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1

Lepton stability  

Science Conference Proceedings (OSTI)

The problem of flavor-changing currents in the lepton sector is reviewed. The emphasis is on the experimental situation, with a brief discussion of the theoretical problems which are addressed by the measurements.

Cooper, M.C.

1981-01-01T23:59:59.000Z

2

Glossary Term - Lepton  

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

Joule Previous Term (Joule) Glossary Main Index Next Term (Liquid Nitrogen) Liquid Nitrogen Lepton Leptons are particles with little mass that interact through the electromagnetic...

3

Quark Lepton Similarity  

E-Print Network (OSTI)

We propose the lepton mixing matrix at high energy scale to be connected to quark mixing matrix by the similar transformation. The similarity between CKM and PMNS significantly narrows down the ranges in physical parameters. The condition requires $\\sin\\theta_{13}$ not to be larger than 0.15, masses to be of quasi-degenerate normal ordering, and $\\tan\\beta$ to be large.

Seungsu Hwang; Kim Siyeon

2010-08-20T23:59:59.000Z

4

Measurement of the $?$-lepton lifetime at Belle  

E-Print Network (OSTI)

The lifetime of the $\\tau$-lepton is measured using the process $e^+e^-\\rightarrow\\tau^+\\tau^-$, where both $\\tau$-leptons decay to $3\\pi\

Belle Collaboration; K. Belous; M. Shapkin; A. Sokolov; I. Adachi; H. Aihara; D. M. Asner; V. Aulchenko; A. M. Bakich; A. Bala; B. Bhuyan; A. Bobrov; A. Bondar; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; D. ?ervenkov; V. Chekelian; A. Chen; B. G. Cheon; K. Chilikin; R. Chistov; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; J. Dalseno; Z. Doleal; D. Dutta; S. Eidelman; D. Epifanov; H. Farhat; J. E. Fast; T. Ferber; V. Gaur; S. Ganguly; A. Garmash; R. Gillard; Y. M. Goh; B. Golob; J. Haba; T. Hara; K. Hayasaka; H. Hayashii; Y. Hoshi; W. -S. Hou; T. Iijima; K. Inami; A. Ishikawa; R. Itoh; T. Iwashita; I. Jaegle; T. Julius; E. Kato; H. Kichimi; C. Kiesling; D. Y. Kim; H. J. Kim; J. B. Kim; M. J. Kim; Y. J. Kim; K. Kinoshita; B. R. Ko; P. Kody; S. Korpar; P. Krian; P. Krokovny; T. Kuhr; A. Kuzmin; Y. -J. Kwon; J. S. Lange; S. -H. Lee; J. Libby; D. Liventsev; P. Lukin; D. Matvienko; H. Miyata; R. Mizuk; G. B. Mohanty; T. Mori; R. Mussa; Y. Nagasaka; E. Nakano; M. Nakao; M. Nayak; E. Nedelkovska; C. Ng; N. K. Nisar; S. Nishida; O. Nitoh; S. Ogawa; S. Okuno; S. L. Olsen; W. Ostrowicz; G. Pakhlova; C. W. Park; H. Park; H. K. Park; T. K. Pedlar; R. Pestotnik; M. Petri?; L. E. Piilonen; M. Ritter; M. Rhrken; A. Rostomyan; S. Ryu; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; D. Santel; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; D. Semmler; K. Senyo; O. Seon; V. Shebalin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; S. Stani?; M. Stari?; M. Steder; T. Sumiyoshi; U. Tamponi; G. Tatishvili; Y. Teramoto; K. Trabelsi; T. Tsuboyama; M. Uchida; S. Uehara; T. Uglov; Y. Unno; S. Uno; Y. Usov; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; K. E. Varvell; A. Vinokurova; V. Vorobyev; M. N. Wagner; C. H. Wang; P. Wang; M. Watanabe; Y. Watanabe; K. M. Williams; E. Won; J. Yamaoka; Y. Yamashita; S. Yashchenko; Y. Yook; C. Z. Yuan; Z. P. Zhang; V. Zhilich; A. Zupanc

2013-10-31T23:59:59.000Z

5

Summary of Lepton Photon 2011  

SciTech Connect

In this lecture, I summarize developments presented at the Lepton Photon 2011 conference and give my perspective on the current situation in high-energy physics. I am grateful to the organizers of Lepton Photon 2011 for providing us a very pleasant and simulating week in Mumbai. This year's Lepton Photon conference has covered the full range of subjects that fall within the scope of high-energy physics, including connections to cosmology, nuclear physics, and atomic physics. The experiments that were discussed detect particles ranging in energy from radio frequencies to EeV.

Peskin, Michael E.; /SLAC

2012-03-14T23:59:59.000Z

6

Limits on tau lepton-flavor violating decays into three charged leptons  

E-Print Network (OSTI)

A search for the neutrinoless, lepton-flavor violating decay of the ? [tau] lepton into three charged leptons has been performed using an integrated luminosity of 468??fb-1 [fb superscript -1] collected with the BABAR ...

Cowan, Ray Franklin

7

Status of Heavy-lepton Searches  

DOE R&D Accomplishments (OSTI)

Searches for heavy leptons using e{sup +}e{sup -} annihilation, lepton-hadron collisions, photon-hadron collisions, hadron-hadron collisions, and studies of macroscopic matter are reviewed. The present experimental status and future possibilities are summarized.

Perl, M. L.

1981-06-00T23:59:59.000Z

8

Phenomenology of heavy vector-like leptons  

E-Print Network (OSTI)

We study the impact that a heavy generation of vector-like leptons can have on the value of the electric dipole moment of the electron, and the rates for the flavor violating processes mu --> e gamma and mu --> 3e. The smallness of the charged lepton masses suggests that at least some of the Yukawa coupling constants of the vector-like leptons to the ordinary leptons or amongst themselves are small, but even with such small couplings experiments trying to detect these quantities are sensitive to extra generation lepton masses up to about 100 TeV.

Koji Ishiwata; Mark B. Wise

2013-07-03T23:59:59.000Z

9

Lepton Photon Symposium 2005: Summary and Outlook  

E-Print Network (OSTI)

Lepton Photon 2005 told the saga of the Standard Model which is still exhilarating because it leaves all questions of consequence unanswered.

Francis Halzen

2005-10-20T23:59:59.000Z

10

Flavour models for TM1 lepton mixing  

E-Print Network (OSTI)

We present a framework for lepton flavour models such that the first column of the lepton mixing matrix is (2,-1,-1)/sqrt(6). We show that the flavour symmetry group adequate for this purpose is S4. Our models are based on a vacuum alignment that can be obtained in a supersymmetric framework.

Varzielas, Ivo de Medeiros

2012-01-01T23:59:59.000Z

11

B to tau Leptonic and Semileptonic Decays  

Science Conference Proceedings (OSTI)

Decays of B mesons to states involving {tau} leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B {yields} {tau}{nu} and B {yields} D{sup (*)}{tau}{nu} is discussed, together with limits on new physics effects from current results. Leptonic and semileptonic decays of B mesons into states involving {tau} leptons remain experimentally challenging, but can prove a useful tool for constraining Standard Model parameters, and also offer to constrain the effects of any new physics that may exist including the presence of a charged Higgs boson.

Barrett, M.; /Brunel U.

2011-11-17T23:59:59.000Z

12

Lepton Flavor Violating Decays - Review & Outlook  

E-Print Network (OSTI)

Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric theories or other models beyond the Standard Model. In contrast to physics of quark flavors that is dominated by the Cabibbo-Kobayashi-Maskawa matrix, LFV in charged leptons is a definitive signal of new physics. Currently active researches are rare tau decay searches at the B factories. The MEG experiment will soon start a sensitive search for the LFV muon decay, mu to e gamma. Prospects for searches at the LHC, a possibility of a fixed target LFV experiment with high energy muons, and a sensitivity of leptonic kaon decays to LFV are also briefly discussed.

Toshinori Mori

2006-05-30T23:59:59.000Z

13

Exotic Leptons: Higgs, Flavor and Collider Phenomenology  

E-Print Network (OSTI)

We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h -> gamma gamma decay rate for new lepton masses in the 300 GeV - 1 TeV range. We analyze vaccum stability implications for different hypercharges. Effects in h -> Z gamma are typically much smaller than in h -> gamma gamma, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at the LHC, and find that signatures with multiple light leptons or taus are already probing interesting regions of parameter space.

Wolfgang Altmannshofer; Martin Bauer; Marcela Carena

2013-08-08T23:59:59.000Z

14

Triangular mass matrices for quarks and leptons  

E-Print Network (OSTI)

We assume that all quark and lepton $3 \\times 3$ mass matrices which appear in the standard model lagrangian (after spontaneous symmetry breaking) with neutrinos treated as Dirac patricles have the triangular form. Such matrices have not only less non-zero elements (three of them are equal to zero) but also lead to very asymmetrical decomposition into one diagonal and two unitary matrices for quarks and leptons. We also assume that unitary matrices which transform flavor into definite mass states for right handed components (weakly non-interacting) in the same weak isodoublet are equal. Using all available experimental data on quark and lepton masses and mixing angles, treating in the universal way quarks and leptons, we determine the triangular mass matrices for up and down type quarks, neutrinos and charged leptons and as a consequence mixing matrices for left-handed and right handed components. As the result of the fit we get predictions for the neutrino masses including smallest neutrino mass. The calculations without CP violation and with inclusion of this effect in quark sector are also presented.

S. Tatur; J. Bartelski

2006-05-24T23:59:59.000Z

15

Exotic Leptons: Higgs, Flavor and Collider Phenomenology  

E-Print Network (OSTI)

We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h -> gamma gamma decay rate for new lepton masses in the 300 GeV - 1 TeV range. We analyze vaccum stability implications for different hypercharges. Effects in h -> Z gamma are typically much smaller than in h -> gamma gamma, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at...

Altmannshofer, Wolfgang; Carena, Marcela

2013-01-01T23:59:59.000Z

16

The Particle Adventure | What is the world made of? | Lepton...  

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

quiz Which lepton decays are possible? Why or why not? (A tau lepton decays into an electron, an electron antineutrino, and a tau neutrino.) Answer Yes Charge, tau number,...

17

Limits on tau lepton flavor violating decays in three charged leptons  

SciTech Connect

A search for the neutrinoless, lepton-flavor violating decay of the {tau} lepton into three charged leptons has been performed using an integrated luminosity of 468 fb{sup -1} collected with the BABAR detector at the PEP-II collider. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1.8-3.3) x 10{sup -8} at 90% confidence level.

Cervelli, Alberto

2010-04-29T23:59:59.000Z

18

Flavor Violating Lepton Family U(1)$_\\lambda$  

E-Print Network (OSTI)

The Standard Model is extended minimally with a new flavor-violating family symmetry ${\\rm U(1)}_\\lambda$, which acts only on leptons including the right-handed neutrinos. The model is anomaly free with family-dependent ${\\rm U(1)}_\\lambda$ charges, and consistent with the observed neutrino mixing angles. It predicts charged lepton flavor-violating processes mediated by a new gauge boson. Under certain conditions, the smallness of $\\theta_{13}$ of neutrino mixing can be justified in terms of the muon-to-tau mass ratio, at the same time explaining the electron-to-tau large mass hierarchy.

La, HoSeong

2013-01-01T23:59:59.000Z

19

Lepton-Flavor Violation and Physics beyond the Standard Model  

E-Print Network (OSTI)

This talk discusses recent studies of (charged) lepton-flavor violation in physics beyond the standard model.

Junji Hisano

2012-12-20T23:59:59.000Z

20

Martin Perl and the Tau Lepton  

Office of Scientific and Technical Information (OSTI)

Martin Perl and the Tau Lepton Martin Perl and the Tau Lepton Resources with Additional Information 'Martin L. Perl, a professor at the Stanford Linear Accelerator Center (SLAC), [was] awarded the 1995 Nobel Prize in physics ... for his 1975 discovery of a new elementary particle known as the tau lepton. ... The tau lepton is a superheavy cousin of the electron, the carrier of electrical current in household appliances. The two particles are identical in all respects except that the tau is more than 3,500 times heavier than the electron and survives less than a trillionth of a second, whereas the electron is stable. Martin Perl Courtesy AIP Emilio Segrè Visual Archives, W.F. Meggers Gallery of Nobel Laureates In the mid-1970s, working at the Stanford Positron-Electron Asymmetric Ring (SPEAR) in collaboration with 30 other physicists from SLAC and Lawrence Berkeley National Laboratory, Perl began to find events recorded by the detector that could not be explained by any of the known subatomic particles. After more than a year of analysis, Perl was able to convince the rest of his research team that they were in fact observing a new and different type of elementary particle, which he named the 'tau'.

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


21

Citation: K. Nakamura et al. (Particle Data Group), JPG 37, 075021 (2010) (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITS Note that LEP results

22

Citation: J. Beringer et al. (Particle Data Group), PR D86, 010001 (2012) (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITS Note that LEP results

23

Test of lepton universality and search for lepton flavor violation in Upsilon(1S,2S,3S) decays at CLEO  

E-Print Network (OSTI)

We present the analysis technique and preliminary results of two ongoing analyses at CLEO which put lepton universality and lepton flavor conservation to the test in Upsilon decays.

Istvan Danko; for the CLEO Collaboration

2006-01-18T23:59:59.000Z

24

Four-Lepton Resonance at the Large Hadron Collider  

E-Print Network (OSTI)

A spin-1 weakly interacting vector boson, Z', is predicted by many new physics theories. Searches at colliders for such a Z' resonance typically focus on lepton-antilepton or top-antitop events. Here we present a novel channel with a Z' resonance that decays to 4 leptons, but not to 2 leptons, and discuss its possible discovery at the Large Hadron Collider. This baryonic gauge boson is well motivated in a supersymmetry framework.

Vernon Barger; Hye-Sung Lee

2011-11-02T23:59:59.000Z

25

Citation: K. Nakamura et al. (Particle Data Group), JPG 37, 075021 (2010) (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

26

Citation: J. Beringer et al. (Particle Data Group), PR D86, 010001 (2012) (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

27

Radiative Transmission of Lepton Flavor Hierarchies  

E-Print Network (OSTI)

We discuss a one loop model for neutrino masses which leads to a seesaw-like formula with the difference that the charged lepton masses replace the unknown Dirac mass matrix present in the usual seesaw case. This is a considerable reduction of parameters in the neutrino sector and predicts a strong hierarchical pattern in the right handed neutrino mass matrix that is easily derived from a $U(1)_H$ family symmetry. The model is based on the left-right gauge group with an additional $Z_4$ discrete symmetry which gives vanishing neutrino Dirac masses and finite Majorana masses arising at the one loop level. Furthermore, it is one of the few models that naturally allow for large (but not necessarily maximal) mixing angles in the lepton sector. A generalization of the model to the quark sector requires three iso-spin singlet vector-like down type quarks, as in $E_6$. The model predicts an inert doublet type scalar dark matter.

Adisorn Adulpravitchai; Manfred Lindner; Alexander Merle; Rabindra N. Mohapatra

2009-08-04T23:59:59.000Z

28

Measurement of tau lepton branching fractions  

SciTech Connect

We present {tau}{sup {minus}} lepton branching fraction measurements based on data from the TPC/Two-Gamma detector at PEP. Using a sample of{tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} events, we examine the resonance structure of the K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} system and obtain the first measurements of branching fractions for {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1270) and {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1400). We also describe a complete set of branching fraction measurements in which all the decays of the {tau}{sup {minus}} lepton are separated into classes defined by the identities of the charged particles and an estimate of the number of neutrals. This is the first such global measurement with decay classes defined by the four possible charged particle species, e, {mu}, {pi}, and K.

Nicol, N.A.

1993-09-30T23:59:59.000Z

29

Higgs. -->. four leptons at the SSC  

SciTech Connect

Detection of an intermediate mass or heavy Higgs boson through its decay into four charged leptons is studied with emphasis on background considerations and detector requirements. The intermediate mass Higgs decay via ZZ* is expected to be a difficult mode to observe due to low event rates. In addition, cuts which are needed to reduce the backgrounds reduce the signal even further. The rapidity coverage and energy resolution requirements for this mode are more severe than for the heavy Higgs. The heavy Higgs boson decay H ..-->.. Z/sup 0/Z/sup 0/ ..-->.. 4/ell//sup +-/ continues to be observable for a Higgs mass between twice the Z mass and about 600 GeV/c/sup 2/ when detector characteristics of generic large SSC detectors are included. A careful study is made of backgrounds from q/bar q/, qq ..-->.. Z + Jets and detector-related issues. It is shown that an isolation cut on the lepton candidates can be expected to reduce the background from this source to low levels. 14 refs., 12 figs., 4 tabs.

Wang, E.M.; Hanson, G.G.

1988-12-01T23:59:59.000Z

30

Phenomenology of a leptonic goldstino and invisible Higgs boson decays  

E-Print Network (OSTI)

Non-linearly realized supersymmetry, combined with the Standard Model field content and SU(3)XSU(2)XU(1) gauge invariance, permits local dimension-six operators involving a goldstino, a lepton doublet and a Higgs doublet. These interactions preserve total lepton number if the left-handed goldstino transforms as an antilepton. We discuss the resulting phenomenology, in the simple limit where the new couplings involve only one lepton family, thus conserving also lepton flavour. Both the Z boson and the Higgs boson can decay into a neutrino and a goldstino: the present limits from the invisible Z width and from other observables leave room for the striking possibility of a Higgs boson decaying dominantly, or at least with a sizable branching ratio, via such an invisible mode. We finally comment on the perspectives at hadron and lepton colliders, and on possible extensions of our analysis.

Ignatios Antoniadis; Marc Tuckmantel; Fabio Zwirner

2004-10-12T23:59:59.000Z

31

A search for close-mass lepton doublet  

SciTech Connect

Described is a search for a heavy charged lepton with an associated neutrino of nearly the same mass, together known as a close-mass lepton doublet. The search is conducted in e/sup +/e/sup/minus// annihilation data taken with the Mark II detector at a center-of-mass energy of 29 GeV. In order to suppress contamination from conventional two-photon reactions, the search applies a novel, radiative-tagging technique. Requiring the presence of an isolated, energetic photon allows exploration for lepton doublets with a mass splitting smaller than that previously accessible to experiment. No evidence for such a new lepton has been found, enabling limits to be placed on allowed mass combinations. Mass differences as low as 250-300 MeV are excluded for charged lepton masses up to 10 GeV. 78 refs., 64 figs., 8 tabs.

Riles, J.K.

1989-04-01T23:59:59.000Z

32

Electronic branching ratio of the. tau. lepton  

Science Conference Proceedings (OSTI)

Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio {ital R}={Gamma}({tau}{r arrow}{ital e}{bar {nu}}{sub {ital e}}{nu}{sub {tau}})/{Gamma}{sub 1}, where {Gamma}{sub 1} is the {tau} decay rate to final states with one charged particle. We find {ital R}=0.2231{plus minus}0.0044{plus minus}0.0073 where the first error is statistical and the second is systematic. Together with the measured topological one-charged-particle branching fraction, this yields the branching fraction of the {tau} lepton to electrons, {ital B}{sub {ital e}}=0.192{plus minus}0.004{plus minus}0.006.

Ammar, R.; Baringer, P.; Coppage, D.; Davis, R.; Kelly, M.; Kwak, N.; Lam, H.; Ro, S.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Perticone, D.; Poling, R.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; Romero, V.; Sun, C.R.; Wang, P.; Zoeller, M.M.; Crawford, G.; Fulton, R.; Gan, K.K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Sung, M.K.; Whitmore, J.; Wilson, P.; Butler, F.; Fu, X.; Kalbfleisch, G.; Lambrecht, M.; Skubic, P.; Snow, J.; Wang, P.; Bortoletto, D.; Brown, D.N.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Modesitt, M.; Shibata, E.I.; Schaffner, S.F.; Shipsey, I.P.J.; Battle, M.; Ernst, J.; Kroha, H.; Roberts, S.; Sparks, K.; Thorndike, E.H.; Wang, C.; Stroynowski, R.; Artuso, M.; Goldberg, M.; Haupt, T.; Horwitz, N.; Kennett, R.; Moneti, G.C.; Playfer, S.; Rozen, Y.; Rubin, P.; Skwarnicki, T.; Stone, S.; Thulasidas, M.; Yao, W.; Zhu, G.; Barnes, A.V.; Bartelt, J.; Csorna, S.E.; Jain, V.; Letson, T.; Mestayer, M.D.; Akerib, D.S.; Barish, B.; Chadha, M.; (CLEO Collaboration)

1992-06-01T23:59:59.000Z

33

Citation: K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton

34

SLAC National Accelerator Laboratory - Lepton-Photon Conference...  

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

was still the biggest news at this year's Lepton-Photon: the discovery of a Higgs boson at CERN's Large Hadron Collider. Progress has been made in the past year: The new...

35

Lepton flavor violation decays with the fourth generation neutrino  

E-Print Network (OSTI)

We investigate the lepton flavor violation decays, $\\tau \\to \\mu\\gamma$, $\\tau \\to e\\gamma$ and $\\mu \\to e\\gamma$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\

Huo, W J; Huo, Wu-Jun; Feng, Tai-Fu

2002-01-01T23:59:59.000Z

36

Phenomenological constraints on minimally coupled exotic lepton triplets  

Science Conference Proceedings (OSTI)

By introducing a set of new triplet leptons (with nonzero hypercharge) that can Yukawa couple to their standard model counterparts, new sources of tree-level flavor changing currents are induced via mixing. In this work, we study some of the consequences of such new contributions on processes such as the leptonic decays of gauge bosons, l{yields}3l{sup '} and l{yields}l{sup '{gamma}}, which violate lepton flavor, and {mu}-e conversion in atomic nuclei. Constraints are then placed on the parameters associated with the exotic triplets by invoking the current low-energy experimental data. Moreover, the new physics contribution to the lepton anomalous magnetic moments is calculated.

Chua, Chun-Khiang; Law, Sandy S. C. [Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan 320 (China)

2011-03-01T23:59:59.000Z

37

The small mixing angle {theta}13 and the lepton asymmetry  

SciTech Connect

We present the correlation of low energy CP phases, and the lepton asymmetry for the baryon asymmetry in the universe, for cases in which the amount of the lepton asymmetry YL turns out to be proportional to {theta}{sub 13}{sup 2}, considering the constraint between two types of CP phases and the relation of YL versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as {theta}13 varies.

Lee, Song-Haeng; Siyeon, Kim [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

2005-12-02T23:59:59.000Z

38

INTENSE NEUTRINO BEAMS AND LEPTONIC CP VIOLATION.  

SciTech Connect

Effects of the Leptonic CP violating phase, {delta}, on 3 generation neutrino oscillation rates and asymmetries are discussed. A figure of merit argument is used to show that our ability to measure the phase 6 is rather insensitive to the value of {theta}{sub 13} (for sin{sup 2} 2{theta}{sub 13} {approx}> 0.01) as well as the detector distance (for very long oscillation baselines). Using a study of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations for BNL-Homestake (2540 km) we show that a conventional horn focused wide band neutrino beam generated by an intense 1-2 MW proton source combined with a very large water Cherenkov detector (250-500 kton) should be able to determine {delta} to about {+-}15{sup o} in 5 x 10{sup 7} sec. of running. In addition, such an effort would also measure the other oscillation parameters ({theta}{sub ij}, {Delta}m{sub ij}{sup 2}) with high precision. Similar findings apply to a Fermilab-Homestake (1280 km) baseline. We also briefly discuss features of Superbeams, Neutrino Factories and Beta-Beams.

MARCIANO, W.; PARSA, Z.

2006-06-13T23:59:59.000Z

39

Nuclear PDF for neutrino and charged lepton data  

E-Print Network (OSTI)

Neutrino Deep Inelastic Scattering on nuclei is an essential process to constrain the strange quark parton distribution functions in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions. Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton lA Deeply Inelastic Scattering and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors F_2^Fe/F_2^D for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

K. Kovarik

2010-12-13T23:59:59.000Z

40

Detecting exotic heavy leptons at the large hadron collider.  

E-Print Network (OSTI)

ar X iv :h ep -p h/ 01 08 09 7v 1 1 0 A ug 2 00 1 Preprint typeset in JHEP style. - HYPER VERSION Cavendish-HEP-01/10 DAMTP-2001-71 CERN-TH/2001-205 Detecting Exotic Heavy Leptons at the Large Hadron Collider B.C. Allanach?, C.M. Harris, M... , CB3 0WA, UK. Abstract: New almost-degenerate charged and neutral heavy leptons are a feature of a number of theories of physics beyond the Standard Model. The prospects for detecting these at the Large Hadron Collider using a time-of-flight technique...

Allanach, B C; Harris, Chris M; Parker, Michael A; Richardson, P; Webber, Bryan R

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


41

A Search for Neutrinoless Tau Decays to Three Leptons  

SciTech Connect

Using approximately 350 million {tau}{sup +}{tau}{sup -} pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction {Beta}({tau} {yields} {ell}{ell}{ell}) in the range (4-8) x 10{sup -8}.

Kolb, Jeffrey A.; /Oregon U. /SLAC

2008-09-24T23:59:59.000Z

42

Review of ''close-mass'' heavy lepton searches  

SciTech Connect

Results from recent searches in e/sup +/e/sup /minus// annihilation at PEP (..sqrt..s = 29 GeV) for a fourth-generation charged lepton associated with a slightly lighter neutrino partner are presented. Some emphasis is given to the most recent search, which uses a novel approach based on radiative tagging, an approach that holds promise as a general tool in searching for exotic events characterized by very low visible energy. Prospects for upcoming sequential lepton searches at SLC and LEP experiments are also discussed. 11 refs., 4 figs.

Riles, K.

1989-05-01T23:59:59.000Z

43

Precision Measurements of Tau Lepton Decays  

SciTech Connect

Using data collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, the branching fractions {Beta}({tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (8.83 {+-} 0.01 {+-} 0.13)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (0.273 {+-} 0.002 {+-} 0.009)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}}) = (0.1346 {+-} 0.0010 {+-} 0.0036)%, and {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}) = (1.58 {+-} 0.13 {+-} 0.12) x 10{sup -5} are measured where the uncertainties are statistical and systematic, respectively. The invariant mass distribution for the {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}, {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} decays are unfolded to correct for detector effects. A measurement of {Beta}({tau}{sup -} {yields} {phi}{pi}{sup -}{nu}{sub {tau}}) = (3.42 {+-} 0.55 {+-} 0.25) x 10{sup -5}, a measurement of {Beta}({tau}{sup -} {yields} {phi}K{sup -}{nu}{sub {tau}}) = (3.39 {+-} 0.20 {+-} 0.28) x 10{sup -5} and an upper limit on {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}[ex.{phi}]) {le} 2.5 x 10{sup -6} {at} 905 CL are determined from a binned maximum likelihood fit of the {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} K{sup +}K{sup -} invariant mass distributions. The branching ratio {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}) is measured to be (6.531 {+-} 0.056 {+-} 0.093) x 10{sup -2} from which |V{sub us}| is determined to be 0.2255 {+-} 0.0023. The branching ratio {Beta}/({tau}{sup -} {yields} {mu}{nu}{sub {tau}}{bar {nu}}{sub {mu}})/{Beta}({tau}{sup -} {yields} e{sup -} {nu}{sub {tau}}{bar {nu}}{sub e}) = (9.796 {+-} 0.016 {+-} 0.035) x 10{sup -1} is measured enabling a precision test of the Standard Model assumption of charged current lepton universality, g{sub {mu}}/g{sub e} = 1.0036 {+-} 0.0020. The branching ratios {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{nu}{sub {tau}}{bar {nu}}{sub e}) = (3.882 {+-} 0.032 {+-} 0.057) x 10{sup -2}, and {Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{nu}{sub {tau}}{bar {nu}}{sub e}) = (5.9545 {+-} 0.014 {+-} 0.061) x 10{sup -1} are measured which provide additional tests of charged current lepton universality, (g{sub {tau}}/g{sub {mu}}){sub {pi}} = 0.9856 {+-} 0.0057 and (g{sub {tau}}/g{sub {mu}}){sub K} = 0.9827 {+-} 0.0086 which can be combined to give (g{sub {tau}}/g{sub {mu}}){sub {pi}/K} = 0.9850 {+-} 0.0054. Any deviation of these measurements from the expected Standard Model values would be an indication of new physics.

Nugent, Ian M.; /Victoria U.

2010-03-16T23:59:59.000Z

44

A Lepton Universality Test at CERN NA62 Experiment  

E-Print Network (OSTI)

The NA62 experiment at CERN collected a large sample of K+ --> enu decays during a dedicated run in 2007, aiming at a precise test of lepton universality by measurement of the helicity suppressed ratio RK = BR(K+ --> enu)/BR(K+ --> munu). A preliminary result of the analysis of a partial data sample of 51089 K+ --> enu candidates is presented.

Evgueni Goudzovski

2010-05-07T23:59:59.000Z

45

CP Violation for Leptons at Higher Energy Scales  

E-Print Network (OSTI)

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.

Cheng-Wei Chiang

2000-11-15T23:59:59.000Z

46

CP Violation for Leptons at Higher Energy Scales  

E-Print Network (OSTI)

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.

Chiang, C W

2001-01-01T23:59:59.000Z

47

Hadronic decays of the tau lepton: Theoretical outlook  

E-Print Network (OSTI)

The structure of the form factors stemmed from the hadronization of QCD currents in the energy region of the resonances can be explored through the analyses of exclusive hadronic decays of the tau lepton. I give a short review on the later theoretical progress achieved in the description of experimental data.

J. Portoles

2007-02-13T23:59:59.000Z

48

The Particle Adventure | What is the world made of? | Lepton type  

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

type conservation type conservation Lepton type conservation Leptons are divided into three lepton families: the electron and its neutrino, the muon and its neutrino, and the tau and its neutrino. We use the terms "electron number," "muon number," and "tau number" to refer to the lepton family of a particle. Electrons and their neutrinos have electron number +1, positrons and their antineutrinos have electron number -1, and all other particles have electron number 0. Muon number and tau number operate analogously with the other two lepton families. One important thing about leptons, then, is that electron number, muon number, and tau number are always conserved when a massive lepton decays into smaller ones. Let's take an example decay.

49

Citation: K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

50

A Zip-code for Quarks, Leptons and Higgs Bosons  

E-Print Network (OSTI)

The location of matter fields and the pattern of gauge symmetry in extra dimensions are crucial ingredients for string model building. We analyze realistic MSSM models from the heterotic Z6 Mini-Landscape and extract those properties that are vital for their success. We find that Higgs bosons and the top quark are not localized in extra dimensions and live in the full D=10 dimensional space-time. The first two families of quarks and leptons, however, live at specific fixed points in extra dimensional space and exhibit a (discrete) family symmetry. Within a newly constructed Z2XZ4 orbifold framework we further elaborate on these location properties and the appearance of discrete symmetries. A similar geometrical picture emerges. This particular Zip-code for quarks, leptons and Higgs bosons seems to be of more general validity and thus a useful guideline for realistic model building in string theory.

Damian Kaloni Mayorga Pena; Hans Peter Nilles; Paul-Konstantin Oehlmann

2012-09-26T23:59:59.000Z

51

Search for Charged Lepton Violation in Narrow Upsilon Decays  

SciTech Connect

Charged lepton flavor violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 10{sup 6} {Upsilon}(2S) decays and 117 x 10{sup 6} {Upsilon}(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions {Beta}({Upsilon}(nS) {yields} e{sup {+-}}{tau}{sup {-+}}) and {Beta}({Upsilon}(nS) {yields} {mu}{sup {+-}}{tau}{sup {-+}}) (n = 2, 3) at the 10{sup -6} level and use these results to place lower limits of order 1 TeV on the mass scale of charged lepton flavor violating effective operators.

Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley; Hawkes, C.M.; /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Columbus Supercond., Genova /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-08-19T23:59:59.000Z

52

Snowmass White Paper CMS Upgrade: Forward Lepton-Photon System  

E-Print Network (OSTI)

This White Paper outlines a proposal for an upgraded forward region to extend CMS lepton (e, mu) and photon physics reach out to 2.2

Bilki, Burak; Onel, Yasar; Winn, David R; Yetkin, Taylan

2013-01-01T23:59:59.000Z

53

Search for the Lepton-Number-Violating Decay $?^- \\to p ?^- ?^-$  

E-Print Network (OSTI)

A sensitive search for the lepton-number-violating decay $\\Xi^-\\to p \\mu^-\\mu^-$ has been performed using a sample of $\\sim10^9$ $\\Xi^-$ hyperons produced in 800 GeV/$c$ $p$-Cu collisions. We obtain $\\mathcal{B}(\\Xi^-\\to p \\mu^-\\mu^-)< 4.0\\times 10^{-8}$ at 90% confidence, improving on the best previous limit by four orders of magnitude.

HyperCP Collaboration; D. Rajaram; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. -S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. D. Jones; D. M. Kaplan; M. J. Longo; L. C. Lu; W. Luebke; K. -B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla

2005-05-12T23:59:59.000Z

54

MEASURING LEPTONIC CP VIOLATION WITH A WATER CERENKOV  

E-Print Network (OSTI)

In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case ?13 ? 3 ? (the limit that can be reached by under-construction experiments), the signal-to-background rate for a ?-beam setup with the radioactive ions accelerated to ? = 350. 1

E. Couce

2006-01-01T23:59:59.000Z

55

Electroweak Penguin and Leptonic Decays at BaBar  

SciTech Connect

Recent BABAR results on electroweak penguin and leptonic decays are reviewed. In particular, the measurements of B {yields} K{sup (*)}l{sup +}l{sup -} and the preliminary results on B {yields} X{sub s}l{sup +}l{sup -} are presented. Also summarized are the preliminary limits on B{sup +} {yields} l{sup +}{nu} (l = e,{mu}) and B{sup +} {yields} K{sup +}{nu}{bar {nu}}.

Bucci, F.; /Pisa U. /INFN, Pisa

2005-08-26T23:59:59.000Z

56

Scaling quark gluon plasma by HBT interferometry with lepton pairs  

E-Print Network (OSTI)

We study the intensity interferometry with lepton pairs for nuclear collisions at RHIC and LHC energies. It is argued that the invariant mass dependence of HBT radii extracted from the correlation functions of dilepton pairs can be used as an efficient tool to scale the size and life time of the quark gluon plasma expected to be formed in nuclear collisions at RHIC and LHC. Quantitatively different magnitudes of HBT radii are obtained at RHIC and LHC indicating stronger radial flow at LHC.

Payal Mohanty; Jan-e Alam

2012-02-10T23:59:59.000Z

57

Nuclear PDF for neutrino and charged lepton data  

SciTech Connect

Neutrino Deep Inelastic Scattering (DIS) on nuclei is an essential process to constrain the strange quark parton distribution functions (PDF) in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions (NPDF). Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton (l{sup {+-}A}) Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors (F{sub 2}{sup Fe}/F{sub 2}{sup D}) for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

Kovarik, K. [Institute for Theoretical Physics, Karlsruhe Institute of Technology, Karlsruhe, D-76128 (Germany)

2011-10-06T23:59:59.000Z

58

Calorimetry for Lepton Collider Experiments - CALICE results and activities  

E-Print Network (OSTI)

The CALICE collaboration conducts calorimeter R&D for highly granular calorimeters, mainly for their application in detectors for a future lepton collider at the TeV scale. The activities ranges from generic R&D with small devices up to extensive beam tests with prototypes comprising up to several 100000 calorimeter cells. CALICE has validated the performance of particle flow algorithms with test beam data and delivers the proof of principle that highly granular calorimeters can be built, operated and understood. The successes achieved in the past years allows the step from prototypes to calorimeter systems for particle physics detectors to be addressed.

