at high baryon number density but low temperature, which is not accessible to relativistic heavy ion collision experiments.
Top quark property measurements at the LHC
Richard Hawkings
2014-10-29T23:59:59.000Z
Measurements of top quark properties performed at the Large Hadron Collider are reviewed, with a particular emphasis on top-pair charge asymmetries, spin correlations and polarization measurements performed by the ATLAS and CMS collaborations. The measurements are generally in good agreement with predictions from next-to-leading-order QCD calculations, and no deviations from Standard Model expectations have been seen.
From Quarks to Real Life Fred Jegerlehner
Röder, Beate
) Atom 10-8 10-4 e.m., QED Nucleus, Electron 10-12 10-3 nuclear power Hadrons: Proton, Neutron 10 photon with charged particles, electrons,.... e+ e- Abelian theory U(1) phase transformations F only, color singlets, color unobservable! « Confinement QUARKS are permanently confined inside HADRONS
Unusual condensates in quark and atomic systems
B. Kerbikov
2005-10-31T23:59:59.000Z
In these lectures we discuss condensates which are formed in quark matter when it is squeezed and in a gas of fermionic atoms when it is cooled. The behavior of these two seemingly very different systems reveals striking similarities. In particular, in both systems the Bose-Einstein condensate to Bardeen--Cooper-Schrieffer (BEC-BCS) crossover takes place.
Photon production from an anisotropic quark-gluon plasma
Bjoern Schenke; Michael Strickland
2006-11-27T23:59:59.000Z
We calculate photon production from a quark-gluon plasma which is anisotropic in momentum space including the Compton scattering and quark/anti-quark annihilation processes. We show that for a quark-gluon plasma which has an oblate momentum-space anisotropy the photon production rate has an angular dependence which is peaked transverse to the beam line. We propose to use the angular dependence of high-energy medium photon production to experimentally determine the degree of momentum-space isotropy of a quark-gluon plasma produced in relativistic heavy-ion collisions.
Single top quark production and Vtb at the Tevatron
Schwienhorst, Reinhard; /Michigan State U.
2010-09-01T23:59:59.000Z
Single top quark production via the electroweak interaction was observed by the D0 and CDF collaborations at the Tevatron proton-antiproton collider at Fermilab. Multivariate analysis techniques are employed to extract the small single top quark signal. The combined Tevatron cross section is 2.76{sub -0.47}{sup +0.58} pb. This corresponds to a lower limit on the CKM matrix element |V{sub tb}| of 0.77. Also reported are measurements of the t-channel cross section, the top quark polarization in single top quark events, and limits on gluon-quark flavor-changing neutral currents and W{prime} boson production.
Susceptibilities with multi-quark interactions in PNJL model
Abhijit Bhattacharyya; Paramita Deb; Anirban Lahiri; Rajarshi Ray
2011-01-06T23:59:59.000Z
We have investigated the fluctuations and the higher order susceptibilities of quark number, isospin number, electric charge and strangeness at vanishing chemical potential for 2+1 flavor Polyakov loop extended Nambu--Jona-Lasinio model. The calculations are performed for the bound effective potential in the quark sector requiring up to eight quark interaction terms. These have been contrasted to the lattice results which currently have somewhat heavier quarks in the light flavor sector. The results show sufficient qualitative agreement. For comparison we also present the results obtained with the conventional effective potential containing upto six quark interaction terms.
Valence quark distributions of the proton from maximum entropy approach
Rong Wang; Xurong Chen
2014-10-14T23:59:59.000Z
We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.
Valence quark distributions of the proton from maximum entropy approach
Wang, Rong
2014-01-01T23:59:59.000Z
We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.
Traditionelles Bauen und Wohnen der Salar in Nordwest-China
Wagner, Mayke; Flitsch, Mareile; Winterstein, Claudia; Lehmann, Heike; Heuß ner, Karl-Uwe; Ren, Xiaoyan; Xiao, Yongming; Cai, Linhai; Wulf-Rheidt, Ulrike; Tarasov, Pavel; Dwyer, Arienne M.
2007-01-01T23:59:59.000Z
aus. Allerdings war zu erkennen, dass viele neuere Bauten mit lokal verfügbaren Baustof fen wie Lehmziegeln oder in moderner Betonbau weise errichtet wurden. Unsere Beobachtungen war fen eine ganze Reihe von Fragen auf: Worin genau bestehen die.... Qinghai. Rechts Haupthaus an der Nordseite, links Westhaus (Foto MW) ABB. 5 Holzrahmenkonstruk tion eines chinesischen Hauses in Lajia, Prov. Qinghai (Foto MW) hingegen Wände einfach und günstig mit lokal ver fügbarem Baumaterial von Laien...
Markert, C
2000-01-01T23:59:59.000Z
$\\Lambda$(1520)-Produktion in Proton-Proton- und zentralen Blei-Blei-Reaktionen bei 158 GeV pro Nukleon
Top Quark Properties at the TeVatron
Yvonne Peters for the CDF; D0 Collaborations
2011-03-29T23:59:59.000Z
Discovered in 1995 by CDF and D0 at the Fermilab Tevatron collider, the top quark remains interesting to test the Standard Model. Having collected more than 7 fb$^{-1}$ of integrated luminosity with both experiments until today, several top quark properties have been measured with increasing precision, while other properties have been investigated for the first time. In this article recent measurements of top quark properties from CDF and D0 are presented, using between 1 fb$^{-1}$ and 4.8 fb$^{-1}$ of data. In particular, the measurement of the top quark mass, the top quark width, the top antitop mass difference, a check of the electric charge of the top quark, measurements of the top antitop quark spin correlation and W helicity as well as a search for charged Higgs bosons are discussed.
I. Bloch, DESY/Hamburg University - CIPANP, Puerto Rico 30.5.-03.06.'06 1Heavy Quarks at HERA Heavy, Puerto Rico 30.5.-03.06.'06 2Heavy Quarks at HERA HERA: ep collisions within H1 & ZEUS 920 GeV protons920/Hamburg University - CIPANP, Puerto Rico 30.5.-03.06.'06 3Heavy Quarks at HERA H1&ZEUS integrated Luminosity: 96
C. G. Duan; N. Liu; G. L. Li
2008-11-05T23:59:59.000Z
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.
Radiative energy loss of high energy quarks in finite-size nuclear matter and quark-gluon plasma
B. G. Zakharov
1997-04-07T23:59:59.000Z
The induced gluon radiation of a high energy quark in a finite-size QCD medium is studied. For a sufficiently energetic quark produced inside a medium we find the radiative energy loss $\\Delta E_{q}\\propto L^{2}$, where L is the distance passed by quark in the medium. It has a weak dependence on the initial quark energy $E_{q}$. The $L^{2}$ dependence turns to $L^{1}$ as the quark energy decreases. Numerical calculations are performed for a cold nuclear matter and a hot quark-gluon plasma. For a quark incident on a nucleus we predict $\\Delta E_{q}\\approx 0.1 E_{q}(L/10 fm)^{\\beta}$, with $\\beta$ close to unity.
Static quark anti-quark free and internal energy in 2-flavor QCD and bound states in the QGP
O. Kaczmarek; F. Zantow
2005-10-21T23:59:59.000Z
We present results on heavy quark free energies in 2-flavour QCD. The temperature dependence of the interaction between static quark anti-quark pairs will be analyzed in terms of temperature dependent screening radii, which give a first estimate on the medium modification of (heavy quark) bound states in the quark gluon plasma. Comparing those radii to the (zero temperature) mean squared charge radii of cha rmonium states indicates that the $J/\\psi$ may survive the phase transition as a bound state, while $\\chi_c$ and $\\psi'$ are expected to show significant thermal modifications at temperatures close to the transition. Furthermore we will analyze the relation between heavy quark free energies, entropy contributions and internal energy and discuss their relation to potential models used to analyze the melting of heavy quark bound states above the deconfinement temperature. Results of different groups and various potential models for bound states in the deconfined phase of QCD are compared.
Free energies of heavy quarks in full-QCD lattice simulations with Wilson-type quark action
Y. Maezawa; S. Aoki; S. Ejiri; T. Hatsuda; N. Ishii; K. Kanaya; H. Ohno; T. Umeda
2009-09-16T23:59:59.000Z
The free energy between a static quark and an antiquark is studied by using the color-singlet Polyakov-line correlation at finite temperature in lattice QCD with 2+1 flavors of improved Wilson quarks. From the simulations on $32^3 \\times 12$, 10, 8, 6, 4 lattices in the high temperature phase, based on the fixed scale approach, we find that, the heavy-quark free energies at short distance converge to the heavy-quark potential evaluated from the Wilson loop at zero temperature, in accordance with the expected insensitivity of short distance physics to the temperature. At long distance, the heavy-quark free energies approach to twice the single-quark free energies, implying that the interaction between heavy quarks is screened. The Debye screening mass obtained from the long range behavior of the free energy is compared with the results of thermal perturbation theory.
PD Dr. Martin Stetter, Siemens AG 1 Lernen von Datenmodellen: Fehlerminimierung und Regularisierung
Popeea, Corneliu - Chair for Foundations of Software Reliability and Theoretical Computer Science
PD Dr. Martin Stetter, Siemens AG 1 Lernen von Datenmodellen: Fehlerminimierung und Regularisierung: Fehlerminimierung #12;PD Dr. Martin Stetter, Siemens AG 2 Maximum-Likelihood und Fehlerminimierung · Likelihood: Fehlerfunktionen #12;PD Dr. Martin Stetter, Siemens AG 3 · Def. Fehlerfunktion: 0))|(,,( wxfyxl yxyyx ,0),,( =lmit
auf die LaufflÃ¤che und geht stramm voran. Er tritt auf der Stelle, wie im Fitness- studio. Doch dieses Stadt am FuÃ?e des Vesuvs Â und tritt doch eigent- lich nur auf der Stelle. Eine ganze Turnhalle fÃ¼r ein
Observation of Single Top Quark Production
Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Alberta U. /Simon Fraser U. /York U., Canada /McGill U.; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan State U. /Northeastern U.
2009-03-01T23:59:59.000Z
We report first observation of the electroweak production of single top quarks in p{bar p} collisions at {radical}s = 1.96 TeV based on 2.3 fb{sup ?1} of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.94 {+-} 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5 x 10{sup ?7}, corresponding to a 5.0 standard deviation significance for the observation.
Continuum Study of Heavy Quark Diffusion
Thomas Neuhaus
2015-04-28T23:59:59.000Z
We report on a lattice investigation of heavy quark momentum diffusion within the pure SU(3) plasma above the deconfinement transition with the quarks treated to leading order in the heavy mass expansion. We measure the relevant "colour-electric" Euclidean correlator and based on several lattice spacing's perform the continuum extrapolation. This is necessary not only to remove cut-off effects but also the analytic continuation for the extraction of transport coefficients is well-defined only when a continuous function of the Euclidean time variable is available. We pay specific attention to scale setting in SU(3). In particular we present our determination for the critical temperature $T_c=1/({N_\\tau}a) $ at values of $N_\\tau \\le 22$.
Top quark and electroweak results from CDF
Sandra Leone
2003-11-04T23:59:59.000Z
In 2001 the Tevatron run II began, after a five year period of significant upgrade of the accelerator itself and of the experiments CDF and D0. After a detector commissioning run, the CDF experiment is now taking high quality data with all subsystems functional. We report in this talk the first preliminary CDF results on top quark and W/Z boson properties, based on run II data. The top quark, discovered in 1995 at the Tevatron, has proven to be a very interesting particle. Its properties allow to perform stringent tests of the Standard Model (SM) and to search for new physics through a deviation from SM predictions. We give here some expectations of what Tevatron run II will ultimately provide to our understanding of matter.
Boson stars: Chemical potential and quark condensates
Jitesh R. Bhatt; V. Sreekanth
2010-05-06T23:59:59.000Z
We study the properties of a star made of self-gravitating bosons gas in a mean-field approximation. A generalized set of Tolman-Oppenheimer-Volkov(TOV) equations is derived to incorporate the effect of chemical-potential in the general relativistic frame work. The metric-dependence of the chemical-potential gives a new class of solutions for the boson stars. It is demonstrated that the maximum mass and radius of the star change in a significant way when the effect of finite chemical-potential is considered. We also discuss the case of a boson star made of quark-condensates. It is found that when the self-interaction between the condensates is small as compared to their mass, the typical density is too high to form a diquark-boson star. Our results indicate that the star of quark-condensate may be formed in a low-density and high-pressure regime.
Collisional energy loss of a fast heavy quark in a quark-gluon plasma
Stephane Peigne; Andre Peshier
2008-02-29T23:59:59.000Z
We discuss the average collisional energy loss dE/dx of a heavy quark crossing a quark-gluon plasma, in the limit of high quark energy E >> M^2/T, where M is the quark mass and T >> M is the plasma temperature. In the fixed coupling approximation, at leading order dE/dx \\propto \\alpha_s^2, with a coefficient which is logarithmically enhanced. The soft logarithm arising from t-channel scattering off thermal partons is well-known, but a collinear logarithm from u-channel exchange had previously been overlooked. We also determine the constant beyond those leading logarithms. We then generalize our calculation of dE/dx to the case of running coupling. We estimate the remaining theoretical uncertainty of dE/dx, which turns out to be quite large under RHIC conditions. Finally, we point out an approximate relation between dE/dx and the QCD Debye mass, from which we derive an upper bound to dE/dx for all quark energies.
B-quark production at hadron colliders
Meng, Ruibin [Argonne National Lab., IL (United States); Riemersma, S. [Southern Methodist Univ., Dallas, TX (United States)
1993-08-01T23:59:59.000Z
Studying B-physics at hadron accelerators requires a good understanding of the total and differential cross sections for b-quark production. This knowledge gives those involved in B{bar B} mixing, rare B decays, and those trying to determine the CKM angles {alpha}, {beta}, and {gamma} an idea of how many events they can expect, given the luminosity and the branching ratios. It is particularly important for those studying rare B decays as they set limits on where we can hope to see new physics. For these reasons and others, the complete {Omicron}({alpha}{sub s}{sup 3}) corrections to heavy-quark production at hadron accelerators were calculated in. Also three groups have attempted to calculate heavy-quark production using resummation techniques in the small-x kinematic region. These resummation techniques are necessary since the b-quark mass m{sub b} is small relative to the center-of-mass energies {radical}S of the TeVatron and the SSC. While these techniques offer some hope of obtaining reasonable predictions for b-production at these machines, the current results can best be considered as preliminary. Thus we must turn to fixed-order perturbative QCD for guidance, as we have no other real choice at this point. However, let us submit a caveat here: fixed-order perturbative QCD works best when all the scales are roughly comparable, i.e. {radical}s {approx} m{sub b} {approx} p{sub t}, {radical}s being the partonic center-of-mass energy. When we are not in this regime, for example at the TeVatron and the SSC, our predictions will then be less reliable. Bearing this in mind, let use continue to the results section.
Some simple models for quark stars
S. D. Maharaj; J. M. Sunzu; S. Ray
2014-12-28T23:59:59.000Z
We find two new classes of exact solutions for the Einstein-Maxwell equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field equations are integrated by specifying forms for the measure of anisotropy and a gravitational potential which are physically reasonable. The solutions found generalize the Mark-Harko model and the Komathiraj-Maharaj model. A graphical analysis indicates that the matter variables are well behaved.
Baryon Spectroscopy and the Constituent Quark Model
A.W. Thomas; R.D. Young
2005-07-26T23:59:59.000Z
We explore further the idea that the lattice QCD data for hadron properties in the region m[^2][_pi] > 0.2GeV^2 can be described by the constituent quark model. This leads to a natural explanation of the fact that nucleon excited states are generally stable for pion masses greater than their physical excitation energies. Finally, we apply these same ideas to the problem of how pentaquarks might behave in lattice QCD, with interesting conclusions.
The Surface Tension of Magnetized Quark Matter
A. F. Garcia; M. B. Pinto
2013-06-13T23:59:59.000Z
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.
KnÃ¼pfer, Christian
tritt am ersten Tage des auf ihre VerÃ¶ffentlichung im Gemeinsamen Amtsblatt des ThÃ¼ringer, FestkÃ¶rperphysik, Kern- und Elementarteilchenphysik) an." 3. Diese Ã?nderung tritt am ersten Tage des auf ihre
Middeldorp, Aart
Studienplan für die neue Studienrichtung ,,Informatik" an der Universität Innsbruck 532. Reform des. Reform des Studienplanes für ein Bakkalaureats- und Magister-Studium Kommunikationswissenschaft an der Universität Salzburg - Begutachtungsverfahren 534. Reform des Studienplanes für das Diplomstudium Architektur
The Top Quark - 2006 and Beyond
John Womersley
2006-04-04T23:59:59.000Z
We know there is new physics at the electroweak scale, but we don't know what it is. Right now, the top quark is our only window on to this physics. In almost all models of electroweak symmetry breaking, top either couples strongly to new particles or its properties are modified in some way. Top is being studied in detail at the Fermilab Tevatron. Its production cross section has been measured in a variety of channels; its mass has been determined to better than 2%, and can be used to constrain the mass of the Higgs. Top quark decays have been tested and non-standard production mechanisms searched for. Single top production probes the electroweak properties of top, and has not yet been observed; searches are now closing in on this process and it should be seen soon. So far, all of the top quark's properties are consistent with the Standard Model. However, the data still to come at the Tevatron will increase the precision of all these measurements, and the enormous statistics available at the LHC will open up new possibilities such as observation of spin correlations and perhaps even CP violation in the top sector.
Quark Nova Model for Fast Radio Bursts
Zachary Shand; Amir Ouyed; Nico Koning; Rachid Ouyed
2015-05-29T23:59:59.000Z
FRBs are puzzling, millisecond, energetic radio transients with no discernible source; observations show no counterparts in other frequency bands. The birth of a quark star from a parent neutron star experiencing a quark nova - previously thought undetectable when born in isolation - provides a natural explanation for the emission characteristics of FRBs. The generation of unstable r-process elements in the quark nova ejecta provides millisecond exponential injection of electrons into the surrounding strong magnetic field at the parent neutron star's light cylinder via $\\beta$-decay. This radio synchrotron emission has a total duration of hundreds of milliseconds and matches the observed spectrum while reducing the inferred dispersion measure by approximately 200 cm$^{-3}$ pc. The model allows indirect measurement of neutron star magnetic fields and periods in addition to providing astronomical measurements of $\\beta$-decay chains of unstable neutron rich nuclei. Using this model, we can calculate expected FRB average energies ($\\sim$ 10$^{41}$ ergs), spectra shapes and provide a theoretical framework for determining distances.
Recent PQCD calculations of heavy quark production
Vitev, I
2006-01-01T23:59:59.000Z
We summarize the results of a recent study of heavy quark production and attenuation in cold nuclear matter. In p+p collisions, we investigate the relative contribution of partonic sub-processes to $D$ meson production and $D$ meson-triggered inclusive di-hadrons to lowest order in perturbative QCD. While gluon fusion dominates the creation of large angle $D\\bar{D}$ pairs, charm on light parton scattering determines the yield of single inclusive $D$ mesons. The distinctly different non-perturbative fragmentation of $c$ quarks into $D$ mesons versus the fragmentation of quarks and gluons into light hadrons results in a strong transverse momentum dependence of anticharm content of the away-side charm-triggered jet. In p+A reactions, we calculate and resum the coherent nuclear-enhanced power corrections from the final-state partonic scattering in the medium. We find that single and double inclusive open charm production can be suppressed as much as the yield of neutral pions from dynamical high-twist shadowing. ...
Top quark physics at the Tevatron
Antonio Sidoti
2004-03-17T23:59:59.000Z
After the successful Run I of the Tevatron (1992-1996),with the top quark discovery, both CDF and D0 experiments were extensively upgraded to meet the challenges of the Tevatron Run II collider. The energy of p{bar p} collisions at the Tevatron was increased from {radical}s = 1.8 TeV to {radical}s = 1.96 TeV. t{bar t} production cross section is expected to increase by a factor of {approx} 30%. Major upgrades in the Tevatron accelerator chain will increase the Run II instantaneous luminosity: the goal is to achieve L = 5 - 20 x 10{sup 31} cm{sup 2}s{sup -1} while the highest luminosity reached up to now (September 2003) is 5.2 x 10{sup 31} cm{sup 2} s{sup -1}. In this paper we will present the top quark properties measured by both CDF and D0 with the first physics-quality data collected during the Run II (March 2002-January 2003). First we will review t{bar t} cross section measurements in the various decay channels; then top quark mass measurements will be presented.
Shear Viscosity in a CFL Quark Star
Cristina Manuel; Antonio Dobado; Felipe J. Llanes-Estrada
2005-09-30T23:59:59.000Z
We compute the mean free path and shear viscosity in the color-flavor locked (CFL) phase of dense quark matter at low temperature T, when the contributions of mesons, quarks and gluons to the transport coefficients are Boltzmann suppressed. CFL quark matter displays superfluid properties, and transport phenomena in such cold regime are dominated by phonon-phonon scattering. We study superfluid phonons within thermal field theory and compute the mean free path associated to their most relevant collision processes. Small-angle processes turn out to be more efficient in slowing transport phenomena in the CFL matter, while the mean free path relevant for the shear viscosity is less sensitive to collinear scattering due to the presence of zero modes in the Boltzmann equation. In analogy with superfluid He4, we find the same T power law for the superfluid phonon damping rate and mean free path. Our results are relevant for the study of rotational properties of compact stars, and correct wrong estimates existing in the literature.
Color superconducting quark matter in compact stars
D. B. Blaschke; T. Klahn; F. Sandin
2007-12-02T23:59:59.000Z
Recent indications for high neutron star masses (M \\sim 2 M_sun) and large radii (R > 12 km) could rule out soft equations of state and have provoked a debate whether the occurence of quark matter in compact stars can be excluded as well. We show that modern quantum field theoretical approaches to quark matter including color superconductivity and a vector meanfield allow a microscopic description of hybrid stars which fulfill the new, strong constraints. For these objects color superconductivity turns out to be an essential ingredient for a successful description of the cooling phenomenology in accordance with recently developed tests. We discuss the energy release in the neutrino untrapping transition as a new aspect of the problem that hybrid stars masquerade themselves as neutron stars. Quark matter searches in future generations of low-temperature/high-density nucleus-nucleus collision experiments such as low-energy RHIC and CBM @ FAIR might face the same problem of an almost crossover behavior of the deconfinement transition. Therefore, diagnostic tools shall be derived from effects of color superconductivity.
Quark-Gluon Bags with Surface Tension
Kyrill Bugaev
2007-03-20T23:59:59.000Z
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.
Quarks Production in the Quark-Gluon Plasma Created in Relativistic Heavy Ion Collisions
Marco Ruggieri; Salvatore Plumari; Francesco Scardina; Vincenzo Greco
2015-02-16T23:59:59.000Z
In this article we report on our results about quark production and chemical equilibration of quark-gluon plasma. Our initial condition corresponds to a classic Yang-Mills spectrum, in which only gluon degrees of freedom are considered; the initial condition is then evolved to a quark-gluon plasma by means of relativistic transport theory with inelastic processes which permit the conversion of gluons to $q\\bar{q}$ pairs. We then compare our results to the ones obtained with a standard Glauber model initialization. We find that regardless of the initial condition the final stage of the system contains an abundant percentage of $q\\bar{q}$ pairs; moreover spanning the possible coupling from weak to strong we find that unless the coupling is unrealistically small, both production rate and final percentage of fermions is quite large.
Quarks Production in the Quark-Gluon Plasma Created in Relativistic Heavy Ion Collisions
Ruggieri, Marco; Scardina, Francesco; Greco, Vincenzo
2015-01-01T23:59:59.000Z
In this article we report on our results about quark production and chemical equilibration of quark-gluon plasma. Our initial condition corresponds to a classic Yang-Mills spectrum, in which only gluon degrees of freedom are considered; the initial condition is then evolved to a quark-gluon plasma by means of relativistic transport theory with inelastic processes which permit the conversion of gluons to $q\\bar{q}$ pairs. We then compare our results to the ones obtained with a standard Glauber model initialization. We find that regardless of the initial condition the final stage of the system contains an abundant percentage of $q\\bar{q}$ pairs; moreover spanning the possible coupling from weak to strong we find that unless the coupling is unrealistically small, both production rate and final percentage of fermions is quite large.
Top-quark mass measurements: Alternative techniques (LHC + Tevatron)
Stefanie Adomeit
2014-11-28T23:59:59.000Z
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.
Quark Wigner distributions in a light-cone spectator model
Liu, Tianbo
2015-01-01T23:59:59.000Z
We investigate the quark Wigner distributions in a light-cone spectator model. The Wigner distribution, as a quasi-distribution function, provides the most general one-parton information in a hadron. Combining the polarization configurations, unpolarized, longitudinal polarized or transversal polarized, of the quark and the proton, we can define 16 independent Wigner distributions at leading twist. We calculate all these Wigner distributions for the $u$ quark and the $d$ quark respectively. In our calculation, both the scalar and the axial-vector spectators are included, and the Melosh-Wigner rotation effects for both the quark and the axial-vector spectator are taken into account. The results provide us a very rich picture of the quark structure in the proton.
Quark-Antiquark Condensates in the Hadronic Phase
A. Tawfik; D. Toublan
2005-05-17T23:59:59.000Z
We use a hadron resonance gas model to calculate the quark-antiquark condensates for light (up and down) and strange quark flavors at finite temperatures and chemical potentials. At zero chemical potentials, we find that at the temperature where the light quark-antiquark condensates entirely vanish the strange quark-antiquark condensate still keeps a relatively large fraction of its value in the vacuum. This is in agreement with results obtained in lattice simulations and in chiral perturbation theory at finite temperature and zero chemical potentials. Furthermore, we find that this effect slowly disappears at larger baryon chemical potential. These results might have significant consequences for our understanding of QCD at finite temperatures and chemical potentials. Concretely, our results imply that there might be a domain of temperatures where chiral symmetry is restored for light quarks, but still broken for strange quark that persists at small chemical potentials. This might have practical consequences for heavy ion collision experiments.
Polarization energy loss in hot viscous quark-gluon plasma
Bing-Feng Jiang; Defu Hou; Jia-Rong Li
2014-05-19T23:59:59.000Z
The gluon polarization tensor for the quark-gluon plasma with shear viscosity is derived with the viscous chromohydrodynamics. The longitudinal and transverse dielectric functions are evaluated from the gluon polarization tensor, through which the polarization energy loss suffered by a fast quark traveling through the viscous quark-gluon plasma is investigated. The numerical analysis indicates that shear viscosity significantly reduces the polarization energy loss.
Top quark mass measurements at the D0 experiment
Alexander Grohsjean
2009-05-30T23:59:59.000Z
The most recent measurements of the top quark mass at the D0 experiment are summarized. Different techniques and final states are used and the top quark mass is determined to be mtop=172.8+-1.6(stat+syst)GeV/c^2. In addition, a new, indirect measurement comparing the measured cross section to theoretical calculations is discussed. Both, the direct and the indirect measurement of the top quark mass are in good agreement.
The Top Quark Forward Backward Asymmetry at CDF
Yen-Chu Chen for the CDF collaboration
2011-07-01T23:59:59.000Z
It has been more than 15 years since the discovery of the top quark. Great strides have been made in the measurement of the top quark mass and the properties of it. Most results show consistency with the standard model. However, using 5 fb$^{-1}$ data, recent measurements of the asymmetry in the production of top and anti-top quark pair have demonstrated surprisingly large values at CDF. Using 4 fb$^{-1}$ data, D0 also has similar effect.
Thermodynamics of QCD at large quark chemical potential
Andreas Gerhold; Andreas Ipp; Anton Rebhan
2005-12-21T23:59:59.000Z
We review the existing weak-coupling results on the thermodynamic potential of deconfined QCD at small and large quark chemical potential and compare with results from lattice gauge theory as well as the exactly solvable case of large-N_f QCD. We also discuss the new analytical results on non-Fermi-liquid effects in entropy and specific heat as well as in dispersion laws of quark quasiparticles at large quark chemical potential.
QCD Thermodynamics with an almost realistic quark mass spectrum
C. Schmidt
2006-01-25T23:59:59.000Z
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.
Quark-Gluon Plasma: a New State of Matter
Brookhaven Lab
2010-01-08T23:59:59.000Z
Physicist Peter Steinberg explains the nature of the quark gluon plasma (QGP), a new state of matter produced at Brookhaven Lab's Relativistic Heavy Ion Collider (RHIC).
Studies of top quark properties at the Tevatron
Shary, Viatcheslav
2012-05-01T23:59:59.000Z
An overview of the recent measurements of the top quark properties in proton antiproton collisions at {radical}s = 1.96 TeV is presented. These measurements are based on 5.4-8.7 fb{sup -1} of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The top quark mass and width measurements, studies of the spin correlation in top quark pair production, W boson helicity measurement, searches for anomalous top quark couplings and Lorentz invariance violation are discussed.
Dynamical electroweak symmetry breaking and the top quark
Chivukula, R.S. [Boston Univ., MA (United States)
1997-01-01T23:59:59.000Z
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.
Light front approach to correlations in hot quark matter
S. Strauss; M. Beyer; S. Mattiello
2006-01-30T23:59:59.000Z
We investigate two-quark correlations in hot and dense quark matter. To this end we use the light front field theory extended to finite temperature $T$ and chemical potential $\\mu$. Therefore it is necessary to develop quantum statistics formulated on the light front plane. As a test case for light front quantization at finite $T$ and $\\mu$ we consider the NJL model. The solution of the in-medium gap equation leads to a constituent quark mass which depends on $T$ and $\\mu$. Two-quark systems are considered in the pionic and diquark channel. We compute the masses of the two-body system using a $T$-matrix approach.
Evolution equation for 3-quark Wilson loop operator
R. E. Gerasimov; A. V. Grabovsky
2012-12-07T23:59:59.000Z
The evolution equation for the 3 quark Wilson loop operator has been derived in the leading logarithm approximation within Balitsky high energy operator expansion.
Nucleon sigma term and quark condensate in nuclear matter
K. Tsushima; K. Saito; A. W. Thomas; A. Valcarce
2007-03-01T23:59:59.000Z
We study the bound nucleon sigma term and its effect on the quark condensate in nuclear matter. In the quark-meson coupling (QMC) model it is shown that the nuclear correction to the sigma term is small and negative. Thus, the correction decelerates the decrease of the quark condensate in nuclear matter. However, the quark condensate in nuclear matter is controlled primarily by the scalar-isoscalar sigma field of the model. It appreciably moderates the decrease relative to the leading term at densities around and larger than the normal nuclear matter density.
anisotropic quark matter: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Sunzu, Jefta M; Ray, Subharthi 2014-01-01 3 Anisotropic admixture in color-superconducting quark matter Nuclear Theory (arXiv) Summary: The analysis of...
Isospin-Breaking quark condensates in Chiral Perturbation Theory
A. Gomez Nicola; R. Torres Andres
2011-11-14T23:59:59.000Z
We analyze the isospin-breaking corrections to quark condensates within one-loop SU(2) and SU(3) Chiral Perturbation Theory including $m_u\
Y. Maezawa; S. Aoki; S. Ejiri; T. Hatsuda; N. Ishii; K. Kanaya; N. Ukita; T. Umeda
2007-10-04T23:59:59.000Z
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.
Surprises from the search for quark-gluon plasma? When was quark-gluon plasma seen?
Richard M. Weiner
2006-03-13T23:59:59.000Z
The historical context of the recent results from high energy heavy ion reactions devoted to the search of quark-gluon plasma (QGP) is reviewed, with emphasis on the surprises encountered. The evidence for QGP from heavy ion reactions is compared with that available from particle reactions.
Quarkonia and heavy-quark relaxation times in the quark-gluon plasma
Riek, F.; Rapp, Ralf.
2010-01-01T23:59:59.000Z
and heavy-quark diffusion on a common basis and thus to obtain mutual constraints. The two-body interaction kernel is approximated within a potential picture for spacelike momentum transfers. An effective field-theoretical model combining color-Coulomb...
Transport coefficients of heavy quarks around $T_c$ at finite quark chemical potential
H. Berrehrah; P. B. Gossiaux; J. Aichelin; W. Cassing; J. M. Torres-Rincon; E. Bratkovskaya
2014-06-20T23:59:59.000Z
The interactions of heavy quarks with the partonic environment at finite temperature $T$ and finite quark chemical potential $\\mu_q$ are investigated in terms of transport coefficients within the Dynamical Quasi-Particle model (DQPM) designed to reproduce the lattice-QCD results (including the partonic equation of state) in thermodynamic equilibrium. These results are confronted with those of nuclear many-body calculations close to the critical temperature $T_c$. The hadronic and partonic spatial diffusion coefficients join smoothly and show a pronounced minimum around $T_c$, at $\\mu_q=0$ as well as at finite $\\mu_q$. Close and above $T_c$ its absolute value matches the lQCD calculations for $\\mu_q=0$. The smooth transition of the heavy quark transport coefficients from the hadronic to the partonic medium corresponds to a cross over in line with lattice calculations, and differs substantially from perturbative QCD (pQCD) calculations which show a large discontinuity at $T_c$. This indicates that in the vicinity of $T_c$ dynamically dressed massive partons and not massless pQCD partons are the effective degrees-of-freedom in the quark-gluon plasma.
Flavor Physics in the Quark Sector
Antonelli, Mario; /Frascati; Asner, David Mark; /Carleton U.; Bauer, Daniel Adams; /Imperial Coll., London; Becher, Thomas G.; /Fermilab; Beneke, M.; /Aachen, Tech. Hochsch.; Bevan, Adrian John; /Queen Mary, U. of London; Blanke, Monika; /Munich, Tech. U. /Munich, Max Planck Inst.; Bloise, C.; /Frascati; Bona, Marcella; /CERN; Bondar, Alexander E.; /Novosibirsk, IYF; Bozzi, Concezio; /INFN, Ferrara; Brod, Joachim; /Karlsruhe U.; Buras, Andrzej J.; /Munich, Tech. U.; Cabibbo, N.; /INFN, Rome /Rome U.; Carbone, A.; /INFN, Bologna; Cavoto, Gianluca; /INFN, Rome; Cirigliano, Vincenzo; /Los Alamos; Ciuchini, Marco; /INFN, Rome; Coleman, Jonathon P.; /SLAC; Cronin-Hennessy, Daniel P.; /Minnesota U.; Dalseno, J.P.; /KEK, Tsukuba /Glasgow U. /Queen Mary, U. of London /Freiburg U. /Charles U. /Pisa U. /Vienna, OAW /Imperial Coll., London /Bergen U. /INFN, Rome /Rome U. /Munich, Tech. U. /INFN, Rome /Rome U. /Southampton U. /INFN, Rome /Nara Women's U. /Florida U. /INFN, Turin /Turin U. /Edinburgh U. /Warwick U. /INFN, Rome /Rome U. /Massachusetts U., Amherst /KEK, Tsukuba /Bern U. /CERN /Munich, Tech. U. /Mainz U., Inst. Phys. /Wayne State U. /Munich, Max Planck Inst. /CERN /Frascati /Brookhaven /Mainz U., Inst. Kernphys. /Munich, Tech. U. /Siegen U. /Imperial Coll., London /Victoria U. /KEK, Tsukuba /Fermilab /Washington U., St. Louis /Frascati /Warwick U. /Indian Inst. Tech., Madras /Melbourne U. /Princeton U. /Beijing, Inst. High Energy Phys. /INFN, Rome /INFN, Rome3 /Fermilab /SLAC /York U., Canada /Brookhaven /UC, Irvine /INFN, Rome /Rome U. /Valencia U., IFIC /INFN, Padua /Padua U. /Munich, Max Planck Inst. /Barcelona U. /Warwick U. /Tata Inst. /Frascati /Mainz U., Inst. Phys. /Vienna U. /KEK, Tsukuba /Orsay, LPT /Frascati /Munich, Tech. U. /Brookhaven /Bern U. /CERN /Mainz U., Inst. Phys. /Wayne State U. /Valencia U., IFIC /CERN /Kentucky U. /Oxford U. /Iowa State U. /Bristol U. /INFN, Rome /Rutherford /CERN /Orsay, LAL /Glasgow U. /INFN, Padua /Queen Mary, U. of London /Texas U. /LPHE, Lausanne /Fermilab /UC, Santa Cruz /Vienna, OAW /Cincinnati U. /Frascati /Orsay, LAL /Ohio State U. /Purdue U. /Novosibirsk, IYF /Frascati /INFN, Rome /Padua U. /INFN, Rome /Bern U. /Karlsruhe U. /Brookhaven /CERN /Paris U., VI-VII /Zurich, ETH /Pisa U. /Frascati /Oxford U. /Orsay, LAL /INFN, Rome2 /INFN, Rome /INFN, Rome3 /Princeton U. /Fermilab /Queen's U., Kingston /KEK, Tsukuba /Melbourne U. /Brookhaven /Indiana U. /INFN, Rome /Rome U. /Pisa U. /Mainz U., Inst. Phys. /Karlsruhe U. /Oxford U. /Cambridge U., DAMTP /Edinburgh U. /CERN
2010-08-26T23:59:59.000Z
In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, 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. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, 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 is the result of the work of the physicists attending the 5th CKM workshop, hosted by the University of Rome 'La Sapienza', September 9-13, 2008. It 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 which has greatly improved in the past decade.
Studies of top quark production at D0
Gerber, Cecilia E.; /Illinois U., Chicago
2011-07-01T23:59:59.000Z
I present recent results on top quark production in pp collisions at a center of mass energy of 1.96 TeV. The studies were performed by the D0 collaboration using approximately 5 fb{sup -1} of data taken during Run II at the Fermilab Tevatron accelerator. The top quark is the heaviest known elementary particle and completes the quark sector of the three-generation structure of the standard model (SM). It differs from the other quarks not only by its much larger mass, but also by its lifetime which is too short to build hadronic bound states. The SM predicts that top quarks are created via two independent production mechanisms at hadron colliders. The primary mode, in which a t{bar t} pair is produced from a gtt vertex via the strong interaction, was used by the D0 and CDF collaborations to establish the existence of the top quark in 1995. The second production mode of top quarks at hadron colliders is the electroweak production of a single top quark from a Wtb vertex. The predicted cross section for single top quark production is about half that of t{bar t} pairs but the signal-to-background ratio is much worse; observation of single top quark production has therefore until recently been impeded by its low rate and difficult background environment compared to the top pair production. In the following sections I will present results for the measurement of the t{bar t} pair and the single top quark production cross section using respectively 5.3 fb{sup -1} and 5.4 fb{sup -1} of data taken by the D0 experiment.
Photon emission from bare quark stars
B. G. Zakharov
2010-08-16T23:59:59.000Z
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.
Top quark mass measurements at the LHC
Fuster, Juan; The ATLAS collaboration
2015-01-01T23:59:59.000Z
The latest measurements of the top quark mass using the ATLAS and CMS experiments at the LHC are presented. The discussion includes the results obtained using the conventional methods (Template/Ideogram) and those derived from the so called alternative methods. Results from the conventional methods using the various top final states (lepton+jets, di-lepton and full hadronic) are reviewed. Determinations using the inclusive ttbar production, the ttbar production with an additional jet and the lepton-b-jet invariant mass distribution are also discussed.
Seismic Search for Strange Quark Nuggets
Eugene T. Herrin; Doris C. Rosenbaum; Vigdor L. Teplitz
2005-12-30T23:59:59.000Z
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.
Seismic search for strange quark nuggets
Herrin, Eugene T.; Rosenbaum, Doris C.; Teplitz, Vigdor L. [Geology Department, Southern Methodist University, Dallas, Texas 75275 (United States); Physics Department, Southern Methodist University, Dallas, Texas 75275 (United States); NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)
2006-02-15T23:59:59.000Z
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 1 ton must be at least an order of magnitude less than would saturate the dark matter in the solar neighborhood.
Quarks in the looking glass | Jefferson Lab
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70COMMUNITY AEROSOL:Quantum Condensed4,2004 Quark04
High temperature QCD with three flavors of improved staggered quarks
The MILC Collaboration; C. Bernard; T. Burch; C. E. DeTar; Steven Gottlieb; Eric Gregory; U. M. Heller; J. Osborn; R. L. Sugar; D. Toussaint
2002-09-05T23:59:59.000Z
We present an update of our study of high temperature QCD with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad staggered quark action. Simulations are being carried out on lattices with Nt=4, 6 and 8 for the case of three degenerate quarks with masses less than or equal to the strange quark mass, $m_s$, and on lattices with Nt=6 and 8 for degenerate up and down quarks with masses in the range 0.2 m_s \\leq m_{u,d} \\leq 0.6 m_s, and the strange quark fixed near its physical value. We also report on first computations of quark number susceptibilities with the Asqtad action. These susceptibilities are of interest because they can be related to event-by-event fluctuations in heavy ion collision experiments. Use of the improved quark action leads to a substantial reduction in lattice artifacts. This can be seen already for free fermions and carries over into our results for QCD.
High temperature QCD with three flavors of improved staggered quarks
Bernard, C; DeTar, C E; Gottlieb, S; Gregory, E; Heller, U M; Osborn, J; Sugar, R L; Toussaint, D; Gottlieb, Steven; Gregory, Eric
2002-01-01T23:59:59.000Z
We present an update of our study of high temperature QCD with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad staggered quark action. Simulations are being carried out on lattices with Nt=4, 6 and 8 for the case of three degenerate quarks with masses less than or equal to the strange quark mass, $m_s$, and on lattices with Nt=6 and 8 for degenerate up and down quarks with masses in the range 0.2 m_s \\leq m_{u,d} \\leq 0.6 m_s, and the strange quark fixed near its physical value. We also report on first computations of quark number susceptibilities with the Asqtad action. These susceptibilities are of interest because they can be related to event-by-event fluctuations in heavy ion collision experiments. Use of the improved quark action leads to a substantial reduction in lattice artifacts. This can be seen already for free fermions and carries over into our results for QCD.
Screening of quark-monopole in N=4 plasma
Wei-shui Xu; Ding-fang Zeng
2014-12-11T23:59:59.000Z
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.