The CALICE Collaboration

2012-12-20T23:59:59.000Z

59

Searches for Leptonic B Decays at BaBar  

SciTech Connect

Measurements of the branching fractions of purely leptonic decays of B-mesons translate into constraints in the plane of the charged Higgs mass versus tan {beta} which are relatively insensitive to the particular theoretical model. Using the full BABAR dataset of 450 million B-decays we search for these decays. No significant signal is found in the decays into electrons or muons and we set upper limits on the branching fractions of the order of a 10{sup -6} at 90% confidence level. We measure the branching fraction of B {yields} {tau}{mu} to be (1.7 {+-} 0.6) x 10{sup -4}.

Nelson, Silke; /SLAC

2012-04-25T23:59:59.000Z

60

Search for the Rare Leptonic Decays B^+ \\to l^+ \  

SciTech Connect

We have performed a search for the rare leptonic decays B{sup +} {yields} {ell}{sup +} {nu}{sub {ell}}({ell} = e,{mu}), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468 x 10{sup 6} B{bar B} pairs we find no evidence for a signal and set an upper limit on the branching fractions B(B{sup +} {yields} e{sup +}{nu}{sub e}) < 1.9 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.

Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2009-06-19T23:59:59.000Z

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


61

Measuring Leptonic CP Violation with a Water Cerenkov  

E-Print Network (OSTI)

In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case $\\theta_{13} \\approx 3^\\circ$ (the limit that can be reached by under-construction experiments), the signal-to-background rate for a $\\beta$-beam setup with the radioactive ions accelerated to $\\gamma = 350$.

E. Couce

2006-07-01T23:59:59.000Z

62

Charged lepton electric dipole moments with the localized leptons and the new Higgs doublet in the two Higgs doublet model  

E-Print Network (OSTI)

We study the lepton electric dipole moments in the split fermion scenario, in the two Higgs doublet model, where the new Higgs scalars are localized around the origin in the extra dimension, with the help of the localizer field. We observe that the numerical value of the electron (muon, tau) electric dipole moment is at the order of the magnitude of 10^{-31} (10^{-24}, 10^{-22}) (e-cm) and this quantity is sensitive the new Higgs localization in the extra dimension.

Erhan Onur Iltan

2005-11-20T23:59:59.000Z

63

Cosmological lepton asymmetry with a nonzero mixing angle $\\theta_{13}$  

E-Print Network (OSTI)

While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of the latest cosmological data, taking into account the effect of flavor oscillations. We present our results for two different values of the neutrino mixing angle \\theta_{13}, and show that for large \\theta_{13} the limits on the total neutrino asymmetry become more stringent, diluting even large initial flavor asymmetries. In particular, we find that the present bounds are still dominated by the limits coming from Big Bang Nucleosynthesis, while the limits on the total neutrino mass from cosmological data are essentially independent of \\theta_{13}. Finally, we perform a forecast for COrE, taken as an example of a future CMB experiment, and find that it could improve the limits on the total lepton asymmetry approximately by up to a factor 5.

Castorina, Emanuele; Lattanzi, Massimiliano; Lesgourgues, Julien; Mangano, Gianpiero; Melchiorri, Alessandro; Pastor, Sergio

2012-01-01T23:59:59.000Z

64

Polarization Effects In The Charged Lepton Pair Production By A Neutrino (Antineutrino) In A Magnetic Field  

Science Conference Proceedings (OSTI)

The probability of the process of the charged lepton pair production by a neutrino (an antineutrino) with allowance for the longitudinal and transverse polarizations of the charged leptons in a magnetic field is presented. The dependence of the probability of the process on the spin variables of the charged leptons and on the azimuthal and polar angles of the initial and final neutrinos (antineutrinos) are investigated. It is shown that the probability of the process is sensitive to the spin variables of the charged leptons and to the direction of the neutrino (antineutrino) momentum. It is determined that the neutrino (antineutrino) energy and momentum loss through the production of a charged lepton pair happens asymmetrically.

Huseynov, Vali A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Ahmad, Ali S. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

2007-06-13T23:59:59.000Z

65

Neutrino masses and heavy triplet leptons at the LHC: Testability of the type III seesaw mechanism  

Science Conference Proceedings (OSTI)

We study LHC signatures of the type III seesaw mechanism in which SU(2){sub L} triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model particles which depend on how light and heavy leptons mix with each other. We concentrate on the usual solutions with small light and heavy lepton mixing of the order of the square root of the ratio of light and heavy masses, (m{sub {nu}}/M{sub {nu}}{sub {sub R}}){sup 1/2}. This class of solutions can lead to a visible displaced vertex detectable at the LHC which can be used to distinguish small mixing and large mixing between light and heavy leptons. We show that, in this case, the couplings of light and heavy triplet leptons to gauge and Higgs bosons, which determine the decay widths and branching ratios, can be expressed in terms of light neutrino masses and their mixing. Using these relations, we study heavy triplet lepton decay patterns and production cross section at the LHC. If these heavy triplet leptons are below a TeV or so, they can be easily produced at the LHC due to their gauge interactions from being nontrivial representations of SU(2){sub L}. We consider two ideal production channels, (1) E{sup +}E{sup -}{yields}l{sup +}l{sup +}l{sup -}l{sup -}jj (l=e, {mu}, {tau}) and (2) E{sup {+-}}N{yields}l{sup {+-}}l{sup {+-}}jjjj in detail. For case 1, we find that with one or two of the light leptons being {tau} it can also be effectively studied. With judicious cuts at the LHC, the discovery of the heavy triplet leptons as high as a TeV can be achieved with 100 fb{sup -1} integrated luminosity.

Li Tong [Center for High Energy Physics, Peking University, Beijing, 100871 (China); He Xiaogang [Center for High Energy Physics, Peking University, Beijing, 100871 (China); Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China)

2009-11-01T23:59:59.000Z

66

Searches for new quarks and leptons in Z boson decays  

SciTech Connect

Searches for the decay of Z bosons into pairs of new quarks and leptons in a data sample including 455 hadronic Z decays are presented. The Z bosons were produced in electon-positron annihilations at the SLAC Linear Collider operating in the center-of-mass energy range from 89.2 to 93.0 GeV. The Standard Model provides no prediction for fermion masses and does not exclude new generations of fermions. The existence and masses of these new particles may provide valuable information to help understand the pattern of fermion masses, and physics beyond the Standard Model. Specific searches for top quarks and sequential fourth generation charge--1/3(b{prime}) quarks are made considering a variety of possible standard and non-standard decay modes. In addition, searches for sequential fourth generation massive neutrinos {nu}{sub 4} and their charged lepton partners L{sup {minus}} are pursued. The {nu}{sub 4} may be stable or decay through mixing to the lighter generations. The data sample is examined for new particle topologies of events with high-momentum isolated tracks, high-energy isolated photons, spherical event shapes, and detached vertices. No evidence is observed for the production of new quarks and leptons. 95% confidence lower mass limits of 40.7 GeV/c{sup 2} for the top quark and 42.0 GeV/c{sup 2} for the b{prime}-quark mass are obtained regardless of the branching fractions to the considered decay modes. A significant range of mixing matrix elements of {nu}{sub 4} to other generation neutrinos for a {nu}{sub 4} mass from 1 GeV/c{sup 2} to 43 GeV/c{sup 2} is excluded at 95% confidence level. Measurements of the upper limit of the invisible width of the Z exclude additional values of the {nu}{sub 4} mass and mixing matrix elements, and also permit the exclusion of a region in the L{sup {minus}} mass versus {nu}{sub 4} mass plane.

Van Kooten, R.J.

1990-06-01T23:59:59.000Z

67

Lepton Mixing Predictions from Delta(6n^2) Family Symmetry  

E-Print Network (OSTI)

We obtain predictions of lepton mixing parameters for direct models based on Delta(6n^2) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Delta(6n^2), we find many new candidates for large n able to yield reactor angle predictions within 3 sigma of recent global fits. We show that such Delta(6n^2) models with Majorana neutrinos predict trimaximal mixing with reactor angle theta_{13} fixed up to a discrete choice, an oscillation phase of either zero or pi and the atmospheric angle sum rules theta_{23}=45 degrees -/+ theta_{13}/sqrt{2}, respectively, which are consistent with recent global fits and will be tested in the near future.

King, Stephen F; Stuart, Alexander J

2013-01-01T23:59:59.000Z

68

Lepton Mixing Predictions from Delta(6n^2) Family Symmetry  

E-Print Network (OSTI)

We obtain predictions of lepton mixing parameters for direct models based on Delta(6n^2) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Delta(6n^2), we find many new candidates for large n able to yield reactor angle predictions within 3 sigma of recent global fits. We show that such Delta(6n^2) models with Majorana neutrinos predict trimaximal mixing with reactor angle theta_{13} fixed up to a discrete choice, an oscillation phase of either zero or pi and the atmospheric angle sum rules theta_{23}=45 degrees -/+ theta_{13}/sqrt{2}, respectively, which are consistent with recent global fits and will be tested in the near future.

Stephen F. King; Thomas Neder; Alexander J. Stuart

2013-05-14T23:59:59.000Z

69

Lepton flavour violating Higgs and tau to mu gamma  

E-Print Network (OSTI)

We update phenomenological constraints on a Two Higgs Doublet Model with lepton flavour non-conserving Yukawa couplings. We review that $\\tan \\beta$ is ambiguous in such "Type III" models, and define it from the $\\tau$ Yukawa coupling. The neutral scalars $\\phi$ could be searched for at hadron colliders in $ \\phi \\to \\tau \\bar{\\mu}$, and are constrained by the rare decay $\\tau \\to \\mu \\gamma$. The Feynman diagrams for the collider process, with Higgs production via gluon fusion, are similar to the two-loop "Barr-Zee" diagrams which contribute to $\\tau \\to \\mu \\gamma$. Some "tuning" is required to obtain a collider cross-section of order the Standard Model expectation for $\\sigma (gg \\to h_{SM} \\to \\tau^+ \\tau^-)$, while agreeing with the current bound from $\\tau \\to \\mu \\gamma$.

Sacha Davidson; Gerald Grenier

2010-01-04T23:59:59.000Z

70

PDF Nuclear Corrections for Charged Lepton and Neutrino Deep Inelastic Scattering Processes  

E-Print Network (OSTI)

We perform a \\chi^2-analysis of Nuclear Parton Distribution Functions (NPDFs) using neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets. The nuclear A dependence of the NPDFs is extracted in a next-to-leading order fit. We compare the nuclear corrections factors F2(Fe)/F2(D) for this charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

I. Schienbein; J. Y. Yu; K. Kovarik; C. Keppel; J. G. Morfin; F. Olness; J. F. Owens

2009-07-14T23:59:59.000Z

71

Unconventional fermions: The Price of Quark-Lepton Unification at TeV Scales  

E-Print Network (OSTI)

The early petite unification (PUT) of quarks and leptons at TeV scales with sin^2 theta_W(M^2_Z) used as a constraint, necessitates the introduction of extra quarks and leptons with unconventional electric charges (up to 4/3 for the quarks and 2 for the leptons). This talk, in honor of Paul Frampton's 60th birthday, will be devoted to the motivation and construction of models of early unification and to their implications, including the issues of rare decays and unconventional fermions.

P. Q. Hung

2004-06-23T23:59:59.000Z

72

REVIEW OF HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* Martin L. Per1  

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

HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* Martin L. Per1 Stanford Linear Accelerator Center Stanford University, Stanford, California 94305 ABSTRACT * The existing data on e f p r , eixT, p xi:, and related events produced in e'e- annihilation are reviewed. All data are consistent with the exist- ence of a new charged lepton, T *, of m a s s 1.9 * . 1 GeV/c2. (Invited talk presented at the 1977 International Symposium on Lepton and Photon Interactions at High Energies, Hambrug, Cfirmany, August 25-31 , 1977.) *Work supported by the Department of Energy. NOTICE-- rpon.wred by the United States Government. Netther the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, Subcontractors, or thou employees. makes

73

Higgs boson decay into heavy quarks and heavy leptons: higher order corrections  

E-Print Network (OSTI)

Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_HHiggs boson into bb and tau+tau- are discussed.

Kim, Victor T

2010-01-01T23:59:59.000Z

74

Yukawaon Model with Anomaly Free Set of Quarks and Leptons in a U(3) Family Symmetry  

E-Print Network (OSTI)

In the so-called "yukawaon" model, the (effective) Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (yukawaons) with $3\\times 3$ components. So far, yukawaons $Y_f$ have been assigned to ${\\bf 6}$ or ${\\bf 6}^*$ of U(3) family symmetry, so that quarks and leptons were not anomaly free in U(3). In this paper, yukawaons are assigned to ${\\bf 8}+{\\bf 1}$ of U(3), so that quarks and leptons are anomaly free. Since VEV relations among yukawaons are also considerably changed, parameter fitting of the model is renewed. After fixing our free parameters by observed mass ratios, we have only two and one remaining free parameters for quark and lepton mixings, respectively. We obtain successful predictions for the quark and lepton mixing parameters including magnitudes of $CP$ violation. The effective Majorana neutrino mass is also predicted.

Yoshio Koide; Hiroyuki Nishiura

2013-08-09T23:59:59.000Z

75

Selection of tau leptons with the CDF Run 2 trigger system  

SciTech Connect

We have implemented triggers for hadronically decaying tau leptons within a framework of the CDF Run 2 trigger system. We describe the triggers, along with their physics motivations, and report on their initial performance.

A. Anastassov; S. Baroiant; M. Chertok

2003-07-01T23:59:59.000Z

76

The energy spectrum of tau leptons induced by the high energy Earth-skimming neutrinos  

E-Print Network (OSTI)

We present a semi-analytic calculation of the tau-lepton flux emerging from the Earth, induced by the incident high energy neutrinos interacting inside the Earth for $10^{5} \\leq E_{\

J. -J. Tseng; T. -W. Yeh; H. Athar; M. A. Huang; F. -F. Lee; G. -L. Lin

2003-05-27T23:59:59.000Z

77

Test of Lepton Flavour Universality in K+ --> l+nu Decays  

E-Print Network (OSTI)

A precision test of lepton flavour universality has been performed by measuring the ratio RK of kaon leptonic decay rates K+ --> e+nu and K+ --> mu+nu in a sample of 59813 reconstructed K+ --> e+nu candidates with (8.71 +- 0.24)% background contamination. The result RK = (2.487 +- 0.013) * 10^{-5} is in agreement with the Standard Model expectation.

C. Lazzeroni et al.

2011-01-25T23:59:59.000Z

78

Physical model of leptons : Massive electrons, muons, tauons and their massless neutrons  

E-Print Network (OSTI)

The physical model (PhsMdl) of the leptons is offered by means of the PhsMdls of the vacuum and electron,described in our recent works. It is assumed that the vacuum is consistent by dynamides, streamlined in junctions of some tight crystalline lattice. Every dynamide contains a neutral pair of massless point-like (PntLk) contrary elementary electric charges (ElmElcChrgs): electrino $(-)$ and positrino $(+)$. The PntLk ElmElcChrgs of the massless electrino and positrino of some dynamide in the fluctuated vacuum may been excited or deviated by means of some energy, introduced by some photon or other micro particles (MicrPrts). The massless leptons (neutrinos) are neutral long-living solitary spherical vortical oscillation excitations of the uncharged fluctuating vacuum. The massive leptons are charged long-living solitary spherical vortical excitations of its fine spread (FnSpr) elementary electric charge (ElmElcChrg). So-called zitterbewegung is self-consistent strong-correlated vortical harmonic oscillation motion of the FnSpr ElmElcChrg of massive leptons. Different leptons have different self-consistent strong-correlated vortical harmonic oscillation motion of different sizes of their FnSpr ElmElcChrg, which is determined by their Kompton length $\\lambda =\\frac{h}{m C} $, where $m$ is the mass of the massive leptons. At mutual transition of one massive lepton into another massive lepton its PntLk ElmElcChrg move up by dint of weak interaction in the form of the charged intermediate vector meson $W$ from one self-consistent strong-correlated vortical harmonic oscillation motion of one size into another self-consistent strong-correlated vortical harmonic oscillation motion of another size.

Josiph Mladenov Rangelov

2000-03-07T23:59:59.000Z

79

Lepton Flavor Violation in Predictive Supersymmetric GUT Models  

E-Print Network (OSTI)

There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially $\\sin^2 2\\theta_{13}$, are obtained, charged lepton flavor violation (LFV) experiments are able to differentiate even further among the models. In this paper, we investigate various rare LFV processes, such as $\\ell_{i} \\to \\ell_{j} + \\gamma$ and $\\mu-e$ conversion, in five predictive supersymmetric (SUSY) SO(10) models and their allowed soft-SUSY breaking parameter space in the constrained minimal SUSY standard model. Utilizing the Wilkinson Microwave Anisotropy Probe dark matter constraints, we obtain lower bounds on the branching ratios of these rare processes and find that at least three of the five models we consider give rise to predictions for $\\mu \\to e + \\gamma$ that will be tested by the MEG Collaboration at PSI. In addition, the next generation $\\mu-e$ conversion experiment has sensitivity to the predictions of all five models, making it an even more robust way to test these models. While generic studies have emphasized the dependence of the branching ratios of these rare processes on the reactor neutrino angle $\\theta_{13}$ and the mass of the heaviest right-handed neutrino $M_3$, we find very massive $M_3$ is more significant than large $\\theta_{13}$ in leading to branching ratios near to the present upper limits.

Carl H. Albright; Mu-Chun Chen

2008-02-28T23:59:59.000Z

80

Measurement of Cabibbo suppressed decays of the $\\tau$ lepton  

E-Print Network (OSTI)

Branching ratios for the dominant Cabibbo-suppressed decays of the \\tau lepton have been measured by CLEO~II in e^+ e^- annihilation at CESR (\\sqrt{s} \\sim 10.6~GeV) using kaons with momenta below 0.7\\ \\rm GeV/c. The inclusive branching ratio into one charged kaon is (1.60 \\pm 0.12 \\pm 0.19)\\%. For the exclusive decays, B(\\tau \\to K^-) = (0.66 \\pm 0.07 \\pm 0.09)\\%, B(\\tau \\to K^- \\pi^0) = (0.51 \\pm 0.10 \\pm 0.07)\\%, and, based on three events, B(\\tau \\to K^- \\pi^0 \\pi^0) < 0.3\\% at the 90\\% confidence level. These represent significant improvements over previous results. B(\\tau\\to K^- \\pi^0) is measured for the first time with exclusive \\pi^0 reconstruction. hardcopies with figures can be obtained by writing to: Pam Morehouse preprint secretary Newman Lab Cornell University Ithaca, NY 14853 or by sending mail to: preprints@lns62.lns.cornell.edu

Battle, M; Kwon, Y; Roberts, S; Thorndike, E H; Wang, C H; Dominick, J; Lambrecht, M; Sanghera, S; Shelkov, V; Skwarnicki, T; Stroynowski, R; Volobuev, I P; Wei, G; Zadorozhny, P; Artuso, M; Goldberg, M; He, D; Horwitz, N; Kennett, R; Mountain, R; Moneti, G C; Muheim, F; Mukhin, Y; Playfer, S; Rozen, Y; Stone, S; Thulasidas, M; Vasseur, G; Zhu, G; Bartelt, J; Csorna, S E; Egyed, Z; Jain, V; Kinoshita, K; Edwards, K W; Ogg, M; Britton, D I; Hyatt, E R F; MacFarlane, D B; Patel, P M; Akerib, D S; Barish, B C; Chadha, M; Chan, S; Cowen, D F; Eigen, G; Miller, J S; O'Grady, C; Urheim, J; Weinstein, A J; Acosta, D; Athanas, M; Masek, G E; Paar, H P; Sivertz, M; Gronberg, J B; Kutschke, R; Menary, S R; Morrison, R J; Nakanishi, S; Nelson, H N; Nelson, T K; Qiao, C; Richman, J D; Ryd, A; Tajima, H; Sperka, D; Witherell, M S; Procario, M; Balest, R; Cho, K; Daoudi, M; Ford, W T; Johnson, D R; Lingel, K; Lohner, M; Rankin, P; Smith, J G; Alexander, J P; Bebek, C; Berkelman, K; Bloom, K; Browder, T E; Cassel, David G; Cho, H A; Coffman, D M; Drell, P S; Ehrlich, R; Gaidarev, P B; Galik, R S; Garca-Sciveres, M; Geiser, B; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Jones, C D; Jones, S L; Kandaswamy, J; Katayama, N; Kim, P C; Kreinick, D L; Ludwig, G S; Masui, J; Mevissen, J; Mistry, N B; Ng, C R; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Salman, S; Sapper, M; Wrthwein, F; Avery, P; Freyberger, A P; Rodrguez, J; Stephens, R; Yang, S; Yelton, J; Cinabro, D; Henderson, S; Liu, T; Saulnier, M; Wilson, R; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Gollin, G; Ong, B; Palmer, M; Selen, M; Thaler, J J; Sadoff, A J; Ammar, R; Ball, S; Baringer, P; Bean, A; Besson, D; Coppage, D; Copty, N K; Davis, R; Hancock, N; Kelly, M; Kwak, N; Lam, H; Kubota, Y; Lattery, M; Nelson, J K; Patton, S; Perticone, D; Poling, R A; Savinov, V; Schrenk, S; Wang, R; Alam, M S; Kim, I J; Nemati, B; O'Neill, J J; Severini, H; Sun, C R; Zoeller, M M; Crawford, G; Daubenmier, C M; Fulton, R; Fujino, D; Gan, K K; Honscheid, K; Kagan, H; Kass, R; Lee, J; Malchow, R L; Skovpen, Y; Sung, M; White, C; Butler, F; Fu, X; Kalbfleisch, G R; Ross, W R; Skubic, P L; Snow, J; Wang, P L; Wood, M; Brown, D N; Fast, J; McIlwain, R L; Miao, T; Miller, D H; Modesitt, M; Payne, D; Shibata, E I; Shipsey, I P J; Wang Pei Ning

1994-01-01T23:59:59.000Z

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81

Lepton Flavor Violation in Predictive SUSY-GUT Models  

SciTech Connect

There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially sin{sup 2} 2{theta}{sub 13}, are obtained, charged lepton flavor violation (LFV) experiments are able to differentiate even further among the models. In this paper, they investigate various rare LFV processes, such as {ell}{sub i} {yields} {ell}{sub j} + {gamma} and {mu} - e conversion, in five predictive SUSY SO(10) models and their allowed soft SUSY breaking parameter space in the constrained minimal SUSY standard model (CMSSM). Utilizing the WMAP dark matter constraints, they obtain lower bounds on the branching ratios of these rare processes and find that at least three of the five models they consider give rise to predictions for {mu} {yields} e + {gamma} that will be tested by the MEG collaboration at PSI. in addition, the next generation {mu} - e conversion experiment has sensitivity to the predictions of all five models, making it an even more robust way to test these models. While generic studies have emphasized the dependence of the branching ratios of these rare processes on the reactor neutrino angle, {theta}{sub 13}, and the mass of the heaviest right-handed neutrino, M{sub 3}, they find very massive M{sub 3} is more significant than large {theta}{sub 13} in leading to branching ratios near to the present upper limits.

Albright, Carl H.; /Northern Illinois U. /Fermilab; Chen, Mu-Chun; /UC, Irvine

2008-02-01T23:59:59.000Z

82

Searches for the baryon- and lepton-number violating decays B[superscript 0]-->Lambda c+l-, B--->Lambda l-, and B--->Lambda[over-bar] l- l-  

E-Print Network (OSTI)

Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either ?c or ? and the lepton is a muon or an electron. These decays violate both baryon and lepton number ...

Cowan, Ray Franklin

83

Search for anomalous production of multiple leptons in association with $W$ and $Z$ bosons at CDF  

Science Conference Proceedings (OSTI)

This paper presents a search for anomalous production of multiple low-energy leptons in association with a W or Z boson using events collected at the CDF experiment corresponding to 5.1 fb{sup -1} of integrated luminosity. This search is sensitive to a wide range of topologies with low-momentum leptons, including those with the leptons near one another. The observed rates of production of additional electrons and muons are compared with the standard model predictions. No indications of phenomena beyond the standard model are found. A 95% confidence level limit is presented on the production cross section for a benchmark model of supersymmetric hidden-valley Higgs production. Particle identification efficiencies are also provided to enable the calculation of limits on additional models.

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

2012-02-01T23:59:59.000Z

84

On the origin of families of quarks and leptons - predictions for four families  

E-Print Network (OSTI)

The approach unifying all the internal degrees of freedom--proposed by one of us--is offering a new way of understanding families of quarks and leptons: A part of the starting Lagrange density in d(=1+13), which includes two kinds of spin connection fields--the gauge fields of two types of Clifford algebra objects--transforms the right handed quarks and leptons into the left handed ones manifesting in d=1+3 the Yukawa couplings of the Standard model. We study the influence of the way of breaking symmetries on the Yukawa couplings and estimate properties of the fourth family--the quark masses and the mixing matrix, investigating the possibility that the fourth family of quarks and leptons appears at low enough energies to be observable with the new generation of accelerators.

G. Bregar; M. Breskvar; D. Lukman; N. S. Mankoc Borstnik

2007-08-21T23:59:59.000Z

85

Spin Asymmetries Arising In Neutrino-Lepton Processes In A Magnetic Field And Their Macroscopic Appearance  

Science Conference Proceedings (OSTI)

We present expressions that determine the differential cross sections and energy and momentum losses for the neutrino-lepton processes {nu}le- {yields} {nu}le-, {nu}-tildele- {yields} {nu}-tildele-, {nu}l{nu}-tildel {yields} e-e+, {nu}l{nu}-tildee {yields} l-e+, {nu}le- {yields} {nu}el- in a magnetic field with allowance for the longitudinal and transverse polarizations of the charged leptons and antileptons and the results on the spin asymmetries arising in these processes.

Huseynov, Vali A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Gasimova, Rasmiyya E.; Akbarova, Nurida Y.; Hajiyeva, Billura T. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

2007-06-13T23:59:59.000Z

86

Exploring anomalous top interactions via the final lepton in ttbar productions/decays at hadron colliders  

E-Print Network (OSTI)

We study momentum distributions of the final-state charged lepton in ppbar/pp --> ttbar --> l^+ X (l=e or mu) at hadron colliders, i.e., Tevatron and Large Hadron Collider (LHC) in order to explore possible new-physics effects in the top-quark sector. Assuming general model-independent ttbar g + ttbar gg and tbW interactions beyond the standard model, we first derive analytical formulas for the corresponding parton-parton processes. We then compute the lepton angular, energy and transverse-momentum distributions in ppbar/pp collisions to clarify how they are affected by those anomalous couplings.

Zenro HIOKI; Kazumasa OHKUMA

2011-04-07T23:59:59.000Z

87

Neutrinos and Lepton Flavour Violation in the Left-Right Twin Higgs Model  

E-Print Network (OSTI)

We analyse the lepton sector of the Left-Right Twin Higgs Model. This model offers an alternative way to solve the "little hierarchy" problem of the Standard Model. We show that one can achieve an effective see-saw to explain the origin of neutrino masses and that this model can accommodate the observed neutrino masses and mixings. We have also studied the lepton flavour violation process l_1 -> l_2 \\gamma and discussed how the experimental bound from these branching ratios constrains the scale of symmetry breaking of this Twin Higgs model.

Asmaa Abada; Irene Hidalgo

2007-11-08T23:59:59.000Z

88

Implications of texture 4 zero lepton mass matrices for U_{e3}  

E-Print Network (OSTI)

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \\Delta m_{12}^2 constrained by SNP and s_{23} and \\Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\

Randhawa, M; Sen-Gupta, M; Randhawa, Monika; Ahuja, Gulsheen; Gupta, Manmohan

2002-01-01T23:59:59.000Z

89

Implications of texture 4 zero lepton mass matrices for U_{e3}  

E-Print Network (OSTI)

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \\Delta m_{12}^2 constrained by SNP and s_{23} and \\Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\

Monika Randhawa; Gulsheen Ahuja; Manmohan Gupta

2002-03-12T23:59:59.000Z

90

Origin of quark-lepton flavor in SO(10) with type II seesaw mechanism  

SciTech Connect

Diverse mass and mixing patterns between the quarks and leptons makes it challenging to construct a simple grand unified theory of flavor. We show that SO(10) supersymmetry grand unified theories with type II seesaw mechanism giving neutrino masses provide a natural framework for addressing this issue. A simple ansatz that the dominant Yukawa matrix (the 10-Higgs coupling to matter) has rank one appears to simultaneously explain both the large lepton mixings as well as the observed quark flavor hierarchy in these models. A testable prediction of this ansatz is the neutrino mixing, U{sub e3}, which should be observable in planned long baseline experiments.

Dutta, Bhaskar [Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Mimura, Yukihiro; Mohapatra, R. N. [Maryland Center for Fundamental Physics and Department of Physics, University of Maryland, College Park, Maryland, 20742 (United States)

2009-11-01T23:59:59.000Z

91

NMSSM in disguise: Discovering singlino dark matter with soft leptons at the LHC  

E-Print Network (OSTI)

, cuts on lepton transverse momentum of even 10 GeV will remove the wast majority of events for points BE, and hence remove the one remaining clue to the non-minimal nature of the scenario. However, one should also notice that the distributions have... benchmark point, corresponding to 10 fb?1 of data. For the SM background we have generated a wide variety of samples that in addition to two, possibly soft, OSSF isolated leptons at low invariant mass, could potentially yield the hard jets and missing energy...

Kraml, S; Raklev, Are R; White, Martin J

92

Search for quark-lepton compositeness in the dimuon final state at D0  

SciTech Connect

We used the upgraded D0 detector at the Tevatron at {radical}s = 1.96 TeV to collect data in a search for a compositeness signature of quarks and leptons. This analysis uses an integrated luminosity of 400 pb{sup -1}. The high-mass dimuon mass spectrum is compared with that predicted by Drell-Yan (DY) scattering, modified by a contact interaction. This interaction is parameterized by a compositeness energy scale factor {Lambda}. Preliminary limits on {lambda} are set at the 95% confidence level for constructive and destructive interference between the DY amplitude and the contact interaction for various quark and lepton chiralities.

Xuan, Nguyen Phuoc; /Notre Dame U.

2005-01-01T23:59:59.000Z

93

Energy-Scale Dependence of the Lepton-Flavor-Mixing Matrix hep-ph/9904292  

E-Print Network (OSTI)

We study an energy-scale dependence of the lepton-flavor-mixing matrix in the minimal supersymmetric standard model with the effective dimension-five operators which give the masses of neutrinos. We analyze the renormalization group equations of ?ijs which are coefficients of these effective operators under the approximation to neglect the corrections of O(?2). As a consequence, we find that all phases in ? do not depend on the energy-scale, and that only ng ? 1 (ng: generation number) real independent parameters in the lepton-flavor-mixing matrix depend on the energyscale.

N. Haba; Y. Matsui; N. Okamura; M. Sugiura

1999-01-01T23:59:59.000Z

94

Early Discoveries of New Gauge Bosons W' and Z' in Leptonic Decay Channels at ATLAS  

E-Print Network (OSTI)

We present the potential of the ATLAS detector to discover new massive gauge bosons in their leptonic decay channels: W' -> l nu_l and Z' -> l+ l-. Emphasis is placed on early data-taking at the LHC with low luminosity (up to 1 fb^-1).

E. N. Thompson; for the ATLAS Collaboration

2008-10-16T23:59:59.000Z

95

Search for [ital B][sup 0] decays to two charged leptons  

Science Conference Proceedings (OSTI)

We have searched for [ital B][sup 0] decays to two charged leptons and set 90% confidence level upper limits on the branching fractions: [ital B]([ital B][sup 0][r arrow][ital e][sup +][ital e][sup [minus

Ammar, R.; Ball, S.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Patton, S.; Perticone, D.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; O'Neill, J.J.; Severini, H.; Sun, C.R.; Zoeller, M.M.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Skovpen, Y.; Sung, M.; White, C.; Butler, F.; Fu, X.; Kalbfleisch, G.; Ross, W.R.; Skubic, P.; Snow, J.; Wang, P.L.; Wood, M.; Brown, D.N.; Fast, J.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Dominick, J.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Zadorozhny, P.; Artuso, M.; Goldberg, M.; He, D.; Horwitz, N.; Kennett, R.; M; (CLEO Collaboration)

1994-06-01T23:59:59.000Z

96

Search for the rare leptonic decays B+-->l+ nu l (l=e,mu)  

E-Print Network (OSTI)

We have performed a search for the rare leptonic decays B+-->?+nu ?(l=e,mu), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468106 BB[over-bar] pairs we find ...

Zhao, M.

97

Inclusive Higgs Boson Searches in Four-Lepton Final States at the LHC  

E-Print Network (OSTI)

The inclusive search for the Standard Model Higgs boson in four-lepton final states with the ATLAS and CMS detectors at the LHC pp collider is presented. The discussion focusses on the H-> ZZ^(*)->4l+X decay mode for a Higgs boson in the mass range 120 ~Higgs boson properties is also given.

Evelyne Delmeire

2007-05-15T23:59:59.000Z

98

Novel inclusive search for the Higgs boson in the four-lepton final state at CDF  

E-Print Network (OSTI)

An inclusive search for the standard model Higgs boson using the four-lepton final state in proton-antiproton collisions produced by the Tevatron at ?s=1.96??TeV is conducted. The data are recorded by the CDF II detector ...

Gomez-Ceballos, Guillelmo

99

Search for narrow resonances in the lepton final state at CMS  

E-Print Network (OSTI)

We discuss the results of searches for high-mass narrow resonances decaying into pairs of leptons using pp collisions at 7 TeV delivered by LHC and collected with the CMS detector in 2010 and 2011. These include searches for the Z' bosons and RS gravitons.

Gennadiy Kukartsev; for the CMS Collaboration

2011-10-13T23:59:59.000Z

100

Search for narrow resonances in the lepton final state at CMS  

E-Print Network (OSTI)

We discuss the results of searches for high-mass narrow resonances decaying into pairs of leptons using pp collisions at 7 TeV delivered by LHC and collected with the CMS detector in 2010 and 2011. These include searches for the Z' bosons and RS gravitons.

Kukartsev, Gennadiy

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "leptons leptons leptons" from the National Library of EnergyBeta (NLEBeta).
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101

Measurement of the top quark pair production cross section in the dilepton channel using lepton+track selection  

SciTech Connect

The production cross section for t{bar t} pairs decaying into two lepton final states was measured using data from the D0 detector at Fermilab. The measurement was made using a lepton+track selection, where one lepton is fully identified and the second lepton is observed as an isolated track. This analysis is designed to complement similar studies using two fully identified leptons [1]. The cross section for the lepton+track selection was found to be {sigma} = 5.2{sub -1.4}{sup +1.6}(stat){sub -0.8}{sup +0.9}(syst) {+-} 0.3(lumi) pb. The combined cross section using both the lepton+track data and the data from the electron+electron, electron+muon, and muon+muon samples is: {sigma} = 6.4{sub -0.9}{sup +0.9}(stat){sub -0.7}{sup +0.8}(syst) {+-} 0.4(lumi) pb.

Wagner, Robert Emil; /Princeton U.

2008-09-01T23:59:59.000Z

102

Electric dipole moments of charged leptons in the split fermion scenario in the two Higgs doublet model  

E-Print Network (OSTI)

We predict the charged lepton electric dipole moments in the split fermion scenario in the framework of the two Higgs doublet model. We observe that the numerical value of the muon (tau) electric dipole moment is at the order of the magnitude of $10^{-22} (e-cm)$ ($10^{-20} (e-cm)$) and there is an enhancement in the case of two extra dimensions, especially for the tau lepton electric dipole moment.