Quark masses, the Dashen phase, and gauge field topology
Creutz, Michael, E-mail: creutz@bnl.gov
2013-12-15T23:59:59.000Z
The CP violating Dashen phase in QCD is predicted by chiral perturbation theory to occur when the up–down quark mass difference becomes sufficiently large at fixed down-quark mass. Before reaching this phase, all physical hadronic masses and scattering amplitudes are expected to behave smoothly with the up-quark mass, even as this mass passes through zero. In Euclidean space, the topological susceptibility of the gauge fields is positive at positive quark masses but diverges to negative infinity as the Dashen phase is approached. A zero in this susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. I discuss potential ambiguities with this determination. -- Highlights: •The CP violating Dashen phase in QCD occurs when the up quark mass becomes sufficiently negative. •Before reaching this phase, all physical hadronic masses and scattering amplitudes behave smoothly with the up-quark mass. •The topological susceptibility of the gauge fields diverges to negative infinity as the Dashen phase is approached. •A zero in the topological susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. •The universality of this definition remains unproven. Potential ambiguities are discussed.
Jet conversions in a quark-gluon plasma
Liu, W.; Ko, Che Ming; Zhang, B. W.
2007-01-01T23:59:59.000Z
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) over bar )g -> gq((q) over bar )and the inelastic q (q) over bar gg...
Search for charged Higgs bosons in top quark decays
Baringer, Philip S.; Bean, Alice; Clutter, Justace Randall; Moulik, Tania; Wilson, Graham Wallace; DØ Collaboration; Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahsan, M.
2009-12-07T23:59:59.000Z
We present a search for charged Higgs bosons in top quark decays. We analyze the e+jetse+jets, ?+jets?+jets, ee, e?, ??, ?e and ?? final states from top quark pair production events, using data from about 1 fb^(?1) of integrated luminosity recorded...
Holography and unquenched quark-gluon plasmas
Bertoldi, G. [Department of Physics, Swansea University, Swansea, SA28PP (United Kingdom); Bigazzi, F. [Physique Theorique et Mathematique and International Solvay Institutes, Universit e Libre de Bruxelles, C.P. 231, B-1050 Bruxelles (Belgium); Cotrone, A. L. [Departament ECM, Facultat de Fisica, Universitat de Barcelona and Institut de Fisica d'Altes Energies, Diagonal 647, E-08028 Barcelona (Spain); Edelstein, J. D. [Departamento de Fisica de Particulas and IGFAE, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile)
2007-09-15T23:59:59.000Z
We employ the string/gauge theory correspondence to study properties of strongly coupled quark-gluon plasmas in thermal gauge theories with a large number of colors and flavors. In particular, we analyze noncritical string duals of conformal (S)QCD, as well as ten-dimensional wrapped fivebrane duals of SQCD-like theories. We study general properties of the dual plasmas, including the drag force exerted on a probe quark and the jet quenching parameter. We find that these plasma observables depend on the number of colors and flavors in the 'QCD dual'; in particular, we find that the jet quenching parameter increases linearly with N{sub f}/N{sub c} at leading order in the probe limit. In the ten-dimensional case we find a nontrivial drag coefficient but a vanishing jet quenching parameter. We comment on the relation of this result with total screening and argue that the same features are shared by all known plasmas dual to fivebranes in ten dimensions. We also construct new D5 black hole solutions with spherical horizon and show that they exhibit the same features.
Flavor Physics in the Quark Sector
Antonelli, M; Bauer, D; Becher, T; Beneke, M; Bevan, A J; Blanke, M; Bloise, C; Bóna, M; Bondar, A; Bozzi, C; Brod, J; Cabibbo, N; Carbone, A; Cavoto, G; Cirigliano, V; Ciuchini, M; Coleman, J P; Cronin-Hennessy, D P; Dalseno, J P; Davies, C H; Di Lodovico, F; Dingfelder, J; Dolezal, Z; Donati, S; Dungel, W; Egede, U; Faccini, R; Feldmann, T; Ferroni, F; Flynn, J M; Franco, E; Fujikawa, M; Furic, I K; Gambino, P; Gardi, E; Gershon, T J; Giagu, S; Golowich, E; Goto, T; Greub, C; Grojean, C; Guadagnoli, D; Haisch, U A; Harr, R F; Hoang, A H; Isidori, G; Jaffe, D E; Jüttner, A; Jäger, S; Khodjamirian, A; Koppenburg, P; Kowalewski, R V; Krokovny, P; Kronfeld, A S; Laiho, J; Lanfranchi, G; Latham, T E; Libby, J; Limosani, A; Pegna, D Lopes; Lü, C D; Lubicz, V; Lunghi, E; Lüth, V G; Maltman, K; Marciano, W J; Martin, E C; Martinelli, G; Martínez-Vidal, F; Masiero, A; Mateu, V; Mescia, F; Mohanty, G; Moulson, M; Neubert, M; Neufeld, H; Nishida, S; Offen, N; Palutan, M; Paradisi, P; Parsa, Z; Passemar, E; Patel, M; Pecjak, B D; Petrov, A A; Pich, A; Pierini, M; Plaster, B; Powell, A; Prell, S; Rademaker, J; Rescigno, M; Ricciardi, S; Robbe, P; Rodrigues, E; Rotondo, M; Sacco, R; Schilling, C J; Schneider, O; Scholz, E E; Schumm, B A; Schwanda, C; Schwartz, A J; Sciascia, B; Serrano, J; Shigemitsu, J; Shipsey, I J; Sibidanov, A; Silvestrini, L; Simonetto, F; Simula, S; Smith, C; Soni, A; Sonnenschein, L; Sordini, V; Sozzi, M; Spadaro, T; Spradlin, P; Stocchi, A; Tantalo, N; Tarantino, C; Telnov, A V; Tonelli, D; Towner, I S; Trabelsi, K; Urquijo, P; Van de Water, R S; Van Kooten, R J; Virto, J; Volpi, G; Wanke, R; Westhoff, S; Wilkinson, G; Wingate, M; Xie, Y; Zupan, J
2010-01-01T23:59:59.000Z
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...
Cooling of Neutron Stars with Color Superconducting Quark Cores
David Blaschke; Dmitri N. Voskresensky; Hovik Grigorian
2005-11-03T23:59:59.000Z
We show that within a recently developed nonlocal chiral quark model the critical density for a phase transition to color superconducting quark matter under neutron star conditions can be low enough for these phases to occur in compact star configurations with masses below 1.3 M_sun. We study the cooling of these objects in isolation for different values of the gravitational mass and argue that, if the quark matter phase would allow unpaired quarks, the corresponding hybrid stars would cool too fast. The comparison with observational data puts tight constraints on possible color superconducting quark matter phases. Possible candidates with diquark gaps of the order of 10 keV - 1 MeV such as the "2SC+X" and the color spin locking (CSL) phase are presented.
Preon Trinity - a new model of leptons and quarks
Jean-Jacques Dugne; Sverker Fredriksson; Johan Hansson; Enrico Predazzi
1999-10-12T23:59:59.000Z
A new model for the substructure of quarks, leptons and weak gauge bosons is discussed. It is based on three fundamental and absolutely stable spin-1/2 preons. Its preon flavour SU(3) symmetry leads to a prediction of nine quarks, nine leptons and nine heavy vector bosons. One of the quarks has charge $-4e/3$, and is speculated to be the top quark (whose charge has not been measured). The flavour symmetry leads to three conserved lepton numbers in all known weak processes, except for some neutrinos, which might either oscillate or decay. There is also a (Cabibbo) mixing of the $d$ and $s$ quarks due to an internal preon-antipreon annihilation channel. An identical channel exists inside the composite $Z^0$, leading to a relation between the Cabibbo and Weinberg mixing angles.
Stand: 25.10.2013 Hochschulleitung und Verwaltung Prsident Prof. Dr. Stefan Leible(5200)
Ullmann, G. Matthias
Prof. Dr. Hans-Werner Schmidt (3200) Kanzler Dr. Markus Zanner (5210) Briefanschrift: 95440 Bayreuth Zanner (5335) Vertretung: N.N. Referat A/1 Mathematik, Physik und Informatik VAe Natascha Mogalle (3197
Manstein, Dietmar J.
.-Psych. Susanne Bauer Dr. Dipl.-Psych. Albina Zeef 18.02.2013 Hysterie als Modus der Konfliktverarbeitung und als am Beispiel der konzentrativen Bewegungstherapie Prof. Dr. Dipl.-Psych. Klaus-Peter Seidler 11
1. Einfhrung in die Stabilitt dnnwandiger Strukturen 1.1.Einleitung und Motivation I
Berlin,Technische UniversitÃ¤t
II Beispiel 2: Plattenbeulen Oberhalb der Last Pcrit tritt Beulen ein Die LÃ¶sung ist ebenfalls ein dÃ¼nnwandiger Strukturen 1.1.Einleitung und Motivation III Beispiel 3: Zylinderbeulen Ab einer Last Pcrit tritt
Nabben, Reinhard
Inkrafttreten, AuÃ?erkrafttreten (1) Diese Ordnung tritt am Tag nach ihrer VerÃ¶ffentlichung im Amtlichen/2006) tritt spÃ¤testens nach Ablauf von acht Semestern nach Inkrafttreten der vorliegenden Studien- und
Knobloch,Jürgen
. Mathematik und Physik Mathematik Physik PLm (30 min) PLm (30 min) 22 15 7 3. 2. Informatik PLs (180 min) 8 1. Praktikum Grundlagen der Automatisierungstechnik PLs (180 min), PLm (30) PLs (120 min) T (Prakt.) PLs (60
Eishhlen stellen noch relativ wenig untersuchte Naturphnomene dar. Alter, Bildung und Fortbestand
Brückl, Ewald
#12;Eishöhlen stellen noch relativ wenig untersuchte Naturphänomene dar. Alter, Bildung und verschiedenster Methoden zur Untersuchung des Eises dar, wobei Die Höhle / 58. Jg. / Heft 1-4/2007 3
AM ABEND DES 20. SEPTEMBER 2002 lste sich eine gigantische Eis-und Steinlawine vom Nord-
Kääb, Andreas
#12;AM ABEND DES 20. SEPTEMBER 2002 löste sich eine gigantische Eis- und Steinlawine vom Nord- hang Eis nur schwer aus- zumachen: ein Teil der Gletscherflächen ist stets mit Schutt bedeckt. ASTER hat
Peters, Norbert
Ã?bung 10: Aufgabe 4-8: Luft tritt mit 300 K und 100 kPa in eine Gasturbine mit AbwÃ¤rmenutzung ein einen Wirkungsgrad von 72% und die Luft tritt mit 1200 K in die Turbine ein. Bei einem adiabten. Luft tritt in den Kompressor mit 300 K und 14 kg/s ein. In der Brennkammer wird die Luft auf 1500 K
Duan Chun-Gui; Liu Na
2008-09-28T23:59:59.000Z
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.
Top Quark Properties in Little Higgs Models
Berger, C.F.; /SLAC; Perelstein, M.; /Cornell U., CIHEP; Petriello, F.; /Wisconsin U., Madison
2005-12-08T23:59:59.000Z
Identifying the mechanism which breaks electroweak symmetry and generates fermion masses is one of the main physics goals for both the LHC and the ILC. Studies of the top quark have the potential to illuminate this issue; since it is the heaviest of the Standard Model (SM) fermions, the top is expected to couple strongly to the symmetry-breaking sector. Consequently, the structure of that sector can have significant, potentially observable effects on the properties of the top. for example, it is well known that the vector and axial t{bar t}Z form factors receive large corrections (of order 5-10%) in certain models of dynamical electroweak symmetry breaking [1]. At future colliders such as the LHC and the ILC, we will be able to pursue a program of precision top physics, similar to the program studying the Z at LEP and SLC. In this manuscript, they study the corrections to the top quark properties in ''Little Higgs'' models of electroweak symmetry breaking [2], and compare the expected deviations from the SM predictions with expected sensitivities of experiments at the LHC and the ILC. In the Little Higgs models, electroweak symmetry is driven by the radiative effects from the top sector, including the SM-like top and its heavy counterpart, a TeV-scale ''heavy top'' T. Probing this structure experimentally is quite difficult. While the LHC should be able to discover the T quark, its potential for studying its couplings is limited [3,4]. Direct production of the T will likely be beyond the kinematic reach of the ILC. However, we will show below that the corrections to the gauge couplings of the SM top, induced by its mixing with the T, will be observable at the ILC throughout the parameter range consistent with naturalness. Measuring these corrections will provide a unique window on the top sector of the Little Higgs. Many Little Higgs models have been proposed in the literature. We will consider two examples in this study, the ''Littlest Higgs'' model [5], and its variation incorporating T parity [6].
Heavy quark production from jet conversions in a quark-gluon plasma
Liu, W.; Fries, Rainer J.
2008-01-01T23:59:59.000Z
/BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973, USA (Received 13 May 2008; published 12 September 2008) Recently, it has been demonstrated that the chemical composition of jets in heavy ion collisions is significantly altered... observables that could be measured at the Relativistic Heavy Ion Collider (RHIC) or the Large Hadron Collider (LHC) [14]. In Ref. [12] it was found that conversions of light quarks to gluons could help solve the puzzle of very similar nuclear modification...
Search for W-prime Boson Resonances Decaying to a Top Quark and a Bottom Quark
Abazov, V.M.; Abbott, B.; /Dubna, JINR; Abolins, M.; /Oklahoma U.; Acharya, B.S.; /Michigan State U.; Adams, M.; /Tata Inst.; Adams, T.; /Illinois U., Chicago; Aguilo, E.; /Florida State U.; Ahn, S.H.; /York U., Canada; Ahsan, M.; /Korea U., KODEL; Alexeev, G.D.; /Kansas State U.; Alkhazov, Georgiy; /Dubna, JINR /St. Petersburg, INP /Northeastern U.
2008-03-01T23:59:59.000Z
We search for the production of a heavy W{prime} gauge boson that decays to third generation quarks in 0.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron collider. We find no significant excess in the final-state invariant mass distribution and set upper limits on the production cross section times branching fraction. For a left-handed W{prime} boson with SM couplings, we set a lower mass limit of 731 GeV. For right-handed W{prime} bosons, we set lower mass limits of 739 GeV if the W{prime} boson decays to both leptons and quarks and 768 GeV if the W{prime} boson decays only to quarks. We also set limits on the coupling of the W{prime} boson to fermions as a function of its mass.
Constituent gluons and the static quark potential
Greensite, Jeff
2015-01-01T23:59:59.000Z
We suggest that Hamiltonian matrix elements between physical states in QCD might be approximated, in Coulomb gauge, by "lattice-improved" tree diagrams; i.e. tree diagram contributions with dressed ghost, transverse gluon, and Coulomb propagators obtained from lattice simulations. Such matrix elements can be applied to a variational treatment of hadronic states which include constituent gluons. As an illustration and first application of this hybrid approach, we derive a variational estimate of the heavy quark potential for distances up to 2.5 fm. The Coulomb string tension in SU(3) gauge theory is about a factor of four times greater than the asymptotic string tension. In our variational approach, using for simplicity a single variational parameter, we can reduce this overshoot by nearly the factor required. The building blocks of our approach are Coulomb gauge propagators, and in this connection we present new lattice results for the ghost and transverse gluon propagators in position space.
Constituent gluons and the static quark potential
Jeff Greensite; Adam P. Szczepaniak
2015-05-19T23:59:59.000Z
We suggest that Hamiltonian matrix elements between physical states in QCD might be approximated, in Coulomb gauge, by "lattice-improved" tree diagrams; i.e. tree diagram contributions with dressed ghost, transverse gluon, and Coulomb propagators obtained from lattice simulations. Such matrix elements can be applied to a variational treatment of hadronic states which include constituent gluons. As an illustration and first application of this hybrid approach, we derive a variational estimate of the heavy quark potential for distances up to 2.5 fm. The Coulomb string tension in SU(3) gauge theory is about a factor of four times greater than the asymptotic string tension. In our variational approach, using for simplicity a single variational parameter, we can reduce this overshoot by nearly the factor required. The building blocks of our approach are Coulomb gauge propagators, and in this connection we present new lattice results for the ghost and transverse gluon propagators in position space.
Heavy Quark Production at the Tevatron
Seidel, Sally; /New Mexico U.
2008-08-01T23:59:59.000Z
Results are presented from four CDF analyses involving heavy quark production in proton-antiproton collisions at center of mass energy 1.96 TeV. The shapes of b-jets are found to be broader than inclusive predictions and broader than both PYTHIA and HERWIG defaults. A measurement of the production cross section for {psi}(2S) is consistent with Run 1 results and with theoretical predictions associated with parton distribution function energy dependence. The inclusive b-jet production cross section is also consistent with theoretical predictions over six orders of magnitude. The b{bar b} differential production cross section is compared to several theoretical models and found to be best described by MC{at}NLO + JIMMY.
Basic features of the pion valence-quark distribution function
Lei Chang; Cédric Mezrag; Hervé Moutarde; Craig D. Roberts; Jose Rodríguez-Quintero; Peter C. Tandy
2014-06-20T23:59:59.000Z
The impulse-approximation expression used hitherto to define the pion's valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression produces the model-independent result that quarks dressed via the rainbow-ladder truncation, or any practical analogue, carry all the pion's light-front momentum at a characteristic hadronic scale. Corrections to the leading contribution may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea-quarks. Working with available empirical information, we use an algebraic model to express the principal impact of both classes of corrections. This enables a realistic comparison with experiment that allows us to highlight the basic features of the pion's measurable valence-quark distribution, $q^\\pi(x)$; namely, at a characteristic hadronic scale, $q^\\pi(x) \\sim (1-x)^2$ for $x\\gtrsim 0.85$; and the valence-quarks carry approximately two-thirds of the pion's light-front momentum.
Combined search for the quarks of a sequential fourth generation
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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
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.
Quarks and the Strong Force Summary/Review Spring 2009 Compton Lecture Series
groups: one with non-zero quark number and the other with zero quark number The non-zero quark number particles are all either spin 1/2 or spin 3/2. The zero quark number particles are all either spin 0 or spin exchange is a residual effect from the color structure of baryons which have no net color Protons
Golden Bars of Consensus and the Truth Quark
Frank D. Tony Smith; jr
2002-05-14T23:59:59.000Z
Scientists are imprisoned by Golden Bars of Consensus, says Burton Richter (hep-ex/0001012). A case in point is the mass of the Truth Quark. The consensus analysis of the experimental data indicates that the mass of the Truth Quark is about 170 GeV. On the other hand, an alternative analysis of the same data indicates that the mass of the Truth Quark is about 130 GeV. If the design of future experiments, including trigger, event selection, data analysis procedures, error analysis, etc., takes into account only the consensus value, and if the consensus value happens to be incorrect, then results of future experiments might be compromised.
Charmonium in strongly coupled quark-gluon plasma
Clint Young; Edward Shuryak
2008-09-22T23:59:59.000Z
The growing consensus that a strongly-coupled quark-gluon plasma (sQGP) has been observed at the SPS and RHIC experiments suggests a different framework for examining heavy quark dynamics. We present both semi-analytical treatment of Fokker-Planck (FP) evolution in pedagogical examples and numerical Langevin simulations of evolving charm quark-antiquark pairs on top of a hydrodynamically expanding fireball. In this way, we may conclude that the survival probability of bound charmonia states is greater than previously estimated, as the spatial equilibration of pairs proceeds through a ``slowly dissolving lump'' stage related to the pair interaction.
Measurements of Top Quark Properties at the Tevatron
Mietlicki, David J.; /Michigan U.
2012-04-01T23:59:59.000Z
The top quark is the most recently discovered of the standard model quarks, and studies of its properties are important tests of the standard model. Many measurements of top properties have been produced by the CDF and D0 collaborations, which study top quarks produced in p{bar p} collisions at the Fermilab Tevatron with a center-of-mass energy {radical}s = 1.96 TeV. We describe recent results from top properties measurements at the Tevatron using datasets corresponding to integrated luminosities up to 8.7 fb{sup -1}.
Calculation of the strange quark mass using domain wall fermions
Tom Blum; Amarjit Soni; Matthew Wingate
2000-09-18T23:59:59.000Z
We present a first calculation of the strange quark mass using domain wall fermions. This paper contains an overview of the domain wall discretization and a pedagogical presentation of the perturbative calculation necessary for computing the mass renormalization. We combine the latter with numerical simulations to estimate the strange quark mass. Our final result in the quenched approximation is 95(26) MeV in the ${\\bar{MS}}$ scheme at a scale of 2 GeV. We find that domain wall fermions have a small perturbative mass renormalization, similar to Wilson quarks, and exhibit good scaling behavior.
Combining Quark and Link Smearing to Improve Extended Baryon Operators
Adam Lichtl; Subhasish Basak; Robert Edwards; George T. Fleming; Urs M. Heller; Colin Morningstar; David Richards; Ikuro Sato; Stephen Wallace
2005-09-29T23:59:59.000Z
The effects of Gaussian quark-field smearing and analytic stout-link smearing on the correlations of gauge-invariant extended baryon operators are studied. Gaussian quark-field smearing substantially reduces contributions from the short wavelength modes of the theory, while stout-link smearing significantly reduces the noise from the stochastic evaluations. The use of gauge-link smearing is shown to be crucial for baryon operators constructed of covariantly-displaced quark fields. Preferred smearing parameters are determined for a lattice spacing a_s ~ 0.1 fm.
On the Energy Loss of High Energy Quarks in a Finite-Size Quark-Gluon Plasma
B. G. Zakharov
2000-12-28T23:59:59.000Z
We study within the light-cone path integral approach the induced gluon emission from a fast quark passing through a finite-size QCD plasma. We show that the leading log approximation used in previous studies fails when the gluon formation length becomes of the order of the length of the medium traversed by the quark. Calculation of the energy loss beyond the leading log approximation gives the energy loss which grows logarithmically with quark energy contrary to the energy independent prediction of the leading log approximation.
Color superconductivity with determinant interaction in strange quark matter
Amruta Mishra; Hiranmaya Mishra
2006-08-28T23:59:59.000Z
We investigate the effect of six fermion determinant interaction on color superconductivity as well as on chiral symmetry breaking. Coupled mass gap equations and the superconducting gap equation are derived through the minimisation of the thermodynamic potential. The effect of nonzero quark -- antiquark condensates on the superconducting gap is derived. This becomes particularly relevant for the case of 2-flavor superconducting matter with unpaired strange quarks in the diquark channel. While the effect of six fermion interaction leads to an enhancement of u-d superconductivity, due to nonvanishing strange quark--antiquark condensates, such an enhancement will be absent at higher densities for u-s or d-s superconductivity due to early (almost) vanishing of light quark-- antiquark condensates.
Black holes and the quark-gluon plasma
George Siopsis
2009-01-26T23:59:59.000Z
I discuss the possibility that the quark-gluon plasma at strong coupling admits a description in terms of a black hole in asymptotically anti-de Sitter space.
Exploration of nucleon structure in lattice QCD with chiral quarks
Syritsyn, Sergey Nikolaevich
2010-01-01T23:59:59.000Z
In this work, we calculate various nucleon structure observables using the fundamental theory of quarks and gluons, QCD, simulated on a lattice. In our simulations, we use the full QCD action including Nf = 2+ 1 dynamical ...
First observation of top quark production in the forward region
Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; d'Argent, Philippe; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Birnkraut, Alex; Bizzeti, Andrea; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Di Ruscio, Francesco; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fohl, Klaus; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gastaldi, Ugo; Gauld, Rhorry; Gavardi, Laura; Gazzoni, Giulio; Geraci, Angelo; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto
2015-01-01T23:59:59.000Z
Top quark production in the forward region in proton-proton collisions is observed for the first time. The $W\\!+\\!b$ final state with $W\\to\\mu\
Summary of the session on the top quark
Butler, Joel N.; /Fermilab
2011-01-01T23:59:59.000Z
The CDF and D0 experiments at the Fermilab Tevatron showed recent results on the production and properties of the top quark. The CMS and ATLAS experiments presented first observations of top events at the LHC. Prospects for the top physics at the LHC over the next few years were discussed. CDF and D0 have made remarkable progress in detemerining the properties of the top quark, which so far, conforms to the expectations of the SM. The sophisticated methods they have developed form the basis of the exploration that is now starting at the LHC. New methods, such as the use of boosted top quark signatures, will be necessary to realize fully the potential of the LHC for finding new high mass particles decaying to top and for searching for deviations from the SM. Prospects for the future of top quark physics are very bright.
Quark mass functions and pion structure in Minkowski space
Biernat, Elmer P. [CFTP, Institute Superior Tecnico; Gross, Franz L. [JLAB; Pena, Maria Teresa [CFTP, Institute Superior Tecnico; Stadler, Alfred [University of Evora
2014-03-01T23:59:59.000Z
We present a study of the dressed quark mass function and the pion structure in Minkowski space using the Covariant Spectator Theory (CST). The quark propagators are dressed with the same kernel that describes the interaction between different quarks. We use an interaction kernel in momentum space that is a relativistic generalization of the linear confining q-qbar potential and a constant potential shift that defines the energy scale. The confining interaction has a Lorentz scalar part that is not chirally invariant by itself but decouples from the equations in the chiral limit and therefore allows the Nambu--Jona-Lasinio (NJL) mechanism to work. We adjust the parameters of our quark mass function calculated in Minkowski-space to agree with LQCD data obtained in Euclidean space. Results of a calculation of the pion electromagnetic form factor in the relativistic impulse approximation using the same mass function are presented and compared with experimental data.
QCD thermodynamics with Wilson quarks at large kappa
Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; A. Hasenfratz; Leo Karkkainen; D. Toussaint; R. L. Sugar
1994-04-12T23:59:59.000Z
We have extended our study of the high temperature transition with two flavors of Wilson quarks on 12^3 x 6 lattices to kappa=0.19. We have also performed spectrum calculations on 12^3 x 24 lattices at kappa=0.19 to find the physical lattice spacing and quark mass. At this value of kappa the transition is remarkable in that the plaquette and psi-bar-psi show a large discontinuity while the Polyakov loop changes very little. This and several other features of the transition are more suggestive of a bulk transition than a transition to a quark-gluon plasma. However, if the temperature is estimated using the rho mass as a standard, the result is about 150 MeV, in agreement with the value found for the thermal transition with Kogut-Susskind quarks. uuencoded compressed Postscript file
Hadron resonances with a quark core embedded in the continuum
Shimizu, Kiyotaka [Department of Physics, Sophia University, Chiyoda-ku, Tokyo 102-8554 (Japan); Takeuchi, Sachiko [Japan College of Social Work, Kiyose, Tokyo 204-8555 (Japan); Takizawa, Makoto [Showa Pharmaceutical University, Machida, Tokyo 194-8543 (Japan)
2011-05-06T23:59:59.000Z
We investigate the excited baryons and mesons which cannot be described in terms of a simple constituent quark model, such as {Lambda}(1405) and X(3872) as a resonance in a coupled channel hadron-hadron (baryon-meson or meson-meson) scattering with a 'bound state embedded in the continuum' (BSEC). For this purpose, we solve the Lippmann-Schwinger equation including a BSEC in the momentum space. This BSEC is introduced by hand, as a state not originated from a simple baryon-meson or meson-meson system. We assume it comes from the three-quark state or quark-anti quark state and show such a picture can describe the {Lambda}(1405) and X(3872) resonances.
arbitrary quark mass: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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. A. P....
Precision Top-Quark Mass Measurement at CDF
Gomez-Ceballos, Guillelmo
We present a precision measurement of the top-quark mass using the full sample of Tevatron ?s=1.96??TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of ...
Measurement of Heavy Quark cross-sections at CDF
A. Annovi
2007-09-28T23:59:59.000Z
The measurement of heavy quark cross-sections provides important tests of the QCD theory. This paper reviews recent measurements of single b-quark and correlated b-quark cross-sections at CDF. Two new measurements of the single b-quark production at CDF agree with the first result from CDF Run II. This clarifies the experimental situation and confirms the recent agreement of theoretical prediction with data. A new measurement of the correlated $b\\bar{b}$ cross-section with dimuon events at CDF is presented. It agrees with theory and it does not confirm the anomalously large $b\\bar{b}$ cross-section seen in Run I by CDF and D${\
approximating chiral quark: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
instantons. Harald Markum; Wolfgang Sakuler; Stefan Thurner 1998-09-20 12 Quark condensates in the chiral bag with the NJL interaction HEP - Phenomenology (arXiv) Summary: We...
Iso-singlet Down Quark Mixing And CP Violation Experiments
Donovan Hawkins; Dennis Silverman
2002-05-01T23:59:59.000Z
We confront the new physics models with extra iso-singlet down quarks in the new CP violation experimental era with $\\sin{(2\\beta)}$ and $\\epsilon'/\\epsilon$ measurements, $K^+ \\to \\pi^+ \
Observation of $t$-channel electroweak top quark production
Triplett, Nathan; /Iowa State U.
2011-04-01T23:59:59.000Z
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.
Gluon Radiation off Massive Quarks in a QCD Medium
N. Armesto; C. A. Salgado; U. A. Wiedemann
2004-05-19T23:59:59.000Z
Medium-induced gluon radiation from massless and massive quarks is treated in the same formalism. The dead cone which regulates gluon radiation from massive quarks in the vacuum at small angles, is filled in the medium but constitutes a small fraction of the available phase space. Our study indicates that the energy loss for charmed hadrons at RHIC should be smaller than for light hadrons, but still sizable.
Dilepton Production In Non-equilibriated Quark Gluon Plasma
S. S. Singh; Agam K. Jha
2006-07-01T23:59:59.000Z
A model of cut-off momentum distribution functions in a Quark Gluon Plasma with finite baryon chemical potential is discussed. This produces a quark gluon plasma signature in Ultra Relativistic Nuclear Collisions with a specific structure of the dilepton spectrum in the transverse momentum region of $(1-4)~GeV$ and the dilepton production rate is found to be a strong decreasing function of the chemical potential.
Reconstructing top quark-antiquark events with one lost jet
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Demina, Regina [Univ. of Rochester, Rochester, NY (United States); Harel, Amnon [Univ. of Rochester, Rochester, NY (United States); Orbaker, Douglas [Univ. of Rochester, Rochester, NY (United States)
2015-07-01T23:59:59.000Z
We present a technique for reconstructing the kinematics of pair-produced top quarks that decay to a charged lepton, a neutrino and four final state quarks in the subset of events where only three jets are reconstructed. We present a figure of merit that allows for a fair comparison of reconstruction algorithms without requiring their calibration. The new reconstruction of events with only three jets is fully competitive with the full reconstruction typically used for four-jet events.
Shear viscosity and spectral function of the quark matter
Masaharu Iwasaki; Hiromasa Ohnishi; Takahiko Fukutome
2006-06-19T23:59:59.000Z
We discuss the shear viscosity of the quark matter by using the Kubo-Mori formula. It is found that the shear viscosity is expressed in terms of the quark spectral function. If the spectral function is approximated by a modified Bright-Wigner type, the viscosity decreases as the width of the spectral function increases. We also discuss dependence of the shear viscosity on the temperature and the density.
Overview of ALICE Results at Quark Matter 2014
Jan Fiete Grosse-Oetringhaus; for the ALICE collaboration
2014-10-07T23:59:59.000Z
The results released by the ALICE collaboration at Quark Matter 2014 address topics from identified-particle jet fragmentation functions in pp collisions, to the search for collective signatures in p-Pb collisions to precision measurements of jet quenching with D mesons in Pb-Pb collisions. This paper gives an overview of the contributions (31 parallel talks, 2 flash talks and 80 posters) by the ALICE collaboration at Quark Matter 2014.
Transverse quark distribution in mesons: QCD sum rule approach
Lee, S.H.; Hatsuda, T.; Miller, G.A. (Department of Physics, FM-15, University of Washingtion, Seattle, Washington 98195 (United States) Department of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of))
1994-04-11T23:59:59.000Z
QCD sum rules are used to compute the first few moments of the mesonic quark momentum. Transverse, longitudinal, and mixed transverse-longitudinal components are examined. The transverse size of the pion is shown to be dictated by the gluon condensate, even though the mass and the longitudinal distribution are dominated by the quark condensate. The implications of our results for color transparency physics and finite temperature QCD are discussed.
Breu, Ruth
2000/2001 Ausgegeben am 16. Mai 2001 21. Stück 438. Reform des Studienplans für die Studienrichtung Begutachtungsverfahren gemäß § 14 UniStG 439. Reform des Studienplanes für das Doktoratsstudium der Sozial- und Wirtschaftswissenschaften an der Karl-Franzens-Universität Graz - Begutachtungsverfahren 440. Reform des Studienplanes für
Middeldorp, Aart
gemäß § 14 UniStG 79. Reform des Studienplans für das Diplomstudium Physik an der Karl-Franzens- Universität Graz 80. Reform des Studienplans für die Studienrichtung Volkskunde an der Karl-Franzens- Universität Graz 81. Reform des Studienplanes Sozialwirtschaft als sozial- und wirtschaftswissenschaftliche
Breu, Ruth
. Stück 291. Reform des Studienplans der Studienrichtung Geschichte an der Karl-Franzens- Universität Graz Anhörungsverfahren gem. § 12 Abs. 2 UniStG 292. Reform der Studienpläne für die Lehramtsfächer Deutsch, Englisch. Reform des Studienplans der Studienrichtung Wirtschaftsingenieurwesen -Technische Chemie und Technische
On the effects of heavy sea quarks at low energies
Mattia Bruno; Jacob Finkenrath; Francesco Knechtli; Bjoern Leder; Rainer Sommer
2014-10-30T23:59:59.000Z
We present a factorisation formula for the dependence of light hadron masses and low energy hadronic scales on the mass $M$ of a heavy quark: apart from an overall factor $Q$, ratios such as $r_0(M)/r_0(0)$ are computable in perturbation theory at large $M$. The mass-independent factor $Q$ is obtained from the theory in the limit $M\\to0$ and the decoupled theory with the heavy quark removed. The perturbation theory part is stable concerning different loop orders and our non-perturbative results match on quantitatively to the perturbative prediction. Upon taking ratios of different hadronic scales at the same mass, the perturbative function drops out and the ratios are given by the decoupled theory up to $M^{-2}$ corrections. Our present numerical results are obtained in a model calculation where there are no light quarks and a heavy doublet of quarks is decoupled. They are limited to masses a factor two below the charm. This is not large enough to see the $M^{-2}$ scaling predicted by the theory, but it is sufficient to verify - in the continuum limit - that the sea quark effects of quarks with masses around the charm mass are very small.
Observation of the top quark with the DO detector
Hadley, N.J. [Univ. of Maryland, College Park, MD (United States)
1997-01-01T23:59:59.000Z
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.
Jet conversions in a quark-gluon plasma
W. Liu; C. M. Ko; B. W. Zhang
2007-05-05T23:59:59.000Z
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(\\bar q)g\\to gq(\\bar q)$ and the inelastic $q\\bar q\\leftrightarrow 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 conversion of quark 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/\\pi^+$ and ${\\bar p}/\\pi^-$ 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 same energy. Implications of our results are discussed.
Big Bang Day: 5 Particles - 2. The Quark
None
2011-04-25T23:59:59.000Z
Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 2. The Quark "Three Quarks for Master Mark! Sure he hasn't got much of a bark." James Joyce's Finnegans Wake left its mark on modern physics when physicist Murray Gell Mann proposed this name for a group of hypothetical subatomic particles that were revealed in 1960 as the fundamental units of matter. Basic particles it seems are made up of even more basic units called quarks that make up 99.9% of visible material in the universe.. But why do we know so little about them? Quarks have never been seen as free particles but instead, inextricably bound together by the Strong Force that in turn holds the atomic nucleus together. This is the hardest of Nature's fundamental forces to crack, but recent theoretical advances, mean that the properties of the quark are at last being revealed.
G. ~Pagliara
2010-12-14T23:59:59.000Z
We study the process of formation of quark phases in protoneutron stars. After calculating the phase transition between nucleonic matter and the 2SC phase at fixed entropy and lepton fraction, we show that an unpairing transition between the 2SC phase and the normal quark phase occurs for low lepton fractions. We then calculate the process of diffusion of neutrinos in protoneutron stars and show that for intermediate values of the mass of the star, the deleptonization triggers the phase transition between the two quark phases after a temporal delay of a few seconds. In less massive stars instead only the normal quark phase is formed at the end of the deleptonization stage. We also discuss the possible astrophysical implications of our scenario.
Quark antiquark energies and the screening mass in a Quark-Gluon plasma at low and high temperatures
O. Kaczmarek; F. Zantow
2005-12-22T23:59:59.000Z
We discuss quark antiquark energies and the screening mass in hot QCD using the non-perturbative lattice approach. For this purpose we analyze properties of quark antiquark energies and entropies at infinitely large separation of the quark antiquark pair at low and high temperatures. In the limit of high temperatures these energies and entropies can be related perturbatively to the temperature dependence of the Debye mass and the coupling. On the one hand our analysis thus suggests that the quark antiquark energies at (infinite) large distances are rather related to the Debye screening mass and the coupling than to the temperature dependence of heavy-light meson masses. On the other hand we find no or only little differences in all mass scales introduced by us when changing from quenched to 2-flavor QCD at temperatures which are only moderately above the phase transition.
Paderborn, Universität
Anforderungen an den Energie- und Leistungsumsatz der POWER TO GAS- Einheit im MICRO GRID eines MICRO GRID angeschlossenen elektrischen Energiespeicher und eine ,,POWER TO GAS" -Anlage kompensiert werden. Die ,,POWER TO GAS" Anlage entnimmt dem MICRO GRID überschüssige elektrische Energie zur
Gollisch, Tim
zentrum hygiene und humangenetik ABTEIlUNG TRANSFUSIONSMEDIZIN centre for hygiene and human@med.uni-goettingen.de www.transfusionsmedizin.med.uni-goettingen.de #12;212 Zentrum Hygiene und Humangenetik ABteilunG trAnsfusionsmedizin Centre for Hygiene and Human Genetics depArtment of trAnsfusion medicine Einleitung Die Aufgabe der
Berns, Karsten
Abendessen plus GetrÃ¤nke mit MÃºsica en Vivo in Kooperation mit der Emmerich-Smola-Musikschule und wissenschaftliche Tagungen zur VerfÃ¼gung. In Kooperation mit: Emmerich-Smola-Musikschule und Musikakademie Kaiserslautern emmerich-smola.musikschule@kaiserslautern.de Telefon: 0631 365-2263 Sie suchen ein interessantes
Taylor, Frank E.
Using a sample of dilepton top-quark pair (t[bar over t]) candidate events, a study is performed of the production of top-quark pairs together with heavy-flavor (HF) quarks, the sum of t[bar over t] + b + X and t[bar over ...
Gomez-Ceballos, Guillelmo
We present a search for a new heavy particle X produced in association with a top quark, pp? ?t(X?t? q) or pp? ?t? (X? ?tq? ), where q stands for up quarks and down quarks. Such a particle may explain the recent anomalous ...
Stadler, Michael; Lipman, Tim; Marnay, Chris
2008-01-01T23:59:59.000Z
Sinne – wie in einem Verbrennungsmotor – statt und dadurchVergleich zu einem Verbrennungsmotor. Der Hauptunterschied
Higgs Bosons from Top Quark Decays
Tao Han; Richard Ruiz
2014-04-28T23:59:59.000Z
In light of the discovery of a Standard Model (SM)-like Higgs boson ($h$) at the LHC, we investigate the top quark to Higgs boson transition $t\\rightarrow W^{*}bh$, which is the leading $t\\to h$ decay mode in the SM. We find the decay branching fraction to be $1.80\\times 10^{-9}$. In comparison, the two-body, loop-induced $t\\rightarrow ch$ transition occurs at $\\sim10^{-14}$ in the SM. We consider the consequences of gauge invariant dimension-6 operators affecting the $t\\bar{t}h$ interaction and find that the decay branching fraction may be increased by a factor of two within current constraints on the coupling parameters from collider experiments. We also extend the calculation to the CP-conserving Type I and Type II Two Higgs Doublet Models (2HDM), including both CP-even and CP-odd Higgs bosons. For neutral scalar masses at about $100$ GeV, the decay rates can be several times larger than the SM result in the allowed range of model parameters. Observation prospects at present and future colliders are briefly addressed.
Top quark physics at the Tevatron
Bhat, P.C.
1998-04-01T23:59:59.000Z
The authors review the analyses of t{bar t} candidate events in various decay channels, carried out using the p{bar p} collider data at {radical}s = 1.8 TeV by the CDF and D0 collaborations at the Fermilab Tevatron. The measurements of the top quark mass (m{sub t}) using lepton+jets channel yield m{sub t} = 173.3 {+-} 7.8 GeV/c{sup 2} from D0 analysis and m{sub t} = 175.9 {+-} 6.9 GeV/c{sup 2} from CDF analysis. The production cross section is measured to be {sigma}{sub t{bar t}} = 7.6{sub -1.5}{sup +1.8} pb by CDF and {sigma}{sub t{bar t}} = 5.6 {+-} 1.8 pb by D0. Further investigations using t{bar t} decays and future prospects are briefly discussed.
Strange Quark Contribution to the Nucleon - (Dissertation)
Dean Darnell
2008-01-23T23:59:59.000Z
The strangeness contribution to the electric and magnetic properties of the nucleon has been under investigation experimentally for many years. Lattice Quantum Chromodynamics (LQCD) gives theoretical predictions of these measurements by implementing the continuum gauge theory on a discrete, mathematical Euclidean space-time lattice which provides a cutoff removing the ultra-violet divergences. In this dissertation we will discuss effective methods using LQCD that will lead to a better determination of the strangeness contribution to the nucleon properties. Strangeness calculations are demanding technically and computationally. Sophisticated techniques are required to carry them to completion. In this thesis, new theoretical and computational methods for this calculation such as twisted mass fermions, perturbative subtraction, and General Minimal Residual (GMRES) techniques which have proven useful in the determination of these form factors will be investigated. Numerical results of the scalar form factor using these techniques are presented. These results give validation to these methods in future calculations of the strange quark contribution to the electric and magnetic form factors.
Tracking down hyper-boosted top quarks
Larkoski, Andrew J; Selvaggi, Michele
2015-01-01T23:59:59.000Z
The identification of hadronically decaying heavy states, such as vector bosons, the Higgs, or the top quark, produced with large transverse boosts has been and will continue to be a central focus of the jet physics program at the Large Hadron Collider (LHC). At a future hadron collider working at an order-of-magnitude larger energy than the LHC, these heavy states would be easily produced with transverse boosts of several TeV. At these energies, their decay products will be separated by angular scales comparable to individual calorimeter cells, making the current jet substructure identification techniques for hadronic decay modes not directly employable. In addition, at the high energy and luminosity projected at a future hadron collider, there will be numerous sources for contamination including initial- and final-state radiation, underlying event, or pile-up which must be mitigated. We propose a simple strategy to tag such "hyper-boosted" objects that defines jets with radii that scale inversely proportion...