E. O. Iltan

2005-02-28T23:59:59.000Z

103

Transverse self-modulation of ultra-relativistic lepton beams in the plasma wakefield accelerator  

SciTech Connect

The transverse self-modulation of ultra-relativistic, long lepton bunches in high-density plasmas is explored through full-scale particle-in-cell simulations. We demonstrate that long SLAC-type electron and positron bunches can become strongly radially self-modulated over centimeter distances, leading to wake excitation in the blowout regime with accelerating fields in excess of 20 GV/m. We show that particles energy variations exceeding 10 GeV can occur in meter-long plasmas. We find that the self-modulation of positively and negatively charged bunches differs when the blowout is reached. Seeding the self-modulation instability mitigates the effect of the competing hosing instability. This work reveals that a proof-of-principle experiment to test the physics of bunch self-modulation can be performed with available lepton bunches and with existing experimental apparatus and diagnostics.

Vieira, J.; Silva, L. O. [GoLP/Instituto de Plasmas e Fusao Nuclear, Laboratorio Associado Instituto Superior Tecnico, Technical University of Lisbon, Lisboa (Portugal); Fang, Y. [University of Southern California, Los Angeles, California 90089 (United States); Mori, W. B. [University of California, Los Angeles, California 90095 (United States); Muggli, P. [University of Southern California, Los Angeles, California 90089 (United States); Max Planck Institute for Physics, Munich (Germany)

2012-06-15T23:59:59.000Z

104

Lepton Number Violating Signals of the Top Partners in the Left-Right Twin Higgs Model  

E-Print Network (OSTI)

We study the collider signatures of the left-right twin Higgs model in the case that the right-handed neutrino mass is less than the mass of the right-handed gauge boson. In this scenario, new leptonic decay chains open up, allowing the particles which cancel the one-loop quadratic divergences of the Higgs, the right-handed gauge bosons and top-partners, to be discovered. Half of these events contain same-sign leptons without missing energy, which have no genuine standard model background and for which the backgrounds are purely instrumental. These signals may be used to complement other collider searches, and in certain regions of parameter space, may be the only way to observe the particles responsible for natural electroweak symmetry breaking in the left-right twin Higgs model.

Hock-Seng Goh; Christopher A. Krenke

2009-11-30T23:59:59.000Z

105

Spin Polarized Photons and Di-leptons from Axially Charged Plasma  

E-Print Network (OSTI)

Axial charge in a QCD plasma is P- and CP-odd. We propose and study P- and CP-odd observables in photon and di-lepton emissions from an axially charged QCD plasma, which may provide possible experimental evidences of axial charge fluctuation and triangle anomaly in the plasma created in heavy-ion collisions. Our observables measure spin alignments of the emitted photons and di-leptons, and are shown to be related to the imaginary part of chiral magnetic conductivity at finite frequency-momentum, which ultimately arises from the underlying triangle anomaly of the QCD plasma with a finite axial charge density. We present an exemplar computation of these observables in strongly coupled regime using AdS/CFT correspondence.

Kiminad A. Mamo; Ho-Ung Yee

2013-07-30T23:59:59.000Z

106

Spin Polarized Photons and Di-leptons from Axially Charged Plasma  

E-Print Network (OSTI)

Axial charge in a QCD plasma is P- and CP-odd. We propose and study P- and CP-odd observables in photon and di-lepton emissions from an axially charged QCD plasma, which may provide possible experimental evidences of axial charge fluctuation and triangle anomaly in the plasma created in heavy-ion collisions. Our observables measure spin alignments of the emitted photons and di-leptons, and are shown to be related to the imaginary part of chiral magnetic conductivity at finite frequency-momentum, which ultimately arises from the underlying triangle anomaly of the QCD plasma with a finite axial charge density. We present an exemplar computation of these observables in strongly coupled regime using AdS/CFT correspondence.

Mamo, Kiminad A

2013-01-01T23:59:59.000Z

107

Search for the standard model Higgs boson in tau lepton pair final states  

Science Conference Proceedings (OSTI)

We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb{sup -1} collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.

Abazov, V.M.

2012-03-01T23:59:59.000Z

108

Search for the Higgs boson in lepton, tau and jets final states  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb^{-1} of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standard model are obtained for orthogonal subsamples that are enriched in either H -> tau tau decays or H -> WW decays, and for the combination of these subsample limits. The observed and expected limit ratios for the combined subsamples at a Higgs boson mass of 125 GeV are 11.3 and 9.0 respectively.

D0 Collaboration

2012-11-29T23:59:59.000Z

109

Lepton Universality Test in Upsilon(1S) Decays at BaBar  

SciTech Connect

Using a sample of 122 million {Upsilon}(3S) decays collected with the BABAR detector at the PEP-II asymmetric energy collider at the SLAC National Accelerator Laboratory, we measure the ratio R{sub {tau}{mu}} = BR({Upsilon}(1S) {yields} {tau}{sup +}{tau}{sup -})/BR({Upsilon}(1S) {yields} {mu}{sup +}{mu}{sup -}); the measurement is intended as a test of lepton universality and as a possible search for a light pseudoscalar Higgs boson in Next to Minimal Supersymmetric Standard Model (NMSSM) scenarios. Such a boson could appear in a deviation of the ratio R{sub {tau}{mu}} from the Standard Model expectation, that is 1, except for small lepton mass corrections. The analysis exploits the decays {Upsilon}(3S) {yields} {Upsilon}(1S){pi}{sup +}{pi}{sup -}, {Upsilon}(1S) {yields} l{sup +}l{sup -}, where l = {mu},{tau}.

Guido, Elisa; /Genoa U. /INFN, Genoa

2012-04-10T23:59:59.000Z

110

The 5D to 4D projection model applied as a Lepton to Galaxy Creation model  

E-Print Network (OSTI)

The 5D to 4D projection is presented in a simple geometry giving the Perelman Theorem, resulting in a 3D doughnut structure for the space manifold of the Lorentz space-time. It is shown that in the lowest quantum state, this Lorentz manifold confines and gives the de Broglie leptons from the massless 5D e-trinos. On the scale of the universe, it allows for a model for the creation of galaxies.

Kai-Wai Wong; Gisela A. M. Dreschhoff; Hgne Jungner

2013-06-02T23:59:59.000Z

111

An SO(10)XS4 Model of Quark-Lepton Complementarity  

E-Print Network (OSTI)

The present observations of Cabbibo angle and solar mixing angle satisfy the empirical relation called Quark-Lepton Complementarity(QLC), namely $\\theta_{12}^l\\sim \\pi/4-\\theta_C$. It suggests the existence of correlation between quarks and leptons which is supported by the idea of grand unification. We propose a specific ansatz for the structure of Yukawa matrices in SO(10) unified theory which leads to such relation if neutrinos get masses through type-II seesaw mechanism. Viability of this ansatz is discussed through detailed analysis of fermion masses and mixing angles all of which can be explained in a model which uses three Higgs fields transforming as 10 and one transforming as $\\bar{126}$ representations under SO(10). It is shown that the proposed ansatz can be derived from an extended model based on the two pairs of 16-dimensional vector-like fermions and an $S_4$ flavor symmetry. The model leads to the lepton mixing matrix that is dominantly bimaximal with ${\\cal O}(\\theta_C)$ corrections related to quark mixing. A generic prediction of the model is the reactor angle $\\theta_{13}^l\\sim \\theta_C/\\sqrt{2}$ which is close to its present experimental upper bound.

Ketan M. Patel

2010-08-30T23:59:59.000Z

112

Neutrino Mixings and Leptonic CP Violation from CKM Matrix and Majorana Phases  

E-Print Network (OSTI)

The high scale mixing unification hypothesis recently proposed by three of us (R. N. M., M. K. P. and G. R.) states that if at the seesaw scale, the quark and lepton mixing matrices are equal then for quasi-degenerate neutrinos, radiative corrections can lead to large solar and atmospheric mixings and small reactor angle at the weak scale in agreement with data. Evidence for quasi-degenerate neutrinos could, within this framework, be interpreted as a sign of quark-lepton unification at high scale. In the current work, we extend this model to show that the hypothesis works quite successfully in the presence of CP violating phases (which were set to zero in the first paper). In the case where the PMNS matrix is identical to the CKM matrix at the seesaw scale, with a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to be ($\\simeq 0.3^{\\circ}$) and leptonic CP-violation parameter $J_{CP} \\simeq (4 - 8)\\times 10^{-5}$ and $\\theta_{13} = 3.5^{\\circ}$. If on the other hand, the PMNS matrix is assumed to also have Majorana phases initially, the resulting theory damps radiative magnification phenomenon for a large range of parameters but nevertheless has enough parameter space to give the two necessary large neutrino mixing angles. In this case, one has $\\theta_{13} = 3.5^{\\circ} - 10^{\\circ}$ and $|J_{CP}|$ as large as $0.02-0.04$ which are accessible to long baseline neutrino oscillation experiments.

S. K. Agarwalla; M. K. Parida; R. N. Mohapatra; G. Rajasekaran

2006-11-16T23:59:59.000Z

113

Leptonic CP Phase in {nu}{sub {mu}}{yields}{nu}{sub {mu}} Oscillations  

Science Conference Proceedings (OSTI)

In the case of large 1-3 mixing angle as sin{sup 2} 2{theta}{sub 13}{>=}0.03, we investigate the possibility for measuring the leptonic CP phase by using only {nu}{sub {mu}}{yields}{nu}{sub {mu}} oscillations independently of {nu}{sub {mu}}{yields}{nu}{sub e} oscillations. As the result, we find that the CP phase can be measured best around the energy E = 0.43 GeV and the baseline length L = 5000 km without depending on the uncertainties of other parameters too much. In this region, the CP phase effect remains even after averaging over neutrino energy.

Kimura, Keiichi; Yoshikawa, Tadashi [Department of Physics, Nagoya University, Nagoya, 464-8602 (Japan); Takamura, Akira [Department of Mathematics, Toyota National College of Technology Eisei-cho 2-1, Toyota-shi, 471-8525 (Japan)

2008-02-21T23:59:59.000Z

114

Trigger Algorithm Design for a SUSY Lepton Trigger based on Forward Proton Tagging  

Science Conference Proceedings (OSTI)

At the Large Hadron Collider (LHC) pair production of SUSY leptons in gamma-gamma interactions will often include intact off-energy protons. Including detectors in the beampipe to measure these protons can give additional information to separate these events from background. We report on expected event rates and background rejection for a slepton trigger design in the Compact Muon Solenoid (CMS) experiment incorporating forward proton information. We conclude that a trigger that can observe an interesting number of events is feasible with the appropriate detector hardware.

Gronberg, J; Hollar, J

2010-03-29T23:59:59.000Z

115

Higgs boson finder and mass estimator: The Higgs boson to WW to leptons decay channel at the LHC  

Science Conference Proceedings (OSTI)

We exploit the spin and kinematic correlations in the decay of a scalar boson into a pair of real or virtual W-bosons, with both W-bosons decaying leptonically, for Higgs boson discovery at 7 TeV LHC energy with 10 fb{sup -1} luminosity. Without reconstruction of the events, we obtain estimators of the Higgs mass from the peak and width of the signal distribution in m{sub ll}. The separation of signal and background with other distributions, such as the azimuthal angle between two W decay planes, the rapidity difference between the two leptons, missing E{sub T}, and the p{sub T} of leptons, are also prescribed. Our approach identifies the salient Higgs to dilepton signatures that allow subtraction of the continuum W*W* background.

Barger, Vernon; Huang, Peisi [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2011-11-01T23:59:59.000Z

116

Searching for new physics in events with three leptons in ATLAS  

E-Print Network (OSTI)

We investigate the potential of the ATLAS detector to discover trilepton final state signatures from decays of supersymmetric particles at the LHC. An inclusive and an exclusive trilepton search have been conducted for a range of different mSUGRA scenarios, in the focus point region, in the bulk region, and at the edge of the current experimental limits on SUSY. It is found that a simple inclusive selection, based on the presence of three leptons and at least one high-$p_T$ jet in the final state, has the potential to be an excellent candidate for an early physics programme at the LHC. The exclusive trilepton selection, optimised for the focus point region, relies on stringent lepton track isolation and also includes cuts on variables such as transverse missing energy and on the hadronic activity in the event. In a heavy SUSY scenario, where all scalar and coloured sparticles may be too heavy to be observed at the LHC, hadronically quiet trilepton final states could be amongst the few accessible channels to d...

Potter, C

2009-01-01T23:59:59.000Z

117

Lepton production at the LHC from singly- and doubly-charged bilepton  

Science Conference Proceedings (OSTI)

Some extensions of the standard model predict the existence of particles having two units of leptonic charge, known as bileptons. One of such models is based on the SU(3){sub c} Multiplication-Sign SU(3){sub L} Multiplication-Sign U(1){sub X} symmetry group (3-3-1). Our search uses the minimal version of this model, having exotic charges for the quarks and gauge bosons. It predicts the existence of bileptons as vector particles having one unit of electric charge (V{sup {+-}}) or two units of electric charge (Y{sup {+-}{+-}}). Our aim is to establish the signatures for the production of four fermions in pp collisions at the LHC for 7 TeV center of mass energy. We present the total cross section and we show the leptons invariant mass and transverse momentum distributions. We conclude that LHC collider can show a clear signature for a process induced by bileptons as a signal of new physics.

Sa Borges, J. [Instituto de Fisica, UERJ, Rio de Janeiro, RJ (Brazil); Coutinho, Y. A. [Instituto de Fisica, UFRJ, Rio de Janeiro, RJ (Brazil); Barreto, E. R. [C C N H, UFABC, Santo Andre, SP (Brazil)

2013-03-25T23:59:59.000Z

118

Measurements of Charged Current Lepton Universality and |Vus| using Tau Lepton Decays to e- v v, __- v v, pi- v and K- v  

SciTech Connect

Using 467 fb{sup -1} of e{sup +}e{sup -} annihilation data collected with the BABAR detector, they measure {Beta}({tau}{sup -} {yields} {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -} {bar {nu}}{sub e}{nu}{sub {tau}}) = (0.9796 {+-} 0.0016 {+-} 0.0036), {Beta}({tau}{sup -} {yields} {pi}{sup -} {nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}) = (0.5945 {+-} 0.0014 {+-} 0.0061), and {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}) = (0.03882 {+-} 0.00032 {+-} 0.00057), where the uncertainties are statistical and systematic, respectively. From these precision {tau} measurements, they test the Standard Model assumption of {mu}-e and {tau}-{mu} charge current lepton universality and provide determinations of |V{sub us}| experimentally independent of the decay of a kaon.

Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-06-30T23:59:59.000Z

119

CDF note 10582 Search for SM Higgs boson production in association with tt using no lepton final state  

E-Print Network (OSTI)

CDF note 10582 Search for SM Higgs boson production in association with t¯t using no lepton final is that t¯t decay all hadronic mode (all t decay into bqq ). In both cases we consider that the Higgs boson discriminant variable from different neural network to discriminate the Higgs boson signal from remained

Fermilab

120

Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector  

SciTech Connect

We present the search for the lepton flavour violating decay {tau} {yields} lK{sup 0}{sub s} with the BaBar experiment data. This process and many other lepton flavour violating {tau} decays, like {tau} {yields} {mu}{gamma} and {tau} {yields} lll, are one of the most promising channel to search for evidence of new physics. According to the Standard Model and the neutrino mixing parameters, branching fractions are estimated well below 10{sup -14}, but many models of new physics allow for branching fractions values close to the present experimental sensitivity. This analysis is based on a data sample of 469fb{sup -1} collected by BABAR detector at the PEP-II storage ring from 1999 to 2007, equivalent to 431 millions of {tau} pairs. the BABAR experiment, initially designed for studying CP violation in B mesons, has demonstrated to be one of the most suitable environments for studying {tau} decays. The tracking system, the calorimeter and the particle identification of BABAR, together with the knowledge of the {tau} initial energy, allow an extremely powerful rejection of background events that, for this analysis, is better than 10{sup -9}. Being {tau} {yields} lK{sup 0}{sub s} a decay mode without neutrinos, the signal {tau} decay can be fully reconstructed. Kinematical constraints are used in a fit that provides a decay tree reconstruction with a high resolution. For this analysis MC simulated events play a decisive role for estimating the signal efficiency and study the residual background. High statistics MC sample are produced simulating detector conditions for different periods of data collection, in order to reduce any discrepancies with the data. When discrepancies can not be removed, we perform studies to compute a correction factor or an estimation of systematic errors that need to be included in the final measurement. A significant improvement of the current result can be reached only with a higher statistics and, therefore, with a new collider providing a luminosity from 10 to 100 times more than PEP-II. A new detector, with improved performance and able to collect data in a high background environment, is also requested to fully exploit the capability of such amount of data. In fact, only keeping the efficiency and the background as similar as possible to present ones, we will be able to scale almost linearly the estimated upper limit according to the luminosity. The strong potential of improvement for the search of lepton flavour violation {tau} decays makes the building of such a machine highly desirable.

Cenci, Riccardo; /SLAC

2009-03-20T23:59:59.000Z

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121

Lepton Universality, |V(Us)| and Search for Second Class Current in Tau Decays  

SciTech Connect

Several hundred million {tau} decays have been studied with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of |V{sub us}| using {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {pi}{sup -}{nu}{sub {tau}}, K{sup -} {nu}{sub {tau}} and K{sub S}{sup 0}{pi}{sup -} {nu}{sub {tau}} decays, and a search for Second Class Current in {tau}{sup -} {yields} {pi}{sup -} {omega}{nu}{sub {tau}} decays are presented, where the charge conjugate decay modes are also implied.

Banerjee, Swagato; /Victoria U.

2011-11-10T23:59:59.000Z

122

The lepton asymmetry: the last chance for a critical-density cosmology?  

E-Print Network (OSTI)

We use a wide range of observations to constrain cosmological models possessing a significant asymmetry in the lepton sector, which offer perhaps the best chance of reconciling a critical-density Universe with current observations. The simplest case, with massless neutrinos, fails to fit many experimental data and does not lead to an acceptable model. If the neutrinos have mass of order one electron-volt (which is favoured by some neutrino observations), then models can be implemented which prove a good fit to microwave anisotropies and large-scale structure data. However, taking into account the latest microwave anisotropy results, especially those from Boomerang, we show that the model can no longer accommodate the observed baryon fraction in clusters. Together with the observed acceleration of the present Universe, this puts considerable pressure on such critical-density models.

Julien Lesgourgues; Andrew R. Liddle

2001-05-21T23:59:59.000Z

123

Lepton flavor violating Higgs bosons and {tau}{yields}{mu}{gamma}  

SciTech Connect

We update phenomenological constraints on a two Higgs doublet model with lepton flavor nonconserving Yukawa couplings. We review that tan{beta} is ambiguous in such 'type III' models, and define it from the {tau} Yukawa coupling. The neutral scalars {phi} could be searched for at hadron colliders in {phi}{yields}{tau}{mu} and are constrained by the rare decay {tau}{yields}{mu}{gamma}. The Feynman diagrams for the collider process, with Higgs production via gluon fusion, are similar to the two-loop ''Barr-Zee'' diagrams, which contribute to {tau}{yields}{mu}{gamma}. Some ''tuning'' is required to obtain a collider cross section of order the standard model expectation for {sigma}(gg{yields}h{sub SM{yields}{tau}}{sup +{tau}-}), while agreeing with the current bound from {tau}{yields}{mu}{gamma}.

Davidson, Sacha; Grenier, Gerald [IPNL, Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, 4 rue E. Fermi 69622 Villeurbanne cedex (France)

2010-05-01T23:59:59.000Z

124

Search for Lepton Flavour Violating Decays tau- to l- Ks with the BaBar experiment  

SciTech Connect

A search for the lepton flavor violating decays {tau}{sup -} {yields} l{sup -} K{sub S}{sup 0} (l = e or {mu}) has been performed using a data sample corresponding to an integrated luminosity of 469 fb{sup -1}, collected with the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} asymmetric energy collider. No statistically significant signal has been observed in either channel and the estimated upper limits on branching fractions are {Beta}({tau}{sup -} {yields} e{sup -} K{sub S}{sup 0}) < 3.3 x 10{sup -8} and {Beta}({tau}{sup -} {yields} {mu}{sup -}K{sub S}{sup 0}) < 4.0 x 10{sup -8} at 90% confidence level.

Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Cahn, R.N.; Jacobsen, R.G.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Karlsruhe U., EKP /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2009-01-06T23:59:59.000Z

125

Improved Limits on the Lepton Flavor Violating Decays Tau -> l V^0  

SciTech Connect

The authors search for the neutrinoless, lepton-flavor-violating tau decays {tau}{sup -} {yields} {ell}{sup -}V{sup 0}, where {ell} is an electron or muon and V{sup 0} is a fector meson reconstructed as {phi} {yields} K{sup +}K{sup -}, {rho} {yields} {pi}{sup +}{pi}{sup -}, K* {yields} K{sup +}{pi}{sup -}, {bar K}* {yields} K{sup -}{pi}{sup +}. The analysis has been performed using 451 fb{sup -1} of data collected at an e{sup +}e{sup -} center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II storage rings. The number of events found in the data is compatible with the background expectation, and upper limits on the branching fractions are set in the range (2.6-19) x 10{sup -8} at the 90% confidence level.

Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2009-06-19T23:59:59.000Z

126

Higgs Search Constraints on Fourth Generation Scenarios with General Lepton Sectors  

E-Print Network (OSTI)

I present a general exclusion bound for the Higgs in fourth generation scenarios with a general lepton sector. Recent Higgs searches in fourth generation scenarios rule out the entire Higgs mass region between 120 and 600 GeV. That such a large range of Higgs masses are excluded is due to the presence of extra heavy flavors of quarks, which substantially increase Higgs production from gluon fusion over the Standard Model rate. However, if heavy fourth generation neutrinos are less than half of the Higgs mass, they can dominate the Higgs decay branching fraction, overtaking the standard Higgs to WW* decay rate. The Higgs mass exclusion in a fourth generation scenario is shown most generally to be 155-600 GeV, and is highly dependent on the fourth generation neutrino mixing parameter.

Linda M. Carpenter

2011-10-21T23:59:59.000Z

127

Dark atoms of dark matter from new stable quarks and leptons  

SciTech Connect

The nonbaryonic dark matter of the Universe can consist of new stable charged leptons and quarks, if they are hidden in elusive 'dark atoms' of composite dark matter. Such possibility can be compatible with the severe constraints on anomalous isotopes, if there exist stable particles with charge -2 and there are no stable particles with charges +1 and -1. These conditions cannot be realized in supersymmetric models, but can be satisfied in several recently developed alternative scenarios. The excessive -2 charged particles are bound with primordial helium in O-helium 'atoms', maintaining specific nuclear-interacting form of the Warmer than Cold Dark Matter. The puzzles of direct dark matter searches appear in this case as a reflection of nontrivial nuclear physics of O-helium.

Khlopov, Maxim Yu. [APC laboratory 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

2012-06-20T23:59:59.000Z

128

Baryon and lepton number violation in the electroweak theory at TeV energies  

Science Conference Proceedings (OSTI)

In the standard Weinberg-Salam electroweak theory baryon and lepton number (B and L) are NOT exactly conserved. The nonconservation of B and L can be traced to the existence of parity violation in the electroweak theory, together with the chiral current anomaly. This subtle effect gives negligibly small amplitudes for B and L violation at energies and temperatures significantly smaller than M{sub w} sin{sup 2} {theta}{sub w}/{alpha} {approximately} 10 TeV. However, recent theoretical work shows that the rate for B and L nonconservation is unsuppressed at higher energies. The consequences of this for cosmology and the baryon asymmetry of the universe, as well as the prospects for direct verification at the SSC are discussed. 13 refs., 3 figs.

Mottola, E.

1990-01-01T23:59:59.000Z

129

A leptonic-hadronic model for the afterglow of gamma-ray burst 090510  

E-Print Network (OSTI)

We model multiwavelength afterglow data from the short Gamma-Ray Burst (GRB) 090510 using a combined leptonic-hadronic model of synchrotron radiation from an adiabatic blast wave. High energy, >100 MeV, emission in our model is dominated by proton-synchrotron radiation, while electron-synchrotron radiation dominates in the X ray and ultraviolet wavelengths. The collimation-corrected GRB energy, depending on the jet-break time, in this model could be as low as 3e51 erg but two orders of magnitude larger than the gamma-ray energy. We also calculated the opacities for electron-positron pair production by gamma rays and found that TeV gamma rays from proton-synchrotron radiation can escape the blast wave at early time, and their detection can provide evidence of a hadronic emission component dominating at high energies.

Soebur Razzaque

2010-04-20T23:59:59.000Z

130

Search for Supersymmetry in Events with Three Leptons and Missing Transverse Momentum in ?s=7??TeV pp Collisions with the ATLAS Detector  

E-Print Network (OSTI)

A search for the weak production of charginos and neutralinos decaying to a final state with three leptons (electrons or muons) and missing transverse momentum is presented. The analysis uses 2.06??fb[superscript -1] of ...

Taylor, Frank E.

131

DELAYED ONSET OF HIGH-ENERGY EMISSIONS IN LEPTONIC AND HADRONIC MODELS OF GAMMA-RAY BURSTS  

SciTech Connect

The temporal-spectral evolution of the prompt emission of gamma-ray bursts is simulated numerically for both leptonic and hadronic models. For weak enough magnetic fields, leptonic models can reproduce the few seconds delay of the onset of GeV photon emission observed by Fermi-LAT, due to the slow growth of the target photon field for inverse Compton scattering. For stronger magnetic fields, the GeV delay can be explained with hadronic models, due to the long acceleration timescale of protons and the continuous photopion production after the end of the particle injection. While the FWHMs of the MeV and GeV light curves are almost the same in one-zone leptonic models, the FWHMs of the 1-30 GeV light curves in hadronic models are significantly wider than those of the 0.1-1 MeV light curves. The amount of the GeV delay depends on the importance of the Klein-Nishina effect in both the leptonic and hadronic models. In our examples of hadronic models the energies of the escaped neutrons are comparable to the gamma-ray energy, although their contribution to the ultra high-energy cosmic rays is still subdominant. The resulting neutrino spectra are hard enough to avoid the flux limit constraint from IceCube. The delay of the neutrino emission onset is up to several times longer than the corresponding delay of the GeV photon emission onset. The quantitative differences in the light curves for various models may be further tested with future atmospheric Cerenkov telescopes whose effective area is larger than that of Fermi-LAT, such as CTA.

Asano, Katsuaki [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Meszaros, Peter, E-mail: asano@phys.titech.ac.jp, E-mail: nnp@astro.psu.edu [Department of Astronomy and Astrophysics, Department of Physics, Center for Particle and Gravitational Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2012-10-01T23:59:59.000Z

132

A proper time dependent measurement of delta M{sup D} using jet charge and soft lepton flavor tagging  

SciTech Connect

This thesis presents a proper time dependent measurement of the B{sup 0}{sub d} mixing frequency {Delta}m{sub d} using jet charge and soft lepton flavor tagging in p-{anti p} collisions at {radical}s=1.8 TeV. The measurement uses the inclusive e and {mu} trigger data of the CDF detector from an integrated luminosity of 91 pb{sup -1}. The proper time at decay is measured from a partial reconstruction of the B associated with the trigger lepton. The measurement of {Delta}m{sub d} yields {Delta}m{sub d}=0.50{+-}0.05{+-}0.05 {h_bar} ps{sup -1} where the first error is statistical and the second systematic. The flavor tagging methods used give a measured effective efficiency {epsilon}D{sup 2} of - Jet Charge: {epsilon}D{sup 2} = (0.78 {+-} 0.12 {+-} 0.09) % - Soft Lepton: {epsilon}D{sup 2} = (1.07 {+-} 0.09 {+-} 0.10) % where the first error is statistical and the second systematic.

O.R. Long

1999-01-26T23:59:59.000Z

133

A proper time dependent measurement of Delta M {sub D} using jet charge and soft lepton flavor tagging  

SciTech Connect

This thesis presents a proper time dependent measurement of the B{sup 0}{sub d} mixing frequency {Delta}M{sub d} using jet charge and soft lepton flavor tagging in p - {anti p} collisions at {radical}s = 1.8 TeV. The measurement uses the inclusive e and {mu} trigger data of the CDF detector from an integrated luminosity of 91 pb{sub -1}. The proper time at decay is measured from a partial reconstruction of the B associated with the trigger lepton. The measurement of {Delta}M{sub d} yields {Delta}M{sub d} = 0.50 {+-} 0.05 {+-} 0.05 {bar h} ps{sup -1} where the first error is statistical and the second systematic. The flavor tagging methods used give a measured effective efficiency {epsilon}D{sup 2} of o Jet Charge: {epsilon}D{sup 2} (0.78 + 0.12 + 0.09) % o Soft Lepton: {epsilon}D{sup 2} (1.07 + 0.09 + 0.10) % where the first error is statistical and the second systematic.

NONE

1998-08-01T23:59:59.000Z

134

Anomalous g-Factors for Charged Leptons in a Fractional Coarse-Grained Approach  

E-Print Network (OSTI)

In this work, we investigate aspects of the electron, muon and tau gyromagnetic ratios (g-factor) in a fractional coarse-grained scenario, by adopting a Modified Riemann-Liouville (MRL) fractional calculus. We point out the possibility of mapping the experimental values of the specie's g-factors into a theoretical parameter which accounts for fractionality, without computing higher-order QED calculations. We wish to understand whether the value of (g-2) may be traced back to a fractionality of space-time.The justification for the difference between the experimental and the theoretical value g=2 stemming from the Dirac equation is given in the terms of the complexity of the interactions of the charged leptons, considered as pseudo-particles and "dressed" by the interactions and the medium. Stepwise, we build up a fractional Dirac equation from the fractional Weyl equation that, on the other hand, was formulated exclusively in terms of the helicity operator. From the fractional angular momentum algebra, in a co...

Weberszpil, J

2013-01-01T23:59:59.000Z

135

Supersymmetry Breaks Itself for Quarks and Leptons in the SUSY Standard Model  

E-Print Network (OSTI)

Models like the Supersymmetric Standard Model (SSM) possess simple, but well-hidden, `Outfields'. These Outfields are composite operators that violate superspace invariance, but in a special way. A new mechanism for SUSY breaking arises from the Outfields, for a special non-minimal version of the SSM, which will be called the CSSM. The CSSM has right neutrinos and a Higgs singlet, which we call J, in addition to the usual SSM. This breaking of SUSY cannot be avoided, because it arises from the local BRST cohomology of the theory, which is also the origin of the Outfields. It can also be seen that the Weak SU(2) group, and the well-known remarkable set of doublets and singlets for the Quarks, Leptons and Higgs, have a raison d'etre which relates to this mechanism. The SUSY breaking here depends on only one parameter, which is the VEV that breaks SU(2) X U(1) to U(1). SUSY itself is not spontaneously broken here, so the vacuum energy remains zero after SUSY breaking. The resulting predictions for SUSY breaking are very constrained by the model.

John A. Dixon

2010-12-21T23:59:59.000Z

136

Search for Lepton-Number Violating Processes in B+ to h- l+ l+ Decays  

SciTech Connect

We have searched for the lepton-number violating processes B{sup +} {yields} h{sup -}{ell}{sup +}{ell}{sup +} with h{sup -} = K{sup -}/{pi}{sup -} and {ell}{sup +} = e{sup +}/{mu}{sup +}, using a sample of 471 {+-} 3 million B{bar B} events collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90% confidence level upper limits on their branching fractions B (B{sup +} {yields} {pi}{sup -}e{sup +}e{sup +}) < 2.3 x 10{sup -8}, {Beta}(B{sup +} {yields} K{sup -}e{sup +}e{sup +}) < 3.0 x 10{sup -8}, {Beta}(B{sup +} {yields} {pi}{sup -}{mu}{sup +}{mu}{sup +}) < 10.7 x 10{sup -8}, and {Beta}(B{sup +} {yields} K{sup -}{mu}{sup +}{mu}{sup +}) < 6.7 x 10{sup -8}.

Lees, J.P.

2012-05-17T23:59:59.000Z

137

Search for the Baryon and Lepton Number Violating Decays tau to Lambda h  

SciTech Connect

The authors have searched for the violation of baryon number B and lepton number L in the (B-L)-conserving modes {tau}{sup -} {yields} {bar {Lambda}}{sup 0}{pi}{sup -} and {tau}{sup -} {yields} {bar {Lambda}}{sup 0}K{sup -} as well as the (B-L)-violating modes {tau}{sup -} {yields} {Lambda}{sup 0}{pi}{sup -} and {tau}{sup -} {yields} {Lambda}{sup 0}K{sup -} using 237 fb{sup -1} of data collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. They do not observe any signal and determine preliminary upper limits on the branching fractions {Beta}({tau}{sup -} {yields} {bar {Lambda}}{sup 0}{pi}{sup -}) < 5.9 x 10{sup -8}, {Beta}({tau}{sup -} {yields} {Lambda}{sup 0}{pi}{sup -}) < 5.8 x 10{sup -8}, {Beta}({tau}{sup -} {yields} {bar {Lambda}}{sup 0}K{sup -}) < 7.2 x 10{sup -8}, and {Beta}({tau}{sup -} {yields} {Lambda}{sup 0}K{sup -}) < 15 x 10{sup -8} at 90% confidence level.

Aubert, B.

2006-11-28T23:59:59.000Z

138

A "Muon Mass Tree" with alpha-quantized Lepton, Quark and Hadron Masses  

E-Print Network (OSTI)

A "muon mass tree" is displayed that contains the excitation systematics for accurately reproducing the masses of the six Standard Model quarks (u,d,s,c,b,t); the heavy leptons; the proton; the phi, J/Psi and Upsilon vector meson thrshold states; the Bc meson; and the mass-averaged W and Z gauge bosons, using a unified mass formalism based on the electron ground state. Multiples of an alpha-quantized 105.04 MeV fermion mass quantum reproduce the states below 12 GeV, and multiples of a doubly-alpha-quantized 14,394 Mev fermion mass quantum reproduce the W-Z and t states above 12 GeV, where alpha ~ 1/137 is the fine structure constant. Masses are additive, and the overall mass accuracy for these states is in the 1% range. A similar "pion mass tree" based on an alpha-quantized 70.03 MeV boson mass quantum accurately reproduces the pseudoscalar meson masses. The mass alpha-quantization follows from a corresponding experimental alpha-spacing of the long-lived particle lifetimes, which occur in well-defined lifetime groups that are each determined by a dominant Standard Model quark substate.

Malcolm H. Mac Gregor

2006-07-20T23:59:59.000Z

139

Neutrino properties deduced from the study of lepton number violating processes at low and high energies  

SciTech Connect

There is nowadays a significant progress in understanding the neutrino properties. The results of the neutrino oscillation experiments have convincingly showed that neutrinos have mass and oscillate, in contradiction with the Standard Model (SM) assumptions, and these are the first evidences of beyond SM physics. However, fundamental properties of the neutrinos like their absolute mass, their character (are they Dirac or Majorana particles?), their mass hierarchy, the number of neutrino flavors, etc., still remain unknown. In this context there is an increased interest in the study of the lepton number violating (LNV) processes, since they could complete our understanding on the neutrino properties. Since recently, the neutrinoless double beta decay was considered the only process able to distinguish between Dirac or Majorana neutrinos and to give a hint on the absolute mass of the electron neutrino. At present, the increased luminosity of the LHC experiments makes feasible the search of LNV processes at high energy as well. In this lecture I will make a brief review on our present knowledge of the neutrino properties, on the present status of the double-beta decay studies and on the first attempts to search LNV processes at LHC.