The rigidity of three flavor quark matter
Sharma, Rishi [Los Alamos National Laboratory; Mannarelli, Massimo [IEEC/CSIC
2008-01-01T23:59:59.000Z
Cold three flavor quark matter at large (but not asymptotically large) densities may exist in a crystalline color superconducting phase. These phases are characterized by a gap parameter {Delta} that varies periodieally in space, forming a crystal structure. A Ginzburg-Landau expansion in {Delta} shows that two crystal structures based on cubic symetry are particularly favorable, and may be the ground state of matter at densities present in neutron star cores. We derive the effective action for the phonon fields that describe space-and time-dependent fluctuations of the crystal structure formed by {Delta}, and obtain the shear modulus from the coefficients of the spatial derivative terms. Within a Ginzburg-Landau approximation, we find shear moduli which are 20 to 1000 times larger than those of neutron star crusts. This phase ofmatter is thus more rigid than any known material in the universe, but at the same time the crystalline color superconducting phase is also superftuid. These properties raise the possibility that the presence of this phase within neutron stars may have distinct implications for their phenomenology. For example, (some) pulsar glitches may originate in crystalline superconducting neutron star cores.
Modeling Quark Gluon Plasma Using CHIMERA
Betty B. I. Abelev
2011-09-19T23:59:59.000Z
We attempt to model Quark Gluon Plasma (QGP) evolution from the initial Heavy Ion collision to the final hadronic gas state by combining the Glauber model initial state conditions with eccentricity fluctuations, pre-equilibrium flow, UVH2+1 viscous hydrodynamics with lattice QCD Equation of State (EoS), a modified Cooper-Frye freeze-out and the UrQMD hadronic cascade. We then evaluate the model parameters using a comprehensive analytical framework which together with the described model we call CHIMERA. Within our framework, the initial state parameters, such as the initial temperature (T$_{\\mathrm{init}}$), presence or absence of initial flow, viscosity over entropy density ($\\eta$/s) and different Equations of State (EoS), are varied and then compared simultaneously to several experimental data observables: HBT radii, particle spectra and particle flow. $\\chi^2$/nds values from comparison to the experimental data for each set of initial parameters will then used to find the optimal description of the QGP with parameters that are difficult to obtain experimentally, but are crucial to understanding of the matter produced.
Modeling Quark Gluon Plasma Using CHIMERA
Abelev, Betty B I
2011-01-01T23:59:59.000Z
We attempt to model Quark Gluon Plasma (QGP) evolution from the initial Heavy Ion collision to the final hadronic gas state by combining the Glauber model initial state conditions with eccentricity fluctuations, pre-equilibrium flow, UVH2+1 viscous hydrodynamics with lattice QCD Equation of State (EoS), a modified Cooper-Frye freeze-out and the UrQMD hadronic cascade. We then evaluate the model parameters using a comprehensive analytical framework which together with the described model we call CHIMERA. Within our framework, the initial state parameters, such as the initial temperature (T$_{\\mathrm{init}}$), presence or absence of initial flow, viscosity over entropy density ($\\eta$/s) and different Equations of State (EoS), are varied and then compared simultaneously to several experimental data observables: HBT radii, particle spectra and particle flow. $\\chi^2$/nds values from comparison to the experimental data for each set of initial parameters will then used to find the optimal description of the QGP wi...
Peters, Norbert
Aufgabe 3-7: Luft tritt mit 1 = 2,21 kg/mÂ³ und v1 = 40 m/s kontinuierlich in eine DÃ¼se ein und, 800 kPa) tritt mit 10 m/s in eine DÃ¼se ein (siehe Abbildung 1). In der DÃ¼se verliert der Dampf WÃ¤rme
Measurement of b-quark Jet Shapes at CDF
Lister, Alison; /Zurich, ETH
2006-03-01T23:59:59.000Z
The main topic of this thesis is the measurement of b-quark jet shapes at CDF. CDF is an experiment located at Fermilab, in the United States, which studies proton-antiproton collisions at a center of mass energy of 1.96TeV. To reach this energy, the particles are accelerated using the Tevatron accelerator which is currently the highest energy collider in operation. The data used for this analysis were taken between February 2002 and September 2004 and represent an integrated luminosity of about 300 pb{sup -1}. This is the first time that b-quark jet shapes have been measured at hadron colliders. The basis of this measurement lies in the possibility of enhancing the b-quark jet content of jet samples by requiring the jets to be identified as having a displaced vertex inside the jet cone. Such jets are called tagged. This enhances the b-quark jet fraction from about 5% before tagging to 20-40% after tagging, depending on the transverse momentum of the jets. I verified that it is possible to apply this secondary vertex tagging algorithm to different cone jet algorithms (MidPoint and JetClu) and different cone sizes (0.4 and 0.7). I found that the performance of the algorithm does not change significantly, as long as the sub-cone inside which tracks are considered for the tagging is kept at the default value of 0.4. Because the b-quark purity of the jets is still relatively low, it is necessary to extract the shapes of b-quark jets in a statistical manner from the jet shapes both before and after tagging. The other parameters that enter into the unfolding equation used to extract the b-quark jet shapes are the b-jet purities, the biases due to the tagging requirement both for b- and nonbjets and the hadron level corrections. The last of these terms corrects the measured b-jet shapes back to the shapes expected at hadron level which makes comparisons with theoretical models and other experimental results possible. This measurement shows that, despite relatively large systematic uncertainties, the measured b-quark jet shapes are significantly different from those expected from the so-called Pythia Tune A Monte Carlo simulation, the most widely used Leading Order Monte Carlo model at CDF. This difference can be mostly attributed to the fact that the fraction of b-quark jets that originate from flavour creation (where a single b-quark is expected inside the same jet cone) over those that originate from gluon splitting (where two b-quarks are expected to be inside the same jet cone) is slightly different in the Pythia Tune A Monte Carlo predictions than in data. This measurement can help in the tuning of the fraction of gluon splitting to flavour creation b-quark jets in the Monte Carlo simulation. This tuning is particularly important for the extrapolation up to LHC energies where many searches will involve b-quark jets. During the first year of my thesis work, I worked on the implementation of a prototype detector control system for the electromagnetic calorimeter which is being built for the CMS experiment at CERN. The prototype which I implemented was used to monitor and control the high voltage, low voltage, cooling and precision temperature monitoring systems during the summer 2003 test-beam. This was one of the first, almost complete, systems implemented and used by an LHC experiment for test-beam monitoring.
Determination of the width of the top quark
Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Abolins, Maris A.; /Michigan State 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 /Nijmegen U.
2010-09-01T23:59:59.000Z
We extract the total width of the top quark, {Lambda}{sub t}, from the partial decay width {Lambda}(t {yields} Wb) measured using the t-channel cross section for single top quark production and from the branching fraction B(t {yields} Wb) measured in t{bar t} events using up to 2.3 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The result is {Lambda}{sub t} = 1.99{sub -0.55}{sup +0.69} GeV, which translates to a top-quark lifetime of {tau}{sub t} = (3.3{sub -0.9}{sup +1.3}) x 10{sup -25} s. Assuming a high mass fourth generation b{prime} quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V{sub tb{prime}}| < 0.63 at 95% C.L.
Sketching the pion's valence-quark generalised parton distribution
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mezrag, C.; Chang, L.; Moutarde, H.; Roberts, C.D.; Rodríguez-Quintero, J.; Sabatié, F.; Schmidt, S.M.
2015-02-01T23:59:59.000Z
In order to learn effectively from measurements of generalised parton distributions (GPDs), it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL) truncation of QCD’s Dyson–Schwinger equations and exemplified via the pion’s valence dressed-quark GPD, Hv?(x, ?, t). Our analysis focuses primarily on ?=0, although we also capitalise on the symmetry-preserving nature of the RL truncation by connecting Hv?(x, ?=±1, t)with the pion’s valence-quark parton distribution amplitude. We explain that the impulse-approximation used hitherto to definemore »the pion’s valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for Hv?(x, 0, t), expressed as the Radon transform of a single amplitude. Therewith we obtain results for Hv?(x, 0, t)and the associated impact-parameter dependent distribution, qv?(x, |#2;b?|), which provide a qualitatively sound picture of the pion’s dressed-quark structure at ahadronic scale. We evolve the distributions to a scale ?=2GeV, so as to facilitate comparisons in future with results from experiment or other nonperturbative methods.« less
Top quark mass measurement using the template method at CDF
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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
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.
XQCAT: eXtra Quark Combined Analysis Tool
D. Barducci; A. Belyaev; M. Buchkremer; J. Marrouche; S. Moretti; L. Panizzi
2014-09-10T23:59:59.000Z
XQCAT (eXtra Quark Combined Analysis Tool) is a tool aimed to determine exclusion Confidence Levels (eCLs) for scenarios of new physics characterised by the presence of one or multiple heavy extra quarks (XQ) which interact through Yukawa couplings with any of the Standard Model (SM) quarks. The code uses a database of efficiencies for pre-simulated processes of Quantum Chromo-Dynamics (QCD) pair production and on-shell decays of extra quarks. In the version 1.0 of XQCAT the efficiencies have been computed for a set of seven publicly available search results by the CMS experiment, and the package is subject to future updates to include further searches by both ATLAS and CMS collaborations. The input for the code is a text file in which masses, branching ratios (BRs) and dominant chirality of the couplings of the new quarks are provided. The output of the code is the eCL of the test point for each implemented experimental analysis considered individually and, when possible, in statistical combination.
Threshold Corrections to the Bottom Quark Mass Revisited
Archana Anandakrishnan; B. Charles Bryant; Stuart Raby
2015-01-29T23:59:59.000Z
Threshold corrections to the bottom quark mass are often estimated under the approximation that tan$\\beta$ enhanced contributions are the most dominant. In this work we revisit this common approximation made to the estimation of the supersymmetric threshold corrections to the bottom quark mass. We calculate the full one-loop supersymmetric corrections to the bottom quark mass and survey a large part of the phenomenological MSSM parameter space to study the validity of considering only the tan$\\beta$ enhanced corrections. Our analysis demonstrates that this approximation underestimates the size of the threshold corrections by $\\sim$12.5% for most of the considered parameter space. We discuss the consequences for fitting the bottom quark mass and for the effective couplings to Higgses. We find that it is important to consider the additional contributions when fitting the bottom quark mass but the modifications to the effective Higgs couplings are typically $\\mathcal{O}$(few)% for the majority of the parameter space considered.
Top Quark Properties from Top Pair Events and Decays
Andrew G. Ivanov; for the CDF; Dzero Collaborations
2008-10-19T23:59:59.000Z
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 Dzero 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 Dzero 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 inv. fb.
Top quark induced effective potential in a composite Higgs model
Maarten Golterman; Yigal Shamir
2015-05-13T23:59:59.000Z
We consider non-perturbative aspects of a composite Higgs model that serves as a prototype for physics beyond the Standard Model, in which a new strongly interacting sector undergoes chiral symmetry breaking, and generates the Higgs particle as a pseudo Nambu-Goldstone boson. In addition, the top quark couples linearly to baryons of the new strong sector, thereby becoming partially composite. We study the dynamics leading to the top quark Yukawa coupling as well as the top quark contribution to the effective potential for the Higgs, obtaining expressions for these couplings in terms of baryonic correlation functions in the underlying strongly interacting theory. We then show that a large-N limit exists in which the top quark contribution to the Higgs effective potential overcomes that of the weak gauge bosons, inducing electroweak symmetry breaking. The same large-N limit also suggests that the baryons that couple to the top quark may be relatively light. This composite Higgs model, and similar ones, can be studied on the lattice with the methods developed for lattice QCD.
Top quark mass measurement using the template method at CDF
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aaltonen, T; Alvarez Gonzalez, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; et al
2011-06-03T23:59:59.000Z
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 amore »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.« less
Measurements of the top quark mass and decay width with the D0 detector
Ilchenko, Yuriy
2011-11-01T23:59:59.000Z
The top quark discovery in 1995 at Fermilab is one of the major proofs of the standard model (SM). Due to its unique place in SM, the top quark is an important particle for testing the theory and probing for new physics. This article presents most recent measurements of top quark properties from the D0 detector. In particular, the measurement of the top quark mass, the top antitop mass difference and the top quark decay width. The discovery of the top quark in 1995 confirmed the existence of a third generation of quarks predicted in the standard model (SM). Being the heaviest elementary particle known, the top quark appears to become an important particle in our understanding of the standard model and physics beyond it. Because of its large mass the top quark has a very short lifetime, much shorter than the hadronization time. The predicted lifetime is only 3.3 {center_dot} 10{sup -25}s. Top quark is the only quark whose properties can be studied in isolation. A Lorentz-invariant local Quantum Field Theory, the standard model is expected to conserve CP. Due to its unique properties, the top quark provides a perfect test of CPT invariance in the standard model. An ability to look at the quark before being hadronized allows to measure directly mass of the top quark and its antiquark. An observation of a mass difference between particle and antiparticle would indicate violation of CPT invariance. Top quark through its radiative loop correction to the W mass constrains the mass of the Higgs boson. A precise measurement of the top quark mass provides useful information to the search of Higgs boson by constraining its region of possible masses. Another interesting aspect is that the top quark's Yukawa coupling to the Higgs boson is very close to unity (0.996 {+-} 0.006). That implies it may play a special role in the electroweak symmetry breaking mechanism.
Quark spectral density and a strongly-coupled quark-gluon plasma.
Qin, S.; Chang, L.; Liu, Y.; Roberts, C. D. (Physics); (Peking Univ.); (Inst. of Applied Physics and Computational Mathematics); (National Lab. of Heavy Ion Accelerator)
2011-07-13T23:59:59.000Z
The maximum entropy method is used to compute the dressed-quark spectral density from the self-consistent numerical solution of a rainbow truncation of QCD's gap equation at temperatures above that for which chiral symmetry is restored. In addition to the normal and plasmino modes, the spectral function also exhibits an essentially nonperturbative zero mode for temperatures extending to 1.4-1.8 times the critical temperature, T{sub c}. In the neighborhood of T{sub c}, this long-wavelength mode contains the bulk of the spectral strength and as long as this mode persists, the system may fairly be described as a strongly-coupled state of matter.
Quark-antiquark bound-state spectroscopy and QCD
Bloom, E.D.
1982-11-01T23:59:59.000Z
The discussion covers quarks as we know them, the classification of ordinary mesons in terms of constituent quarks, hidden charm states and charmed mesons, bottom quarks, positronium as a model for quarti q, quantum chromodynamics and its foundation in experiment, the charmonium model, the mass of states, fine structure and hyperfine structure, classification, widths of states, rate and multipolarity of gamma transitions, questions about bottom, leptonic widths and the determination of Q/sub b/, the mass splitting of the n/sup 3/S/sub 1/ states, the center of gravity of the masses of the n/sup 3/P; states, n/sup 3/ P; fine structure and classification, branching ratios for upsilon' ..-->.. tau chi/sub 6j/ and the tau cascade reactions, hyperfine splitting, and top. (GHT)
Measurement of the top quark mass in the dilepton channel
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Agelou, M.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Hefei, CUST /Andes U., Bogota /Charles U.
2006-09-01T23:59:59.000Z
We present a measurement of the top quark mass in the dilepton channel based on approximately 370 pb{sup -1} of data collected by the D0 experiment during Run II of the Fermilab Tevatron collider. We employ two different methods to extract the top quark mass. We show that both methods yield consistent results using ensemble tests of events generated with the D0 Monte Carlo simulation. We combine the results from the two methods to obtain a top quark mass m{sub t} = 178.1 {+-} 8.2 GeV. The statistical uncertainty is 6.7 GeV and the systematic uncertainty is 4.8 GeV.
Top-quark processes at NLO in production and decay
Campbell, John M.; Ellis, R.Keith
2012-04-01T23:59:59.000Z
We describe the implementation of top production and decay processes in the parton-level Monte Carlo program MCFM. By treating the top quark as being on-shell, we can factorize the amplitudes for top-pair production, s-channel single-top production, and t-channel single-top production into the product of an amplitude for production and an amplitude for decay. In this way we can retain all spin correlations. Both the production and the decay amplitudes are calculated consistently at next-to-leading order in alpha_s. The full dependence on the b-quark mass is also kept. Phenomenological results are presented for various kinematic distributions at the LHC and for the top quark forward-backward asymmetry at the Tevatron.
Dilepton emission at temperature dependent baryonic quark-gluon plasma
S. Somorendro Singh; Yogesh Kumar
2012-08-04T23:59:59.000Z
A fireball of QGP is evoluted at temperature dependent chemical potential by a statistical model in the pionic medium. We study the dilepton emission rate at temperature dependent chemical potential (TDCP) from such a fireball of QGP. In this model, we take the dynamical quark mass as a finite value dependence on temparature and parametrization factor of the QGP evolution. The temperature and factor in quark mass enhance in the growth of the droplets as well as in the dilepton emission rates. The emission rate from the plasma shows dilepton spectrum in the intermediate mass region (IMR) of (1.0-4.0) GeV and its rate is observed to be a strong increasing function of the temperature dependent chemical potential for quark and antiquark annihilation.
Can quark effects be observed in intermediate heavy ion collisions?
D. T. da Silva; D. Hadjimichef
2003-09-18T23:59:59.000Z
In recent years a tentative description of the short-range part of hadron interactions with constituent quark interchange has been developed providing an alternative approach to meson physics. Quark interchange plays a role, for example, in the nucleon-nucleon ($NN$) phase-shifts and cross-section. In heavy ion collision simulations at intermediate energies one of the main features is the $NN$ cross-section in the collisional term, where in most cases it is an input adjusted to the free space value. In this paper we introduce the quark degrees of freedom to the $NN$ cross-section in the Vlasov-Uehling-Uhlenbeck (VUU) model and explore the possibility that these effects appear in the observables at lower energies.
Thermodynamics of an exactly solvable confining quark model
Guimaraes, M S; Palhares, L F
2015-01-01T23:59:59.000Z
The grand partition function of a model of confined quarks is exactly calculated at arbitrary temperatures and quark chemical potentials. The model is inspired by a softly BRST-broken version of QCD and possesses a quark mass function compatible with nonperturbative analyses of lattice simulations and Dyson-Schwinger equations. Even though the model is defined at tree level, we show that it produces a nontrivial and stable thermodynamic behaviour at any temperature or chemical potential. Results for the pressure, the entropy and the trace anomaly as a function of the temperature are qualitatively compatible with the effect of nonperturbative interactions as observed in lattice simulations. The finite density thermodynamics is also shown to contain nontrivial features, being far away from an ideal gas picture.
Net quark number probability distribution near the chiral crossover transition
Kenji Morita; Bengt Friman; Krzysztof Redlich; Vladimir Skokov
2013-08-23T23:59:59.000Z
We investigate properties of the probability distribution of the net quark number near the chiral crossover transition in the quark-meson model. The calculations are performed within the functional renormalization group approach, as well as in the mean-field approximation. We find, that there is a substantial influence of the underlying chiral phase transition on the properties of the probability distribution. In particular, for a physical pion mass, the distribution which includes the effect of mesonic fluctuations, differs considerably from both, the mean-field and Skellam distributions. The latter is considered as a reference for a non-critical behavior. A characteristic feature of the net quark number probability distribution is that, in the vicinity of the chiral crossover transition in the O(4) universality class, it is narrower than the corresponding mean-field and Skellam function. We study the volume dependence of the probability distribution, as well as the resulting cumulants, and discuss their approximate scaling properties.
Measurements of the Properties of the Top Quark
Brandt, Oleg
2011-08-01T23:59:59.000Z
We review recent measurements of the properties of the top quark: the decay width of the top quark, of spin correlations between the top and the antitop quarks in t{bar t} production, the W boson helicity in top decays, the strong colour flow in t{bar t} events, and the asymmetry of t{bar t} production due to the strong colour charge. The measurements are performed on data samples of up to 5.4 fb{sup -1} of integrated luminosity acquired by the CDF and D0 collaborations in Run II of the Fermilab Tevatron p{bar p} collider at a centre-of-mass energy of {radical}s = 1.96 TeV.
The effects of colored quark entropy on the bag pressure
Miller, David E
2004-01-01T23:59:59.000Z
We study the effects of the ground state entropy of colored quarks upon the bag pressure at low temperatures. The vacuum expectation values of the quark and gluon fields are used to express the interactions in QCD ground state in the limit of low temperatures and chemical potentials. Apparently, the inclusion of this entropy in the equation of state provides the hadron constituents with an additional heat which causes a decrease in the effective latent heat inside the hadronic bag and consequently decreases the non-perturbative bag pressure. We have considered two types of baryonic bags, $\\Delta$ and $\\Omega^-$. In both cases we have found that the bag pressure decreases with the temperature. On the other hand, when the colored quark ground state entropy is not considered, the bag pressure as conventionally believed remains constant for finite temperature.
ads-qcd quark-antiquark potential: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
S. Kuzmenko 2003-02-17 2 Relation between quark-antiquark potential and quark-antiquark free energy in hadronic matter HEP - Phenomenology (arXiv) Summary: We study the relation...
Direct Measurement of the Total Decay Width of the Top Quark
Gomez-Ceballos, Guillelmo
We present a measurement of the total decay width of the top quark using events with top-antitop quark pair candidates reconstructed in the final state with one charged lepton and four or more hadronic jets. We use the ...
Aufgabe S1 F10 Die Bauteile 1,2,3 sind gelenkig miteinander verbunden, in A und B gelagert und
Peters, Norbert
(E) = 0 Cy 8a + B 4a = 0 Cy = - 1 2 B M(D) = 0 Cy 2a - Cx 2a + Ay 4a = 0 Cx = Cy + 2Ay = - 1 2 B + 2Ay sin 4 - Cx cos 4 - Cy sin 4 Fy = 0 Q = +Ax sin 4 - Ay cos 4 - Cx sin 4 - Cy cos 4 M=0 Mb = Ax2a - Ay2a Schnittreaktionen im Schnitt unterhalb des Gelenkes (obige Formeln ohne Cx und Cy): Fx
Baryon number fluctuation and the quark-gluon plasma
Lin, ZW; Ko, Che Ming.
2001-01-01T23:59:59.000Z
baryon number are also studied. DOI: 10.1103/PhysRevC.64.041901 PAC A new state of matter, the quark-gluon plasma, is ex- pected to be formed in heavy ion collisions at ultrarelativistic energies, such as at the Relativistic Heavy Ion Collider ~RHIC...! that has just begun its operation at the Brookhaven National Laboratory. Many observables have been proposed as possible signatures for the quark-gluon plasma phase dur- ing the collisions @1#, such as strangeness enhancement @2#, J/c suppression @3...
Jet Multiplicity in Top-Quark Pair Events at CMS
A. Descroix for the CMS Collaboration
2014-11-11T23:59:59.000Z
The normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity. Using a procedure to associate jets to decay products of the top quarks, the differential cross section of the ttbar production is determined as a function of the additional jet multiplicity. The fraction of events with no additional jets is measured as a function of the threshold required for the transverse momentum of the additional jet. The measurements are compared with predictions from perturbative quantum chromodynamics and no significant deviations are observed.
Relating quarks and leptons with the T7 flavour group
Bonilla, Cesar; Peinado, Eduardo; Valle, Jose W F
2014-01-01T23:59:59.000Z
In this letter we present a model for quarks and leptons based on T7 as flavour symmetry, predicting a canonical mass relation between charged leptons and down-type quarks proposed earlier. Neutrino masses are generated through a Type-I seesaw mechanism, with predicted correlations between the atmospheric mixing angle and neutrino masses. Compatibility with oscillation results lead to lower bounds for the lightest neutrino mass as well as for the neutrinoless double beta decay rates, even for normal neutrino mass hierarchy.
Hyperspherical harmonic study of identical-flavor four-quark systems
J. Vijande; N. Barnea; A. Valcarce
2006-10-23T23:59:59.000Z
We present an exact method based on a hyperspherical harmonic expansion to study systems made of quarks and antiquarks of the same flavor. Our formalism reproduces and improves the results obtained with variational approaches. This analysis shows that identical-flavor four-quark systems with non-exotic $2^{++}$ quantum numbers may be bound independently of the quark mass. $0^{+-}$ and $1^{+-}$ states become attractive only for larger quarks masses.
Paris-Sud XI, UniversitÃ© de
477 Short term thermal energy storage A. Abhat Institut fÃ¼r Kernenergetik und Energiesysteme the problem of short term thermal energy storage for low temperature solar heating applications. The techniques of sensible and latent heat storage are discussed, with particular emphasis on the latter
APuZAus Politik und Zeitgeschichte 10/2010 8. Mrz 2010
Franz, Sven Oliver
Millenniums- erklärung mit acht konkreten Millenni- umsentwicklungszielen (MEZ) an. 2 Diese bil- den seitdem Globalisierung und die weltweite Entwicklungspolitik. Die MEZ be- ziehen sich auf Aspekte der ökonomischen, so weltweiten Ent- wicklungspartnerschaft. 3 Die Verständigung auf die acht MEZ war ein großer Schritt
Usage Mining for the World Wide Web WenChen Hu, wenchen@cs.und.edu
Hu, Wen-Chen
Usage Mining for the World Wide Web WenChen Hu, wenchen@cs.und.edu Department of Computer Science@mail.tku.edu.tw Department of Information Engineering, Tamkang University, Tamsui, Taiwan ABSTRACT Web usage mining is used an overview and analysis of current Web usage mining technologies and systems. A Web usage mining system
Buchmann, Erik
Awareness"4 Dr.-Ing. Erik Buchmann - Kapitel 9: Smart Environments Smart Environments das "Aware Home" vom Computing Smart Environments Erik Buchmann (buchmann@kit.edu) #12;IPD, Nachwuchsgruppe ,,Privacy Awareness"2 Dr.-Ing. Erik Buchmann - Kapitel 9: Smart Environments Inhalte und Lernziele dieses Kapitels Smart
Buchmann, Erik
Awareness"4 Dr.-Ing. Erik Buchmann - Kapitel 10: Smart Environments Smart Environments das "Aware Home" vom Computing Smart Environments Erik Buchmann (buchmann@kit.edu) #12;IPD, Nachwuchsgruppe ,,Privacy Awareness"2 Dr.-Ing. Erik Buchmann - Kapitel 10: Smart Environments Inhalte und Lernziele dieses Kapitels
On Path diagrams and Stirling permutations Institut fur Diskrete Mathematik und Geometrie
Kuba, Markus
On Path diagrams and Stirling permutations M. Kuba Institut fÂ¨ur Diskrete Mathematik und Geometrie of this article is to extend the notion of local types to k-Stirling permutations, establish a relation diagrams. In the case of the classical Stirling permutations, we give an alternative continued fraction
On Path diagrams and Stirling permutations Institut fur Diskrete Mathematik und Geometrie
Kuba, Markus
On Path diagrams and Stirling permutations M. Kuba Institut fÂ¨ur Diskrete Mathematik und Geometrie is to introduce the notion of local types in k-Stirling permutations, to relate these local types with nodes types, Stirling permutations, Increasing trees, local types, formal power series 2000 Mathematics Subject
NANOTECHNOLOGY CENTER Eine Partnerschaft in Nanotechnologie von IBM Research und ETH Zrich
Cachin, Christian
NANOTECHNOLOGY CENTER Eine Partnerschaft in Nanotechnologie von IBM Research und ETH Zürich and Rohrer Nanotechnology Center is part of a strategic partnership in nanosciences with ETH Zurich, one FACT SHEET Above: The campus of IBM Research - Zurich Right: The Binnig and Rohrer Nanotechnology
CDF/ANAL/TOP/PUB/7680 Measurement of the Top Quark Mass using the Template Method
Quigg, Chris
CDF/ANAL/TOP/PUB/7680 Measurement of the Top Quark Mass using the Template Method in the Lepton, 2005) We report a measurement of the top quark mass in the lepton plus jets channel of tÂ¯t events from, which brings 138 tÂ¯t candidates separated into four subsamples. A top quark mass is reconstructed
CDF/PHYS/TOP/PUBLIC/7303 Measurement of the Top Quark Mass
Quigg, Chris
CDF/PHYS/TOP/PUBLIC/7303 Measurement of the Top Quark Mass using the Neutrino Weighting Algorithm the top quark mass using 46 t #22; t candidate events in which both W bosons from top quarks decay events according to the t #22; t decay hypothesis and we measure a top mass of 170:6 +7:1 6:6 (stat) #6
CDF/PUB/TOP/CDFR/11076 First Search for s-channel Electroweak Single Top Quark
Quigg, Chris
CDF/PUB/TOP/CDFR/11076 First Search for s-channel Electroweak Single Top Quark Production, 2014) Abstract The first search for electroweak single top quark production from the exchange of an s-model backgrounds is observed. Assuming that this excess is due to electroweak production of top quarks of mass 172
THE TOP QUARK Updated December 2011 by T.M. Liss (Univ. Illinois) and A.
1 THE TOP QUARK Updated December 2011 by T.M. Liss (Univ. Illinois) and A. Quadt (Univ. G¨ottingen). A. Introduction: The top quark is the Q = 2/3, T3 = +1/2 member of the weak-isospin doublet" for more information). This note summarizes the properties of the top quark (mass, production cross section
FREE QUARK SEARCHES The basis for much of the theory of particle scattering and
to "unglue" quarks. Accelerator searches at increasing energies have pro- duced no evidence for free quarks 1 FREE QUARK SEARCHES The basis for much of the theory of particle scattering and hadron as free particles but are confined to mesons and baryons. Experiments show that it is at best difficult
Nonperturbative study of the action parameters for anisotropic-lattice quarks
Foley, Justin; Cais, Alan O; Peardon, Mike; Ryan, Sinead M. [School of Mathematics, Trinity College, Dublin 2 (Ireland)
2006-01-01T23:59:59.000Z
A quark action designed for highly anisotropic-lattice simulations is discussed. The mass-dependence of the parameters in the action is studied and the results are presented. Applications of this action in studies of heavy quark quantities are described and results are presented from simulations at an anisotropy of six, for a range of quark masses from strange to bottom.
TRANSITION TEMPERATURE IN QCD WITH PHYSICAL LIGHT AND STRANGE QUARK MASSES.
KARSCH, F.
2006-11-14T23:59:59.000Z
We present results from a calculation of the transition temperature in QCD with two light (up, down) and one heavier (strange) quark mass as well as for QCD with three degenerate quark masses. Furthermore, we discuss first results from an ongoing calculation of the QCD equation of state with almost realistic light and strange quark masses.
Strandberg, Jonas; /Stockholm U.
2006-04-01T23:59:59.000Z
This thesis presents two measurements of the to pquark using 230 pb{sup -1} of data recorded with the D0 detector at the Tevatron accelerator. The first measurement determines the top pair production cross section at {radical}s = 1.96 TeV in proton-antiproton collisions. In the standard model of particle physics the top quark decays almost exclusively into a W boson and a b quark. Candidate events are selected by requiring that at least one jet in the event is tagged with the secondary vertex algorithm.
Hadron production from quark coalescence and jet fragmentation
Greco, V.; Ko, Che Ming; Vitev, I.
2005-01-01T23:59:59.000Z
Transverse momentum spectra of pions, protons, and antiprotons in Au+Au collisions at intermediate RHIC energy root s(NN)=62 GeV are studied in a model that includes both quark coalescence from the dense partonic matter and fragmentation...
Observation of Electroweak Single Top-Quark Production
Xie, Si
We report the observation of single top-quark production using 3.2??fb[superscript -1] of pp? collision data with ?s=1.96??TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 ...
Heavy Quarks: Lessons Learned from HERA and Tevatron
Fredrick Olness; Ingo Schienbein
2008-12-17T23:59:59.000Z
We review some of the recent developments which have enabled the heavy quark mass to be incorporated into both the calculation of the hard-scattering cross section and the PDFs. We compare and contrast some of the schemes that have been used in recent global PDF analyses, and look at issues that arise when these calculations are extended to NNLO.
Gauge cooling in complex Langevin for QCD with heavy quarks
Erhard Seiler; Dénes Sexty; Ion-Olimpiu Stamatescu
2012-11-20T23:59:59.000Z
We employ a new method, "gauge cooling", to stabilize complex Langevin simulations of QCD with heavy quarks. The results are checked against results obtained with reweigthing; we find agreement within the estimated errors. The method allows us to go to previously unaccessible high densities.
On the Dynamics of Unstable Quark-Gluon Plasma
Stanislaw Mrowczynski
2009-10-30T23:59:59.000Z
Since the quark-gluon plasma, which is unstable due to anisotropic momentum distribution, evolves fast in time, plasma's characteristics have to be studied as initial value problems. The chromodynamic fluctuations and the momentum broadening of a fast parton traversing the plasma are discussed here. The two quantities are shown to exponentially grow in time.
J/Psi Production by Charm Quark Coalescence
D. E. Kahana; S. H. Kahana
2010-06-30T23:59:59.000Z
Production of $c\\bar c$ pairs in elementary hadron-hadron collisions is introduced in a simulation of relativistic heavy ion collisions. Coalescence of charmed quarks and antiquarks into various charmonium states is performed and the results are compared to PHENIX J$/\\psi$ Au+Au data. The $\\chi$ and $\\psi$' bound states must be included as well as the ground state J$/\\psi$, given the appreciable feeding from the excited states down to the J$/\\psi$ via gamma decays. Charmonium coalescence is found to take place at relatively late times: generally after $c$($\\bar c$)-medium interactions have ceased. Direct production of charmonia through hadron-hadron interactions, {\\it ie.} without explicit presence of charm quarks, occurring only at early times, is suppressed by collisions with comoving particles and accounts for some $\\sim 5\\%$ of the total J$/\\psi$ production. Coalescence is especially sensitive to the level of open charm production, scaling naively as $n_{c\\bar c}^2$. The J$/\\psi$ transverse momentum distribution is dependent on the charm quark transverse momentum distribution and early charm quark-medium interaction, thus providing a glimpse of the initial collision history.
Search for rare top-quark decays at the LHC
Veloso, Filipe; The ATLAS collaboration
2015-01-01T23:59:59.000Z
Flavour-changing neutral-current (FCNC) top quark decays are suppressed by the GIM mechanism, but are enhanced by BSM models. Any evidence for top-quark FCNC decays could be an evidence for new physics. Searches for the FCNC decays $t\\to qX$ where $X=Z,\\gamma,H,g$ and $q=u,c$ performed by the ATLAS and CMS Collaborations are presented. Data collected during 2011 and 2012 from proton-proton ($pp$) collisions at the LHC at a centre-of-mass energy of $\\sqrt{s}=7$ and 8 TeV, corresponding to integrated luminosities ranging from 2.1 fb$^{-1}$ to 25 fb$^{-1}$, are analysed. Top-quark pair-production events with one top quark decaying through the $t\\to qZ,q\\gamma,qH$ channels and the other through the dominant Standard Model mode $t\\to bW$ are considered as signal, as well as direct top production for the $t\\to qg$ channel. No evidence for FCNC signals are found and upper limits on the $t\\to qX$ branching ratios are set at 95\\% confidence level.
Precision Top-Quark Mass Measurements at CDF
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
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}.
Influence of pions on the hadron-quark phase transition
Lourenco, O.; Dutra, M.; Frederico, T.; Malheiro, M. [Departamento de Fisica, Instituto Tecnologico de Aeronautica-CTA, 12228-900, Sao Jose dos Campos (Brazil); Delfino, A. [Instituto de Fisica, Universidade Federal Fluminense, Av. Litoranea s/n, 24210-150, Boa Viagem, Niteroi RJ (Brazil)
2013-05-06T23:59:59.000Z
In this work we present the features of the hadron-quark phase transition diagrams in which the pions are included in the system. To construct such diagrams we use two different models in the description of the hadronic and quark sectors. At the quark level, we consider two distinct parametrizations of the Polyakov-Nambu-Jona-Lasinio (PNJL) models. In the hadronic side, we use a well known relativistic mean-field (RMF) nonlinear Walecka model. We show that the effect of the pions on the hadron-quark phase diagrams is to move the critical end point (CEP) of the transitions lines. Such an effect also depends on the value of the critical temperature (T{sub 0}) in the pure gauge sector used to parametrize the PNJL models. Here we treat the phase transitions using two values for T{sub 0}, namely, T{sub 0}= 270 MeV and T{sub 0}= 190 MeV. The last value is used to reproduce lattice QCD data for the transition temperature at zero chemical potential.
Weak interactions of quarks and leptons: experimental status
Wojcicki, S.
1984-09-01T23:59:59.000Z
The present experimental status of weak interactions is discussed with emphasis on the problems and questions and on the possible lines of future investigations. Major topics include; (1) the quark mixing matrix, (2) CP violation, (3) rare decays, (4) the lepton sector, and (5) right handed currents. 118 references. (WHK)
Quark number susceptibility of high temperature and finite density QCD
Ari Hietanen; Kari Rummukainen
2007-10-26T23:59:59.000Z
We utilize lattice simulations of the dimensionally reduced effective field theory (EQCD) to determine the quark number susceptibility of QCD at high temperature ($T>2T_c$). We also use analytic continuation to obtain results at finite density. The results extrapolate well from known perturbative expansion (accurate in extremely high temperatures) to 4d lower temperature lattice data
Direct Top-Quark Width Measurement at CDF
Bauer, Gerry P.
We present a measurement of the top-quark width in the lepton+jets decay channel of tt? events produced in pp? collisions at Fermilab’s Tevatron collider and collected by the CDF II detector. From a data sample corresponding ...
Hypercentral Constituent Quark Model with a Meson Cloud
D. Y. Chen; Y. B. Dong; M. M. Giannini; E. Santopinto
2006-11-07T23:59:59.000Z
The results for the elastic nucleon form factors and the electromagnetic transition amplitudes to the Delta(1232) resonance, obtained with the Hypercentral Constituent Quark Model with the inclusion of a meson cloud correction are briefly presented. The pion cloud effects are explicitly discussed.
Osnabrück, Universität
Herr Dr. Carsten Bödecker Rechtswissenschaften Herr Dr. Klaus Brinkmann Rechtswissenschaften Rechtswissenschaften Herr Dr. Andreas Bauer ja ja Papier FESEM Seminar zum Familien und Erbrecht Rechtswissenschaften Herr KlausDieter Benner ja ja Papier FEVOR Kapitalmarktstrafrecht Rechtswissenschaften Herr Dr. Ge
Vormann, Matthias
In-situ measurement of ground impedances Von der Fakultät für Mathematik und Naturwissenschaften .............................................................................................22 Summary: In-situ impedance measurement.Definitions..........................................................................................................................11 VI.Surface impedance measurement methods
Infrared and Ultraviolet QCD dynamics with quark mass for J=0,1 mesons
Nicholas Souchlas
2010-06-04T23:59:59.000Z
By using a previously developed phenomenological kernel for the study of the light quark QCD sector and dynamical chiral symmetry breaking effects we will examine the relative infrared and ultraviolet QCD dynamics for J=0,1 meson properties. For the same reasons we extend and explore a quark mass depended generalization of the kernel in the heavy quark region and we also compare with the original model. The relation between the dynamics of the quark propagator and the effective kernel with the J=0,1 QQ and qQ mesons and quarks Compton size is also discussed.
What does it mean to have `seen' the quark-gluon plasma?
Scott Pratt
2012-10-01T23:59:59.000Z
Identifying the quark-gluon plasma requires convincing experimental evidence that partons move independently throughout the environment created in a heavy ion collision and with densities expected from equilibrium considerations. In lattice calculations, charge correlations suggest that quarks exist independently, and are not merely exchanged from hadronic object to another. Many experimental signatures (J/Psi suppression, quark number scaling, etc.) suggest that quarks are not confined to their original singlets, but these signatures do not make a clear case that quarks move independently or that they have the expected densities. I discuss a class of measurements that parallel lattice observables and has the prospect of investigating whether partonic charges move independently.
Calculation of associated production of a top quark and a W ? at the LHC
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Cao, Qing-Hong; Berger, Edmond L.; Yu, Jiang-Hao; Yuan, C.-P.
2011-11-01T23:59:59.000Z
We investigate collider signatures of a top-philic W' model, in which the W' boson couples only to the third-generation quarks of the standard model. The main discovery channel for this W' is through associated production of the W' and top quark, yielding a top-quark pair plus an extra bottom-quark jet as a signal. We do a full simulation of the signal and relevant backgrounds. We develop a method of analysis that allows us to conclude that discovery of the W' is promising at the LHC despite large standard model backgrounds. Bottom-quark tagging of the extra jet is key to suppressing the backgrounds.
Uncovering the single top: observation of electroweak top quark production
Benitez, Jorge Armando; /Michigan State U.
2009-08-01T23:59:59.000Z
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.
Y. Maezawa; S. Aoki; S. Ejiri; T. Hatsuda; K. Kanaya; H. Ohno; T. Umeda
2009-11-02T23:59:59.000Z
The free energy between a static quark and an antiquark is studied by using the color-singlet Polyakov-line correlation at finite temperature. We perform simulations on $32^3 \\times 12$, 10, 8, 6, 4 lattices in the high temperature phase with the RG-improved gluon action and 2+1 flavors of the clover-improved Wilson quark action. Since the simulations are based on the fixed scale approach that the temperature can be varied without changing the spatial volume and renormalization factor, it is possible to investigate temperature dependence of the heavy-quark free energy without any adjustment of the overall constant. We find that, the heavy-quark free energies at short distance converge to the heavy-quark potential evaluated from the Wilson-loop operator at zero temperature, in accordance with the expected insensitivity of short distance physics to the temperature. At long distance, the heavy-quark free energies approach to twice the single-quark free energies, implying that the interaction between heavy quarks is screened. The Debye screening mass obtained from the long range behavior of the heavy-quark free energy is compared with results of the thermal perturbation theory and those of $N_f=2$ and $N_f=0$ lattice simulations.
Scalar-Quark Systems and Chimera Hadrons in SU(3)_c Lattice QCD
Iida, H; Takahashi, T T
2007-01-01T23:59:59.000Z
Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation in strong interaction without chiral symmetry breaking. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi which are the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\simeq 1GeV. We find that the constituent scalar-quark and quark picture is satisfied for all the new-type hadrons. Namely, the mass of the new-type hadron composed of m \\phi's and n \\psi's, M_{{m}\\phi+{n}\\psi}, satisfies M_{{m}\\phi+{n}\\psi}\\simeq {m} M_\\phi +{n} M_\\psi, where M_\\phi and M_\\psi are the constituent scalar-quark and quark...