Stoica, Sabin [Horia Hulubei Foundation, P.O. Box MG-12, 077125 Magurele-Bucharest (Romania) and Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, Magurele-Bucharest 077125 (Romania)

2012-11-20T23:59:59.000Z

140

A Time Dependent Leptonic Model for Microquasar Jets: Application to LSI 61 303  

E-Print Network (OSTI)

The Galactic high-mass X-ray binary and jet source (microquasar) LSI +61 303 has recently been detected at TeV gamma-ray energies by the MAGIC telescope. We have applied a time-dependent leptonic jet model to the broadband spectral energy distribution and suggested (though not unambiguously detected) orbital modulation of the very high energy gamma-ray emission of this source. Our model takes into account time dependent electron injection and acceleration, and the adiabatic and radiative cooling of non-thermal electrons. It includes synchrotron, synchrotron self-Compton and external inverse Compton (with seed photons from the companion star), as well as gamma-gamma absorption of gamma-rays by starlight photons. The model can successfully reproduce the available multiwavelength observational data. Our best fit to the SED indicates that a magnetic field of B_0 ~ 5 X 10^3 G at ~ 10^3 R_g is required, and electrons need to be accelerated out to TeV energies (gamma_2 = 10^6) with a nonthermal injection spectrum with a spectral index of q = 1.7, indicating the operation of acceleration mechanisms beyond the standard first-order Fermi mechanism at relativistic or non-relativistic shocks. The orbital modulation of the VHE gamma-ray emission can be explained solely by the geometrical effect of changes in the relative orientation of the stellar companion with respect to the compact object and jet as it impacts the position and depth of the gamma-gamma absorption trough. Such a scenario predicts a trend of spectral hardening during VHE gamma-ray low orbital phases.

Swati Gupta; Markus Boettcher

2006-06-23T23:59:59.000Z

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141

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

Science Conference Proceedings (OSTI)

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

Mills, Corrinne Elaine; /UC, Santa Barbara

2007-06-01T23:59:59.000Z

142

Light Vector Meson Photoproduction off of H at Jefferson Lab and rho-omega Interference in the Leptonic Decay Channel  

SciTech Connect

Recent studies of light vector meson production in heavy nuclear targets has generated interest in {rho}-{omega} interference in the leptonic e{sup +}e{sup -} decay channel. An experimental study of the elementary process provides valuable input for theoretical models and calculations. In experiment E04-005 (g12), high statistics photoproduction data has been taken in Jefferson Lab's Hall B with the Cebaf Large Acceptance Spectrometer (CLAS). The invariant mass spectrum is fitted with two interfering relativistic Breit-Wigner functions to determine the interference phase. Preliminary analysis indicate a measurable {rho}-{omega} interference.

Chaden Djalali

2011-12-01T23:59:59.000Z

143

Search for anomalous production of prompt like-sign lepton pairs at $\\sqrt{s}$ = 7 TeV with the ATLAS detector  

E-Print Network (OSTI)

An inclusive search for anomalous production of two prompt, isolated leptons with the same electric charge is presented. The search is performed in a data sample corresponding to 4.7 fb-1 of integrated luminosity collected in 2011 at $\\sqrt{s}$ = 7 TeV with the ATLAS detector at the LHC. Pairs of leptons (ee, emu, and mumu) with large transverse momentum are selected, and the dilepton invariant mass distribution is examined for any deviation from the Standard Model expectation. No excess is found, and upper limits on the production cross section of like-sign lepton pairs from physics processes beyond the Standard Model are placed as a function of the dilepton invariant mass within a fiducial region close to the experimental selection criteria. The 95% confidence level upper limits on the cross section of anomalous ee, emu, or mumu production range between 1.7 fb and 64 fb depending on the dilepton mass and flavour combination.

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; kesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; sman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimares da Costa, Joo; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jrg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard

2012-01-01T23:59:59.000Z

144

Leptonic decay-constant ratio f_{K^+}/f_{pi^+} from lattice QCD with physical light quarks  

E-Print Network (OSTI)

A calculation of the ratio of leptonic decay constants f_{K^+}/f_{\\pi^+} makes possible a precise determination of the ratio of CKM matrix elements |V_{us}|/|V_{ud}| in the Standard Model, and places a stringent constraint on the scale of new physics that would lead to deviations from unitarity in the first row of the CKM matrix. We compute f_{K^+}/f_{\\pi^+} numerically in unquenched lattice QCD using gauge-field ensembles recently generated that include four flavors of dynamical quarks: up, down, strange, and charm. We analyze data at four lattice spacings a ~ 0.06, 0.09, 0.12, and 0.15 fm with simulated pion masses down to the physical value 135 MeV. We obtain f_{K^+}/f_{\\pi^+} = 1.1947(26)(37), where the errors are statistical and total systematic, respectively. This is our first physics result from our N_f = 2+1+1 ensembles, and the first calculation of f_{K^+}/f_{\\pi^+} from lattice-QCD simulations at the physical point. Our result is the most precise lattice-QCD determination of f_{K^+}/f_{\\pi^+}, with an error comparable to the current world average. When combined with experimental measurements of the leptonic branching fractions, it leads to a precise determination of |V_{us}|/|V_{ud}| = 0.2309(9)(4) where the errors are theoretical and experimental, respectively.

A. Bazavov; C. Bernard; C. DeTar; J. Foley; W. Freeman; Steven Gottlieb; U. M. Heller; J. E. Hetrick; J. Kim; J. Laiho; L. Levkova; M. Lightman; J. Osborn; S. Qiu; R. L. Sugar; D. Toussaint; R. S. Van de Water; R. Zhou

2013-01-24T23:59:59.000Z

145

Lepton flavour violating Higgs Boson decays, tau --> mu gamma and B(s) --> mu+mu- in the constrained MSSM+NR with large tan beta  

E-Print Network (OSTI)

Realistic predictions are made for the rates of lepton flavour violating Higgs boson decays, tau --> mu gamma, mu --> e gamma, Bs --> mu+mu-, Bs --> tau mu and tau --> 3mu, via a top-down analysis of the Minimal Supersymmetric Standard Model(MSSM) constrained by SU(5) unification with right-handed Neutrinos and large tan beta. The third family neutrino Yukawa coupling is chosen to be of order 1, in this way our model bares a significant resemblance to supersymmetric SO(10). In this framework the large PMNS mixings result in potentially large lepton flavour violation. Our analysis predicts tau --> mu gamma and mu --> e gamma rates in the region (10^{-8}-10^{-6}) and (10^{-15}-10^{-14}) respectively. We also show that the rates for lepton flavour violating Higgs decays can be as large as 10^{-7}. The non-decoupling nature of H --> tau mu is observed which leads to its decay rate becoming comparable to that for tau --> mu gamma for large values of m_0 and M_1/2. We also find that the present bound on Bs --> mu+mu- is an important constraint on the rate of lepton flavour violating Higgs decays. The recently measured Bs-Bsbar mixing parameter Delta Ms is also investigated.

J. K. Parry

2005-10-24T23:59:59.000Z

146

Measurement of R = B(t?Wb)/B(t?Wq) in top-quark-pair decays using lepton+jets events and the full CDF run II dataset  

E-Print Network (OSTI)

We present a measurement of the ratio of the top-quark branching fractions R=B(t?Wb)/ B(t?Wq), where q represents quarks of type b, s, or d, in the final state with a lepton and hadronic jets. The measurement uses ?s=1.96??TeV ...

Gomez-Ceballos, Guillelmo

147

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

SciTech Connect

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

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

2008-05-01T23:59:59.000Z

148

Measurement of the top quark mass in $p \\bar{p}$ collisions using events with two leptons  

Science Conference Proceedings (OSTI)

We present a measurement of the top quark mass (m{sub t}) in p{bar p} collisions at {radical}s = 1.96 TeV using t{bar t} events with two leptons (ee, e{mu} or {mu}{mu}) in the final state in 4.3 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider. We analyze the kinematically underconstrained dilepton events by integrating over the neutrino rapidity distributions. We reduce the dominant systematic uncertainties from jet energy calibration using a correction obtained from t{bar t} {yields} {ell} + jets events. We also correct jets in simulated events to replicate the quark flavor dependence of the jet response in data. In combination with our previous analysis, we measure m{sub t} = 174.0 {+-} 2.4(stat) {+-} 1.4(syst) GeV.

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.; Aoki, Masato; /Fermilab; Askew, Andrew Warren; /Florida State U. /Stockholm U.

2012-01-01T23:59:59.000Z

149

Measurement of the Top Quark Mass at CDF Using the Template Method in the Lepton + Jets Channel  

SciTech Connect

A measurement of the top quark mass in p{bar p} collisions at {radical}s = 1.96 TeV is presented. The analysis uses a template method, in which the overconstrained kinematics of the Lepton+Jets channel of the t{bar t} system are used to measure a single quantity, the reconstructed top quark mass, that is strongly correlated with the true top quark mass. in addition, the dijet mass of the hadronically decaying W boson is used to constrain in situ the uncertain jet energy scale in the CDF detector. Two-dimensional probability density functions are derived using a kernel density estimate-based machinery. Using 1.9 fb{sup -1} of data, the top quark mass is measured to be 171.8{sub -1.9}{sup +1.9}(stat.) {+-} 1.0(syst.)GeV/c{sup 2}.

Adelman, Jahred A.; /Chicago U.

2008-05-01T23:59:59.000Z

150

Searches for the baryon- and lepton-number violating decays $B^0\\rightarrow\\Lambda_c^ \\ell^-$, $B^-\\rightarrow\\Lambda\\ell^-$, and $B^-\\rightarrow\\bar{\\Lambda}\\ell^-$  

SciTech Connect

Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either {Lambda}{sub c} or {Lambda} and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2 - 520) x 10{sup -8} are set on the branching fractions at the 90% confidence level.

del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Milan U. /Milan U. /Milan U. /Milan U. /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-06-22T23:59:59.000Z

151

A Very Intense Neutrino Super Beam Experiment for Leptonic CP Violation Discovery based on the European Spallation Source Linac: A Snowmass 2013 White Paper  

E-Print Network (OSTI)

Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European Spallation Source currently under construction in Lund, Sweden to deliver, in parallel with the spallation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spallation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few $\\mu$s with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300-600 km from Lund will make it possible to discover leptonic CP violation at 5 $\\sigma$ significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 $\\sigma$ if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented.

E. Baussan; M. Blennow; M. Bogomilov; E. Bouquerel; J. Cederkall; P. Christiansen; P. Coloma; P. Cupial; H. Danared; C. Densham; M. Dracos; T. Ekelof; M. Eshraqi; E. Fernandez Martinez; G. Gaudiot; R. Hall-Wilton; J. -P. Koutchouk; M. Lindroos; R. Matev; D. McGinnis; M. Mezzetto; R. Miyamoto; L. Mosca; T. Ohlsson; H. Ohman; F. Osswald; S. Peggs; P. Poussot; R. Ruber; J. Y. Tang; R. Tsenov; G. Vankova-Kirilova; N. Vassilopoulos; E. Wildner; J. Wurtz

2013-09-26T23:59:59.000Z

152

Determination of J/{psi} leptonic branching fraction via {psi}(2S){r_arrow}{pi}{sup +}{pi}{sup {minus}}J/{psi}  

SciTech Connect

A comparison of the rates for {psi}(2S){r_arrow}{pi}{sup +}{pi}{sup {minus}}J/{psi}, J/{psi}{r_arrow}l{sup +}l{sup {minus}} and J/{psi}{r_arrow} anything is used to determine the J/{psi} leptonic branching fractions. The results are B(J/{psi}{r_arrow}e{sup +}e{sup {minus}})=(5.90{plus_minus}0.05{plus_minus}0.10){percent} and B(J/{psi}{r_arrow}{mu}{sup +}{mu}{sup {minus}})=(5.84{plus_minus}0.06{plus_minus}0.10){percent}, where the first error is statistical and the second is systematic. Assuming lepton universality, the leptonic branching fraction of the J/{psi} is B(J/{psi}{r_arrow}l{sup +}l{sup {minus}})=(5.87{plus_minus}0.04{plus_minus}0.09){percent} per species. This result is used to estimate the QCD scale factor {Lambda}{sub {ovr MS}}{sup (4)} and the strong coupling constant {alpha}{sub s}. {copyright} {ital 1998} {ital The American Physical Society}

Bai, J.Z.; Bian, J.G.; Chai, Z.W.; Chen, G.P.; Chen, J.C.; Chen, Y.; Chen, Y.B.; Chen, Y.Q.; Cheng, B.S.; Cui, X.Z.; Ding, H.L.; Ding, L.Y.; Dong, L.Y.; Du, Z.Z.; Feng, S.; Gao, C.S.; Gao, M.L.; Gao, S.Q.; Gu, J.H.; Gu, S.D.; Gu, W.X.; Gu, Y.F.; Guo, Y.N.; Han, S.W.; Han, Y.; He, J.; He, J.T.; Hu, G.Y.; Hu, H.M.; Hu, J.L.; Hu, Q.H.; Hu, T.; Hu, X.Q.; Huang, J.D.; Huang, Y.Z.; Jiang, C.H.; Jin, Y.; Ke, Z.J.; Lai, Y.F.; Lang, P.F.; Li, C.G.; Li, D.; Li, H.B.; Li, J.; Li, P.Q.; Li, R.B.; Li, W.; Li, W.D.; Li, W.G.; Li, X.H.; Li, X.N.; Liu, H.M.; Liu, J.; Liu, J.H.; Liu, R.G.; Liu, Y.; Lu, F.; Lu, J.G.; Lu, J.Y.; Lu, L.C.; Luo, C.H.; Ma, A.M.; Ma, E.C.; Ma, J.M.; Mao, H.S.; Mao, Z.P.; Meng, X.C.; Nie, J.; Qi, N.D.; Qi, X.R.; Qiu, J.F.; Qu, Y.H.; Que, Y.K.; Rong, G.; Shao, Y.Y.; Shen, B.W.; Shen, D.L.; Shen, H.; Shen, X.Y.; Sheng, H.Y.; Shi, H.Z.; Song, X.F.; Sun, F.; Sun, H.S.; Tang, S.Q.; Tong, G.L.; Wang, F.; Wang, L.S.; Wang, L.Z.; Wang, M.; Wang, M.; Wang, P.; Wang, P.L.; Wang, S.M.; Wang, T.J.; Wang, Y.Y.; Wei, C.L.; Wu, Y.G.; Xi, D.M.; Xia, X.M.; Xie, P.P.; Xie, Y.; Xie, Y.H.; Xiong, W.J.; Xu, C.C.; Xu, G.F.; Xue, S.T.; Yan, J.; Yan, W.G.; Yang, C.M.; Yang, C.Y.; Yang, J.; Yang, X.F.; Ye, M.H.; Yi, K.; Yu, C.S.; Yu, C.X.; Yu, Z.Q.; Yu, Z.T.; Yuan, C.Z.; Yuan, Y.; Zhang, B.Y.; Zhang, C.C.; Zhang, D.H.; Zhang, D.; Zhang, H.L.; Zhang, J.; Zhang, J.L.; Zhang, J.W.; Zhang, L.S.; Zhang, Q.J.; Zhang, S.Q.; Zhang, Y.; Zhang, Y.Y.; Zhao, D.X.; Zhao, H.W.; Zhao, J.W.; Zhao, M.; Zhao, W.R.; Zhao, Z.G.; Zheng, J.P.; Zheng, L.S.; Zheng, Z.P.; Zhou, G.P.; Zhou, H.S.; Zhou, L.; Zhu, Q.M.; Zhu, Y.C.; Zhu, Y.S.; Zhuang, B.A. [Institute of High Energy Physics, Beijing 100039, Peoples Republic of (China)] [Institute of High Energy Physics, Beijing 100039, Peoples Republic of (China); Hitlin, D.G.; Kelsey, M.H.; Oyang, J.; Panetta, J.; Porter, F.; Weaver, M. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Chen, J.; Malchow, R.; Toki, W.; Yang, W. [Colorado State University, Fort Collins, Colorado 80523 (United States)] [Colorado State University, Fort Collins, Colorado 80523 (United States)

1998-11-01T23:59:59.000Z

153

Does DaYa-Bay Reactor Play an Important Role in Theta_{13} of Lepton Mixing (PMNS) Matrix ?  

E-Print Network (OSTI)

Reactor neutrinos play an important role in determining parameter theta_{13} in the lepton mixing (PMNS) matrix. Next important step on measuring PMNS matrix could be to build another reactor neutrino experiment in DaYa bay, China, to search the possible oscillations via sin^2 (2theta_{13}) and Delta m^2_{13}. We consider 4 different schemes for positions of three 8-ton detectors of this experiment, and simulate the results with respect to an array of assumed ''true'' values of physics parameters. Using three kinds of analysis method, we suggest a best scheme for DaYa-Bay which is to place a detector 2200m ~ 2500m symmetrically away from two reactors, and to put the other two detectors closer to their corresponding reactors respectively, almost at a 100m \\~ 200m distance. Moreover, with conservative assumption on the experimental technique, we construct series of allowed regions from our simulation results, and give detailed explanations therein. The movable detectors in DaYa-Bay can measure solar neutrino pa...

Liu, Q Y; Chen, B L; Yang, P

2004-01-01T23:59:59.000Z

154

Inclusive search for doubly charged Higgs in leptonic final states with the 2011 data at 7 TeV  

E-Print Network (OSTI)

A search for the doubly charged Higgs boson in $pp$ collisions at $\\sqrt{s}=7$\\TeV is presented. The data correspond to an integrated luminosity of \\lumitot collected by the CMS experiment at the LHC. The doubly charged Higgs is a member of $SU(2)_L$ scalar triplet $\\Phi$ in extensions of the Standard Model which include the seesaw mechanism of type II. The search is inclusive and is performed in events with three or more isolated charged leptons of all flavors originating from the decays of pair produced triplet components $\\Phi^{++}\\Phi^{--}$ and $\\Phi^{++}\\Phi^{-}.$ No signal is observed and new lower limits at the 95\\% confidence level are set on the $\\Phi^{\\pm\\pm}$ mass, under specific assumption on the $\\dblh$ branching fraction. Upper bounds of \\mmres\\GeV in the $\\mu\\mu$ channel, of \\emres\\GeV in e$\\mu$ channel, of \\eeres\\GeV in the $ee$ channel, of \\mtres\\GeV in the $\\mu\\tau$ channel, of \\etres\\GeV in the e$\\tau$ channel, of \\ttres\\GeV in the $\\tau\\tau$ channel and between \\bponeres\\GeV and \\bptwores\\...

CMS Collaboration

2012-01-01T23:59:59.000Z

155

First evidence for WW and WZ diboson production with semi-leptonic decays at a Hadron Collider  

SciTech Connect

Presented is a measurement of the simultaneous production of a W{sup {+-}} boson in association with a second weak boson (W{sup {+-}} or Z{sup 0}) in p{bar p} collisions at {radical}s = 1.96 TeV. Events are consider with one electron or one muon, missing transverse energy, and at least two hadronic jets. The data were collected by the D0 detector in Run IIa of the Tevatron accelerator and correspond to 1.07 fb{sup -1} of integrated luminosity for each of the two channels (WW/WZ {yields} e{nu}q{bar q} and WW/WZ {yields} {mu}{nu}q{bar q}). The cross section for WW + WZ production is measured to be 20.2 {+-} 2.5(stat) {+-} 3.6(sys) {+-} 1.2(lum) pb with a Gaussian significance of 4.4 standard deviations above the background-only scenario. This measurement is consistent with the Standard Model prediction and represents the first direct evidence for WW and WZ production with semi-leptonic decays at a hadron collider.

Haley, Joseph Glenn Biddle; /Princeton U.

2009-03-01T23:59:59.000Z

156

Collider Detector at Fermilab (CDF): Data from W, Z bosons and Drell Yan lepton pairs research of the CDF Electroweak Group  

DOE Data Explorer (OSTI)

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

157

Measurement of the leptonic asymmetry in ttbar events produced in ppbar collisions at sqrt(s)=1.96 TeV  

E-Print Network (OSTI)

We measure the asymmetry in the charge-weighted rapidity of the lepton in semileptonic ttbar decays recorded with the CDF II detector using the full Tevatron Run II sample, corresponding to an integrated luminosity of 9.4/fb. A parametrization of the asymmetry as a function of the charge-weighted rapidity is used to correct for the finite acceptance of the detector and recover the production-level asymmetry. The result of afb(lep) = 0.094 +0.032 -0.029 is to be compared to the standard model next-to-leading-order prediction of afb(lep) = 0.038 +-0.003.

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

2013-08-05T23:59:59.000Z

158

Possible Lepton Decay Quiz  

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

Posibles decaimientos del leptón Posibles decaimientos del leptón Cuestionario Volver Principal ESTOY PERDIDO!!! ¿Qué decaimientos de leptón son posibles? ¿Si responde no, diga por qué no? Ayuda: ¿Se conservan la energía, la carga, y número leptónico (electrones, muones, y partículas tau)? Respuesta (presione y mantenga): Si. Se conserva la energía, la carga, el número de electrones y partículas tau. Respuesta (presione y mantenga): No. El número del muones no se conserva. Respuesta (presione y mantenga): No. El número de muones y la carga no se conservan. Respuesta (presione y mantenga): Si. El número de parículas tau, la carga, y la energía se conservan. Respuesta (presione y mantenga): No. La energía no se conserva. La masa de un electrón es menor que la masa de un muón.

159

An Inclusive Search for the Higgs Boson in the Four Lepton Final State The Higgs boson is the last undiscovered particle of the Standard Model of Particle Physics (SM).  

E-Print Network (OSTI)

An Inclusive Search for the Higgs Boson in the Four Lepton Final State The Higgs boson is the last undiscovered particle of the Standard Model of Particle Physics (SM). A search for SM Higgs boson decays transverse energy. Our search is optimized for Higgs boson decays to Z-boson pairs but is sensitive, due

Fermilab

160

Study of ttH (H -> mu mu) in the three lepton channel at sqrt(s) = 14 TeV; A Snowmass white paper  

E-Print Network (OSTI)

The H -> mu mu signature provides excellent mass resolution for Higgs bosons, and is therefore an important Higgs boson decay channel despite the small dimuon branching ratio. We present an optimization of selection criteria in a search for trilepton ttH (H -> mu mu) events, in which the top quark pair decays semi-leptonically, at a simulated High Luminosity LHC (HL-LHC) running at 14 TeV. The study is performed with 3000 fb^(-1) of simulated data with an average pileup of = 140. In this ultimate HL-LHC data set, we find that ttH (H -> mu mu) will be a very difficult signature to observe due to the very small expected signal.

Jared Vasquez; Jahred Adelman; Andrey Loginov; Paul Tipton

2013-10-03T23:59:59.000Z

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161

The left-right forward-backward asymmetry of heavy quarks measured with jet charge and with leptons at the SLD  

SciTech Connect

The authors present direct measurements of the left-right asymmetry of b- and c-quarks from the decay of Z{sup 0} bosons produced in the annihilation of longitudinally polarized electrons and unpolarized positrons. Two complementary techniques are presented: (1) Z{sup 0} {yields} b{bar b} decays are tagged using track impact parameters with b{bar b} discrimination provided by momentum-weighted track charge; (2) semileptonic b-decays are tagged using high p and p{sub T} muons and electrons. The preliminary results from their 1993 data sample are: A{sub b} = 0.93 {+-} 0.13 {+-} 0.13 for the jet charge and A{sub b} = 0.93 {+-} 0.14 {+-} 0.09, and A{sub c} = 0.40 {+-} 0.23 {+-} 0.20 for the leptons, where the first error is statistical and the second systematic.

Williams, D.C. [Massachusetts Institute of Technology, Cambridge, MA (United States)]|[Stanford Univ., CA (United States). Stanford Linear Accelerator Center

1994-10-01T23:59:59.000Z

162

CP violation, single lepton polarization asymmetry, and polarized CP asymmetry in B{yields}K{sup *}l{sup +}l{sup -} decay in the four-generation standard model  

SciTech Connect

In this paper we present a study of CP asymmetry, single lepton polarization asymmetry and polarized CP asymmetry in B{yields}K*l{sup +}l{sup -} decay within the four-generation standard model. Taking |V{sub t{sup '}}{sub s}*V{sub t{sup '}}{sub b}|=0.01, 0.02, 0.03 with phase {l_brace}60 deg. -120 deg.{r_brace}, which is consistent with the b{yields}sl{sup +}l{sup -} rate and the Bs mixing parameter {delta}m{sub Bs}, we find that CP asymmetry, single lepton polarization asymmetry and polarized CP asymmetry are sensitive to the existence of the fourth generation. This can serve as an indirect method to search for new physics effects, in particular, to search for the fourth-generation quarks(t{sup '},b{sup '}) via their indirect manifestations in loop diagrams.

Bashiry, V. [Engineering Faculty, Cyprus International University, Via Mersin 10 (Turkey); Shirkhanghah, N. [Islamic Azad University, Khalkhal Branch, Valiasr Street, Khalkhal (Iran, Islamic Republic of); Zeynali, K. [Faculty of Physics, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of)

2009-07-01T23:59:59.000Z

163

Preliminary measurement of time-dependent B{sub d}{sup 0}-B{sub d}{sup 0} mixing using topology and charge selected semi-leptonic B decays  

SciTech Connect

The time dependence of B{sub d}{sup 0}-B{sub d}{sup 0} mixing has been measured using a sample of 150,000 hadronic Z{sup 0} decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons with high (p, p{sub t}) leptons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. Vertex charge is used to enrich the selection of neutral over charged B mesons. This method results in a sample of 581 neutral decays with high charge purity. The B candidate is tagged at production with a combined tag that exploits the large polarized b forward-backward asymmetry in conjunction with the opposite hemisphere b jet charge. The final state is tagged by the sign of the high (p, p{sub t}) lepton. From their preliminary analysis the authors find a mass difference between the two B{sub d}{sup 0} mass eigenstates of, {Delta}m{sub d} = 0.452 {+-} 0.074(stat) {+-} 0.049(syst) ps{sup {minus}1}.

NONE

1996-07-01T23:59:59.000Z

164

Measurement of the top-quark pair production cross-section in events with two leptons and bottom-quark jets using the full CDF data set  

E-Print Network (OSTI)

We present a measurement of the top-quark pair production cross-section in proton-antiproton collisions at $\\sqrt{s}$=1.96 TeV. The data were collected at the Fermilab Tevatron by the CDF II detector and correspond to an integrated luminosity of 8.8 fb$^{-1}$, representing the complete CDF Run II data set. We select events consistent with the production of top-quark pairs by requiring the presence of two reconstructed leptons, an imbalance in the total event transverse momentum, and jets. At least one jet is required to be identified as consistent with the fragmentation of a bottom quark using a secondary-vertex-finding algorithm. The 246 candidate events are estimated to have a signal purity of 91%. We measure a cross section of $\\sigma_{\\ttbar}$ = 7.09 $\\pm$ 0.84 pb, assuming a top-quark mass of 172.5 GeV/$c^{2}$. The results are consistent with the standard model as predicted by next-to-leading-order calculations.

CDF Collaboration

2013-04-30T23:59:59.000Z

165

A search for the production of Direct Leptons in nucleon-nucleus and nucleus-nucleus collisions. Progress report, April 1, 1991--December 1, 1993  

Science Conference Proceedings (OSTI)

The purpose of this report is to describe activities performed by the Intermediate Energy Nuclear Physics Group (IENPG) at the Louisiana State University (LSU) under the terms of grant FG05-88ER40445. The report will cover, for the most part, the period of time between April 1, 1991, and the present. The principal focus of our activities is currently the muon subgroup of the PHENIX Collaboration. We are, however, in the process of concluding other activities, specifically our memberships in the Di-Lepton Spectrometer (DLS) Collaboration at LBL and the AMY Collaboration at KEK. These activities have been thoroughly discussed in previous progress reports and renewal proposals, and further discussion of these activities is possibly repetitious. However, this report has been prepared under the assumption that none of the referees with the exception of the grant monitor is familiar with the group or its previous work. Consequently we shall cite a few examples of our contributions to these collaborations when there seem to be valid reasons for so doing.

Kirk, P.N.

1993-12-15T23:59:59.000Z

166

Structure Functions in Deep Inelastic Lepton Scattering: Data from DOE laboratory experiments as compiled in data reviews by the Durham High Energy Physics Database Group  

DOE Data Explorer (OSTI)

Gehrmann, Roberts, and Whalley in their 1999 paper, A Compilation of Structure Functions in Deep Inelastic Scattering, published in volume 25 of Journal of Physics G (Nuclear and Particle Physics) note that these data will continue to be relevant to the next generation of hadron colliders. They present data on the unpolarized structure functions F2 and xF3, R D ._L=_T /, the virtual photon asymmetries A1 and A2 and the polarized structure functions g1 and g2, from deep inelastic lepton scattering off protons, deuterium and nuclei. Data are presented in both tabular and graphical format and include predictions based on the MRST98 and CTEQ4 parton distribution functions as well. The data gathered from the relevant collaborations at DOE's Fermilab, SLAC, and JLAB are available, and so are data from related collaborations based at CERN and DESY. The Durham High Energy Physics (HEP) Database Group makes these data, extracted from papers and data reviews, available in one place in an easy-to-access format. These data are also include in the Durham HEP Reaction Data Database which can be searched at http://durpdg.dur.ac.uk/spires/hepdata/reac.html

Gehrmann, T; Roberts, R. G.; Whalley, M. R.; Durham HEP Database Group

167

The Discovery of the Tau Lepton: Part 1, The Early History Through 1975; Part 2, Confirmation of the Discovery and Measurement of Major Properties, 1976--1982  

DOE R&D Accomplishments (OSTI)

Several previous papers have given the history of the discovery of the {tau} lepton at the Stanford Linear Accelerator Center (SLAC). These papers emphasized (a) the experiments which led to our 1975 publication of the first evidence for the existence of the {tau}, (b) the subsequent experiments which confirmed the existence of the r, and (c) the experiments which elucidated the major properties of the {tau}. That history will be summarized in Part 2 of this talk. In this Part 1, I describe the earlier thoughts and work of myself and my colleagues at SLAC in the 1960's and early 1970's which led to the discovery. I also describe the theoretical and experimental events in particle physics in the 1960's in which our work was immersed. I will also try to describe for the younger generations of particle physicists, the atmosphere in the 1960's. That was before the elucidation of the quark model of hadrons, before the development of the concept of particle generations The experimental paths to program we hot as clear as they are today and we had to cast a wide experimental net.

Perl, M. L.

1994-08-00T23:59:59.000Z

168

Search for the Higgs Boson Decaying to Two Tau Leptons in Proton-Antiproton Collisions at a Center of Mass Energy of 1.96 TeV  

E-Print Network (OSTI)

A search for the Higgs boson decaying to tau tau using 7.8 fb^-1 of pp collisions at 1.96 TeV collected with CDF II detector is presented. The search is sensitive to four production mechanisms of the Higgs boson: ggH, WH, ZH and VBF. Modes where one tau decay leptonically, and another decay, hadronically, are considered. Two novel techniques are developed and used in the search. A Probabilistic Particle Flow Algorithm is used for energy measurements of the hadronic tau candidates. The signal is discriminated from backgrounds by the Missing Mass Calculator, which allows for full invariant mass reconstruction of tau tau pair. The data are found to be consistent with the background only hypothesis. Therefore a 95% confidence level upper limit on the Standard Model Higgs boson cross section was set. At M_H=120 GeV/c^2 observed limit is 14.9 x sigma_SM x Br(H -> tau tau).

Elagin, Andrey

2011-12-01T23:59:59.000Z

169

A Measurement of the t anti-t Cross Section in p anti-p Collisions at s**(1/2) = 1.96-TeV using Dilepton Events with a Lepton plus Track Selection  

Science Conference Proceedings (OSTI)

This paper reports a measurement of the cross section for the pair production of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron. The data was collected from the CDF II detector in a set of runs with a total integrated luminosity of 1.1 fb{sup -1}. The cross section is measured in the dilepton channel, the subset of t{bar t} events in which both top quarks decay through t {yields} Wb {yields} {ell}{nu}b, where {ell} = e, {mu}, or {tau}. The lepton pair is reconstructed as one identified electron or muon and one isolated track. The use of an isolated track to identify the second lepton increases the t{bar t} acceptance, particularly for the case in which one W decays as W {yields} {tau}{nu}. The purity of the sample may be further improved at the cost of a reduction in the number of signal events, by requiring an identified b-jet. They present the results of measurements performed with and without the request of an identified b-jet. the former is the first published CDF result for which a b-jet requirement is added to the dilepton selection. In the CDF data there are 129 pretag lepton + track candidate events, of which 69 are tagged. With the tagging information, the sample is divided into tagged and untagged sub-samples, and a combined cross section is calculated by maximizing a likelihood. The result is {sigma}{sub t{bar t}} = 9.6 {+-} 1.2(stat.){sub -0.5}{sup +0.6}(sys.) {+-} 0.6(lum.) pb, assuming a branching ratio of BR(W {yields} {ell}{nu}) = 10.8% and a top mass of m{sub t} = 175 GeV/c{sup 2}.

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

2009-03-01T23:59:59.000Z

170

Search for the Standard Model Higgs boson produced in association with a W Boson in the isolated-track charged-lepton channel using the Collider Detector at Fermilab  

SciTech Connect

The Higgs boson is the only elementary particle predicted by the Standard Model (SM) that has not yet been observed experimentally. If it exists, it explains the spontaneous electroweak symmetry breaking and the origin of mass for gauge bosons and fermions. We test the validity of the SM by performing a search for the associated production of a Higgs boson and a W boson in the channel where the Higgs boson decays to a bottom-antibottom quark pair and the W boson decays to a charged lepton and a neutrino (the WH channel). We study a dataset of proton-antiproton collisions at a centre-of-mass energy {radical}s = 1.96 TeV provided by the Tevatron accelerator, corresponding to an integrated luminosity of 5.7 fb{sup -1}, and recorded using the Collider Detector at Fermilab (CDF).We select events consistent with the signature of exactly one charged lepton (electron or muon), missing transverse energy due to the undetected neutrino (MET) and two collimated streams of particles (jets), at least one of which is required to be identified as originating from a bottom quark. We improve the discrimination of Higgs signal from backgrounds through the use of an artificial neural network. Using a Bayesian statistical inference approach, we set for each hypothetical Higgs boson mass in the range 100-150 GeV/c{sup 2} with 5 GeV/c{sup 2} increments a 95% credibility level (CL) upper limit on the ratio between the Higgs production cross section times branching fraction and the SM prediction. Our main original contributions are the addition of a novel charged lepton reconstruction algorithm with looser requirements (ISOTRK) with respect the electron or muon tight criteria (TIGHT), as well as the introduction of a novel trigger-combination method that allows to maximize the event yield while avoiding trigger correlations and that is used for the ISOTRK category. The ISOTRK candidate is a high-transverse-momentum good-quality track isolated from other activity in the tracking system and not required to match a calorimeter cluster, as for a tight electron candidate, or an energy deposit in the muon detector, as for a tight muon candidate. The ISOTRK category recovers real charged leptons that otherwise would be lost in the non-instrumented regions of the detector. This allows the reconstruction of more W boson candidates, which in turn increases the number of reconstructed WH signal candidate events, and therefore improves the sensitivity of the WH search. For the TIGHT charged lepton categories, we employ charged-lepton-dedicated triggers to improve the rate of WH signal acceptance during data taking. Since there is no ISOTRK-dedicated trigger at CDF, for the ISOTRK charged lepton category we employ three MET-plus-jets-based triggers. For each trigger we first identify the jet selection where the trigger efficiency is flat with respect to jet information (transverse energy and direction of motion in the transverse plane for the two jets in the event) and then we parametrize the trigger efficiency as a function of trigger MET. On an event-by-event basis, for each trigger we compute a trigger efficiency as a function of trigger parametrization, trigger MET, jet information, trigger prescale and information about whether the trigger is defined or not. For the ISOTRK category we combine the three triggers using a novel method, which allows the combination of any number of triggers in order to maximize the event yield while avoiding trigger correlations. On an event-by-event basis, only the trigger with the largest efficiency is used. By avoiding a logical 'OR' between triggers, the loss in the yield of events accepted by the trigger combination is compensated by a smaller and easier-to-compute corresponding systematic uncertainty. The addition of the ISOTRK charged lepton category to the TIGHT category produces an increase of 33% in the WH signal yield and a decrease of 15.5% to 19.0% in the median expected 95% CL cross-section upper limits across the entire studied Higgs mass interval. The improvement in analysis sensitivity is smaller than the i

Buzatu, Adrian; /McGill U.