Bound States of (Anti-)Scalar-Quarks in SU(3)c Lattice QCD
Iida, H.; Takahashi, T. T. [Yukawa Institute for Theoretical Physics, Kyoto University, Sakyo, Kyoto 606-8502 (Japan); Suganuma, H. [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)
2007-06-13T23:59:59.000Z
Light scalar-quarks {phi} (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)c lattice QCD in terms of mass generation. We investigate 'scalar-quark mesons' {phi}{dagger}{phi} and 'scalar-quark baryons' {phi}{phi}{phi} as the bound states of scalar-quarks {phi}. We also investigate the bound states of scalar-quarks {phi} and quarks {psi}, i.e., {phi}{dagger}{psi}, {psi}{psi}{phi} and {phi}{phi}{psi}, which we name 'chimera hadrons'. All the new-type hadrons including {phi} are found to have a large mass due to large quantum corrections by gluons, even for zero bare scalar-quark mass m{phi} = 0 at a-1 {approx} 1GeV. We conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects.
Top quark physics in the ATLAS detector: summary of Run I results
Moreno Llacer, Maria; The ATLAS collaboration
2015-01-01T23:59:59.000Z
An overview of the most recent results on top quark physics obtained using proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider at $\\sqrt{s}$ = 7 TeV or $\\sqrt{s}$ = 8 TeV centre-of-mass energy are presented. Measurements for inclusive and differential top quark pair and single top quark production in different final states are reviewed. The latest measurements of the top quark mass, top quark properties such as charge asymmetry and spin correlations, constraints on the coupling of the top quark to the W boson and the recent evidence of top quark pairs produced in associated with vector bosons are also presented.
Nonzero Mean Squared Momentum of Quarks in the Non-Perturbative QCD Vacuum
Li-Juan Zhou; Leonard S. Kisslinger; Wei-xing Ma
2010-04-21T23:59:59.000Z
The non-local vacuum condensates of QCD describe the distributions of quarks and gluons in the non-perturbative QCD vacuum. Physically, this means that vacuum quarks and gluons have nonzero mean-squared momentum, called virtuality. In this paper we study the quark virtuality which is given by the ratio of the local quark-gluon mixed vacuum condensate to the quark local vacuum condensate. The two vacuum condensates are obtained by solving Dyson-Schwinger Equations of a fully dressed quark propagator with an effective gluon propagator. Using our calculated condensates, we obtain the virtuality of quarks in the QCD vacuum state. Our numerical predictions differ from the other theoretical model calculations such as QCD sum rules, Lattice QCD and instanton models.
Scalar-Quark Systems and Chimera Hadrons in SU(3)_c Lattice QCD
H. Iida; H. Suganuma; T. T. Takahashi
2007-05-28T23:59:59.000Z
Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation in strong interaction without chiral symmetry breaking. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi which are the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\simeq 1GeV. We find that the constituent scalar-quark and quark picture is satisfied for all the new-type hadrons. Namely, the mass of the new-type hadron composed of m \\phi's and n \\psi's, M_{{m}\\phi+{n}\\psi}, satisfies M_{{m}\\phi+{n}\\psi}\\simeq {m} M_\\phi +{n} M_\\psi, where M_\\phi and M_\\psi are the constituent scalar-quark and quark mass, respectively. M_\\phi at m_\\phi=0 estimated from these new-type hadrons is 1.5-1.6GeV, which is larger than that of light quarks, M_\\psi\\simeq 400{\\rm MeV}. Therefore, in the systems of scalar-quark hadrons and chimera hadrons, scalar-quarks acquire large mass due to large quantum corrections by gluons. Together with other evidences of mass generations of glueballs and charmonia, we conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects.
Photon production from gluon mediated quark-anti-quark annihilation at confinement
Sarah Campbell
2015-04-07T23:59:59.000Z
Heavy ion collisions at RHIC produce direct photons at low transverse momentum, $p_{T}$ from 1-3 GeV/c, in excess of the $p$$+$$p$ spectra scaled by the nuclear overlap factor, $T_{AA}$. These low $p_{T}$ photons have a large azimuthal anisotropy, $v_{2}$. Theoretical models, including hydrodynamic models, struggle to quantitatively reproduce the large low $p_{T}$ direct photon excess and $v_{2}$ in a self-consistent manner. This paper presents a description of the low $p_{T}$ photon flow as the result of increased photon production from soft-gluon mediated $q$-$\\bar{q}$ interactions as the system becomes color-neutral. This production mechanism will generate photons that follow constituent quark number, $n_{q}$, scaling of $v_{2}$ with an $n_{q}$ value of two for direct photons. $\\chi^{2}$ comparisons of the published PHENIX direct photon and identified particle $v_{2}$ measurements finds that $n_{q}$-scaling applied to the direct photon $v_{2}$ data prefers the value $n_{q}=1.8$ and agrees with $n_{q}=2$ within errors in most cases. The 0-20\\% and 20-40\\% Au$+$Au direct photon data are compared to a coalescence-like Monte Carlo simulation that calculates the direct photon $v_{2}$ while describing the shape of the direct photon $p_{T}$ spectra in a consistent manner. The simulation, while systematically low, is in agreement with the Au$+$Au measurement at $p_{T}<3$ GeV/c in both centrality bins. Furthermore, this model predicts that higher order flow harmonics, $v_{n}$, in direct photons will follow the $n_{q}$-scaling laws seen in identified hadron $v_{n}$ with an $n_{q}$ value of approximately two.
Heiz, Ulrich
, können wir die Standorte der TUM in München, Garching und Weihenstephan verbin- den und schaffen es in Munich, Garching and Weihenstephan and even reach as far as the airport. From there, we could jump
Y. Maezawa; T. Umeda; S. Aoki; S. Ejiri; T. Hatsuda; K. Kanaya; H. Ohno
2012-10-24T23:59:59.000Z
Free energies between static quarks and Debye screening masses in the quark-gluon plasma are studied on the basis of Polyakov-line correlations in lattice simulations of 2+1 flavors QCD with the renormalization-group improved gluon action and the $O(a)$-improved Wilson quark action. We perform simulations at $m_{\\rm PS}/m_{\\rm V} = 0.63$ (0.74) for light (strange) flavors with lattice sizes of $32^3 \\times N_t$ with $N_t=4$--12. We adopt the fixed-scale approach, where temperature can be varied without changing the spatial volume and renormalization factor. We find that, at short distance, the free energies of static quarks in color-singlet channel converge to the static-quark potential evaluated from the Wilson-loop at zero-temperature, in accordance with the expected insensitivity of short distance physics to the temperature. At long distance, the free energies of static quarks approach to twice the single-quark free energies, implying that the interaction between static quarks is fully screened. The screening properties can be well described by the screened Coulomb form with appropriate Casimir factor at high temperature. We also discuss a limitation of the fixed-scale approach at high temperature.
WHOT-QCD Collaboration; :; Y. Maezawa; N. Ukita; S. Aoki; S. Ejiri; T. Hatsuda; N. Ishii; K. Kanaya
2007-02-13T23:59:59.000Z
We study Polyakov loop correlations and spatial Wilson loop at finite Temperature in two-flavor QCD simulations with the RG-improved gluon action and the clover-improved Wilson quark action on a $ 16^3 \\times 4$ lattice. From the line of constant physics at $m_{\\rm PS}/m_{\\rm V}=0.65$ and 0.80, we extract the heavy-quark free energies, the effective running coupling $g_{\\rm eff}(T)$ and the Debye screening mass $m_D(T)$ for various color channels of heavy quark--quark and quark--anti-quark pairs above the critical temperature. The free energies are well approximated by the screened Coulomb form with the appropriate Casimir factors at high temperature. The magnitude and the temperature dependence of the Debye mass are compared to those of the next-to-leading order thermal perturbation theory and to a phenomenological formula in terms of $g_{\\rm eff}(T)$. We make a comparison between our results with the Wilson quark action and the previous results with the staggered quark action. The spatial string tension is also studied in the high temperature phase and is compared to the next-to-next-leading order prediction in an effective theory with dimensional reduction.
Quark-lepton symmetric model at the LHC
Jackson D. Clarke; Robert Foot; Raymond R. Volkas
2012-02-04T23:59:59.000Z
We investigate the quark-lepton symmetric model of Foot and Lew in the context of the Large Hadron Collider (LHC). In this `bottom-up' extension to the Standard Model, quark-lepton symmetry is achieved by introducing a gauged `leptonic colour' symmetry which is spontaneously broken above the electroweak scale. If this breaking occurs at the TeV scale, then we expect new physics to be discovered at the LHC. We examine three areas of interest: the Z$'$ heavy neutral gauge boson, charge $\\pm1/2$ exotic leptons, and a colour triplet scalar diquark. We find that the LHC has already explored and/or will explore new parameter space for these particles over the course of its lifetime.
Forward-backward asymmetry in top quark-antiquark production
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
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.
NLO evolution of 3-quark Wilson loop operator
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Balitsky, Ian; Grabovsky, A V
2015-01-01T23:59:59.000Z
It is well known that high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-lines operator with respect to the rapidity of the Wilson lines. We calculate the evolution of the 3-quark Wilson loop operator in themore »next-to-leading order (NLO) and present a quasi-conformal evolution equation for a composite 3-Wilson-lines operator. We also obtain the linearized version of that evolution equation describing the amplitude of the odderon exchange at high energies.« less
NLO evolution of 3-quark Wilson loop operator
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Balitsky, Ian [ODU, JLAB; Grabovsky, A V [Novosibirsk
2015-01-01T23:59:59.000Z
It is well known that high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-lines operator with respect to the rapidity of the Wilson lines. We calculate the evolution of the 3-quark Wilson loop operator in the next-to-leading order (NLO) and present a quasi-conformal evolution equation for a composite 3-Wilson-lines operator. We also obtain the linearized version of that evolution equation describing the amplitude of the odderon exchange at high energies.
Chiral Magnetic Effect in the Anisotropic Quark-Gluon Plasma
Mohammad Ali-Akbari; Seyed Farid Taghavi
2014-08-27T23:59:59.000Z
An anisotropic thermal plasma phase of a strongly coupled gauge theory can be holographically modelled by an anisotropic AdS black hole. The temperature and anisotropy parameter of the AdS black hole background of interest [1] is specified by the location of the horizon and the value of the Dilaton field at the horizon. Interestingly, for the first time, we obtain two functions for the values of the horizon and Dilaton field in terms of the temperature and anisotropy parameter. Then by introducing a number of spinning probe D7-branes in the anisotropic background, we compute the value of the chiral magnetic effect (CME). We observe that in the isotropic and anisotropic plasma the value of the CME is equal for the massless quarks. However, at fixed temperature, raising the anisotropy in the system will increase the value of the CME for the massive quarks.
Search for electroweak single top quark production with CDF
Kemp, Y.; /Karlsruhe U.
2005-01-01T23:59:59.000Z
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.
Measurements of the top quark mass at the tevatron
Brandt, Oleg
2012-01-01T23:59:59.000Z
The mass of the top quark (\\mtop) is a fundamental parameter of the standard model (SM). Currently, its most precise measurements are performed by the CDF and D0 collaborations at the Fermilab Tevatron $p\\bar p$ collider at a centre-of-mass energy of $\\sqrt s=1.96 \\TeV$. We review the most recent of those measurements, performed on data samples of up to 8.7 \\fb\\ of integrated luminosity. The Tevatron combination using up to 5.8 fb$^{-1}$ of data results in a preliminary world average top quark mass of $m_{\\rm top} = 173.2 \\pm 0.9$ GeV. This corresponds to a relative precision of about 0.54%. We conclude with an outlook of anticipated precision the final measurement of \\mtop at the Tevatron.
Measurements of the top quark mass at the tevatron
Oleg Brandt; for the CDF Collaboration; for the D0 Collaboration
2012-04-04T23:59:59.000Z
The mass of the top quark (\\mtop) is a fundamental parameter of the standard model (SM). Currently, its most precise measurements are performed by the CDF and D0 collaborations at the Fermilab Tevatron $p\\bar p$ collider at a centre-of-mass energy of $\\sqrt s=1.96 \\TeV$. We review the most recent of those measurements, performed on data samples of up to 8.7 \\fb\\ of integrated luminosity. The Tevatron combination using up to 5.8 fb$^{-1}$ of data results in a preliminary world average top quark mass of $m_{\\rm top} = 173.2 \\pm 0.9$ GeV. This corresponds to a relative precision of about 0.54%. We conclude with an outlook of anticipated precision the final measurement of \\mtop at the Tevatron.
Measurements of the top quark mass at the Tevatron
Brandt, Oleg; /Gottingen U., II. Phys. Inst.
2012-04-01T23:59:59.000Z
The mass of the top quark (m{sub top}) is a fundamental parameter of the standard model (SM). Currently, its most precise measurements are performed by the CDF and D0 collaborations at the Fermilab Tevatron p{bar p} collider at a centre-of-mass energy of {radical}s = 1.96 TeV. We review the most recent of those measurements, performed on data samples of up to 8.7 fb{sup -1} of integrated luminosity. The Tevatron combination using up to 5.8 fb{sup -1} of data results in a preliminary world average top quark mass of m{sub top} = 173.2 {+-} 0.9 GeV. This corresponds to a relative precision of about 0.54%. We conclude with an outlook of anticipated precision the final measurement of m{sub top} at the Tevatron.
Energy profile of b-jet for boosted top quarks
Yoshio Kitadono
2014-09-05T23:59:59.000Z
We analyse the semileptonic decay of a polarised top-quark with a large velocity based on the perturbative QCD factorisation framework. Thanks to the factorisation and the spin decomposition, the production part and the decay part can be factorised and the spin dependence is introduced in the decay part. The decay part is converted to the top-jet function which describes the distribution of jet observables and the spin is translated to the helicity of the boosted top. Using this top-jet function, the energy profile of b-jet is investigated and it is turned out that the sub-jet energy for the helicity-minus top is accumulated faster than that for the helicity-plus top. This behaviour for the boosted top can be understood with the negative spin-analysing-power of b-quark in the polarised-top decay.
Thermal axion production in the primordial quark-gluon plasma
Graf, Peter; Steffen, Frank Daniel [Max-Planck-Institut fuer Physik, Foehringer Ring 6, D-80805 Munich (Germany)
2011-04-01T23:59:59.000Z
We calculate the rate for thermal production of axions via scattering of quarks and gluons in the primordial quark-gluon plasma. To obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling, we use systematic field theoretical methods such as hard thermal loop resummation and the Braaten-Yuan prescription. The thermally produced yield, the decoupling temperature, and the density parameter are computed for axions with a mass below 10 meV. In this regime, with a Peccei-Quinn scale above 6x10{sup 8} GeV, the associated axion population can still be relativistic today and can coexist with the axion cold dark matter condensate.
Thermal axion production in the primordial quark-gluon plasma
Peter Graf; Frank Daniel Steffen
2011-04-20T23:59:59.000Z
We calculate the rate for thermal production of axions via scattering of quarks and gluons in the primordial quark-gluon plasma. To obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling, we use systematic field theoretical methods such as hard thermal loop resummation and the Braaten-Yuan prescription. The thermally produced yield, the decoupling temperature, and the density parameter are computed for axions with a mass below 10 meV. In this regime, with a Peccei-Quinn scale above 6x10^8 GeV, the associated axion population can still be relativistic today and can coexist with the axion cold dark matter condensate.
The SF running coupling with four flavours of staggered quarks
P. Perez-Rubio; S. Sint
2007-10-03T23:59:59.000Z
In order to study the running coupling in four-flavour QCD, we review the set-up of the Schr\\"odinger functional (SF) with staggered quarks. Staggered quarks require lattices which, in the usual counting, have even spatial lattice extent $L/a$ while the time extent $T/a$ must be odd. Setting $T=L$ is therefore only possible up to ${\\rm O}(a)$, which introduces different cutoff effects already in the pure gauge theory. We re-define the SF such as to cope with this situation and determine the corresponding classical background field. A perturbative calculation yields the coefficient of the pure gauge ${\\rm O}(a)$ boundary counterterm to one-loop order.
NLO evolution of 3-quark Wilson loop operator
I. Balitsky; A. V. Grabovsky
2014-08-15T23:59:59.000Z
It is well known that high-energy scattering of a meson from some hadronic target can be described by the interaction of that target with a color dipole formed by two Wilson lines corresponding to fast quark-antiquark pair. Moreover, the energy dependence of the scattering amplitude is governed by the evolution equation of this color dipole with respect to rapidity. Similarly, the energy dependence of scattering of a baryon can be described in terms of evolution of a three-Wilson-lines operator with respect to the rapidity of the Wilson lines. We calculate the evolution of the 3-quark Wilson loop operator in the next-to-leading order (NLO) and present a quasi-conformal evolution equation for a composite 3-Wilson-lines operator. We also obtain the linearized version of that evolution equation describing the amplitude of the odderon exchange at high energies.
Forward-backward asymmetry in top quark-antiquark production
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D; Alkhazov, Georgiy D; Alton, Andrew K; Alverson, George O; Alves, Gilvan Augusto; et al
2011-12-12T23:59:59.000Z
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)%.more »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.« less
Angular correlations in top quark decays in standard model extensions
Batebi, S. [Science and Research Branch, Islamic Azad University (IAU), Tehran (Iran, Islamic Republic of); Etesami, S. M. [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Physics Department, Isfahan University of Technology (IUT), P.O. Box 11365-9161, Isfahan (Iran, Islamic Republic of); Mohammadi-Najafabadi, M. [Physics Department, Isfahan University of Technology (IUT), P.O. Box 11365-9161, Isfahan (Iran, Islamic Republic of)
2011-03-01T23:59:59.000Z
The CMS Collaboration at the CERN LHC has searched for the t-channel single top quark production using the spin correlation of the t-channel. The signal extraction and cross section measurement rely on the angular distribution of the charged lepton in the top quark decays, the angle between the charged lepton momentum and top spin in the top rest frame. The behavior of the angular distribution is a distinct slope for the t-channel single top (signal) while it is flat for the backgrounds. In this Brief Report, we investigate the contributions which this spin correlation may receive from a two-Higgs doublet model, a top-color assisted technicolor (TC2) and the noncommutative extension of the standard model.
Meson mass splittings in unquenched quark models (EEF70)
T. J. Burns
2014-11-10T23:59:59.000Z
General results are obtained for meson mass splittings and mixings in unquenched (coupled-channel) quark models. Theorems derived previously in perturbation theory are generalised to the full coupled-channel system. A new formula is obtained for the mass splittings of physical states in terms of the splittings of the valence states. The S-wave hyperfine splitting decreases due to unquenching, but its relation to the vector $e^+e^-$ width is unchanged; this yields a prediction for the missing $\\eta_b(3S)$. The ordinary (quenched) quark model result that the P-wave hyperfine splitting vanishes also survives unquenching. A ratio of mass splittings used to discriminate quarkonium potential models is scarcely affected by unquenching.
Forward-backward asymmetry in top quark-antiquark production
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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
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.
Onset of cavitation in the quark-gluon plasma
Mathis Habich; Paul Romatschke
2014-07-11T23:59:59.000Z
We study the onset of bubble formation (cavitation) in the quark-gluon plasma as a result of the reduction of the effective pressure from bulk-viscous corrections. By calculating velocity gradients in typical models for quark-gluon plasma evolution in heavy-ion collisions, we obtain results for the critical bulk viscosity above which cavitation occurs. Since present experimental data for heavy-ion collisions seems inconsistent with the presence of bubbles above the phase transition temperature of QCD, our results may be interpreted as an upper limit of the bulk viscosity in nature. Our results indicate that bubble formation is consistent with the expectation of hadronisation in low-temperature QCD.
Cavitation from bulk viscosity in neutron stars and quark stars
Jes Madsen
2009-09-30T23:59:59.000Z
The bulk viscosity in quark matter is sufficiently high to reduce the effective pressure below the corresponding vapor pressure during density perturbations in neutron stars and strange stars. This leads to mechanical instability where the quark matter breaks apart into fragments comparable to cavitation scenarios discussed for ultra-relativistic heavy-ion collisions. Similar phenomena may take place in kaon-condensed stellar cores. Possible applications to compact star phenomenology include a new mechanism for damping oscillations and instabilities, triggering of phase transitions, changes in gravitational wave signatures of binary star inspiral, and astrophysical formation of strangelets. At a more fundamental level it points to the possible inadequacy of a hydrodynamical treatment of these processes in compact stars.
Transverse momentum dependent quark densities from Lattice QCD
Bernhard Musch,Philipp Hagler,John Negele,Andreas Schafer
2011-02-01T23:59:59.000Z
We study transverse momentum dependent parton distribution functions (TMDs) with non-local operators in lattice QCD, using MILC/LHPC lattices. Results obtained with a simpli?ed operator geometry show visible dipole de- formations of spin-dependent quark momentum densities. We discuss the basic concepts of the method, including renormalization of the gauge link, and an ex- tension to a more elaborate operator geometry that would allow us to analyze process-dependent TMDs such as the Sivers-function.
Non-perturbative Heavy Quark Effective Theory: Introduction and Status
Rainer Sommer
2015-01-13T23:59:59.000Z
We give an introduction to Heavy Quark Effective Theory (HQET). Our emphasis is on its formulation non-perturbative in the strong coupling, including the non-perturbative determination of the parameters in the HQET Lagrangian. In a second part we review the present status of HQET on the lattice, largely based on work of the ALPHA collaboration in the last few years. We finally discuss opportunities and challenges.
Jet conversions in a quark-gluon plasma
Liu, W.; Ko, Che Ming; Zhang, B. W.
2007-01-01T23:59:59.000Z
.75.?q One of the most interesting observations in central heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) is the suppressed production of hadrons with large transverse momentum [1,2]. This phenomenon has been attributed... transverse momentum pions at RHIC can indeed be described. Initial jet distributions and heavy ion collision dynamics. To see the effect of conversions between quark and gluon jets on their energy losses in QGP, we consider central Au+Au collisions...
Identifying the Charge Carriers of the Quark-Gluon Plasma
Scott Pratt
2012-03-20T23:59:59.000Z
Charge correlations in lattice gauge calculations suggest that up, down and strange charges move independently in the QGP (quark-gluon plasma), and that the density of such charges is similar to what is expected from simple thermal arguments. Here, we show how specific elements of the charge-charge correlation matrix in the QGP survive hadronization and become manifest in final-state charge-charge correlation measurements.
Statistical Understanding of Quark and Lepton Masses in Gaussian Landscapes
Lawrence J. Hall; Michael P. Salem; Taizan Watari
2007-08-10T23:59:59.000Z
The fundamental theory of nature may allow a large landscape of vacua. Even if the theory contains a unified gauge symmetry, the 22 flavor parameters of the Standard Model, including neutrino masses, may be largely determined by the statistics of this landscape, and not by any symmetry. Then the measured values of the flavor parameters do not lead to any fundamental symmetries, but are statistical accidents; their precise values do not provide any insights into the fundamental theory, rather the overall pattern of flavor reflects the underlying landscape. We investigate whether random selection from the statistics of a simple landscape can explain the broad patterns of quark, charged lepton, and neutrino masses and mixings. We propose Gaussian landscapes as simplified models of landscapes where Yukawa couplings result from overlap integrals of zero-mode wavefunctions in higher-dimensional supersymmetric gauge theories. In terms of just five free parameters, such landscapes can account for all gross features of flavor, including: the hierarchy of quark and charged lepton masses; small quark mixing angles, with 13 mixing less than 12 and 23 mixing; very light Majorana neutrino masses, with the solar to atmospheric neutrino mass ratio consistent with data; distributions for leptonic 12 and 23 mixings that are peaked at large values, while the distribution for 13 mixing is peaked at low values; and order unity CP violating phases in both the quark and lepton sectors. While the statistical distributions for flavor parameters are broad, the distributions are robust to changes in the geometry of the extra dimensions. Constraining the distributions by loose cuts about observed values leads to narrower distributions for neutrino measurements of 13 mixing, CP violation, and neutrinoless double beta decay.
Measurement of the Top Quark Mass With 2012 CMS Data
Richard Nally
2014-09-01T23:59:59.000Z
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.
Search for scalar top and bottom quarks at the Tevatron
Calfayan, Philippe; /Munich U.
2009-01-01T23:59:59.000Z
This document reviews recent results on the search for scalar top and scalar bottom quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The analyses presented are based on data samples with integrated luminosities from 1.0 to 1.9 fb{sup -1} recorded at the Tevatron with the D0 and CDF detectors.
Top Quark Production Cross Section at the Tevatron
Shabalina, E.; /Chicago U.
2006-05-01T23:59:59.000Z
An overview of the preliminary results of the top quark pair production cross section measurements at a center-of-mass energy of 1.96 TeV carried out by the CDF and D0 collaborations is presented. The data samples used for the analyses are collected in the current Tevatron run and correspond to an integrated luminosity from 360 pb{sup -1} up to 760 pb{sup -1}.
Top quark pair production cross section at the Tevatron
Cortiana, Giorgio; /INFN, Padua /Padua U.
2008-04-01T23:59:59.000Z
Top quark pair production cross section has been measured at the Tevatron by CDF and D0 collaborations using different channels and methods, in order to test standard model predictions, and to search for new physics hints affecting the t{bar t} production mechanism or decay. Measurements are carried out with an integrated luminosity of 1.0 to 2.0 fb{sup -1}, and are found to be consistent with standard model expectations.
Quark Coalescence at High Energies University of Alabama in Huntsville/
Lin, Zi-wei
: ZWL,Ko&Pal, PRL89(02) v4, v6, ...: Chen,Ko&ZWL, PRC69(04) Flavor ordering of v2 at high Pt: ZWL&Ko, PRL89(02) Amplification of quark v2 and ordering: Voloshin, NPA715(03); Molnar&Voloshin, PRL91 et al, PRL90(03); Greco,Ko&Levai, PRL90(03); ... #12;Near hadronization, gluons may decouple (serve
Sommer 2011 Erstellt am: 26. September 2011 Fakultt fr Mathematik, Physik und Informatik
Dettweiler, Michael
Sommer 2011 Erstellt am: 26. September 2011 Seite 1 FakultÃ¤t fÃ¼r Mathematik, Physik und Informatik:00 - 10:00 woch NW II - S 79 Bauer-Catanese,Ingrid Fragestunde zur Linearen Algebra II #12;Sommer 2011,Wolfgang Di 08:00 - 10:00 woch NW II - H 19 Neidhardt,Wolfgang #12;Sommer 2011 Erstellt am: 26. September 2011
Modulliste Bachelor EI 02/14 ANLAGE 1: Pflichtmodule der Grundlagen-und Orientierungsprfung
Kuehnlenz, Kolja
Modulliste Bachelor EI 02/14 ANLAGE 1: Pflichtmodule der Grundlagen- und Orientierungsprüfung/Ü/P SWS Prüfungsart/Dauer Sprache EI0001 Schaltungstechnik 1 WS 6 4/2/0 6 s, 90 min D PH9009 Physik für Elektroingenieure WS 6 4/2/0 6 s, 90 min D EI0006 Digitaltechnik WS 5 3/2/0 5 s, 60 min D MA9409 Lineare Algebra WS
Numerical Simulation of the Hydrodynamical Combustion to Strange Quark Matter
Brian Niebergal; Rachid Ouyed; Prashanth Jaikumar
2010-08-27T23:59:59.000Z
We present results from a numerical solution to the burning of neutron matter inside a cold neutron star into stable (u,d,s) quark matter. Our method solves hydrodynamical flow equations in 1D with neutrino emission from weak equilibrating reactions, and strange quark diffusion across the burning front. We also include entropy change due to heat released in forming the stable quark phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04 times the speed of light, much faster than previous estimates derived using only a reactive-diffusive description. Analytic solutions to hydrodynamical jump conditions with a temperature dependent equation of state agree very well with our numerical findings for fluid velocities. The most important effect of neutrino cooling is that the conversion front stalls at lower density (below approximately 2 times saturation density). In a 2-dimensional setting, such rapid speeds and neutrino cooling may allow for a flame wrinkle instability to develop, possibly leading to detonation.
The Surface Tension of Quark Matter in a Geometrical Approach
Marcus B. Pinto; Volker Koch; Jorgen Randrup
2012-07-21T23:59:59.000Z
The surface tension of quark matter plays a crucial role for the possibility of quark matter nucleation during the formation of compact stellar objects, because it determines the nucleation rate and the associated critical size. However, this quantity is not well known and the theoretical estimates fall within a wide range, $\\gamma_0 \\approx 5-300 MeV/fm^2$. We show here that once the equation of state is available one may use a geometrical approach to obtain a numerical value for the surface tension that is consistent with the model approximations adopted. We illustrate this method within the two-flavor linear \\sigma model and the Nambu--Jona-Lasinio model with two and three flavors. Treating these models in the mean-field approximation, we find $\\gamma_0 \\approx 7-30 MeV/fm^2$. Such a relatively small surface tension would favor the formation of quark stars and may thus have significant astrophysical implications. We also investigate how the surface tension decreases towards zero as the temperature is raised from zero to its critical value.
The Fluid Nature of Quark-Gluon Plasma
W. A. Zajc
2008-02-25T23:59:59.000Z
Collisions of heavy nuclei at very high energies offer the exciting possibility of experimentally exploring the phase transformation from hadronic to partonic degrees of freedom which is predicted to occur at several times normal nuclear density and/or for temperatures in excess of $\\sim 170$ MeV. Such a state, often referred to as a quark-gluon plasma, is thought to have been the dominant form of matter in the universe in the first few microseconds after the Big Bang. Data from the first five years of heavy ion collisions of Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) clearly demonstrate that these very high temperatures and densities have been achieved. While there are strong suggestions of the role of quark degrees of freedom in determining the final-state distributions of the produced matter, there is also compelling evidence that the matter does {\\em not} behave as a quasi-ideal state of free quarks and gluons. Rather, its behavior is that of a dense fluid with very low kinematic viscosity exhibiting strong hydrodynamic flow and nearly complete absorption of high momentum probes. The current status of the RHIC experimental studies is presented, with a special emphasis on the fluid properties of the created matter, which may in fact be the most perfect fluid ever studied in the laboratory.
Local Gauge Transformation for the Quark Propagator in an SU(N) Gauge Theory
Aslam, M Jamil; Gutierrez-Guerrero, L X
2015-01-01T23:59:59.000Z
In an SU(N) gauge field theory, the n-point Green functions, namely, propagators and vertices, transform under the simultaneous local gauge variations of the gluon vector potential and the quark matter field in such a manner that the physical observables remain invariant. In this article, we derive this intrinsically non perturbative transformation law for the quark propagator within the system of covariant gauges. We carry out its explicit perturbative expansion till O(g_s^6) and, for some terms, till O(g_s^8). We study the implications of this transformation for the quark-anti-quark condensate, multiplicative renormalizability of the massless quark propagator, as well as its relation with the quark-gluon vertex at the one-loop order. Setting the color factors C_F=1 and C_A=0, Landau-Khalatnikov-Fradkin transformation for the abelian case of quantum electrodynamics is trivially recovered.
CDF/PUB/TOP/PUBLIC/10793 Measurement of Single Top Quark Production
Quigg, Chris
CDF/PUB/TOP/PUBLIC/10793 Measurement of Single Top Quark Production in 7.5 fb-1 of CDF Data Using a measurement of single top quark production in lepton plus jets final state using 7.5 fb-1 of pÂ¯p collision a bottom quark. We use the new POWHEG Monte Carlo generator for single top signal samples in s-channel, t
CDF/ANAL/TOP/PUB/7153 Measurement of the Top Quark Mass using the Template Method
Quigg, Chris
CDF/ANAL/TOP/PUB/7153 Measurement of the Top Quark Mass using the Template Method in the Lepton of the top quark mass in the lepton plus jets channel of t #22; t events from p#22;p collisions at p s = 1; t candidates with at least one identi#12;ed b jet. A top quark mass is reconstructed for each event by using
Search of anomalous $Wtb$ couplins in single top quark prodution at D0
Joshi, Jyoti; Beri, Suman; /Panjab U.
2011-12-01T23:59:59.000Z
The large mass of the top quark, close to the electroweak symmetry-breaking scale, makes it a good candidate for probing physics beyond the Standard Model, including possible anomalous couplings. D0 has made measurements of single top quark production using 5.4 fb{sup -1} of integrated luminosity. We examine the data to study the Lorentz structure of the Wtb coupling. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. In 2009, the electroweak single top quark production was observed by the D0 and CDF collaborations. Electroweak production of top quarks at the Tevatron proceeds mainly via the decay of a time-like virtual W boson accompanied by a bottom quark in the s-channel (tb = t{bar b} + {bar t}b), or via the exchange of a space-like virtual W boson between a light quark and a bottom quark in the t-channel (tqb = tq{bar b} + {bar t}qb, where q refers to the light quark). For a top quark mass of 172.5 GeV, The Standard Model (SM) prediction of single top production rate at next-to-leading order with soft-gluon contributions at next-to-next-to-leading order are 1.04 {+-} 0.04 pb (s-channel) and 2.26 {+-} 0.12 pb (t-channel). The large mass of the top quark implies that it has large couplings to the electroweak symmetry breaking sector of the SM and may have non-standard interactions with the weak gauge bosons. Single top quark production provides a unique probe to study the interactions of the top quark with the W boson.
Determination of the quark coupling strength $|V_{ub}|$ using baryonic decays
LHCb collaboration; R. Aaij; B. Adeva; M. Adinolfi; A. Affolder; Z. Ajaltouni; S. Akar; J. Albrecht; F. Alessio; M. Alexander; S. Ali; G. Alkhazov; P. Alvarez Cartelle; A. A. Alves Jr; S. Amato; S. Amerio; Y. Amhis; L. An; L. Anderlini; J. Anderson; M. Andreotti; J. E. Andrews; R. B. Appleby; O. Aquines Gutierrez; F. Archilli; A. Artamonov; M. Artuso; E. Aslanides; G. Auriemma; M. Baalouch; S. Bachmann; J. J. Back; A. Badalov; C. Baesso; W. Baldini; R. J. Barlow; C. Barschel; S. Barsuk; W. Barter; V. Batozskaya; V. Battista; A. Bay; L. Beaucourt; J. Beddow; F. Bedeschi; I. Bediaga; I. Belyaev; E. Ben-Haim; G. Bencivenni; S. Benson; J. Benton; A. Berezhnoy; R. Bernet; A. Bertolin; M. -O. Bettler; M. van Beuzekom; A. Bien; S. Bifani; T. Bird; A. Bizzeti; T. Blake; F. Blanc; J. Blouw; S. Blusk; V. Bocci; A. Bondar; N. Bondar; W. Bonivento; S. Borghi; M. Borsato; T. J. V. Bowcock; E. Bowen; C. Bozzi; S. Braun; D. Brett; M. Britsch; T. Britton; J. Brodzicka; N. H. Brook; A. Bursche; J. Buytaert; S. Cadeddu; R. Calabrese; M. Calvi; M. Calvo Gomez; P. Campana; D. Campora Perez; L. Capriotti; A. Carbone; G. Carboni; R. Cardinale; A. Cardini; P. Carniti; L. Carson; K. Carvalho Akiba; R. Casanova Mohr; G. Casse; L. Cassina; L. Castillo Garcia; M. Cattaneo; Ch. Cauet; G. Cavallero; R. Cenci; M. Charles; Ph. Charpentier; M. Chefdeville; S. Chen; S. -F. Cheung; N. Chiapolini; M. Chrzaszcz; X. Cid Vidal; G. Ciezarek; P. E. L. Clarke; M. Clemencic; H. V. Cliff; J. Closier; V. Coco; J. Cogan; E. Cogneras; V. Cogoni; L. Cojocariu; G. Collazuol; P. Collins; A. Comerma-Montells; A. Contu; A. Cook; M. Coombes; S. Coquereau; G. Corti; M. Corvo; I. Counts; B. Couturier; G. A. Cowan; D. C. Craik; A. C. Crocombe; M. Cruz Torres; S. Cunliffe; R. Currie; C. D'Ambrosio; J. Dalseno; P. N. Y. David; A. Davis; K. De Bruyn; S. De Capua; M. De Cian; J. M. De Miranda; L. De Paula; W. De Silva; P. De Simone; C. -T. Dean; D. Decamp; M. Deckenhoff; L. Del Buono; N. Déléage; D. Derkach; O. Deschamps; F. Dettori; B. Dey; A. Di Canto; F. Di Ruscio; H. Dijkstra; S. Donleavy; F. Dordei; M. Dorigo; A. Dosil Suárez; D. Dossett; A. Dovbnya; K. Dreimanis; LD Dufour; G. Dujany; F. Dupertuis; P. Durante; R. Dzhelyadin; A. Dziurda; A. Dzyuba; S. Easo; U. Egede; V. Egorychev; S. Eidelman; S. Eisenhardt; U. Eitschberger; R. Ekelhof; L. Eklund; I. El Rifai; Ch. Elsasser; S. Ely; S. Esen; H. M. Evans; T. Evans; A. Falabella; C. Färber; C. Farinelli; N. Farley; S. Farry; R. Fay; D. Ferguson; V. Fernandez Albor; F. Ferreira Rodrigues; M. Ferro-Luzzi; S. Filippov; M. Fiore; M. Fiorini; M. Firlej; C. Fitzpatrick; T. Fiutowski; P. Fol; M. Fontana; F. Fontanelli; R. Forty; O. Francisco; M. Frank; C. Frei; M. Frosini; J. Fu; E. Furfaro; A. Gallas Torreira; D. Galli; S. Gallorini; S. Gambetta; M. Gandelman; P. Gandini; Y. Gao; J. García Pardiñas; J. Garofoli; J. Garra Tico; L. Garrido; D. Gascon; C. Gaspar; U. Gastaldi; R. Gauld; L. Gavardi; G. Gazzoni; A. Geraci; E. Gersabeck; M. Gersabeck; T. Gershon; Ph. Ghez; A. Gianelle; S. Gianì; V. Gibson; L. Giubega; V. V. Gligorov; C. Göbel; D. Golubkov; A. Golutvin; A. Gomes; C. Gotti; M. Grabalosa Gándara; R. Graciani Diaz; L. A. Granado Cardoso; E. Graugés; E. Graverini; G. Graziani; A. Grecu; E. Greening; S. Gregson; P. Griffith; L. Grillo; O. Grünberg; B. Gui; E. Gushchin; Yu. Guz; T. Gys; C. Hadjivasiliou; G. Haefeli; C. Haen; S. C. Haines; S. Hall; B. Hamilton; T. Hampson; X. Han; S. Hansmann-Menzemer; N. Harnew; S. T. Harnew; J. Harrison; J. He; T. Head; V. Heijne; K. Hennessy; P. Henrard; L. Henry; J. A. Hernando Morata; E. van Herwijnen; M. Heß; A. Hicheur; D. Hill; M. Hoballah; C. Hombach; W. Hulsbergen; T. Humair; N. Hussain; D. Hutchcroft; D. Hynds; M. Idzik; P. Ilten; R. Jacobsson; A. Jaeger; J. Jalocha; E. Jans; A. Jawahery; F. Jing; M. John; D. Johnson; C. R. Jones; C. Joram; B. Jost; N. Jurik; S. Kandybei; W. Kanso; M. Karacson; T. M. Karbach; S. Karodia; M. Kelsey; I. R. Kenyon; M. Kenzie; T. Ketel; B. Khanji; C. Khurewathanakul; S. Klaver; K. Klimaszewski; O. Kochebina; M. Kolpin; I. Komarov; R. F. Koopman; P. Koppenburg; M. Korolev; L. Kravchuk; K. Kreplin; M. Kreps; G. Krocker; P. Krokovny; F. Kruse; W. Kucewicz; M. Kucharczyk; V. Kudryavtsev; K. Kurek; T. Kvaratskheliya; V. N. La Thi; D. Lacarrere; G. Lafferty; A. Lai; D. Lambert; R. W. Lambert; G. Lanfranchi; C. Langenbruch; B. Langhans; T. Latham; C. Lazzeroni; R. Le Gac; J. van Leerdam; J. -P. Lees; R. Lefèvre; A. Leflat; J. Lefrançois; O. Leroy; T. Lesiak; B. Leverington; Y. Li; T. Likhomanenko; M. Liles; R. Lindner; C. Linn; F. Lionetto; B. Liu; S. Lohn; I. Longstaff; J. H. Lopes; P. Lowdon; D. Lucchesi; H. Luo; A. Lupato; E. Luppi; O. Lupton; F. Machefert; F. Maciuc; O. Maev; K. Maguire; S. Malde; A. Malinin; G. Manca; G. Mancinelli; P Manning; A. Mapelli; J. Maratas; J. F. Marchand; U. Marconi
2015-04-07T23:59:59.000Z
In the Standard Model of particle physics, the strength of the coupling of the $b$ quark to the $u$ quark, $|V_{ub}|$, is governed by the coupling of the quarks to the Higgs boson. Using data from the LHCb experiment at the Large Hadron Collider, it is shown that $|V_{ub}| = (3.27 \\pm 0.23) \\times 10^{-3}$, from a measurement of $\\Lambda^0_b \\to p \\mu^- \\overline{\
Baron, Frank
2009-01-01T23:59:59.000Z
Herausgegeben von Frank Baron In Verbindung mit einer kritischen Edition des Textes von 1585 von Benedikt Sommer Series: Studium Literarum 17 Publisher: Weidler Buchverlag Year: 2009... ---------------------------------------------------------------------------------------------------------------------------------- Table of Contents: Frank Baron, Einleitung (Introduction) I. Benedikt Sommer, Christlich bedencken und erjnnerung von Zauberey, kritische Edition II. Untersuchungen (Essays) Benedikt Sommer, Das Leben und Werk Hermann Witekinds Otto Ulbricht...
Arndt, Holger
() = -1...---1...10. 1. Fall: 0, also zk() = und -1 = 0. Tritt Ã?berlauf ein, so ist 2 2-1 , also 2--1 . Also ist eine der Ziffern -1, ..., --1 gleich 1, aber -1 = 0. Tritt kein Ã?berlauf ein, so sind alle, also zk() = 2 + und -1 = 1. Tritt Ã?berlauf ein, so ist 2
Rey Juan Carlos, Universidad
Desde 1953, SSL Schwellenwerk und Steuerungstechnik Linz GmbH es un fabricante líder de traviesas de presentación, en inglés o alemán, a: SSL Schwellenwerk und Steuerungstechnik Linz GmbH, A-4030 Linz Attn. Sra. Nicole Preuer E-mail: mail@ssl-linz.at #12;