2011-08-01T23:59:59.000Z

171

Exotic atoms and leptonic conservations  

DOE Green Energy (OSTI)

The major 1989 efforts have been on two aspects of experiments at TRIUMF. One effort was production of muonic hydrogen and muonic deuterium into a vacuum. We study rates relevant to muonic catalyzed fusion, and if there are found an adequate number of muons in the 2s state then we plan to measure precision energies. The second effort was to develop plans for kaonic atoms at the kaon factory. We also completed analyses from the experiments with pionic atoms at LAMPF.

Kunselman, R.

1990-01-01T23:59:59.000Z

172

Tau lepton physics at LEP  

E-Print Network (OSTI)

The talk covers three contributions on (i) the final measurement of branching ratios and spectral functions of t decays using the full LEP-I data from ALEPH, (ii) a preliminary measurement of the t hadronic branching ratios from DELPHI and (iii) a measurement of the strange spectral function in hadronic t decays from OPAL. These measurements are discussed and the relevant physics topics are briefly reviewed.

Z. Zhang; the ALEPH; DELPHI; OPAL Collaboration

2006-02-24T23:59:59.000Z

173

Search for the standard model Higgs boson decaying to a $b\\bar{b}$ pair in events with no charged leptons and large missing transverse energy using the full CDF data set  

E-Print Network (OSTI)

We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at $\\sqrt{s} = 1.96$ TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb$^{-1}$. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a $b$ quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and $150 \\mathrm{GeV}/c^2$. For a Higgs boson mass of $125 \\mathrm{GeV}/c^2$, the observed (expected) limit is 6.7 (3.6) times the standard model prediction.

The CDF Collaboration

2012-07-06T23:59:59.000Z

174

Search for Pair Production of a Heavy Up-Type Quark Decaying to a W Boson and a b Quark in the lepton plus jets Channel with the ATLAS Detector  

Science Conference Proceedings (OSTI)

A search is presented for production of a heavy up-type quark (t{prime}) together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t{prime}{bar t}{prime} {yields} W{sup +}bW{sup -}{bar b}. The search is based on 1.04 fb{sup -1} of proton-proton collisions at {radical}s = 7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum, and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit of 404 GeV is set for the mass of the t{prime} quark.

Aad G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; et al.

2012-06-25T23:59:59.000Z

175

Measurement of the t-tbar production cross section in p-pbar collisions at s**(1/2) = 1.96 TeV using lepton+jets events in the CDF detector at Fermilab  

SciTech Connect

The top quark is the most massive fundamental particle observed so far, and the study of its properties is interesting for several reasons ranging from its possible special role in electroweak symmetry breaking to its sensitivity to physics beyond the standard model (SM). In particular, the measurement of the top quark pair production cross section {sigma}{sub t{bar t}} is of interest as a test of QCD predictions. Recent QCD calculations done with perturbation theory to next-to-leading order predict {sigma}{sub t{bar t}} with an uncertainty of less than 15%, which motivate measurements of comparable precision. In this thesis, the author reports a measurement of the cross section for pair production of top quarks in the lepton+jets channel in 318 pb{sup -1} of p{bar p} collision data at {radical}s = 1.96 TeV. The data were recorded between March 2002 and September 2004, during Run II of the Tevatron, by the CDF II detector, a general purpose detector which combines charged particle trackers, sampling calorimeters, and muon detectors. processes in which a W boson is produced in association with several jets with large transverse momentum can be misidentified at t{bar t}, since they have the same signature. In order to separate the t{bar t} events from this background, they develop a method to tag b-jets based on tracking information from the silicon detector. The main event selection requires at least one tight (more restrictive) b tag in the event. As a cross check, they also measure the cross section using events with a loose (less restrictive) b tag and events which have at least two tight or at least two loose b tags. Background contributions from heavy flavor production processes, such as Wb{bar b}, Wc{bar c} or Wc, misidentified W bosons, electroweak processes, single top production, and mistagged jets are estimated using a combination of Monte Carlo calculations and independent measurements in control data samples. An excess over background in the number of events that contain a lepton, missing energy and three or more jets with at least one b-tag is assumed to be a signal of t{bar t} production and is used to measure the production cross section {sigma}{sub t{bar t}}.

Palencia, Enrique; /Cantabria Inst. of Phys. /Cantabria U., Santander

2006-12-01T23:59:59.000Z

176

Measurement of the t anti-t Production Cross Section in p anti-p collisions at s**(1/2) = 1.96-TeV using Lepton + Jets Events with Jet Probability b-tagging  

Science Conference Proceedings (OSTI)

The authors present a measurement of the t{bar t} production cross section using events with one charged lepton and jets from p{bar p} collisions at a center-of-mass energy of 1.96 TeV. A b-tagging algorithm based on the probability of displaced tracks coming from the event interaction vertex is applied to identify b quarks from top decay. Using 318 pb{sup -1} of data collected with the CDF II detector, they measure the t{bar t} production cross section in events with at least one restrictive (tight) b-tagged jet and obtain 8.9{sub -1.0}{sup +1.0}(stat.){sub -1.0}{sup +1.1}(syst.) pb. The cross section value assumes a top quark mass of m{sub t} is presented in the paper. This result is consistent with other CDF measurements of the t{bar t} cross section using different samples and analysis techniques, and has similar systematic uncertainties. They have also performed consistency checks by using the b-tagging probability function to vary the signal to background ratio and also using events that have at least two b-tagged jets.

Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara /Cantabria Inst. of Phys.

2006-07-01T23:59:59.000Z

177

Search for the production of ZW and ZZ boson pairs decaying into charged leptons and jets in proton-antiproton collisions at sqrt(s)=1.96 TeV  

E-Print Network (OSTI)

We present a measurement of the production cross section for ZW and ZZ boson pairs in final states with a pair of charged leptons, from the decay of a Z boson, and at least two jets, from the decay of a W or Z boson, using the full sample of proton-antiproton collisions recorded with the CDF II detector at the Tevatron, corresponding to 8.9 fb^(-1) of integrated luminosity. We increase the sensitivity to vector boson decays into pairs of quarks using a neural network discriminant that exploits the differences between the spatial spread of energy depositions and charged-particle momenta contained within the jet of particles originating from quarks and gluons. Additionally, we employ new jet energy corrections to Monte Carlo simulations that account for differences in the observed energy scales for quark and gluon jets. The number of signal events is extracted through a simultaneous fit to the dijet mass spectrum in three classes of events: events likely to contain jets with a heavy-quark decay, events likely to contain jets originating from light quarks, and events that fail these identification criteria. We determine the production cross section to be 2.5 +2.0 -1.0 pb (< 6.1 pb at the 95% confidence level), consistent with the standard model prediction of 5.1 pb.

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

2013-09-30T23:59:59.000Z

178

Measurement of the top quark mass with the dynamical likelihood method using lepton plus jets events with b-tags in p anti-p collisions at s**(1/2) = 1.96-TeV  

SciTech Connect

This report describes a measurement of the top quark mass, M{sub top}, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/anti-top (t{bar t}) pairs in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318 pb{sup -1}. They use the t{bar t} candidates in the ''lepton+jets'' decay channel, requiring at least one jet identified as a b quark by finding an displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of M{sub top} per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 t{bar t} candidates observed in the data, with 9.2 events expected from background, they measure the top quark mass to be 173.2{sub -2.4}{sup +2.6}(stat.) {+-} 3.2(syst.) GeV/c{sup 2}, or 173.2{sub -4.0}{sup +4.1} GeV/c{sup 2}.

Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, Anthony A.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

2005-12-01T23:59:59.000Z

179

Predicting ?-lepton polarization at the LHC  

E-Print Network (OSTI)

This is a master's thesis and it is written in Lithuanian language. The goal of this thesis is to predict the polarization of a \\tau-particle produced at the LHC and coming from a real W boson. This is achieved by calculating the projection of the expectation value of the polarization vector of the \\tau-particle. Calculations are done in the frame of the Standard Model. In this model only left-chiral currents couple to W bosons. The mass of the \\tau-particle is left non-zero, therefore one can see the influence of helicity mixing on polarization. The initial colliding particles at the LHC are protons and the most important channels for W production are quark fusion: $q\\bar{q} -> W^+ -> \\tau^+ \

Adomas Jelinskas

2013-10-07T23:59:59.000Z

180

Exotic atoms and leptonic conservations. [Univ. of Wyoming, Laramie, Wyoming  

DOE Green Energy (OSTI)

The major 1989 efforts have been on two aspects of experiments at TRIUMF. One effort was production of muonic hydrogen and muonic deuterium into a vacuum. The study includes rates relevant to muon-catalyzed fusion, and if there are found an adequate number of muons in the 2-S state, then precision energies will be measured. The second effort was to develop plans for kaonic atoms at the kaon factory. In addition, analyses from the experiments with pionic atoms at LAMPF were completed.

Kunselman, R.

1991-01-01T23:59:59.000Z

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181

A 233 km tunnel for lepton and hadron colliders  

SciTech Connect

A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e{sup +}e{sup -}, pp-bar , and {mu}{sup +}{mu}{sup -} collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e{sup +}e{sup -} colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e{sup +}e{sup -} collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV pp-bar collider uses the high intensity Fermilab p-bar source, exploits high cross sections for pp-bar production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.

Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T. [Dept. of Physics and Astronomy, University of Mississippi-Oxford, University, MS 38677 (United States)

2012-12-21T23:59:59.000Z

182

TESLA*HERA as Lepton (Photon)-Hadron Collider  

E-Print Network (OSTI)

New facilities for particle and nuclear physics research, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

O. Yavas; A. K. Ciftci; S. Sultansoy

2000-04-11T23:59:59.000Z

183

Radiative proton-antiproton annihilation to a lepton pair  

Science Conference Proceedings (OSTI)

The annihilation of proton and antiproton to an electron-positron pair, including radiative corrections due to the emission of virtual and real photons is considered. The results are generalized to leading and next-to leading approximations. The relevant distributions are derived and numerical applications are given in the kinematical range accessible to the PANDA experiment at the FAIR facility.

Ahmadov, A. I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute of Physics, Azerbaijan National Academy of Sciences, Baku (Azerbaijan); Bytev, V. V.; Kuraev, E. A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Tomasi-Gustafsson, E. [CEA, IRFU, SPhN, Saclay, 91191 Gif-sur-Yvette Cedex, France, and CNRS/IN2P3, Institut de Physique Nucleaire, UMR 8608, 91405 Orsay (France)

2010-11-01T23:59:59.000Z

184

Non-leptonic decays in an extended chiral quark model  

Science Conference Proceedings (OSTI)

We consider the color suppressed (nonfactorizable) amplitude for the decay mode B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0}. We treat the b-quark in the heavy quark limit and the energetic light (u,d,s) quarks within a variant of Large Energy Effective Theory combined with an extension of chiral quark models. Our calculated amplitude for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} is suppressed by a factor of order {Lambda}{sub QCD}/m{sub b} with respect to the factorized amplitude, as it should according to QCD-factorization. Further, for reasonable values of the (model dependent) gluon condensate and the constituent quark mass, the calculated nonfactorizable amplitude for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} can easily accomodate the experimental value. Unfortunately, the color suppressed amplitude is very sensitive to the values of these model dependent parameters. Therefore fine-tuning is necessary in order to obtain an amplitude compatible with the experimental result for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0}.

Eeg, J. O. [Dept. of Physics, Univ. of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway)

2012-10-23T23:59:59.000Z

185

Implementing initial state radiation for lepton induced processes in AMEGIC++.  

E-Print Network (OSTI)

algorithm 15 B. Program Parameters 17 1. Introduction Initial State Radiation (ISR) is the most important QED correction to the Born cross section. For instance, in the case of electron positron annihilations at energies beyond the Zthreshold it leads... . In this way, the correction term becomes several times as large as the Born term at the initial center of mass energy. Evidently, the effect of ISR is of great significance for the interpretation of experimental results. However, since initial state photons...

Schalicke, A; Krauss, F; Kuhn, R; Soff, G

186

Leptonic dipole moments in the left-right supersymmetric ... - Springer  

Science Conference Proceedings (OSTI)

doscalar Higgs boson can give significant contributions to dipole moments at two loop level, coming from Barr-Zee. Fig. 2. Chargino, neutralino and left-right...

187

Measurements of Charged Current Lepton Universality and $|V_{us}|$ using Tau Lepton Decays to $e^- \\bar{\  

E-Print Network (OSTI)

Using 467 $fb^{-1}$ of $e^+e^-$ annihilation data collected with the BaBar detector, we measure $\\frac{{\\cal{B}}(\\tau^- \\to \\mu^- \\bar{\

Aubert, B

2009-01-01T23:59:59.000Z

188

s025.dvi  

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

Charged Lepton Searches Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Sequential Charged Heavy...

189

Exotic atoms and leptonic conservations. Technical progress report, February 1, 1990--January 31, 1991  

DOE Green Energy (OSTI)

The major 1989 efforts have been on two aspects of experiments at TRIUMF. One effort was production of muonic hydrogen and muonic deuterium into a vacuum. The study includes rates relevant to muon-catalyzed fusion, and if there are found an adequate number of muons in the 2-S state, then precision energies will be measured. The second effort was to develop plans for kaonic atoms at the kaon factory. In addition, analyses from the experiments with pionic atoms at LAMPF were completed.

Kunselman, R.

1991-12-31T23:59:59.000Z

190

Charged lepton electric dipole moment enhancement in the Lorentz violated extension of the standard model  

E-Print Network (OSTI)

We consider the Lorentz violated extension of the standard model. In this framework, there are terms that explicitly violate CP-symmetry. We examine the CPT-even $d_{\\mu\

M. Haghighat; I. Motie; Z. Rezaei

2013-08-06T23:59:59.000Z

191

Theta-13 as a Probe of Mu-Tau symmetry for Leptons  

E-Print Network (OSTI)

Many experiments are being planned to measure the neutrino mixing parameter $\\theta_{13}$ using reactor as well as accelerator neutrino beams. In this note, the theoretical significance of a high precision measurement of this parameter is discussed. It is emphasized that it will provide crucial information about different ways to understand the origin of large atmospheric neutrino mixing and move us closer towards determining the neutrino mass matrix. For instance if exact $\\mu\\leftrightarrow \\tau$ symmetry in the neutrino mass matrix is assumed to be the reason for maximal $\

R. N. Mohapatra

2004-08-17T23:59:59.000Z

192

Observable T{sub 7] lepton flavor symmetry at the large hadron collider.  

SciTech Connect

More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T{sub 7} and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.

Cao, Q.-H.; Khalil, S.; Ma, E.; Okada, H. (High Energy Physics); (Univ. of Chicago); (British Univ. in Egypt); (Ain Shams Univ.); (Univ. of California at Riverside)

2011-03-29T23:59:59.000Z

193

The Higgs field can be expressed through the lepton and quark fields  

E-Print Network (OSTI)

The Higgs field is a central point of the Standard Model supplying masses to other fields through the symmetry breaking mechanism. However, it is associated with an elementary particle which is not yet discovered experimentally. In this short note I suggest a way for expressing the Higgs field through other fields of the Standard Model. If this is the case, being not an independent field, the Higgs field does not require an elementary particle to be associated with it.

Ruslan Sharipov

2007-03-01T23:59:59.000Z

194

Search for Higgs decays to tau lepton pairs at the Tevatron  

E-Print Network (OSTI)

We present a search for neutral supersymmetric Higgs bosons decaying to tau+tau- pairs produced in ppbar collisions at sqrt{s}=1.96 TeV. The data have been collected with the CDF II and D0 detectors at the Tevatron collider at Fermilab (1 fb^-1 of integrated luminosity per experiment). No significant excess above the standard model backgrounds is observed. We set exclusion limits on the Higgs production cross-section times the branching fraction of its decay to tau+tau- pairs for Higgs masses in the range from 90 to 250 GeV/c^2. We also set exclusion limits on MSSM parameters m_A and tan_beta in several benchmark scenarios.

I. Kravchenko; for the CDF; D0 Collaborations

2007-10-26T23:59:59.000Z

195

Search for the Higgs boson in its decay into tau leptons at CMS  

E-Print Network (OSTI)

A search for the Standard Model Higgs boson in the H --> rr channel is presented. The search is performed on proton collision data collected by the Compact Muon Solenoid at the Large Hadron Collider. The data corresponds ...

Chan, Matthew Hans

2013-01-01T23:59:59.000Z

196

Determining the spin of supersymmetric particles at the LHC using lepton charge asymmetry.  

E-Print Network (OSTI)

, the production processes qg ? qg and qg ? qg (8) will produce more squarks than anti-squarks. This is because the quark parton distribution function (PDF) is larger than that of the anti-quark due to the presence of the valence quarks. For a significant q...

Barr, Alan

197

Search for the Standard Model Higgs boson in the fully leptonic WW decay channel at CMS.  

E-Print Network (OSTI)

??A search for the Standard Model Higgs boson decaying to W?W? is presented. Data is taken from pp collisions with center of mass energy sqrt(s) (more)

LeBourgeois, Matthew

2012-01-01T23:59:59.000Z

198

Effects of W/sub R/ and charged Higgs in the leptonic decay of /tau/  

Science Conference Proceedings (OSTI)

Experimental test of the existence of the right-hand W boson and the charged Higgs particle is suggested. The experiment involves measurement of muon polarization from the decay of polarized /tau/'s. 8 refs., 2 figs., 1 tab.

Tsai, Yung Su

1989-07-01T23:59:59.000Z

199

Search for Supersymmetry in the one Lepton Channel at the LHC  

E-Print Network (OSTI)

gauge bosons, and Higgs boson of the Standard Model. Thereof the massive spin-zero Higgs boson. Figure from [13]. Afor the standard model higgs boson with the atlas detector

Luthra, Arun

2013-01-01T23:59:59.000Z

200

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

E-Print Network (OSTI)

if the particle P has spin different from zero. The process of eq. (1.1) has production angular correlations if its matrix elements have a non-trivial dependence on (di a), (dib), or (diX). It is therefore clear that the decay chain approximation can account...

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

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


201

Search for the Standard Model Higgs boson in the fully leptonic WW decay channel at CMS  

E-Print Network (OSTI)

of the Higgs boson . . . . . . . . . . . . . . . . . . . . .the Higgs boson . . . . . . . . . . . . . . . . . . . . . .5 Search for the Higgs Boson in the WW Decay Channel . . .

LeBourgeois, Matthew; LeBourgeois, Matthew

2012-01-01T23:59:59.000Z

202

Application of nuclear density functionals to lepton number violating weak processes  

Science Conference Proceedings (OSTI)

We present an application of energy density functional methods with the Gogny interaction to the calculation of nuclear matrix elements (NME) for neutrinoless double beta decay and double electron capture. Beyond mean field effects have been included by particle number and angular momentum restoration and shape mixing within the generator coordinate method (GCM) framework. We analyze in detail the NME for {sup 116}Cd nucleus which is one of the most promising candidates to detect neutrinoless double beta decay.

Rodriguez, Tomas R.; Martinez-Pinedo, Gabriel [Technische Universitaet Darmstadt, Magdalenenstr. 12, D-64289, Darmstadt (Germany) and GSI Helmholtzzentrum fuer Schwerionenforschung, Plankstr. 1, D-64291 Darmstadt (Germany)

2012-10-20T23:59:59.000Z

203

Measurement of the WW+WZ Production Cross Section Using the Lepton+Jets Final State at CDF II  

SciTech Connect

We report two complementary measurements of the diboson (WW + WZ) cross section in the final state consisting of an electron or muon, missing transverse energy, and jets, performed using p{bar p} collision data at {radical}s = 1.96 TeV collected by the Collider Detector at Fermilab. The first method uses the dijet invariant mass distribution while the second method uses more of the kinematic information in the event through matrix-element calculations of the signal and background processes and has a higher sensitivity. The result from the second method has a signal significance of 5.4{sigma} and is the first observation of WW + WZ production using this signature. Combining the results from both methods gives {sigma}{sub WW+WZ} = 16.0 {+-} 3.3 pb, in agreement with the standard model prediction.

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

2009-11-01T23:59:59.000Z

204

A study on dual readout crystal calorimeter for hadron and jet energy measurement at a future lepton collider  

SciTech Connect

Studies of requirements and specifications of crystals are necessary to develop a new generation of crystals for dual readout crystal hadron or total absorption calorimeter. This is a short and basic study of the characteristics and hadron energy measurement of PbWO4 and BGO crystals for scintillation and Cerenkov Dual Readout hadron calorimeter.

Yeh, G.P.; /Fermilab

2010-01-01T23:59:59.000Z

205

Search for the Standard Model Higgs Boson in the Lepton + Missing Transverse Energy + Jets Final State in ATLAS  

E-Print Network (OSTI)

A search for the Standard Model Higgs boson has been performed in the H \\rightarrow WW \\rightarrow l{\

Mark S. Neubauer; for the ATLAS Collaboration

2011-10-11T23:59:59.000Z

206

Herwig++ Monte Carlo At Next-To-Leading Order for e+e- annihilation and lepton pair production.  

E-Print Network (OSTI)

Divergences in Mqq in dead region D 44 G.1.1 Region D : (0, 1), (0, ?1) 44 G.1.2 Region D : (1, 0) 45 G.2 Divergences in Mqg in dead region D 46 G.3 Divergences in (M ? MC)qq in jet region J 46 G.4 Divergences in (M ? MC)qg in jet region J 47 1. Introduction... ++ evolution variables, z and q in (3.6) [15]: dP (q ? qg) = CF 2? ?S [z 2(1? z)2q2]dq 2 q2 dz 1? z [1 + z 2 ? 2m 2 zq2 ] (3.6) where z is the momentum fraction of the quark after gluon emission relative to the parent quark and q is an angular variable...

Latunde-Dada, Oluseyi

207

Optimal use of information for measuring M(t) in lepton + jets t anti-t events  

SciTech Connect

The observation of the top (t) quark served as one of the major confirmations of the validity of the standard model (SM) of particle interactions. Through radiative corrections of the SM, the mass of the top quark, along with that of the W boson, provide the best indication for the value of the mass of the hypothesized Higgs boson. The mass of the W is known to a precision of < 0.1%, while the uncertainty on the mass of the top quark is at the 4% level. Improvements in both measurements are required to limit the range of mass that the Higgs boson can assume in the SM, and, of course, to check whether that agrees with expectation. It is therefore important to develop techniques for extracting the mass of the top quark that can provide the sharpest values possible.

Juan Estrada

2003-10-14T23:59:59.000Z

208

Majorana CP-violating phases in neutrino-antineutrino oscillations and other lepton-number-violating processes  

E-Print Network (OSTI)

If the massive neutrinos are identified to be the Majorana particles via a convincing measurement of the neutrinoless double beta (0\

Zhi-zhong Xing; Ye-Ling Zhou

2013-05-24T23:59:59.000Z

209

Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix Element Method and in situ Jet Energy Calibration  

E-Print Network (OSTI)

A precision measurement of the top quark mass m_t is obtained using a sample of ttbar events from ppbar collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m_t and a parameter DJES to calibrate the jet energy scale /in situ/. Using a total of 1087 events, a value of m_t = 173.0 +/- 1.2 GeV/c^2 is measured.

T. Aaltonen et al.

2010-10-21T23:59:59.000Z

210

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

SciTech Connect

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

Freeman, John; /Fermilab

2004-12-01T23:59:59.000Z

211

Nobel Prize in Physics 1995  

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

contributions to lepton physics, specifically for the discovery of the tau lepton" Martin L. Perl Button 12 of prize Button USA Button born 1927 Button CA - Stanford Linear...

212

quarklep_s054-web.dvi  

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

SEARCHES FOR QUARK AND LEPTON COMPOSITENESS Revised 2001 by K. Hagiwara (KEK), and K. Hikasa and M. Tanabashi (Tohoku University). If quarks and leptons are made of constituents,...

213

The Particle Adventure | Glossary  

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

Lepton A fundamental fermion that does not participate in strong interactions. The electrically-charged leptons are the electron (e-), the muon ( ), the tau ( ), and their...

214

Particle Data Group - 2009 Particle Listings  

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

for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy...

215

Particle Data Group - Particle Listings - 2007 update  

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

for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy...

216

Particle Data Group - 2011 Particle Listings  

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

for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy...

217

Muon performance aspects and measurement of the inclusive ZZ production cross section through the four lepton final state with the ATLAS experiment at the LHC  

E-Print Network (OSTI)

The "Large Hadron Collider" (LHC) is currently the most powerful particle accelerator. It provides particle collisions at a center of mass energy in the Tera-electronvolt range, which had never been reached in a laboratory before. Thereby a new era in high energy particle physics has began. Now it is possible to test one of the most precise theories in physics, the Standard Model of particle physics, at these high energies. The purpose is particularly served by four large experiments installed at the LHC, namely "A Toroidal LHC ApparatuS" (ATLAS), the "Compact-Muon-Solenoid" (CMS), the "Large Hadron Collider beauty" (LHCb) and "A Large Ion Collider Experiment" (ALICE). Besides exploring the high energy behavior of the well-established portions of the Standard Model, one of the main objectives is to find the Higgs boson included in the model, but not discovered by any preceding effort. It is of tremendous importance since fermions and heavy electroweak gauge bosons acquire mass because of this boson. Although ...

Meyer, Jochen; Strhmer, Raimund

2013-07-08T23:59:59.000Z

218

Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix Element Method and \\textit{in situ} Jet Energy Calibration  

SciTech Connect

A precision measurement of the top quark mass m{sub t} is obtained using a sample of t{bar t} events from p{bar p} collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used to calibrate the jet energy scale in situ. Using a total of 1087 events, a value of m{sub t} = 173.0 {+-} 1.2 GeV/c{sup 2} is measured.

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

2010-10-01T23:59:59.000Z

219

Search for the Standard Model Higgs Boson Decaying to a bb? Pair in Events with Two Oppositely Charged Leptons Using the Full CDF Data Set  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45??fb[superscript ...

Gomez-Ceballos, Guillelmo

220

Search for pair-produced heavy quarks decaying to Wq in the two-lepton channel at root(s)=7 TeV with the ATLAS detector  

SciTech Connect

A search is presented for heavy-quark pair production (QQ{sup -}) under the decay hypothesis QQ{sup -} {yields} W{sup +}qW{sup -}q{sup -} with q=d, s, b for up-type Q or q=u, c for down-type Q. The search is performed with 1.04 fb{sup -1} of integrated luminosity from pp collisions at {radical}s = 7 TeV collected by the ATLAS detector at the CERN LHC. Dilepton final states are selected, requiring large missing transverse momentum and at least two jets. Mass reconstruction of heavy-quark candidates is performed by assuming that the W boson decay products are nearly collinear. The data are in agreement with standard model expectations; a heavy quark with mass less than 350 GeV is excluded at 95% confidence level.

Aad G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; et al.

2012-07-23T23:59:59.000Z

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


221

Search for the standard model Higgs boson decaying to a bb pair in events with two oppositely-charged leptons using the full CDF data set  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45/fb. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production cross section times the H -> bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^2 we observe (expect) a limit of 7.1 (3.9) times the standard model value.

CDF Collaboration

2012-07-06T23:59:59.000Z

222

A search for new physics with Z bosons, jets, and missing transverse energy at CMS  

E-Print Network (OSTI)

effiency, and lepton selection efficiency uncertainties are assessed as flat uncertainties. The hadronic energy

Andrews, Warren T.

2012-01-01T23:59:59.000Z

223

Outlook: The Next Twenty Years  

E-Print Network (OSTI)

reactor anti- neutrinos, K-physics, Lepton Flavor Violation, Cos- mic Microwave Background, string theory,

Murayama, Hitoshi

2009-01-01T23:59:59.000Z

224

The Particle Adventure | Glossary  

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

Tau ( ) The third flavor of charged lepton (in order of increasing mass), with electric charge -1...

225

Glossary Term - Liquid Nitrogen  

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

Lepton Previous Term (Lepton) Glossary Main Index Next Term (Mercury) Mercury Liquid Nitrogen Liquid nitrogen boils in a frying pan on a desk. The liquid state of the element...

226

The Particle Adventure | Glossary  

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

Flavor The name used for the different quarks types (up, down, strange, charm, bottom, top) and for the different lepton types (electron, muon, tau). For each charged lepton flavor...

227

Glossary Term - Joule  

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

Isotope Previous Term (Isotope) Glossary Main Index Next Term (Lepton) Lepton Joule A joule is the amount of work done when a force of one Newton is applied through a distance of...

228

Update on the ILC Positron Source Study at ANL  

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

GeV THPEC036 Proceedings of IPAC'10, Kyoto, Japan 4134 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques T02 Lepton Sources beam will lose less energy...

229

unknown title  

E-Print Network (OSTI)

(DOI: will be inserted by hand later) A broadband leptonic model for gamma-ray emitting microquasars

V. Bosch-ramon; G. E. Romero; J. M. Paredes

2005-01-01T23:59:59.000Z

230

Search for Higgs Bosons Predicted in Two-Higgs-Doublet Models via Decays to Tau Lepton Pairs in 1.96 TeV pp[over-bar] Collisions  

E-Print Network (OSTI)

We present the results of a search for Higgs bosons predicted in two-Higgs-doublet models, in the case

Bauer, Gerry P.

231

Search for t[ over t] resonances in the lepton plus jets final state with ATLAS using 4.7??fb[superscript -1] of pp collisions at ?s=7??TeV  

E-Print Network (OSTI)

A search for new particles that decay into top quark pairs (tt? ) is performed with the ATLAS experiment at the LHC using an integrated luminosity of 4.7??fb[superscript -1] of protonproton (pp) collision data collected ...

Taylor, Frank E.

232

Measurement of the tt-bar cross section in pp-bar collisions at sqrt[s]=1.96 TeV using dilepton events with a lepton plus track selection  

E-Print Network (OSTI)

This paper reports a measurement of the cross section for the pair production of top quarks in pp? collisions at ?s=1.96??TeV at the Fermilab Tevatron. The data were collected from the CDF run II detector in a set of runs ...

Xie, Si

233

Search for the Standard Model Higgs Boson Decaying to a bb? Pair in Events with No Charged Leptons and Large Missing Transverse Energy using the Full CDF Data Set  

E-Print Network (OSTI)

We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at ?s=1.96??TeV recorded by the CDF II detector at the Tevatron, ...

Gomez-Ceballos, Guillelmo

234

Search for Supersymmetry Using Final States with One Lepton, Jets, and Missing Transverse Momentum with the ATLAS Detector in ?s=7??[square root of s=7] TeV pp Collisions  

E-Print Network (OSTI)

This Letter presents the first search for supersymmetry in final states containing one isolated electron or muon, jets, and missing transverse momentum from ?s=7??[square root of s=7] TeV proton-proton collisions at the ...

Taylor, Frank E.

235

Study of B_s Mixing at the D-Zero Detector at Fermilab Using the Semi-leptonic Decay B_s -> D_s mu nu X  

SciTech Connect

B{sub s}{sup 0} mixing studies provide a precision test of Charge-Parity violation in the Standard Model. A measurement of {Delta}m{sub s} constrains elements of the CKM quark rotation matrix [1], providing a probe of Standard Model Charge-Parity violation. This thesis describes a study of B{sub s}{sup 0} mixing in the semileptonic decay B{sub s}{sup 0} {yields} D{sub s}{sup -} {mu}{sup +}{nu}X, where D{sub s}{sup -} {yields} {phi}{pi}{sup -}, using data collected at the D-Zero detector at Fermi National Accelerator in Batavia, Illinois. Approximately 2.8 fb{sup -1} of data collected between April 2002 and August 2007 was used, covering the entirety of the Tevatron's RunIIa (April 2002 to March 2006) and part of RunIIb (March 2006-August 2007). Taggers using both opposite-side and same-side information were used to obtain the flavor information of the B{sub s}{sup 0} meson at production. The charge of the muon in the decay B{sub s}{sup 0} {yields} D{sub s}{sup -}{mu}{sup +}{nu}X was used to determine the flavor of the B{sub s}{sup 0} at decay. The B{sub d}{sup 0} mixing frequency, {Delta}m{sub d}, was measured to verify the analysis procedure. A log-likelihood calculation was performed, and a measurement of {Delta}m{sub s} was obtained. The final result was {Delta}m{sub s} = 18.86 {+-} 0.80(stat.) {+-} 0.37(sys.) with a significance of 2.6{sigma}.

Anzelc, Meghan; /Northwestern U.

2008-06-01T23:59:59.000Z

236

Search for the standard model Higgs boson decaying to a bb pair in events with one charged lepton and large missing transverse energy using the full CDF data set  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson produced in association with a W boson in sqrt(s) = 1.96 TeV p-pbar collision data collected with the CDF II detector at the Tevatron corresponding to an integrated luminosity of 9.45 fb-1. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a neutrino, we set 95% credibility level upper limits on the WH production cross section times the H->bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c2 we observe (expect) a limit of 4.9 (2.8) times the standard model value.

The CDF Collaboration

2012-07-06T23:59:59.000Z

237

s025.dvi  

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

Heavy Heavy Charged Lepton Searches NODE=S025 Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS Charged Heavy Lepton MASS LIMITS NODE=S025205 Sequential Charged Heavy Lepton (L ± ) MASS LIMITS Sequential Charged Heavy Lepton (L ± ) MASS LIMITS Sequential Charged Heavy Lepton (L ± ) MASS LIMITS Sequential Charged Heavy Lepton (L ± ) MASS LIMITS NODE=S025MS These experiments assumed that a fourth generation L ± decayed to a fourth generation NODE=S025MS ν L (or L 0 ) where ν L was stable, or that L ± decays to a light ν ℓ via mixing. See the "Quark and Lepton Compositeness, Searches for" Listings for limits on radia- tively decaying excited leptons, i.e. ℓ ∗ → ℓ γ. See the "WIMPs and other Particle Searches" section for heavy charged particle search limits in which the charged particle could be a lepton. NODE=S025MS;CHECK

238

Citation: K. Hagiwara  

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

Heavy Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Note that LEP results in combination with REUSSER 91 exclude a fourth stable neutrino with m< 2400 GeV. VALUE (GeV) CL% DOCUMENT ID TECN COMMENT >45.0 >45.0 >45.0 >45.0 95 ABREU 92B DLPH Dirac >39.5 >39.5 >39.5 >39.5 95 ABREU 92B DLPH Majorana >44.1 95 ALEXANDER 91F OPAL Dirac >37.2 95 ALEXANDER 91F OPAL Majorana none 3-100 90 SATO 91 KAM2 Kamiokande II >42.8 95 1 ADEVA 90S L3 Dirac >34.8 95 1 ADEVA 90S L3 Majorana >42.7 95 DECAMP 90F ALEP Dirac 1 ADEVA 90S limits for the heavy neutrino apply if the mixing with the charged leptons satisfies U 1 j 2

239

s077.dvi  

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

Neutral Neutral Leptons, Searches for (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Note that LEP results in combination with REUSSER 91 exclude a fourth stable neutrino with m< 2400 GeV. VALUE (GeV) CL% DOCUMENT ID TECN COMMENT >45.0 >45.0 >45.0 >45.0 95 ABREU 92B DLPH Dirac >39.5 >39.5 >39.5 >39.5 95 ABREU 92B DLPH Majorana >44.1 95 ALEXANDER 91F OPAL Dirac >37.2 95 ALEXANDER 91F OPAL Majorana none 3-100 90 SATO 91 KAM2 Kamiokande II >42.8 95 1 ADEVA 90S L3 Dirac >34.8 95 1 ADEVA 90S L3 Majorana >42.7 95 DECAMP 90F ALEP Dirac 1 ADEVA 90S limits for the heavy neutrino apply if the mixing with the charged leptons satisfies U 1 j 2 + U 2

240

Challenges in Accelerator Beam Instrumentation  

E-Print Network (OSTI)

The challenges in beam instrumentation and diagnostics for present and future particle accelerator projects are presented. A few examples for advanced hadron and lepton beam diagnostics are given.

Wendt, M

2009-01-01T23:59:59.000Z

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


241

Challenges in Accelerator Beam Instrumentation  

Science Conference Proceedings (OSTI)

The challenges in beam instrumentation and diagnostics for present and future particle accelerator projects are presented. A few examples for advanced hadron and lepton beam diagnostics are given.

Wendt, M.

2009-12-01T23:59:59.000Z

242

s077.dvi  

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

Heavy Heavy Neutral Leptons, Searches for NODE=S077 (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons (A) Heavy Neutral Leptons NODE=S077245 Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS Stable Neutral Heavy Lepton MASS LIMITS NODE=S077340 Note that LEP results in combination with REUSSER 91 exclude a fourth NODE=S077340 stable neutrino with m< 2400 GeV. NODE=S077MNS;CHECK LIMITS VALUE (GeV) CL% DOCUMENT ID TECN COMMENT >45.0 >45.0 >45.0 >45.0 95 ABREU 92B DLPH Dirac OCCUR=2 >39.5 >39.5 >39.5 >39.5 95 ABREU 92B DLPH Majorana >44.1 95 ALEXANDER 91F OPAL Dirac OCCUR=2 >37.2 95 ALEXANDER 91F OPAL Majorana none 3-100 90 SATO 91 KAM2 Kamiokande II >42.8 95 1 ADEVA 90S L3 Dirac OCCUR=2 >34.8 95 1 ADEVA 90S L3 Majorana >42.7 95 DECAMP 90F ALEP Dirac

243

SLAC-PUB-2446  

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

2446 2446 December 1979 (T/E) THE TAU LEPTON" Martin L. Per1 Stanford Linear Accelerator Center Stanford University, Stanford, California 94305 U.S.A. Submitted to Annual Review of Nuclear and Particle Science * Work supported by the Department of Energy, contract DE-AC03-76SF00515. TAU LEPTON TABLE OF CONTENTS -2- -1. SI INTRODUCTION 1.1 The Definition of a Lepton 1.2 The Tau Lepton 2. THEORETICAL FRAMEWORK 2.1 2.2 2.3 2.4 Weak Interactions and Lepton Conservation Simple Models for New Charged Leptons 2.2.1 SEQUENTIAL LEPTON MODEL 2.2.2 ORTHOLEPTON MODEL 2.2.3 PARALEPTON MODEL e-p- T Universality Leptons and Quarks 3. THE IDENTIFICATION OF THE TAU AS A LEPTON 3.1 Decay Process Signatures 3.2 e+e- Production Process Signatures 3.2.1 THEORY 3.2.2 EXPERIMENTAL RESULTS BELOW 8 GeV

244

The Particle Adventure | Glossary  

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

Quark (t) The sixth flavor of quark (in order of increasing mass), with electric charge 23. Its mass is much greater than any other quark or lepton...

245

Bringing the Higgs Boson to Rest.  

E-Print Network (OSTI)

??Within the Standard Model of particle physics, the Higgs boson can decay to a pair of W bosons which decay leptonically. Despite its relatively large (more)

van Nieuwkoop, Koos

2013-01-01T23:59:59.000Z

246

First Evidence For Atmospheric Neutrino-Induced Cascades with the IceCube Detector  

E-Print Network (OSTI)

G. Puhlhofer, and H. J. Volk. Theory of cosmic ray and47] E. G. Berezhko and H. J. Volk. Hadronic versus leptonic

D'Agostino, Michelangelo

2009-01-01T23:59:59.000Z

247

The Particle Adventure | Glossary  

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

Neutrino ( ) A lepton with no electric charge. Neutrinos participate only in weak and gravitational interactions and are therefore very difficult to detect. There are three known...

248

The Particle Adventure | Glossary  

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

Weak Interaction The interaction responsible for all processes in which flavor changes, hence for the instability of heavy quarks and leptons, and particles that contain them. Weak...

249

Glossary of Scientific Terms  

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

Atmosphere Cyclotron Deuterium Deuteron Dry Ice Electron Electron Capture Electron Volt (eV) Gluon Half-life Helios Isotope Joule Lepton Liquid Nitrogen Mercury Mole Neptune...

250

Generation of Neutrino Masses and Mixings in Gauge Theories  

E-Print Network (OSTI)

I review models which present large flavor mixings of the lepton sector based on the gauge theory. (Invited talk at WIN99) 1

Morimitsu Tanimoto

1999-01-01T23:59:59.000Z

251

The Particle Adventure | Glossary  

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

Electron The least massive electrically-charged particle, hence absolutely stable. It is the most common lepton, with electric charge -1...

252

Electric dipole moments, from e to tau  

E-Print Network (OSTI)

We derive an upper limit on the electric dipole moment (EDM) of the tau-lepton, which follows from the precision measurements of the electron EDM.

Grozin, A G; Rudenko, A S

2008-01-01T23:59:59.000Z

253

Constraints on Non-Standard Neutrino Interactions and Unparticle Physics with Neutrino-Electron Scattering at the Kuo-Sheng Nuclear Power Reactor  

E-Print Network (OSTI)

Neutrino-electron scatterings are purely leptonic processes with robust Standard Model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. The $\

M. Deniz er al.; TEXONO Collaboration

2010-06-10T23:59:59.000Z

254

Search for the Standard Model Higgs boson with the ATLAS experiment at the LHC leading to the observation of a new particle compatible with the Higgs boson.  

E-Print Network (OSTI)

??Le sujet de cette thse est la recherche du boson de Higgs du Modle Standard par sa dsintgration en quatre leptons avec lexprience ATLAS au (more)

Mountricha, Eleni

2012-01-01T23:59:59.000Z

255

Rare and forbidden decays - Springer  

Science Conference Proceedings (OSTI)

a flavor-blind, doubly charged Higgs boson in a left-right symmetric model. [760]. Constraints on lepton number violation come from various reactions,.

256

Considerations for a Dielectric-based Two-beam-accelerator Linear...  

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

WEPE033 Proceedings of IPAC'10, Kyoto, Japan 3428 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A03 Linear Colliders high coupling coefficient...

257

Numerical and Experimental Studies of Dispersive, Active, and...  

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

breakdown. Proceedings of IPAC'10, Kyoto, Japan THPD070 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A14 Advanced Concepts 4443 Figure 2. Kerr medium;...

258

Experiment on a Tunable Dielectric-Loaded Accelerating Structure  

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

Proceedings of IPAC'10, Kyoto, Japan THPD068 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A14 Advanced Concepts 4437 is connected to the...

259

Observation of Wakefields in a Beam-Driven Photonic Band Gap...  

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

Proceedings of IPAC'10, Kyoto, Japan THPD066 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A14 Advanced Concepts 4431 Figure 1: Schematic...

260

Standard Model Quiz  

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

los cientos de partculas conocidas? RESPUESTA: S, 6 quarks, 6 leptones, 6 antiquarks 6 antileptones, y los portadores de fuerza. Regreso a la ruta del Modelo Standard......

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


261

leptoquark_s056230-web.dvi  

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

particles carrying both baryon number (B) and lepton number (L). The possible quantum num- bers of leptoquark states can be restricted by assuming that their direct...

262

mxxx005-tab.dvi  

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

- - 0.008 π - modes are charge conjugates of the modes below. For decay limits to particles which are not established, see the section on Searches for Axions and Other Very Light Bosons. p π + DECAY MODES π + DECAY MODES π + DECAY MODES π + DECAY MODES Fraction (Γ i /Γ) Confidence level (MeV /c) µ + ν µ [b] (99.98770± 0.00004) % 30 µ + ν µ γ [c] ( 2.00 ± 0.25 ) × 10 -4 30 e + ν e [b] ( 1.230 ± 0.004 ) × 10 -4 70 e + ν e γ [c] ( 7.39 ± 0.05 ) × 10 -7 70 e + ν e π 0 ( 1.036 ± 0.006 ) × 10 -8 4 e + ν e e + e - ( 3.2 ± 0.5 ) × 10 -9 70 e + ν e ν ν < 5 × 10 -6 90% 70 Lepton Family number (LF) or Lepton number (L) violating modes Lepton Family number (LF) or Lepton number (L) violating modes Lepton Family number (LF) or Lepton number (L) violating modes Lepton Family number (LF) or Lepton number (L) violating modes µ + ν e L [d] < 1.5 × 10 -3 90% 30 µ + ν e LF [d] < 8.0 × 10 -3 90% 30 µ - e + e + ν LF < 1.6 × 10 -6 90% 30 HTTP://PDG.LBL.GOV

263

mxxx005-sumtab.dvi  

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

- 0.008 π - modes are charge conjugates of the modes below. For decay limits to particles which are not established, see the section on Searches for Axions and Other Very Light Bosons. p π + DECAY MODES π + DECAY MODES π + DECAY MODES π + DECAY MODES Fraction (Γ i /Γ) Confidence level (MeV /c) µ + ν µ [b] (99.98770± 0.00004) % 30 µ + ν µ γ [c] ( 2.00 ± 0.25 ) × 10 -4 30 e + ν e [b] ( 1.230 ± 0.004 ) × 10 -4 70 e + ν e γ [c] ( 7.39 ± 0.05 ) × 10 -7 70 e + ν e π 0 ( 1.036 ± 0.006 ) × 10 -8 4 e + ν e e + e - ( 3.2 ± 0.5 ) × 10 -9 70 e + ν e ν ν < 5 × 10 -6 90% 70 Lepton Family number (LF) or Lepton number (L) violating modes Lepton Family number (LF) or Lepton number (L) violating modes Lepton Family number (LF) or Lepton number (L) violating modes Lepton Family number (LF) or Lepton number (L) violating modes µ + ν e L [d] < 1.5 × 10 -3 90% 30 µ + ν e LF [d] < 8.0 × 10 -3 90% 30 µ - e + e + ν LF < 1.6 × 10 -6 90% 30 π 0 π

264

Tau identification at the Tevatron  

SciTech Connect

Methods for reconstructing and identifying the hadronic decays of tau leptons with the CDF and D0 detectors at the Fermilab Tevatron collider in Run II are described. Precision electroweak measurements of W and Z gauge boson cross sections are presented as well as results of searches for physics beyond the Standard Model with hadronically decaying tau leptons in the final state.

Levy, Stephen; /Chicago U., EFI

2005-07-01T23:59:59.000Z

265

Tau Physics 2006: Summary & Outlook  

E-Print Network (OSTI)

A large amount of new results have been presented at TAU2006. The highlights of the workshop, the present status of a few selected topics on lepton physics (universality, QCD tests, Vus determination from ? decay, g ? 2, ? oscillations, lepton-flavour violation) and the prospects for future improvements are briefly summarized. 1.

A. Pich A

2007-01-01T23:59:59.000Z

266

Tau Physics 2006: Summary & Outlook  

E-Print Network (OSTI)

A large amount of new results have been presented at TAU2006. The highlights of the workshop, the present status of a few selected topics on lepton physics (universality, QCD tests, V_{us} determination from tau decay, g-2, neutrino oscillations, lepton-flavour violation) and the prospects for future improvements are briefly summarized.

Antonio Pich

2007-02-07T23:59:59.000Z

267

Common Origin of (-)^L, (-)^{3B}, and Strong CP Conservation  

E-Print Network (OSTI)

The multiplicative conservation of both lepton and baryon numbers, i.e. (-)^L and (-)^{3B}, is connected to an axionic solution of the strong CP problem in a supersymmetric, unifiable model of quark and lepton interactions. New particles are predicted at the TeV scale, with verifiable consequences at the Large Hadron Collider.

Ernest Ma

2008-04-24T23:59:59.000Z

268

Particle Data Group - 2012 Particle Listings  

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

Cut-off date for this update was January 15, 2012. Cut-off date for this update was January 15, 2012. GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-), Searches for Heavy Bosons, Other Than Higgs Bosons, Searches for (rev.) Axions (A0) and Other Very Light Bosons, Searches for (rev.) Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings (rev.) Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay (rev.) Introduction to Three-Neutrino Mixing Parameters Listings Neutrino Mixing (rev.) Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...) Note on the Quark Masses (rev.)

269

Particle Data Group - 2008 Particle Listings  

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

GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-), Searches for Heavy Bosons, Other Than Higgs Bosons, Searches for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay Neutrino Mixing Solar Neutrinos Review Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...) Note on the Quark Masses LIGHT QUARKS --- u, d, s c quark b quark t quark b' quark (4**th Generation) t' quark (4**th Generation) Free Quark Searches

270

Particle Data Group - 2013 Particle Listings  

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

. . and 2013 partial update for the 2014 edition. Cut-off date for this update was January 15, 2013. GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-) Heavy Bosons, Other Than Higgs Bosons, Searches for (rev.) Axions (A0) and Other Very Light Bosons, Searches for (rev.) Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings (rev.) Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay (rev.) Introduction to Three-Neutrino Mixing Parameters Listings Neutrino Mixing (rev.) Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...)

271

Particle Data Group - 2010 Particle Listings  

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

GAUGE AND HIGGS BOSONS (gamma, g, W, Z, ...) gamma g (gluon) graviton W boson Z boson Higgs Bosons (H0 and H+-), Searches for Heavy Bosons, Other Than Higgs Bosons, Searches for Axions (A0) and Other Very Light Bosons, Searches for Collapse Gauge and Higgs Boson table LEPTONS (e, mu, tau, neutrinos, heavy leptons ...) electron muon tau Heavy Charged Lepton Searches Introduction to the Neutrino Properties Listings Neutrino Properties Number of Neutrino Types Double-beta Decay Note on Neutrinoless Double-beta Decay Introduction to Three-Neutrino Mixing Parameters Listings Neutrino Mixing Heavy Neutral Leptons, Searches for Collapse Leptons table QUARKS (u, d, s, c, b, t, ...) Note on the Quark Masses LIGHT QUARKS --- u, d, s c quark b quark t quark b' quark (4**th Generation)

272

neutrino_mixing_s805.dvi  

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

NEUTRINO NEUTRINO PHYSICS AS EXPLORED BY FLAVOR CHANGE Written May 2002 by B. Kayser (Fermilab). I. The physics of flavor change: The rather convincing evidence that atmospheric neutrinos change from one flavor to another has now been joined by new, very strong evidence that the solar neutrinos do this as well. Neutrino flavor change implies that neutrinos have nonzero masses. That is, there is a spectrum of three or more neutrino mass eigenstates, ν 1 , ν 2 , ν 3 , . . ., that are the analogues of the charged-lepton mass eigenstates, e, µ, and τ . Neutrino flavor change also implies leptonic mixing. That is, the weak interaction coupling the W boson to a charged lepton and a neutrino can couple any charged-lepton mass eigenstate α to any neutrino mass eigenstate ν i . Here, α = e, µ, or τ , and e is the electron, etc. Leptonic W + decay can yield a particular + α in association with any ν i . The amplitude

273

On the origin of families of fermions and their mass matrices  

E-Print Network (OSTI)

We are proposing a new way of describing families of quarks and leptons, using the approach unifying all the internal degrees of freedom, proposed by one of us. Spinors, living in d(=1+13)-dimensional space, carry in this approach only the spin and interact with only the gravity through vielbeins and two kinds of the spin connection fields - the gauge fields of the Poincare group and the second kind of the Clifford algebra objects. All the quarks and the leptons of one family appear in one Weyl representation of a chosen handedness of the Lorentz group, if analyzed with respect to the Standard model gauge groups: the right handed (with respect to SO(1,3)) weak chargeless quarks and leptons and the left handed weak charged quark and leptons. A part of the starting Lagrange density of a Weyl spinor in d=1+13 transforms right handed quarks and leptons into left handed quarks and leptons manifesting as the Yukawa couplings of the Standard model. The second kind of Clifford algebra objects generates families and contributes to diagonal and off diagonal Yukawa couplings. The approach predicts an even number of families, treating leptons and quarks equivalently. In this paper we investigate within this approach the appearance of the Yukawa couplings within one family of quarks and leptons as well as among the families (without assuming any Higgs fields). We present the mass matrices for four families and investigate whether our way of generating families might explain the origin of families of quarks and leptons as well as their observed properties - the masses and the mixing matrices. Numerical results are presented in the paper following this one.

Anamarija Borstnik Bracic; Norma Susana Mankoc Borstnik

2005-12-05T23:59:59.000Z

274

Search for r-parity violating supersymmetry in the multilepton final state  

SciTech Connect

This thesis presents a search for physics beyond the standard model of elementary particles in events containing three or more charged leptons in the final state. The search is based on an R-parity violating supersymmetric model that assumes supersymmetric particles are pair produced at hadron colliders and the R-parity violating coupling is small enough so that these particles ''cascade'' decay into the lightest supersymmetric particle. The lightest supersymmetric particle may only decay into two charged leptons (electrons or muons) plus a neutrino through a lepton number violating interaction. Proton-antiproton collision events produced with {radical} s= 1.96 TeV are collected between March 2002 and August 2004 with an integrated luminosity of 346 pb{sup -1}. R-parity violating supersymmetry is sought for in two data samples, one with exactly three leptons and one with four or more leptons. The trilepton sample has a modest background primarily from Drell-Yan events where an additional lepton is a result of photon conversions or jet misidentification while the four or more lepton sample has an extremely low background. In the three lepton samples 6 events are observed while in the four or more lepton sample zero events are observed. These results are consistent with the standard model expectation and are interpreted as mass limits on the lightest neutralino and lightest chargino particles. The neutralino mass is constrained to be heavier than 97.7 to 110.4 GeV/c{sup 2}, while the chargino mass is constrained to be heavier than 185.3 to 202.7 GeV/c{sup 2}, depending on the supersymmetry scenario.

Attal, Alon J.; /UCLA

2006-11-01T23:59:59.000Z

275

Search for Supersymmetry in the Dilepton Final State with Taus at CDF Run II  

SciTech Connect

This thesis presents the results a search for chargino and neutralino supersymmetric particles yielding same signed dilepton final states including one hadronically decaying tau lepton using 6.0 fb{sup -1} of data collected by the the CDF II detector. This signature is important in SUSY models where, at high tan {beta}, the branching ratio of charginos and neutralinos to tau leptons becomes dominant. We study event acceptance, lepton identification cuts, and efficiencies. We set limits on the production cross section as a function of SUSY particle mass for certain generic models.

Forrest, Robert David; /California U., Davis

2011-09-01T23:59:59.000Z

276

Fermilab Today  

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

4:00 p.m. Accelerator Physics and Technology Seminar - 1 West Speaker: E. Gianfelice-Wendt, DESY Title: The Lepton Beam Polarisation in the Frame of the Hera Luminosity Upgrade...

277

Future directions in particle and nuclear physics at multi-GeV hadron beam facilities  

Science Conference Proceedings (OSTI)

This report contains papers on the following topics in particle and nuclear physics: hadron dynamics; lepton physics; spin physics; hadron and nuclear spectroscopy; hadronic weak interactions; and Eta physics. These papers have been indexed separately elsewhere.

Geesaman, D.F. [Argonne National Lab., IL (United States)] [ed.

1993-11-01T23:59:59.000Z

278

Scalar meson mediated nuclear mu-e conversion  

E-Print Network (OSTI)

We study the nuclear mu-e conversion in the general framework of the effective Lagrangian approach without referring to any specific realization of the physics beyond the standard model (SM) responsible for lepton flavor violation (LFV). We analyze the role of scalar meson exchange between the lepton and nucleon currents and show its relevance for the coherent channel of mu-e conversion. We show that this mechanism introduces modifications in the predicted mu-e conversion rates in comparison with the conventional direct nucleon mechanism, based on the contact type interactions of the nucleon currents with the LFV leptonic current. We derive from the experimental data lower limits on the mass scales of the generic LFV lepton-quark contact terms and demonstrate that they are more stringent than the similar limits existing in the literature.

Amand Faessler; Th. Gutsche; Sergey Kovalenko; V. E. Lyubovitskij; Ivan Schmidt

2005-07-04T23:59:59.000Z

279

Higgs mechanism as a collective effect due to an extra dimension  

Science Conference Proceedings (OSTI)

the chiral lepton SU(2) multiplets, and the dots denote similar terms for quark fields. The minimum of ..... The fields Xi, which may produce nonpositive-norm states, enter the interaction only in the combina- tions. ? = ? ? ..... search (Grant No.

280

A study of tau identification with the CMS detector at the LHC  

E-Print Network (OSTI)

In this thesis I explore the identification of [tau] leptons from simulated reconstructed data that will be collected by the Compact Muon Solenoid (CMS) detector on the Large Hadron Collider (LHC) at CERN. The two components ...

Ilten, Philip James

2008-01-01T23:59:59.000Z

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


281

??e??MEG  

Science Conference Proceedings (OSTI)

The MEG experiment started a search for a lepton violating (LFV) muon decay ? + ?e + ? at Paul Scherrer Institut(PSI) in Switzerland. The LFV muon decay does not occur in the standard model while new theories

Ryu Sawada; the MEG collaboration

2009-01-01T23:59:59.000Z

282

Commissioning of Particle ID at ATLAS and CMS with Early LHC Data  

E-Print Network (OSTI)

This paper describes latest results on lepton (electron, muon and tau) and photon particle identification at the ATLAS and CMS experiments, with emphasis on how the particle identification can be validated and its performance determined using early LHC data.

T. Berger-Hryn'ova; for the ATLAS; CMS collaborations

2008-08-28T23:59:59.000Z

283

gutsrpp.dvi  

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

and 2013 update for the 2014 edition (http:pdg.lbl.gov) December 18, 2013 11:57 2 15. Grand Unified Theories Although quarks and leptons are unified with the states of one family...

284

The Particle Adventure | Glossary  

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

Particle A particle with no internal substructure. In the Standard Model the quarks, leptons, photons, gluons, W+ and W- bosons, and the Z bosons are fundamental. All other objects...

285

The Particle Adventure | Glossary  

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

Generation A set of one of each charge type of quark and lepton, grouped by mass. The first generation contains the up and down quarks, the electron and the electron neutrino....

286

Particle Data Group - 2011 Summary Tables  

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

Gauge and Higgs Bosons (gamma, g, W, Z, ...) Leptons (e, mu, tau, ... neutrinos ...) Quarks (u, d, s, c, b, t, b', t', Free) Mesons contents Baryons contents Searches (Monopoles,...

287

Development of the 4th Concept Detector  

Science Conference Proceedings (OSTI)

For the support of a new technology high energy collider ("4th") for potential use at a new lepton collider. In addition, support for dual-readout calorimetry, CERN RD52.

John M. Hauptman

2013-03-01T23:59:59.000Z

288

Particle Data Group - 2010 Summary Tables  

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

Gauge and Higgs Bosons (gamma, g, W, Z, ...) Leptons (e, mu, tau, ... neutrinos ...) Quarks (u, d, s, c, b, t, b', t', Free) Mesons errata contents Baryons errata contents...

289

Particle Data Group - 2009 Summary Tables  

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

Gauge and Higgs Bosons (gamma, g, W, Z, ...) Leptons (e, mu, tau, ... neutrinos ...) Quarks (u, d, s, c, b, t, b', t', Free) Mesons contents Baryons contents Searches (Monopoles,...

290

Particle Data Group - 2008 Summary Tables  

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

Gauge and Higgs Bosons (gamma, g, W, Z, ...) Leptons (e, mu, tau, ... neutrinos ...) Quarks (u, d, s, c, b, t, b', t', Free) Mesons contents Baryons contents Searches (Monopoles,...

291

Observation  

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

the large mass of the implies an affinity to Higgs bosons. Within the SM, the Higgs boson is related to the mechanism by which the quarks, leptons and force-carrying gauge...

292

The Particle Adventure  

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

is the number of 4-lepton events we predict will occur from decays not involving a Higgs boson. The blue part (following page) represents the "signal" prediction, which is the...

293

Searches at the Tevatron  

Science Conference Proceedings (OSTI)

The CDF and D collider experiments at Fermilab have searched for evidence of physics beyond the Standard Model of particle physics. We report on the results of searches for extra heavy gauge bosons quark?lepton compositeness

Robert Illingworth; CDF collaboration; D collaboration

2005-01-01T23:59:59.000Z

294

The physics of heavy flavors  

SciTech Connect

We review the physics of heavy quark flavors, including weak decays, onium, tau leptons, mixing, the Kobayashi-Maskawa matrix, and CP violation in B decay. 36 refs., 12 figs.

Gilman, F.J.

1987-12-01T23:59:59.000Z

295

Achim Hillenbrand Pan Pacific Spin 2009,Yamagata, Japan1 HERMES overview  

E-Print Network (OSTI)

section asymmetry in synchrotron radiation emission leads to build-up of transverse polarization (Sokolov excellent lepton/hadron separation RICH: two radiators allow hadron separation between 2-15 GeV Aerogel; n=1

296

Particle Data Group - Figures from 2012 edition of RPP  

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

Leptons Quarks Mesons Baryons Searches Figures from the Reviews in the Gauge and Higgs Boson Listings: The Mass and Width of the W Boson (rev.) Fig. 1 Fig. 2 Higgs Bosons:...

297

Particle Data Group - Figures from 2009 edition of RPP  

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

Leptons Quarks Mesons Baryons Searches Figures from the Reviews in the Gauge and Higgs Boson Listings: The Mass and Width of the W Boson (Rev.) Fig. 1 Fig. 2 Higgs Bosons:...

298

Particle Data Group - Figures from 2007 web update of RPP  

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

Leptons Quarks Mesons Baryons Searches Figures from the Reviews in the Gauge and Higgs Boson Listings: The Mass of the W Boson Fig. 1 Searches for Higgs Bosons Fig. 1 Fig. 2...

299

Particle Data Group - Figures from 2008 edition of RPP  

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

Leptons Quarks Mesons Baryons Searches Figures from the Reviews in the Gauge and Higgs Boson Listings: The Mass and Width of the W Boson Fig. 1 Fig. 2 Higgs Bosons: Theory and...

300

Particle Data Group - Figures from 2010 edition of RPP  

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

Leptons Quarks Mesons Baryons Searches Figures from the Reviews in the Gauge and Higgs Boson Listings: The Mass and Width of the W Boson (rev.) Fig. 1 Fig. 2 Higgs Bosons:...

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301

Particle Data Group - Figures from 2011 edition of RPP  

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

Leptons Quarks Mesons Baryons Searches Figures from the Reviews in the Gauge and Higgs Boson Listings: The Mass and Width of the W Boson (2010) Fig. 1 Fig. 2 Higgs Bosons:...

302

Search for the Standard Model Higgs Boson Produced in Association with a Z Boson in the Electron-Muon Final State and the Higgs Boson Decaying into Bottom Quarks.  

E-Print Network (OSTI)

??A search for the standard model Higgs boson is presented in the associated production channel Z(??)H(bb) where each tau decays leptonically, one to an electron, (more)

Bartek, Rachel A.

2013-01-01T23:59:59.000Z

303

Determining the heavy seesaw neutrino mass matrix from low-energy parameters  

E-Print Network (OSTI)

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with inter-family or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.

He, Xiao-Gang; Volkas, Raymond R

2008-01-01T23:59:59.000Z

304

Determining the heavy seesaw neutrino mass matrix from low-energy parameters  

E-Print Network (OSTI)

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with inter-family or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.

Xiao-Gang He; Sandy S. C. Law; Raymond R. Volkas

2008-10-07T23:59:59.000Z

305

Determining the heavy seesaw neutrino mass matrix from low-energy parameters  

Science Conference Proceedings (OSTI)

We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intrafamily symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with interfamily or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.

He Xiaogang [Department of Physics, Center for Theoretical Sciences and LeCosPA Center, National Taiwan University, Taipei 10617, Taiwan (China); Law, Sandy S. C.; Volkas, Raymond R. [School of Physics, University of Melbourne, Victoria 3010 (Australia)

2008-12-01T23:59:59.000Z

306

Reconstruction and selection of Z ?????+?? jet +? s decays at the CMS experiment  

Science Conference Proceedings (OSTI)

At the LHC tau leptons are expected in final states of many important physics processes including Supersymmetry and the production of Higgs boson(s) and other exotic particles. An efficient and accurate ? reconstruction and identification are therefore an important part of the CMS physics programme. Z 0 ?? + ? ? decays are often considered the standard candle of tau reconstruction as they validate tau lepton identification and provide a test bench for Higgs searches (for which they constitute the main irreducible background).

Letizia Lusito; The CMS Collaboration

2010-01-01T23:59:59.000Z

307

Conference Summary  

E-Print Network (OSTI)

Having heard of the tremendous progress seen in the last year in the field of flavor physics and CP violation, I would like to invite the audience to contemplate some of the questions we are ultimately trying to answer, and to ponder how much progress has been made towards answering them. Some of these deep questions are Why are there several generations of quarks and leptons? Are there precisely three? Is there some underlying structure that explains the presence of generations? Are the generations really identical except for the mass, or is there some basic distinction between them? Is there a fundamental explanation to the hierarchy of masses? Is there are a relation between quark and lepton masses, or between quarks/leptons of different generations? What gives rise to the texture of mixings between generations? Is this related to the masses of quarks and leptons? Is flavor physics tied to Electro-Weak symmetry breaking? What is the origin of the observed CP violation? Is the CP violation in the mixings (of quarks and leptons) enough to accommodate baryogenesis or leptogenesis? Else, what is

Benjamn Grinstein

2004-01-01T23:59:59.000Z

308

Search for new physics in trilepton events and limits on the associated chargino-neutralino production at CDF  

E-Print Network (OSTI)

We perform a search for new physics using final states consisting of three leptons and a large imbalance in transverse momentum resulting from proton-antiproton collisions at 1.96 TeV center-of-mass energy. We use data corresponding to 5.8 fb-1 of integrated luminosity recorded by the CDF II detector at the Tevatron collider. Our main objective is to investigate possible new low-momentum (down to 5 GeV/c) multi-leptonic final states not investigated by LHC experiments. Relative to previous CDF analyses, we expand the geometric and kinematic coverage of electrons and muons and utilize tau leptons that decay hadronically. Inclusion of tau leptons is particularly important for supersymmetry (SUSY) searches. The results are consistent with standard-model predictions. By optimizing our event selection to increase sensitivity to the minimal supergravity (mSUGRA) SUSY model, we set limits on the associated production of chargino and neutralino, the SUSY partners of the electroweak gauge bosons. We exclude cross sections up to 0.1 pb and chargino masses up to 168 GeV/c^2 at 95% CL, for a suited set of mSUGRA parameters. We also exclude a region of the two-dimensional space of the masses of the neutralino and the supersymmetric partner of the tau lepton, not previously excluded at the Tevatron.

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

2013-09-28T23:59:59.000Z

309

A Higgs Quadruplet for Type III Seesaw and Implications for $?\\to e?$ and $?- e$ Conversion  

E-Print Network (OSTI)

In Type III seesaw model the heavy neutrinos are contained in leptonic triplet representations. The Yukawa couplings of the triplet fermion and the left-handed neutrinos with the doublet Higgs field produce the Dirac mass terms. Together with the Majorana masses for the leptonic triplets, the light neutrinos obtain non-zero seesaw masses. We point out that it is also possible to have a quadruplet Higgs field to produce the Dirac mass terms to facilitate the seesaw mechanism. The vacuum expectation value of the quadruplet Higgs is constrained to be small by electroweak precision data. Therefore the Yukawa couplings of a quadruplet can be much larger than those for a doublet. We also find that unlike the usual Type III seesaw model where at least two copies of leptonic triplets are needed, with both doublet and quadruplet Higgs representations, just one leptonic triplet is possible to have a phenomenologically acceptable model because light neutrino masses can receive sizable contributions at both tree and one loop levels. Large Yukawa couplings of the quadruplet can induce observable effects for lepton flavor violating processes $\\mu \\to e \\gamma$ and $\\mu - e$ conversion. Implications of the recent $\\mu \\to e\\gamma$ limit from MEG and also limit on $\\mu - e $ conversion on Au are also given. Some interesting collider signatures for the doubly charged Higgs boson in the quadruplet are discussed.

Bo Ren; Koji Tsumura; Xiao-Gang He

2011-07-29T23:59:59.000Z

310

Higgs quadruplet for the type III seesaw model and implications for {mu}{yields}e{gamma} and {mu}-e conversion  

SciTech Connect

In the type III seesaw model, the heavy neutrinos are contained in leptonic triplet representations. The Yukawa couplings of the triplet fermion and the left-handed neutrinos with the doublet Higgs field produce the Dirac mass terms. Together with the Majorana masses for the leptonic triplets, the light neutrinos obtain nonzero seesaw masses. We point out that it is also possible to have a quadruplet Higgs field to produce the Dirac mass terms to facilitate the seesaw mechanism. The vacuum expectation value of the quadruplet Higgs is constrained to be small by electroweak precision data. Therefore, the Yukawa couplings of a quadruplet can be much larger than those for a doublet. We also find that unlike the usual type III seesaw model where at least two copies of leptonic triplets are needed, with both doublet and quadruplet Higgs representations, just one leptonic triplet is possible to have a phenomenologically acceptable model because light neutrino masses can receive sizable contributions at both tree and one-loop levels. Large Yukawa couplings of the quadruplet can induce observable effects for lepton flavor violating processes {mu}{yields}e{gamma} and {mu}-e conversion. Implications of the recent {mu}{yields}e{gamma} limit from MEG and the limit on {mu}-e conversion on Au are also given. Some interesting collider signatures for the doubly charged Higgs boson in the quadruplet are discussed.

Ren Bo [INPAC, Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Tsumura, Koji [Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China); He Xiaogang [INPAC, Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China)

2011-10-01T23:59:59.000Z

311

Tau Trigger at the ATLAS Experiment  

Science Conference Proceedings (OSTI)

Many theoretical models, like the Standard Model or SUSY at large tan({beta}), predict Higgs bosons or new particles which decay more abundantly to final states including tau leptons than to other leptons. At the energy scale of the LHC, the identification of tau leptons, in particular in the hadronic decay mode, will be a challenging task due to an overwhelming QCD background which gives rise to jets of particles that can be hard to distinguish from hadronic tau decays. Equipped with excellent tracking and calorimetry, the ATLAS experiment has developed tau identification tools capable of working at the trigger level. This contribution presents tau trigger algorithms which exploit the main features of hadronic tau decays and describes the current tau trigger commissioning activities. Many of the SM processes being investigated at ATLAS, as well as numerous BSM searches, contain tau leptons in their final states. Being able to trigger effectively on the tau leptons in these events will contribute to the success of the ATLAS experiment. The tau trigger algorithms and monitoring infrastructure are ready for the first data, and are being tested with the data collected with cosmic muons. The development of efficiency measurements methods using QCD and Z {yields} {tau}{tau} events is well advanced.

Benslama, K.; Kalinowski, A.; /Regina U.; Belanger-Champange, C.; Brenner, R.; /Uppsala U.; Bosman, M.; Casado, P.; Osuna, C.; Perez, E.; Vorwerk, V.; /Barcelona, IFAE; Czyczula, Z.; Dam, M.; Xella, S.; /Copenhagen U.; Demers, S.; /SLAC; Farrington, S.; /Oxford U.; Igonkina, O.; /NIKHEF, Amsterdam; Kanaya, N.; Tsuno, S.; /Tokyo U.; Ptacek, E.; Reinsch, A.; Strom, David M.; Torrence, E.; /Oregon U. /Sydney U. /Lancaster U. /Birmingham U.

2011-11-09T23:59:59.000Z

312

Inquiring Minds  

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

is the world made of? is the world made of? The building blocks Physicists have identified 12 building blocks that are the fundamental constituents of matter. Our everyday world is made of just three of these building blocks: the up quark, the down quark and the electron. This set of particles is all that's needed to make protons and neutrons and to form atoms and molecules. The electron neutrino, observed in the decay of other particles, completes the first set of four building blocks. The building blocks of matter: six quarks and six leptons. For some reason nature has elected to replicate this first generation of quarks and leptons to produce a total of six quarks and six leptons, with increasing mass. Like all quarks, the sixth quark, named top, is much smaller than a proton (in fact, no one knows how small quarks are), but the

313

PDFs for nuclear targets  

E-Print Network (OSTI)

Understanding nuclear effects in parton distribution functions (PDF) is an essential component needed to determine the strange and anti-strange quark contributions in the proton. In addition Nuclear Parton Distribution Functions (NPDF) are critically important for any collider experiment with nuclei (e.g. RHIC, ALICE). Here two next-to-leading order chi^2-analyses of NPDF are presented. The first uses neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors (F_2^Fe/F_2^D) for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

Karol Kovarik

2010-06-25T23:59:59.000Z

314

Searches for MSSM Higgs bosons at ATLAS and CMS  

E-Print Network (OSTI)

The Minimal Supersymmetric extension of the Standard Model (MSSM) predicts the existence of three neutral and two charged Higgs bosons. Searches for these MSSM Higgs bosons are presented, based on proton-proton collisions recorded in 2011 and 2012 by the ATLAS and CMS experiments at the LHC. The neutral Higgs bosons are searched through their decays into pairs of oppositely charged tau leptons. The exclusion limits at 95% confidence level are shown as a function of the $m_A$ and $\\tan\\beta$ parameters. The search for the charged Higgs bosons is based on their production through the decays of top quarks in the $t\\bar{t}$ process, $t \\to bH^+$. The Higgs bosons subsequently decay predominantly into a tau lepton and a neutrino. Upper limits are set on the branching fraction $B(t \\to bH^+)$, combining the final states with leptonic and hadronic tau decay modes.

Stan Lai

2013-03-17T23:59:59.000Z

315

Signals of an invisibly decaying Higgs in a scalar dark matter scenario: a study for the Large Hadron Collider  

E-Print Network (OSTI)

We consider the collider phenomenology of a singlet Majoron model with softly broken lepton number. Lepton number is spontaneously broken when the real part of a new singlet scalar develops vacuum expectation value. With the additional soft terms violating lepton numbers, the imaginary part of this singlet scalar becomes a massive pseudo-Majoron which can account for the dark matter. In presence of the coupling of the pseudo-Majoron with the Standard Model (SM) Higgs, the SM Higgs mostly decays into a pair of pseudo-Majorons, giving rise to missing transverse energy signals at a hadron collider. Since the Higgs visible decay branching fractions get reduced in presence of this invisible decay mode, the bounds on the SM Higgs mass from the LEP and Tevatron experiments get diluted and the invisible decay channel of the Higgs become important for the discovery of low mass Higgs at the Large Hadron Collider.

Kirtiman Ghosh; Biswarup Mukhopadhyaya; Utpal Sarkar

2011-05-29T23:59:59.000Z

316

Search for Higgs boson production in trilepton and like-charge electron-muon final states with the D0 detector  

E-Print Network (OSTI)

We present a search for Higgs bosons in multilepton final states in pp-bar collisions at sqrt(s)=1.96 TeV recorded with the D0 detector at the Fermilab Tevatron Collider, using the full Run II data set with integrated luminosities of up to 9.7 fb-1. The multilepton states considered are two electron plus muon, electron with two muons, muon with two hadronic tau leptons, and like-charge electron-muon pairs. These channels directly probe the HVV (V=W,Z) coupling of the Higgs boson in production and decay. The muon with two hadronic tau lepton channel is also sensitive to H to tau lepton pair decays. Upper limits at the 95% C.L on the rate of standard model Higgs boson production are derived in the mass range 100 Higgs boson model.

D0 Collaboration

2013-02-22T23:59:59.000Z

317

Measurement of sigma(ppbar->Z) Br(Z->tau+tau-) and search for Higgs bosons decaying to tau+tau- at s**(1/2) = 1.96 TeV  

SciTech Connect

The resonant production of tau-lepton pairs is as interesting for the study of Standard Model (SM) physics as the production of lighter leptons pairs. For new phenomena, such as Higgs boson production or in case new particles beyond the SM would arise, the detection of (resonant) pairs of tau leptons becomes much more interesting. This is due to the fact that tau leptons are much heavier than the other leptons, which increases the chance that these new phenomena would be observed first in this channel. Unfortunately their clean detection is far more difficult than that of muons or electrons. The cross section times branching ratio {sigma}{center_dot} Br for the process p{bar p} {yields} Z {yields} {tau}{sup +}{tau}{sup -} was measured at {radical}s = 1.96 GeV using 1.0 fb{sup -1} of data collected by the D0 experiment. This measurement was performed in the channel in which one of the tau leptons decays to a muon and neutrinos, while the other decays either hadronically or to an electron and neutrinos. A set of 1511 events, of which about 20% estimated background, passed all selection criteria. The trigger and muon reconstruction efficiencies, as well as the efficiency for track reconstruction were obtained from data using the 'tag and probe' method on Z {yields} {mu}{sup +}{mu}{sup -} events. The multijet background was estimated from the sample of events which passed all selection criteria but in which the muon and the tau candidate had the same charge. The W {yields} {mu}{nu} + jets background was modeled by Monte Carlo simulations, but normalized to data. All the other backgrounds, as well as the efficiency for Z {yields} {tau}{sup +}{tau}{sup -} events were estimated using simulated events normalized to the theoretical calculations of cross sections at next-to-leading order or next-to-next-to-leading order. The energy of the tau candidates was corrected for the estimated response of the charged pions in the calorimeter, which is of the order 50-80%. Since the charged pion response in data was not well reproduced by the default simulation of hadronic interactions (Geisha), a different simulation (gCALOR) was used to obtain an estimated charged pion response consistent with the one measured in data. This tau energy correction method makes use of the superior resolution of the track momentum measurement compared to the resolution of the tau candidate energy as measured by the calorimeter, which leads to a better data--simulation agreement and a decrease of 10% in the resolution of the visible mass peak. The result of this measurement is {sigma}(p{bar p} {yields} Z) {center_dot} Br(Z {yields} {tau}{sup +}{tau}{sup -}) = 240 {+-} 8(stat) {+-} 12(syst) {+-} 15(lumi) pb, in good agreement with the theoretical predictions of 241.6{sub -3.2}{sup +3.6} pb [79] or 251.9{sub -12}{sup +5.1} pb [93-95], as well as with other measurements performed by the D0 and CDF experiments in all channels in which the Z boson decays leptonically [96-100]. This is the most precise Z boson cross section measurement to date performed in the tau lepton channel at hadron colliders. The analysis demonstrates the ability of the D0 experiment to identify tau leptons decaying hadronically with good efficiency and high purity, a challenging task in p{bar p} collisions where the number of jets resembling tau leptons is very high. This achievement forms a solid basis for other analyses using hadronic tau lepton decays, such as the search for the Higgs boson decaying into tau-lepton pairs, which was performed for the last part of this thesis.

Galea, Cristina Florina; /Nijmegen U.

2008-01-01T23:59:59.000Z

318

Report of the Snowmass 2013 energy frontier QCD working group  

E-Print Network (OSTI)

This is the summary report of the energy frontier QCD working group prepared for Snowmass 2013. We review the status of tools, both theoretical and experimental, for understanding the strong interactions at colliders. We attempt to prioritize important directions that future developments should take. Most of the efforts of the QCD working group concentrate on proton-proton colliders, at 14 TeV as planned for the next run of the LHC, and for 33 and 100 TeV, possible energies of the colliders that will be necessary to carry on the physics program started at 14 TeV. We also examine QCD predictions and measurements at lepton-lepton and lepton-hadron colliders, and in particular their ability to improve our knowledge of strong coupling constant and parton distribution functions.

J. M. Campbell; K. Hatakeyama; J. Huston; F. Petriello; J. Andersen; L. Barze; H. Beauchemin; T. Becher; M. Begel; A. Blondel; G. Bodwin; R. Boughezal; S. Carrazza; M. Chiesa; G. Dissertori; S. Dittmaier; G. Ferrera; S. Forte; N. Glover; T. Hapola; A. Huss; X. Garcia i Tormo; M. Grazzini; S. Hoche; P. Janot; T. Kasprzik; M. Klein; U. Klein; D. Kosower; Y. Li; X. Liu; P. Mackenzie; D. Maitre; E. Meoni; K. Mishra; G. Montagna; M. Moretti; P. Nadolsky; O. Nicrosini; F. Piccinini; L. Reina; V. Radescu; J. Rojo; J. Russ; S. Sapeta; A. Schwartzman; P. Skands; J. Smillie; I. W. Stewart; F. J. Tackmann; F. Tramontano; R. Van de Water; J. R. Walsh; S. Zuberi

2013-10-19T23:59:59.000Z

319

Form invariance and symmetry in the neutrino mass matrix  

SciTech Connect

We present the general form of the unitary matrices keeping invariant the Majorana neutrino mass matrix of specific texture suitable for explaining oscillation data. In the case of the tri-bimaximal pattern with two degenerate masses, we give a specific realization of the underlying U(1) symmetry which can be uplifted to a symmetry in a complete theory including charged leptons. For this, we present a model with three light SM-like Higgs doublets and one heavy Higgs triplet and find that one can accommodate the hierarchy of the charged-lepton masses. The lepton mass spectrum can also be achieved in another model extending the SM with three SM-singlet scalars transforming nontrivially under the flavor symmetry. We discuss how such a model has room for generating enough baryon asymmetry through leptogenesis in the framework of type-I and -II seesaw mechanisms.

Lashin, E. I. [Department of Physics and Astronomy, College of Science, King Saud University, Riyadh (Saudi Arabia); Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Nasri, S.; Malkawi, E. [Department of Physics, UAE University, P.O. Box 17551, Al-Ain (United Arab Emirates); Chamoun, N. [Physics Department, HIAST, P.O. Box 31983, Damascus (Syrian Arab Republic)

2011-01-01T23:59:59.000Z

320

Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass  

Science Conference Proceedings (OSTI)

It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0{nu}{beta}{beta}-decay in three different nuclei, e.g. {sup 76}Ge, {sup 100}Mo and {sup 130}Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.

Vergados, J. D. [Physics Department, University of Ioannina, Ioannina, GR 451 10, Greece and Theory Division, CERN 1211, Geneva 23 (Greece)

2011-12-16T23:59:59.000Z

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


321

The Universe Adventure - Fundamental Particles  

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

Fundamental Particles Fundamental Particles Chart of Fundamental Particles All matter in the universe is comprised of fundamental particles. So what exactly makes up this matter? All matter is made of fundamental particles that came into being at the birth of the Universe. Quarks experience the strong force which is carried by massless particles called gluons. They bond together in specific combinations to form protons, neutrons, and other hadrons. Leptons do not experience the strong force but may interact via the electromagnetic force, the weak force, or both. Anti-quarks and anti-leptons are exactly the same as their quark and lepton counterparts, but have an opposite charge. All massive particles are influenced by the force of gravity. Quark-Gluon Plasma: 10-12 Seconds After the Big Bang

322

A Model of Proton  

E-Print Network (OSTI)

I suggest to consider a proton as a body in a state of free precession. Such approach allows to define a proton as periodic system with two rotary degrees of freedom with corresponding frequency ratio and resonances. In result on a power scale the points corresponding to a birth of leptons are designated. The interrelation between masses of leptons is established through a fine structure constant. The given approach is distributed to a nucleus. Other representation is given on the nature of X-rays which connect with a charge of a nucleus and its mass.

Vladislav Shchegolev

2005-06-14T23:59:59.000Z

323

When will we know a muon collider is feasible? Status and directions of muon accelerator R&D  

E-Print Network (OSTI)

Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture, accelerate and collide high intensity beams of muons. At present, a high-luminosity multi-TeV muon collider presents a viable option for the next generation lepton-lepton collider, which is believed to be needed to fully explore high energy physics in the era following the LHC discoveries. This article briefly reviews the status of the accelerator R&D, addresses the question of the feasibility of a Muon Collider, what needs to be done to prove it and presents projected timeline of the project.

Vladimir Shiltsev

2010-03-16T23:59:59.000Z

324

A light triplet boson and Higgs-to-diphoton in supersymmetric type II seesaw  

E-Print Network (OSTI)

The supersymmetric type II seesaw may leave a limit where a triplet boson along with the standard Higgs boson remains light. Working in this limit with small triplet vacuum expectation vlaues, we explore how much such a light triplet boson can contribute to the Higgs boson decay to diphoton, and analyze the feasibility to observe it through same-sign di-lepton and tetra-lepton signals in the forthcoming LHC run after setting a LHC7 limit in a simplified parameter space of the triplet vaccum expectation value and the doubly charged boson mass.

Eung Jin Chun; Pankaj Sharma

2013-01-08T23:59:59.000Z

325

HIggs Boson Mass in the Minimal Unified Subquark Model  

E-Print Network (OSTI)

In the original paper entitled, "Masses of Fundamental Particles", not only the masses of fundamental particles including the weak bosons, Higgs scalar, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite model of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

Hidezumi Terazawa

2011-09-17T23:59:59.000Z

326

Search for B+ --> mu+ nu_mu With Inclusive Reconstruction at BaBar  

SciTech Connect

We search for the purely leptonic decay B{sup {+-}} {yields} {mu}{sup {+-}}{nu}{sub {mu}} in the full BABAR dataset, having an integrated luminosity of approximately 426 fb{sup -1}. We adopt a fully inclusive approach, where the signal candidate is identified by the highest momentum lepton in the event and the companion B is inclusively reconstructed without trying to identify its decay products. We set a preliminary upper limit on the branching fraction of {Beta}(B{sup {+-}} {yields} {mu}{sup {+-}}{nu}{sub {mu}}) < 1.3 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.

Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, Antimo; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, Bjarne; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Cahn, Robert N.; Jacobsen, R.G.; /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Banca di Roma /Frascati /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2008-08-01T23:59:59.000Z

327

Dipole Moment Bounds on Dark Matter Annihilation  

E-Print Network (OSTI)

We consider constraints on simplified models in which scalar dark matter annihilates to light charged leptons through the exchange of charged mediators. We find that loop diagrams will contribute corrections to the magnetic and electric dipole moments of the light charged leptons, and experimental constraints on these corrections place significant bounds on the dark matter annihilation cross section. In particular, annihilation to electrons with an observable cross section would be ruled out, while annihilation to muons is only permitted if the dominant contributions arise from CP-violating interactions.

Keita Fukushima; Jason Kumar

2013-07-26T23:59:59.000Z

328

Measuring Neutrinos with the ANTARES Telescope  

Science Conference Proceedings (OSTI)

The ANTARES underwater neutrino telescope has been taking data since construction began in 2006. The telescope, completed in May of 2008, detects the Cerenkov radiation of charged leptons produced by high energy neutrinos interacting in or around the detector. The lepton trajectory is reconstructed with high precision, revealing the direction of the incoming neutrino. The performance of the detector will be discussed and recent data showing muons, electromagnetic showers and atmospheric neutrinos will be presented. Studies have been underway to search for neutrino point sources in the ANTARES data since 2007. Results from these studies will be presented, and the sensitivity of the telescope will be discussed.

Reed, Corey [National Institute for Subatomic Physics (Nikhef), Amsterdam (Netherlands)

2009-12-17T23:59:59.000Z

329

Low scale seesaw, electron EDM and leptogenesis in a model with spontaneous CP violation  

SciTech Connect

Strong correlations between leptogenesis and low energy CP violating leptonic processes have been shown by us to exist fin the minimal left-right symmetric model with spontaneous CP violation. In this note, they investigate the implications of this model for the electric dipole moment of the electron. With an additional broken U(1){sub H} symmetry, the seesaw scale can be lowered to close to the electroweak scale. This additional symmetry also makes the connection between CP violation in quark sector to that in the lepton sector possible.

Chen, Mu-Chun; /Fermilab /UC, Irvine; Mahanthappa, K.T.; /Colorado U.

2006-09-01T23:59:59.000Z

330

s049.dvi  

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

± ± /B 0 ADMIXTURE B DECAY MODES B DECAY MODES B DECAY MODES B DECAY MODES The branching fraction measurements are for an admixture of B mesons at the Υ(4S). The values quoted assume that B(Υ(4S) → B B) = 100%. For inclusive branching fractions, e.g., B → D ± anything, the values usually are multiplicities, not branching fractions. They can be greater than one. B modes are charge conjugates of the modes below. Reactions indicate the weak decay vertex and do not include mixing. Scale factor/ Mode Fraction (Γ i /Γ) Confidence level Semileptonic and leptonic modes Semileptonic and leptonic modes Semileptonic and leptonic modes Semileptonic and leptonic modes Γ 1 B → e + ν e anything [a] ( 10.73 ± 0.28 ) % Γ 2 B → p e + ν e anything < 5.9 × 10 -4 CL=90% Γ 3 B → µ + ν µ anything [a] Γ 4 B → + ν anything [a,b] ( 10.73 ± 0.28 ) % Γ 5 B → D - + ν anything [b] ( 2.8 ± 0.9 ) % Γ 6 B → D 0 + ν

331

Electric Charge Quantization in Standard Model  

E-Print Network (OSTI)

In the framework of Standard Model for the arbitrary values of Higgs and fermions fields hypercharges, taking into account parity invariance of electromagnetic interaction, expressions for the fermions charges, testifying the electric charge quantization are obtained. From the chiral anomalies cancellation condition within one family of leptons and quarks, numerical values of fermions charges, coinciding with standard values of charges have been obtained.

O. B. Abdinov; F. T. Khalil-zade; S. S. Rzaeva

2008-07-28T23:59:59.000Z

332

Quantum Tachyon Dynamics  

E-Print Network (OSTI)

It is suggested that charged tachyons of extremely large mass M could not only contribute to the dark matter needed to fit astrophysical observations, but could also provide an explanation for gamma ray bursts and ultra high energy cosmic rays. The present paper defines a quantum field theory of tachyons, the latter similar to ordinary leptons, but with momenta larger than energy.

H. M. Fried; Y. Gabellini

2005-05-31T23:59:59.000Z

333

Fermilab Steering Group Report  

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

E: Muon-to-electron conversion in nuclei E: Muon-to-electron conversion in nuclei With the discovery of neutrino masses and mixings we have learned that neutral lepton flavor quantum numbers are violated in nature. An immediate question arises: "Does lepton flavor violation also occur at an appreciable rate with the charged leptons?" While the Standard Model predicts negligible rates for charged lepton flavor violation, many models, including various versions of supersymmetry, predict CLFV at an appreciable and potentially observable rate. Searches for CLFV are the most powerful and promising probes for new physics at and above the TeV scale. illustration The sensitivity to a new physics scale Λ in a μ→e conversion experiment in 48Ti that can probe a normalized capture rate of 10-17 and 10-19, and a μ→eγ search that is sensitive to a branching ratio of 10-13. The sensitivity is plotted as a function of κ, a parameter that interpolates between a fl avor transition magnetic moment-type operator (κ>1). Also depicted is the region already excluded from searches for both μ→eγ and μ→e conversion in 48Ti.

334

taudec-web.dvi  

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

τ τ -LEPTON DECAY PARAMETERS Updated August 2011 by A. Stahl (RWTH Aachen). The purpose of the measurements of the decay parameters (i.e., Michel parameters) of the τ is to determine the structure (spin and chirality) of the current mediating its decays. Leptonic Decays: The Michel parameters are extracted from the energy spectrum of the charged daughter lepton ℓ = e, µ in the decays τ → ℓν ℓ ν τ . Ignoring radiative corrections, neglect- ing terms of order (m ℓ /m τ ) 2 and (m τ / √ s) 2 , and setting the neutrino masses to zero, the spectrum in the laboratory frame reads dΓ dx = G 2 τ ℓ m 5 τ 192 π 3 × f 0 (x) + ρf 1 (x) + η m ℓ m τ f 2 (x) - P τ [ξg 1 (x) + ξδg 2 (x)] , (1) with f 0 (x) = 2 - 6 x 2 + 4 x 3 f 1 (x) = - 4 9 + 4 x 2 - 32 9 x 3 g 1 (x) = - 2 3 + 4 x - 6 x 2 + 8 3 x 3 f 2 (x) = 12 (1 - x) 2 g 2 (x) = 4 9 - 16 3 x + 12 x 2 - 64 9 x 3 . The quantity x is the fractional energy of the daughter lepton ℓ, i.e., x = E ℓ /E ℓ,max ≈

335

Backgrounds To Higgs Boson Searches from Asymmetric Internal Conversion  

E-Print Network (OSTI)

A class of potential backgrounds for Higgs boson searches in the W W to di-lepton channel at both the Tevatron and Large Hadron Collider is presented. Backgrounds from W photon production with external conversion of the on-shell photon in detector material to an asymmetric electron-positron pair, with loss of the trailing electron or positron has been treated adequately in Higgs searches. Here we consider analogous backgrounds from the production of a W with an off-shell photon and with the internal conversion of the off-shell photon in vacuum to an asymmetric lepton-anti-lepton pair. While the former process yields almost entirely electrons or positrons, the latter can give electron, positron, muon, and anti-muon backgrounds in roughly equal amounts. We estimate that asymmetric internal conversion backgrounds are comparable to the Higgs boson signal in the standard signal region of phase space. These processes also represent potential backgrounds for new physics searches in same-sign di-lepton channels. Some data driven methods to characterize asymmetric internal conversion backgrounds are suggested.

Richard C. Gray; Can Kilic; Michael Park; Sunil Somalwar; Scott Thomas

2011-10-06T23:59:59.000Z

336

Nuclear physics aspects of double beta decay  

E-Print Network (OSTI)

Comprehensive description of the phenomenology of the $\\beta\\beta$ decay is given, with emphasis on the nuclear physics aspects. After a brief review of the neutrino oscillation results and of motivation to test the lepton number conservation, the mechanism of the $0\

Petr Vogel

2008-07-15T23:59:59.000Z

337

Nuclear Shadowing and Diffraction  

E-Print Network (OSTI)

The relation between diffraction in lepton-proton collisions and shadowing of nuclear structure functions which arises from Gribov inelastic shadowing, is described. A model realizing such relation, which produces a parameter-free description of experimental data on nuclear structure functions at small $x$, is presented. The application to the description of multiplicities in nuclear collisions is discussed and related to other approaches.

J. L. Albacete; N. Armesto; A. Capella; A. B. Kaidalov; C. A. Salgado

2004-10-12T23:59:59.000Z

338

H.E.S.S. upper limit on the very high energy gamma-ray emission from the globular cluster 47 Tucanae  

E-Print Network (OSTI)

Observations of the globular cluster 47 Tucanae (NGC 104), which contains at least 23 millisecond pulsars, were performed with the H.E.S.S. telescope system. The observations lead to an upper limit of F(E>800 GeV) conversion efficiency of spin-down power to gamma-ray photons or to relativistic leptons.

Aharonian, F

2009-01-01T23:59:59.000Z

339

A Black Hole Conjecture and Rare Decays in Theories with Low Scale Gravity  

E-Print Network (OSTI)

In models with large extra dimensions, where the fundamental gravity scale can be in the electroweak range, gravitational effects in particle physics may be noticeable even at relatively low energies. In this paper, we perform simple estimates of the decays of elementary particles with a black hole intermediate state. Since black holes are believed to violate global symmetries, particle decays can violate lepton and baryon numbers. Whereas previous literature has claimed incompatibility between these rates (e.g. $p$-decay) and existing experimental bounds, we find suppressed baryon and lepton-violating rates due to a new conjecture about the nature of the virtual black holes. We assume here that black holes lighter than the (effective) Planck mass must have zero electric and color charge and zero angular momentum -- this statement is true in classical general relativity and we make the conjecture that it holds in quantum gravity as well. If true, the rates for proton-decay, neutron-antineutron oscillations, and lepton-violating rare decays are suppressed to below experimental bounds even for large extra dimensions with TeV-scale gravity. Neutron-antineutron oscillations and anomalous decays of muons, $\\tau$-leptons, and $K$ and $B$-mesons open a promising possibility to observe TeV gravity effects with a minor increase of existing experimental accuracy.

C. Bambi; A. D. Dolgov; K. Freese

2006-06-30T23:59:59.000Z

340

Jet acollinearity and quark form factors  

Science Conference Proceedings (OSTI)

Perturbative Quantum Chromodynamic corrections involving the emission of gluons which are both soft and collinear are discussed for both hadronic production of lepton pairs and e/sup +/e/sup -/ annihilation. The result is an exponential, double logarithmic quark form factor. The effect of sub-leading corrections and the possible experimental observation of the form factor are discussed.

Stirling, W.J.

1980-01-01T23:59:59.000Z

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


341

Exotic Gauge Bosons in the 331 Model  

SciTech Connect

We analize the bosonic sector of the 331 model which contains exotic leptons, quarks and bosons (E,J,U,V) in order to satisfy the weak gauge SU(3){sub L} invariance. We develop the Feynman rules of the entire kinetic bosonic sector which will let us to compute some of the Z(0)' decays modes.

Romero, D.; Ravinez, O.; Diaz, H.; Reyes, J. [Instituto de Fisica Universidad Nacional de Ingenieria (Peru)

2009-04-30T23:59:59.000Z

342

LC-PHSM-2000-037 CMS NOTE 2000/046  

E-Print Network (OSTI)

measurement will require, however, reconstruction of the Higgs boson rest-frame. Then, questions generator providing Higgs boson production and subsequent decay into a pair of #28; leptons. Examples;ects of beamstrahlung may be critical to the quality of the measurement of the Higgs boson, unless some

343

FAKULTT FR MATHEMATIK UND INFORMATIK Mathematisches Institut  

E-Print Network (OSTI)

.G.: Interfacial kinetics effect in planar solidification problems without initial undercooling. - In: Math. mod alloys. - In: J. of diff. equat. 112 (1994) S. 325-350. Chen, Z.; Hoffmann, K.-H.; Liang, J.: On a non-321. Ball, P.: Finite mass corrections to leptonic decay constants in the heavy quark effective theory. - In

Cengarle, María Victoria

344

Stability conditions for hydrogen-antihydrogenlike quasimolecules Alejandro Ferrn* and Pablo Serra  

E-Print Network (OSTI)

bound and unbound regions separated by a first-order critical line. Calculations of the leptonic but are slightly longer lived than they would be in the absence of the other pairing; that is, the positronium is three orders of magnitude slower than proton-antiproton annihilation 7 . In this work, we have

Kais, Sabre

345

Thermal masses in leptogenesis  

E-Print Network (OSTI)

We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles.

Kiessig, Clemens P

2009-01-01T23:59:59.000Z

346

MEG Experiment?New Result and Prospects?  

Science Conference Proceedings (OSTI)

The MEG Experiment searches for a lepton flavour violating muon decay ? + ???e + ? with a branching ratio sensitivity of 10 ?13 in order to explore the parameter region predicted by many theoretical models beyond the Standard Model. The first physics run has been performed in 2008

Hajime Nishiguchi; The MEG collaboration

2011-01-01T23:59:59.000Z

347

PoS(EPS-HEP2011)390 Testing fundamental principles with high-energy  

E-Print Network (OSTI)

in models incorporating a privileged local reference frame (the "vacuum rest frame", VRF [4, 5 for nucleons, quarks, leptons and the photon [6, 7]. If a VRF exists, LSV can modify the internal structure. A crucial question is that of the existence of a VRF. Contrary to the old ether, the vacuum of quantum field

Paris-Sud XI, Université de

348

Testing fundamental principles with high-energy cosmic rays  

E-Print Network (OSTI)

in models incorporating a privileged local reference frame (the "vacuum rest frame", VRF [4, 5 for nucleons, quarks, leptons and the photon [6, 7]. If a VRF exists, LSV can modify the internal structure question is that of the existence of a VRF. Contrary to the old ether, the vacuum of quantum field theory

349

Exploring higher dimensional black holes at the large hadron collider.  

E-Print Network (OSTI)

formation in the grazing collision of high-energy particles, Phys. Rev. D67 (2003) 024009, [gr-qc/0209003]. [27] C. M. Harris, Physics Beyond the Standard Model: Exotic Leptons and Black Holes at Future Colliders. PhD thesis, University of Cambridge, 2003...

Harris, Chris M; Palmer, M J; Parker, Michael A; Richardson, P

350

Model measurements for new accelerating techniques  

Science Conference Proceedings (OSTI)

We summarize the work carried out for the past two years, concerning some different ways for achieving high-field gradients, particularly in view of future linear lepton colliders. These studies and measurements on low power models concern the switched power principle and multifrequency excitation of resonant cavities. 15 refs., 12 figs.

Aronson, S.; Haseroth, H.; Knott, J.; Willis, W.

1988-06-01T23:59:59.000Z

351

A Grand Delta(96) x SU(5) Flavour Model  

E-Print Network (OSTI)

Recent results from the Daya Bay and RENO reactor experiments have measured the smallest lepton mixing angle and found it to have a value of theta_13 approximately 9 degrees. This result presents a new challenge for the existing paradigms of discrete flavour symmetries which attempt to describe all quark and lepton masses and mixing angles. Here we propose a Supersymmetric Grand Unified Theory of Flavour based on Delta(96) x SU(5), together with a U(1) x Z3 symmetry, including a full discussion of Delta(96) in a convenient basis. The Grand Delta(96) x SU(5) Flavour Model relates the quark mixing angles and masses in the form of the Gatto-Sartori-Tonin relation and realises the Georgi-Jarlskog mass relations between the charged leptons and down-type quarks. We predict a Bi-trimaximal (not Tri-bimaximal) form of neutrino mixing matrix, which, after including charged lepton corrections with zero phase, leads to the following GUT scale predictions for the atmospheric, solar, and reactor mixing angles: theta_23=36...

King, Stephen F; Stuart, Alexander J

2012-01-01T23:59:59.000Z

352

Neutrino Mass and Mixing with Discrete Symmetry  

E-Print Network (OSTI)

This is a review article about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of see-saw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mechanisms for flavon vacuum alignment and different model building strategies that have been proposed to generate the reactor angle. We then briefly review grand unified theories (GUTs) and how they may be combined with discrete family symmetry to describe all quark and lepton masses and mixing. Finally we discuss three model examples which combine an SU(5) GUT with the discrete family symmetries A4, S4 and Delta(96).

Stephen F. King; Christoph Luhn

2013-01-07T23:59:59.000Z

353

A Grand Delta(96) x SU(5) Flavour Model  

E-Print Network (OSTI)

Recent results from the Daya Bay and RENO reactor experiments have measured the smallest lepton mixing angle and found it to have a value of theta_13 approximately 9 degrees. This result presents a new challenge for the existing paradigms of discrete flavour symmetries which attempt to describe all quark and lepton masses and mixing angles. Here we propose a Supersymmetric Grand Unified Theory of Flavour based on Delta(96) x SU(5), together with a U(1) x Z3 symmetry, including a full discussion of Delta(96) in a convenient basis. The Grand Delta(96) x SU(5) Flavour Model relates the quark mixing angles and masses in the form of the Gatto-Sartori-Tonin relation and realises the Georgi-Jarlskog mass relations between the charged leptons and down-type quarks. We predict a Bi-trimaximal (not Tri-bimaximal) form of neutrino mixing matrix, which, after including charged lepton corrections with zero phase, leads to the following GUT scale predictions for the atmospheric, solar, and reactor mixing angles: theta_23=36.9 degrees, theta_12=32.7 degrees and theta_13=9.6 degrees, in good agreement with recent global fits, and a zero Dirac CP phase delta~0.

Stephen F. King; Christoph Luhn; Alexander J. Stuart

2012-07-24T23:59:59.000Z

354

The Interplay Between GUT and Flavour Symmetries in a Pati-Salam x S4 Model  

E-Print Network (OSTI)

Both Grand Unified symmetries and discrete flavour symmetries are appealing ways to describe apparent structures in the gauge and flavour sectors of the Standard Model. Both symmetries put constraints on the high energy behaviour of the theory. This can give rise to unexpected interplay when building models that possess both symmetries. We investigate on the possibility to combine a Pati-Salam model with the discrete flavour symmetry $S_4$ that gives rise to quark-lepton complementarity. Under appropriate assumptions at the GUT scale, the model reproduces fermion masses and mixings both in the quark and in the lepton sectors. We show that in particular the Higgs sector and the running Yukawa couplings are strongly affected by the combined constraints of the Grand Unified and family symmetries. This in turn reduces the phenomenologically viable parameter space, with high energy mass scales confined to a small region and some parameters in the neutrino sector slightly unnatural. In the allowed regions, we can reproduce the quark masses and the CKM matrix. In the lepton sector, we reproduce the charged lepton masses, including bottom-tau unification and the Georgi-Jarlskog relation as well as the two known angles of the PMNS matrix. The neutrino mass spectrum can present a normal or an inverse hierarchy, and only allowing the neutrino parameters to spread into a range of values between $\\lambda^{-2}$ and $\\lambda^2$, with $\\lambda\\simeq0.2$. Finally, our model suggests that the reactor mixing angle is close to its current experimental bound.

Reinier de Adelhart Toorop; Federica Bazzocchi; Luca Merlo

2010-03-23T23:59:59.000Z

355

Recent Measurements of the cos( n? h ( Azimuthal Modulations of the Unpolarized Deep Inelastic Scattering Cross?section at HERMES  

Science Conference Proceedings (OSTI)

The cross section for hadron production in deep?inelastic lepton scattering contains azimuthal modulations which can be related to transverse momentum dependent (TMD) distribution and fragmentation functions. The former provide a picture of how the quarks are moving within nucleons. Specifically

Rebecca Lamb; Francesca Giordano; on behalf of the HERMES Collaboration

2009-01-01T23:59:59.000Z

356

Measuring Smuon-Selectron Mass Splitting at the LHC and Patterns of Supersymmetry Breaking  

E-Print Network (OSTI)

01 . The enhancement diverges as the slepton mass approaches ei- ther neutralino mass. The benefits of the enhancement may be diluted for highly degenerate spectra by the fact that leptons coming from such chains will tend to be softer and thus harder...

Allanach, B C; Conlon, Jo; Lester, Christopher G

2008-01-01T23:59:59.000Z

357

Physics of Binary Information  

E-Print Network (OSTI)

Basic concepts of theoretical particle physics, including quantum mechanics and Poincar\\'e invariance, the leptonic mass spectrum and the proton mass, can be derived, without reference to first principles, from intrinsic properties of the simplest elements of information represented by binary data. What we comprehend as physical reality is, therefore, a reflection of mathematically determined logical structures, built from elements of binary data.

Walter Smilga

2005-05-05T23:59:59.000Z

358

More Signatures of the Intermediate Mass Higgs Boson  

E-Print Network (OSTI)

We examine the potential signatures of the Higgs boson when it decays into a tau-lepton pair. We show that with the proper identification of the tau-jet, this decay mode can lead to the identification of the Higgs boson over most of the intermediate mass range (\\mW $<$ \\mH $<$ 2 \\mW).

Pankaj Agrawal

1998-02-28T23:59:59.000Z

359

Predicting Large Hadron Collider Observations using Kazuo Kondo's Mass Quantum Cascade  

E-Print Network (OSTI)

The late Kazuo Kondo left a hitherto unknown a priori particle theory which provides predictions of massive particles which may be detected by the Large Hadron Collider (LHC). This article briefly introduces Kondo's work and documents the derivation and masses of his expected hyper-mesons, hyper-hadrons, heavy leptons and massive neutrinos. Several particles in these classes may have already been detected.

Grenville J. Croll

2008-04-27T23:59:59.000Z

360

Signatures for right-handed neutrinos at the Large Hadron Collider  

E-Print Network (OSTI)

We explore possible signatures for right-handed neutrinos in TeV scale B-L extension of the Standard Model (SM) at the Large Hadron Collider (LHC). The studied four lepton signal has a tiny SM background. We find the signal experimentally accessible at LHC for the considered parameter regions.

Katri Huitu; Shaaban Khalil; Hiroshi Okada; Santosh Kumar Rai

2008-03-19T23:59:59.000Z

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


361

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy at CMS  

E-Print Network (OSTI)

The results of searches for Supersymmetry in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state are presented. The searches use pp collisions at 7 TeV collected in 2011 by the CMS experiment.

Weinberg, M

2011-01-01T23:59:59.000Z

362

Slow proton production in semi-inclusive DIS off nuclei: the role of final state interaction  

E-Print Network (OSTI)

The effects of the final state interaction on the production of slow protons in semi-inclusive deep-inelastic lepton scattering off nuclei is considered within the spectator mechanism and a realistic approach in which the rescattering in the medium of both the recoiling proton and the hadronizing nucleon debris are taken into account.

M. Alvioli; C. Ciofi degli Atti; V. Palli

2006-09-13T23:59:59.000Z

363

Search for the Standard Model Higgs Boson in the Decay Channel H?ZZ?4l in pp Collisions at ?s=7??TeV  

E-Print Network (OSTI)

A search for a Higgs boson in the four-lepton decay channel H?ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range of 110

Alver, Burak Han

364

Measuring the fermionic couplings of the Higgs boson at future colliders as a probe of a non-minimal flavor structure  

E-Print Network (OSTI)

We study the fermionic couplings of the neutral Higgs bosons in the THDM, assuming a four-texture structure for the Yukawa matrices. We then derive the low-energy constraints on the model, focusing in b-quark and lepton physics, and apply them to study Higgs boson detection at future colliders.

J. L. Diaz-Cruz; R. Noriega-Papaqui; A. Rosado

2004-10-28T23:59:59.000Z

365

Search for a Low-Mass Standard Model Higgs Boson in the ?? Decay Channel in pp? Collisions at ?s=1.96??TeV  

E-Print Network (OSTI)

We report on a search for the standard model Higgs boson decaying into pairs of ? leptons in pp? collisions produced by the Tevatron at ?s=1.96??TeV. The analyzed data sample was recorded by the CDFII detector and corresponds ...

Bauer, Gerry P.

366

Search for the Higgs boson produced in association with Z-->l^{+}l^{-} using the matrix element method at CDF II  

E-Print Network (OSTI)

We present a search for associated production of the standard model Higgs boson and a Z boson where the Z boson decays to two leptons and the Higgs decays to a pair of b quarks in pp? collisions at the Fermilab Tevatron. ...

Xie, Si

367

High Energy Photoproduction  

E-Print Network (OSTI)

The experimental and phenomenological status of high energy photoproduction is reviewed. Topics covered include the structure of the photon, production of jets, heavy flavours and prompt photons, rapidity gaps, energy flow and underlying events. The results are placed in the context of the current understanding of QCD, with particular application to present and future hadron and lepton colliders.

J. M. Butterworth; M. Wing

2005-09-15T23:59:59.000Z

368

Nuclear p_t broadening at HERMES  

E-Print Network (OSTI)

The first direct measurement of p_t-broadening effects in cold nuclear matter has been studied as a function of several kinematic variables for different hadron types. The data have been accumulated by the HERMES experiment at DESY, in which the HERA 27.6 GeV lepton beam scattered off several nuclear gas targets.

Yves Van Haarlem; Anton Jgoun; Pasquale Di Nezza

2007-04-27T23:59:59.000Z

369

Neutrinology  

SciTech Connect

We present various topics of theoretical and experimental interest in the search for signals of massive neutrinos. We discuss implications of massive neutrinos for model building beyond the Standard Model. We emphasize one example where the scale of lepton number breaking is linked to that of the breaking of the axion symmetry.

Ramond, P.

1991-01-01T23:59:59.000Z

370

Neutrinology  

SciTech Connect

We present various topics of theoretical and experimental interest in the search for signals of massive neutrinos. We discuss implications of massive neutrinos for model building beyond the Standard Model. We emphasize one example where the scale of lepton number breaking is linked to that of the breaking of the axion symmetry.

Ramond, P.

1991-12-31T23:59:59.000Z

371

REPORT OF RESEARCH ACTIVITIES FOR THE YEARS 2000 - 2003; HIGH ENERGY PHYSICS GROUP; SOUTHERN METHODIST UNIVERSITY; EXPERIMENTAL TASK A AND THEORY TASK B  

SciTech Connect

The experimental program in High Energy Physics at SMU was initiated in 1992. Its main goal is the search for new physics phenomena beyond the Standard Model (SSC, LHC) and the study of the properties of heavy quarks and leptons (CLEO, BTeV).

Dr. Ryszard Stroynowski

2003-07-01T23:59:59.000Z

372

Searches for new gauge bosons at future colliders  

SciTech Connect

The search reaches for new gauge bosons at future hadron and lepton colliders are summarized for a variety of extended gauge models. Experiments at these energies will vastly improve over present limits and will easily discover a Z` and/or W` in the multi-TeV range.

Rizzo, T.G.

1996-09-01T23:59:59.000Z

373

Research and Development of Future Muon Collider  

SciTech Connect

Muon collider is a considerable candidate of the next generation high-energy lepton collider machine. A novel accelerator technology must be developed to overcome several intrinsic issues of muon acceleration. Recent research and development of critical beam elements for a muon accelerator, especially muon beam phase space ionization cooling channel, are reviewed in this paper.

Yonehara, K.; /Fermilab

2012-05-01T23:59:59.000Z

374

B->lnu - Belle results and outlook for Belle II  

E-Print Network (OSTI)

We report the measurements of the leptonic decays B->lnu obtained at the Belle experiment. The results are consistent with the Standard Model expectations, and provide stringent constraints on new physics models including charged Higgs bosons. We also report an outlook of the measurements of B->lnu for the Belle II experiment.

Horii, Y

2013-01-01T23:59:59.000Z

375

B->lnu - Belle results and outlook for Belle II  

E-Print Network (OSTI)

We report the measurements of the leptonic decays B->lnu obtained at the Belle experiment. The results are consistent with the Standard Model expectations, and provide stringent constraints on new physics models including charged Higgs bosons. We also report an outlook of the measurements of B->lnu for the Belle II experiment.

Y. Horii

2013-02-01T23:59:59.000Z

376

Study of Bs->mu+mu- in CMS  

E-Print Network (OSTI)

We present a Monte Carlo simulation study of measuring the rare leptonic decay Bs->mu+mu- with the CMS experiment at the LHC. The study is based on a full detector simulation for signal and background events. We discuss the high-level trigger algorithm and the offline event selection.

Urs Langenegger

2006-10-13T23:59:59.000Z

377

Why does set theory necessary to describe charge structure of particles ?  

E-Print Network (OSTI)

It is pointed out that the set theory gave the exact symmetry while the group theory did not. The triplicity of quarks and leptons is also pointed out. The reason of seven families of particles and in each family eight number of particles is elaborated.

Amjad Hussain Shah Gilani

2005-02-13T23:59:59.000Z

378

Search for the Standard Model Higgs boson decaying to two W bosons at CMS  

E-Print Network (OSTI)

In this thesis, we search for the production of the Standard Model Higgs boson at the Large Hadron Collider, through its decay mode to two W bosons, which each in turn decay into a charged lepton and a neutrino. The Higgs ...

Xie, Si, Ph. D. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

379

LCPHSM2004006 Study of Higgs Boson Pair Production at  

E-Print Network (OSTI)

LC­PHSM­2004­006 March 2004 Study of Higgs Boson Pair Production at Linear Collider K. Desch a , TV for the measurement of the neutral Higgs boson properties within the framework of the MSSM. The process of associated Higgs boson production with subsequent decays of Higgs bosons into b­quark and #­lepton pairs

380

LCPHSM2004005 Study of Higgs Boson Pair Production at  

E-Print Network (OSTI)

LC­PHSM­2004­005 March 2004 Study of Higgs Boson Pair Production at Linear Collider K. Desch a , TV for the measurement of the neutral Higgs boson properties within the framework of the MSSM. The process of associated Higgs boson production with subsequent decays of Higgs bosons into b­quark and #­lepton pairs

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


381

From the Big Bang to the Higgs Boson in Less Than an Hour  

E-Print Network (OSTI)

From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D neutrino Z0 W + W -g gluon (8) photon Z boson W bosons Quarks Leptons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong force EM force Weak force #12;Par7cles

Fygenson, Deborah Kuchnir

382

Exploration of decaying dark matter in a left-right symmetric model  

E-Print Network (OSTI)

$SU(2)_L$ triplet scalars appear in models motivated for the left-right symmetry, neutrino masses and dark matter (DM), etc.. If the triplets are the main decay products of the DM particle, and carry nonzero lepton numbers, they may decay dominantly into lepton pairs, which can naturally explain the current experimental results reported by PAMELA and Fermi-LAT or ATIC. We discuss this possibility in an extended left-right symmetric model in which the decay of DM particle is induced by tiny soft charge-conjugation ($C$) violating interactions, and calculate the spectra for cosmic-ray positrons, neutrinos and gamma-rays. We show that the DM signals in the flux of high energy neutrinos can be significantly enhanced, as the triplets couple to both charged leptons and neutrinos with the same strength. In this scenario, the predicted neutrino-induced muon flux can be several times larger than the case in which DM particle only directly decays into charged leptons. In addition, the charged components of the triplet may give an extra contribution to the high energy gamma-rays through internal bremsstrahlung process, which depends on the mass hierarchy between the DM particle and the triplet scalars.

Wan-Lei Guo; Yue-Liang Wu; Yu-Feng Zhou

2010-01-03T23:59:59.000Z

383

Search for the standard model Higgs boson in associated $WH$ production in 9.7 fb$^{-1}$ of $p\\bar{p}$ collisions with the D0 detector  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson in final states with a charged lepton (electron or muon), missing transverse energy, and two or three jets, at least one of which is identified as a $b$-quark jet. The search is primarily sensitive to $WH\\to\\ell\

The D0 Collaboration

2012-08-03T23:59:59.000Z

384

Supported by the National Science Foundation and the State of Florida Collaboration with Grenoble  

E-Print Network (OSTI)

by two turbo-molecular pumps with a combined speed of 4400 l s 1 . During operation the chamber pressure lepton beam direction 6 #12; HERA beam beam pipe exit window turbo pump collimator C2 holding frame iron.2.4, this may induce resonant nuclear depolarization of the target gas. The induced resonances can be avoided

Weston, Ken

385

Precision measurements of the top quark mass and width with the D0 detector  

Science Conference Proceedings (OSTI)

Since the discovery of the top quark in 1995 at the Fermliab Tevatron Collider, top quark properties have been measured with ever higher precision. In this article, recent measurements of the top quark mass and its width using up to 3.6 fb{sup -1} of D0 data are summarized. Different techniques and final states have been examined and no deviations within these measurements have been observed. In addition to the direct measurements, a measurement of the top quark mass from its production cross section and a measurement of the top-antitop quark mass difference are discussed. With a mass of 173.3 {+-} 1.1 GeV, the top quark is the heaviest of all known fundamental particles. Due to the high mass, its Yukawa coupling is close to unity suggesting that it may play a special role in electroweak symmetry breaking. Precise measurements of both, the W boson and the top quark mass, constrain the mass of the yet unobserved Higgs boson and allow to restrict certain extensions of the Standard Model. At the Tevatron collider with a center-of-mass energy of 1.96 TeV, 85% of the top quark pairs are produced in quark-antiquark annihilation; 15% originate from gluon fusion. Top quarks are predicted to decay almost exclusively to a W boson and a bottom quark. According to the number of hadronic W decays, top events are classified into all-jets, lepton+jets and dilepton events. The lepton+jets channel is characterized by four jets, one isolated, energetic charged lepton and missing transverse energy. With 30%, the branching fraction of the lepton+jets channel is about seven times larger than the one of the dilepton channel whereas the signal to background ratio is about three times smaller. The main background in this final state comes from W +jets events. Instrumental background arises from events in which a jet is misidentified as an electron and events with heavy hadrons that decay into leptons which pass the isolation requirements. The topology of the dilepton channel is described by two jets, two isolated, energetic charged leptons and significant missing transverse energy from the undetected neutrinos. The main background are Z + jets and diboson events (WW/WZ/ZZ+jets) as well as instrumental background as characterized above. At the D0 experiment, different techniques are used to measure the top quark mass. They are summarized in the following sections together with the first measurement of the top anti-top quark mass difference and the first precise determination of the top quark width.

Grohsjean, Alexander; /IRFU, SPP, Saclay

2010-01-01T23:59:59.000Z

386

Z:\Professor Perl\Tau Discovery\Floppy THREE\SLAC-PUB-10150.prn.pdf  

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

0150 0150 October 2003 Submitted to Physics in Perspective *Work supported by Department of Energy contract DE-AC03-76SF00515. Tau Discovery THE DISCOVERY OF THE TAU LEPTON AND THE CHANGES IN ELEMENTARY PARTICLE PHYSICS IN 40 YEARS Martin L. Perl Stanford Linear Accelerator Center and Stanford University, Stanford, CA 94309 Phone: 650-926-4286 Fax: 650-926-4001 Email: martin@slac.stanford.edu Introduction This is a history of my discovery of the tau lepton in the 1970s for which I was awarded the Nobel Prize in Physics. I have previously described some aspects of the discovery. In 1996 in my collection of papers entitled, "Reflections on Experimental Science," 1 I gave a straightforward account of the experimental method and the physics involved in the

387

Method and system for improved resolution of a compensated calorimeter detector  

DOE Patents (OSTI)

An improved method and system for a depleted uranium calorimeter detector used in high energy physics experiments. In a depleted uranium calorimeter detector, the energy of a particle entering the calorimeter detector is determined and the output response of the calorimeter detector is compensated so that the ratio of the integrated response of the calorimeter detector from a lepton to the integrated response of the calorimeter detector from a hadron of the same energy as the lepton is approximately equal to 1. In the present invention, the energy of a particle entering the calorimeter detector is determined as a function of time and the hadron content of the response of the calorimeter detector is inferred based upon the time structure of the energy pulse measured by the calorimeter detector. The energy measurement can be corrected based on the inference of the hadron content whereby the resolution of the calorimeter can be improved.

Dawson, John W. (Willowbrook, IL)

1991-01-01T23:59:59.000Z

388

Measurement of top quark polarization in top-antitop events from proton-proton collisions at ?s = 7 TeV using the ATLAS detector  

E-Print Network (OSTI)

This Letter presents measurements of the polarization of the top quark in topantitop quark pair events, using 4.7 fb$^{1}$ of protonproton collision data recorded with the ATLAS detector at the Large Hadron Collider at ?s = 7 TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of $\\alpha_l P$, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving (CPC) or a CP violating (CPV) production process. The measurements obtained, $\\alpha_l P_{CPC} = ?0.035 0.014(stat) 0.037(syst)$ and $\\alpha_l P_{CPV} = 0.020 0.016(stat)^{+0.013} _{-0.017}(syst)$, are in good agreement with the Standard Model prediction of negligible top quark polarization.

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Aefsky, Scott; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; kesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ask, Stefan; sman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Astbury, Alan; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimares da Costa, Joo; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jrg; Bernard, Clare; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Bittner, Bernhard

2013-01-01T23:59:59.000Z

389

Method and system for improved resolution of a compensated calorimeter detector  

DOE Patents (OSTI)

An improved method and system for a depleted uranium calorimeter detector was used in high energy physics experiments. In a depleted uranium calorimeter detector, the energy of a particle entering the calorimeter detector is determined and the output response of the calorimeter detector is compensated so that the ratio of the integrated response of the calorimeter detector from a lepton to the integrated response of the calorimeter detector from a hadron of the same energy as the lepton is approximately equal to 1. In the present invention, the energy of a particle entering the calorimeter detector is determined as a function of time and the hadron content of the response of the calorimeter detector is inferred based upon the time structure of the energy pulse measured by the calorimeter detector. The energy measurement can be corrected based on the inference of the hadron content whereby the resolution of the calorimeter can be improved. 2 figs.

Dawson, J.W.

1989-05-23T23:59:59.000Z

390

Synchrotron radiation by fast fermions in heavy-ion collisions  

SciTech Connect

We study the synchrotron radiation of gluons by fast quarks in strong magnetic field produced by colliding relativistic heavy ions. We argue that due to high electric conductivity of plasma, the magnetic field is almost constant during the entire plasma lifetime. We calculate the energy loss due to synchrotron radiation of gluons by fast quarks. We find that the typical energy loss per unit length for a light quark at the Large Hadron Collider is a few GeV per fm. This effect alone predicts quenching of jets with p{sub perpendicular} up to about 20 GeV. We also show that the spin-flip transition effect accompanying the synchrotron radiation leads to a strong polarization of quarks and leptons with respect to the direction of the magnetic field. Observation of the lepton polarization may provide a direct evidence of existence of strong magnetic field in heavy-ion collisions.

Tuchin, Kirill [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States) and RIKEN BNL Research Center, Upton, New York 11973-5000 (United States)

2010-09-15T23:59:59.000Z

391

A search for double-charged Higgs bosons at the Tevatron  

Science Conference Proceedings (OSTI)

We search for the pair production of doubly charged Higgs particles followed by the lepton-flavor violating decay of each Higgs into electron-and-tau and muon-and-tau pairs using 350 pb{sup -1} of data collected by the CDF II experiment at the Fermilab Tevatron. Separate searches investigate cases where three or four final state leptons are detected, and the limits for each exclusive decay mode reflect the combined results of both searches. Assuming the H{sup {+-}{+-}}{sub L} decays exclusively into like sign electron-and-tau pairs, we set a lower limit on its mass of 114 GeV/c2 at the 95 % confidence level. In the case of exclusive muon-and-tau decays, we set a lower mass limit of 112 GeV/c2 also at the 95% confidence level.

Baraoiant, Sasha; /UC, Davis

2006-01-01T23:59:59.000Z

392

W boson production and mass at the Tevatron  

Science Conference Proceedings (OSTI)

The CDF and D0 collaborations have analyzed up to {approx} 200 pb{sup -1} of Run 2 physics data to measure W production properties such as the W cross section, the W width, lepton universality and the W charge asymmetry. From the cross section measurements, CDF obtains a lepton universality of g{sub {mu}}/g{sub e} = 0.998 {+-} 0.012 and g{sub {tau}}/g{sub e} = 0.99 {+-} 0.04 and an indirect W width of {Lambda}{sub W} = 2079 {+-} 41 MeV. D0 measured the W width directly and finds {Lambda}{sub W} = 2011 {+-} 142 MeV. CDF has estimated the uncertainties on the W boson mass measurements in the electron and muon decay channels and obtains an overall uncertainty of 76 MeV.

Stelzer-Chilton, Oliver; /Toronto U.

2005-06-01T23:59:59.000Z

393

Search for the Higgs Boson in $H\\to WW^{*}\\to\\ell\  

Science Conference Proceedings (OSTI)

We present a search for the standard model (SM) Higgs boson decaying to a pair of W bosons that in turn decay leptonically, H {yields} WW* {yields} {ell}{nu}{ell}{nu}. We consider events produced in p{bar p} collisions at {radical}s = 1.96 TeV, with two oppositely charged lepton candidates (e{sup +}e{sup -}, e{sup {+-}}{mu}{sup {+-}}, or {mu}{sup +}{mu}{sup -}), and missing transverse energy. The data were collected with the D0 detector at the Fermilab Tevatron collider, and correspond to an integrated luminosity of 5.4 fb{sup -1}. No excess of events over background is observed, and limits on SM Higgs boson production are determined.

Gerbaudo, Davide; /Princeton U.

2010-05-30T23:59:59.000Z

394

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC  

E-Print Network (OSTI)

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H --> gamma-gamma, H --> ZZ* --> 4 leptons and H --> WW --> 2 leptons + 2 neutrinos. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of about 25/fb. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson.

ATLAS Collaboration

2013-07-04T23:59:59.000Z

395

Search for D0 - D0bar Mixing and Rare Charm Decays  

E-Print Network (OSTI)

Based on a dataset acquired by the BaBar experiment running on and near the $\\Upsilon(4S)$ resonance from 1999-2002, limits are set on the rate of $D^0$-- $\\kern 0.2em\\bar{\\kern -0.2em D}{}^0$ mixing using the decay mode $D^{*+} \\to D^0 \\pi^{+}$, followed by a semi-leptonic decay of the $D^0$. Results are compared to previous BaBar analysis using hadronic decays. We also report on a search for the flavor-changing neutral current decays $D^0 \\to e^{+} e^{-}$ ($\\mu^{+} \\mu^{-}$) and the lepton-flavor violation decays $D^0 \\to e^{\\pm} \\mu^{\\mp}$.

U. Egede; for the BABAR Collaboration

2004-10-12T23:59:59.000Z

396

Angular correlations in top quark decays in standard model extensions  

SciTech Connect

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.

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

397

Low energy phenomena in a model with symmetry group SUSY SO(10) x $\\Delta$(48) x U(1)  

E-Print Network (OSTI)

Fermion masses and mixing angles including that of neutrinos are studied in a model with symmetry group SUSY SO(10)\\times \\Delta (48) \\times U(1). Universality of Yukawa coupling of superfields is assumed. The resulting texture of mass matrices in the low energy region depends only on a single coupling constant and VEVs caused by necessary symmetry breaking. 13 parameters involving masses and mixing angles in the quark and charged lepton sector are successfully described by only five parameters with two of them determined by the scales of U(1), SO(10) and SU(5) symmetry breaking compatible with the requirement of grand unification and proton decay. The neutrino masses and mixing angles in the leptonic sector are also determined with the addition of a Majorana coupling term. It is found that LSND \\bar{\

Chou, K C

1995-01-01T23:59:59.000Z

398

Search for the Higgs Boson in the ZH->vvbb Channel at CDF Run II  

SciTech Connect

This analysis focuses on a low mass Higgs boson search with 1.7 fb{sup -1} of data. The focus is on Higgs events in which it is produced in association with a W or Z boson. Such events are expected to leave a distinct signature of large missing transverse energy for either a Z {yields} {nu}{nu} decay or a leptonic W decay in which the lepton goes undetected, as well as jets with taggable secondary vertices from the H {yields} b{bar B} decay. Utilizing a new track based technique for removing QCD multi-jet processes as well as a neural network discriminant, an expected limit of 8.3 times the Standard Model prediction at the 95% CL for a Higgs boson mass of 115 GeV/c{sup 2} is calculated, with an observed limit of 8.0*SM.

Parks, Brandon Scott; /Ohio State U.

2008-07-01T23:59:59.000Z

399

FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.  

SciTech Connect

The concept of using a muon storage ring to provide a well characterized beam of muon and electron neutrinos (a Neutrino Factory) has been under study for a number of years now at various laboratories throughout the world. The physics program of a Neutrino Factoryis focused on the relatively unexplored neutrino sector. In conjunction with a detector located a suitable distance from the neutrino source, the facility would make valuable contributions to the study of neutrino masses and lepton mixing. A Neutrino Factory is expected to improve the measurement accuracy of sin{sup 2}(2{theta}{sub 23}) and {Delta}m{sup 2}{sub 32} and provide measurements of sin{sup 2}(2{theta}{sub 13}) and the sign of {Delta}m{sup 2}{sub 32}. It may also be able to measure CP violation in the lepton sector.

GALLARDO,J.C.; OZAKI,S.; PALMER,R.B.; ZISMAN,M.

2001-06-30T23:59:59.000Z

400

Quark mixing sum rules and the right unitarity triangle  

E-Print Network (OSTI)

In analogy with the recently proposed lepton mixing sum rules, we derive quark mixing sum rules for the case of hierarchical quark mass matrices with 1-3 texture zeros, in which the separate up and down type 1-3 mixing angles are approximately zero, and $V_{ub}$ is generated from $V_{cb}$ as a result of 1-2 up type quark mixing. Using the sum rules, we discuss the phenomenological viability of such textures, including up to four texture zeros, and show how the right-angled unitarity triangle, i.e., $\\alpha \\approx 90^\\circ$, can be accounted for by a remarkably simple scheme involving real mass matrices apart from a single element being purely imaginary. In the framework of grand unified theories we show how the quark and lepton mixing sum rules may combine to yield an accurate prediction for the reactor angle.

Antusch, Stefan; Malinsky, Michal; Spinrath, Martin

2009-01-01T23:59:59.000Z

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401

A SUSY GUT of Flavour with S4 x SU(5) to NLO  

E-Print Network (OSTI)

We construct a Supersymmetric (SUSY) Grand Unified Theory (GUT) of Flavour based on S4 x SU(5), together with an additional (global or local) Abelian symmetry, and study it to next-to-leading order (NLO) accuracy. The model includes a successful description of quark and lepton masses and mixing angles at leading order (LO) incorporating the Gatto-Sartori-Tonin (GST) relation and the Georgi-Jarlskog (GJ) relations. We study the vacuum alignment arising from F-terms to NLO and such corrections are shown to have a negligible effect on the results for fermion masses and mixings achieved at LO. Tri-bimaximal (TB) mixing in the neutrino sector is predicted very accurately up to NLO corrections of order 0.1%. Including charged lepton mixing corrections implies small deviations from TB mixing described by a precise sum rule, accurately maximal atmospheric mixing and a reactor mixing angle close to three degrees.

Claudia Hagedorn; Stephen F. King; Christoph Luhn

2010-03-22T23:59:59.000Z

402

Quark mixing sum rules and the right unitarity triangle  

E-Print Network (OSTI)

In analogy with the recently proposed lepton mixing sum rules, we derive quark mixing sum rules for the case of hierarchical quark mass matrices with 1-3 texture zeros, in which the separate up and down type 1-3 mixing angles are approximately zero, and $V_{ub}$ is generated from $V_{cb}$ as a result of 1-2 up type quark mixing. Using the sum rules, we discuss the phenomenological viability of such textures, including up to four texture zeros, and show how the right-angled unitarity triangle, i.e., $\\alpha \\approx 90^\\circ$, can be accounted for by a remarkably simple scheme involving real mass matrices apart from a single element being purely imaginary. In the framework of grand unified theories we show how the quark and lepton mixing sum rules may combine to yield an accurate prediction for the reactor angle.

Stefan Antusch; Stephen F. King; Michal Malinsky; Martin Spinrath

2009-10-27T23:59:59.000Z

403

A SUSY GUT of Flavour with S4 x SU(5) to NLO  

E-Print Network (OSTI)

We construct a realistic Supersymmetric (SUSY) Grand Unified Theory (GUT) of Flavour based on S4 x SU(5), together with an additional (global or local) Abelian symmetry, and study it to next-to-leading order (NLO) accuracy. The model includes a successful description of quark and lepton masses and mixing angles at leading order (LO) incorporating the Gatto-Sartori-Tonin (GST) relation and the Georgi-Jarlskog (GJ) relations. We study the vacuum alignment arising from F-terms to NLO and such corrections are shown to have a negligible effect on the results for fermion masses and mixings achieved at LO. Tri-bimaximal (TB) mixing in the neutrino sector is predicted very accurately up to NLO corrections of order 0.1%. Including charged lepton mixing corrections implies small deviations from TB mixing described by a precise sum rule, accurately maximal atmospheric mixing and a reactor mixing angle close to three degrees.

Hagedorn, Claudia; Luhn, Christoph

2010-01-01T23:59:59.000Z

404

THE ROLE OF STOCHASTIC ACCELERATION IN THE PROMPT EMISSION OF GAMMA-RAY BURSTS: APPLICATION TO HADRONIC INJECTION  

Science Conference Proceedings (OSTI)

We study effects of particle re-acceleration (or heating) in the post-shock region via magnetohydrodynamic/plasma turbulence, in the context of a mixed hadronic-leptonic model for the prompt emission of gamma-ray bursts, using both analytical and numerical methods. We show that stochastically accelerated (or heated) leptons, which are injected via pp and p{gamma} reactions and subsequent pair cascades, are plausibly able to reproduce the Band function spectra with {alpha} {approx} 1 and {beta} {approx} 2-3 in the {approx}MeV range. An additional hard component coming from the proton-induced cascade emission is simultaneously expected, which can be compatible with observed extra power-law spectra far above the MeV range. We also discuss the specific implications of hadronic models for ongoing high-energy neutrino observations.

Murase, Kohta [Department of Physics, Center for Cosmology and AstroParticle Physics, Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210 (United States); Asano, Katsuaki; Terasawa, Toshio [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Meszaros, Peter [Department of Astronomy and Astrophysics, Center for Particle Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2012-02-20T23:59:59.000Z

405

Forward-backward asymmetry in top quark-antiquark production  

SciTech Connect

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

Abazov, V.M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Aoki, M.; Arov, M.; Askew, A.; Asman, B.; Atramentov, O.; Avila, C.; BackusMayes, J.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Beale, S.; Bean, A.; Begalli, M.; Begel, M.; Belanger-Champagne, C.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besancon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Burnett, T. H.; Buszello, C. P.; Calpas, B.; Camacho-Perez, E.; Carrasco-Lizarraga, M. A.; Casey, B. C. K.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chen, G.; Chevalier-Thery, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; De, K.; de Jong, S. J.; De La Cruz-Burelo, E.; Deliot, F.; Demarteau, M.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dorland, T.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph; Grivaz, J. -F.; Grohsjean, A.; Gruenendahl, S.; Gruenewald, M. W.; Guillemin, T.; Guo, F.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Hubacek, Z.; Huske, N.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffre, M.; Jamin, D.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, M.; Johnston, D.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kirby, M. H.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kurca, T.; Kuzmin, V. A.; Kvita, J.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Liu, Z.; Lobodenko, A.; Lokajicek, M.; de Sa, R. Lopes; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; Madar, R.; Magana-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martinez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Muanza, G. S.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Novaes, S. F.; Nunnemann, T.; Obrant, G.; Orbaker, D.; Orduna, J.; Osman, N.; Osta, J.; et. al.

2011-12-12T23:59:59.000Z

406

First Measurement of the Branching Fraction of the Decay $\\psi(2S) \\to \\tau\\tau$  

E-Print Network (OSTI)

The branching fraction of the psi(2S) decay into tau pair has been measured for the first time using the BES detector at the Beijing Electron-Positron Collider. The result is $B_{\\tau\\tau}=(2.71\\pm 0.43 \\pm 0.55) \\times 10^{-3}$, where the first error is statistical and the second is systematic. This value, along with those for the branching fractions into e+e- and mu+mu of this resonance, satisfy well the relation predicted by the sequential lepton hypothesis. Combining all these values with the leptonic width of the resonance the total width of the psi(2S) is determined to be $(252 \\pm 37)$ keV.

Bai, J Z; Bian, J G; Blum, I K; Chen, G P; Chen, H F; Chen, J; Chen Jia Chao; Chen, Y; Chen, Y B; Chen, Y Q; Cheng Bao Sen; Cui, X Z; Ding, H L; Dong, L Y; Du, Z Z; Dunwoodie, W M; Gao, C S; Gao, M L; Gao, S Q; Gratton, P; Gu, J H; Gu, S D; Gu, W X; Gu, Y F; Guo, Z J; Guo, Y N; Han, S W; Han, Y; Harris, F A; He, J; He, J T; He, K L; He, M; Heng, Y K; Hitlin, D G; Hu, G Y; Hu, H M; Hu, J L; Hu, Q H; Hu, T; Hu Xiao Qing; Huang, G S; Huang, Y Z; Izen, J M; Jiang, C H; Jin, Y; Jones, B D; Ju, X; Ke, Z J; Kelsey, M H; Kim, B K; Kong, D; Lai, Y F; Lang, P F; Lankford, A J; Li, C G; Li, D; Li, H B; Li, J; Li, J C; Li, P Q; Li, R B; Li, W; Li, W G; Li, X H; Li Xiao Nan; Liu, H M; Liu, J; Liu, R G; Liu, Y; Lou, X C; Lowery, B; Lu, F; Lu, J G; Luo, X L; Ma, E C; Ma, J M; Malchow, R; Mao, H S; Mao, Z P; Meng, X C; Nie, J; Olsen, S L; Oyang, J Y T; Paluselli, D; Pan, L J; Panetta, J; Porter, F; Qi, N D; Qi, X R; Qian, C D; Qiu, J F; Qu, Y H; Que, Y K; Rong, G; Schernau, M; Shao, Y Y; Shen, B W; Shen, D L; Shen, H; Shen, X Y; Sheng, H Y; Shi, H Z; Song, X F; Standifird, J; Sun, F; Sun, H S; Sun, Y; Sun, Y Z; Tang, S Q; Toki, W; Tong, G L; Varner, G S; Wang, F; Wang, L S; Wang, L Z; Wang, M; Wang, P; Wang, P L; Wang, S M; Wang, T J; Wang, Y Y; Weaver, M; Wei, C L; Wu, J M; Wu, N; Wu, Y G; Xi, D M; Xia, X M; Xie, P P; Xie, Y; Xie, Y H; Xu, G F; Xue, S T; Yan, J; Yan, W G; Yang, C M; Yang, C Y; Yang, H X; Yang, J; Yang, W; Yang, X F; Ye, M H; Ye Shu Wei; Ye, Y X; Yu, C S; Yu, C X; Yu, G W; Yu Yu Hei; Yu, Z Q; Yuan, C Z; Yuan, Y; Zhang Bing Yun; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H L; Zhang, J; Zhang, J W; Zhang, L; Zhang, L S; Zhang, P; Zhang, Q J; Zhang, S Q; Zhang, X Y; Zhang, Y Y; Zhao, D X; Zhao, H W; Zhao Jia Wei; Zhao, M; Zhao Wei Ren; Zhao, Z G; Zheng Jian Ping; Zheng Lin Sheng; Zheng Zhi Peng; Zhou, B Q; Zhou, G P; Zhou, H S; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhuang, B A

2002-01-01T23:59:59.000Z

407

Inclusive production of dijets at the LHeC  

Science Conference Proceedings (OSTI)

We investigate the production of a quark-antiquark pair in inclusive photon-proton scattering, considering distinct gluon distribution functions. The role played by the parton saturation effects is studied for the kinematic regime of the upcoming Large Hadron Electron Collider (LHeC). This proposed lepton-hadron (nucleus) collider will reach energies higher than the available at DESY HERA experiment. This fact will open a new regime to probe the gluon and sea quark distributions in nucleon and on nucleus. In deep inelastic scattering in lepton-hadron colliders, events with two jets and the scattered proton in the final state are predicted to be observable, with an important contribution from charm production. Thus, the contribution from heavy quarks should be investigated in details.

Gay Ducati, M. B.; Griep, M. T.; Machado, M. V. [Instituto de Fisica, Av. Bento Goncalves 9500, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2013-03-25T23:59:59.000Z

408

Semidirect product gauge group [SU(3){sub c}xSU(2){sub L}]xU(1){sub Y} and quantization of hypercharge  

Science Conference Proceedings (OSTI)

In the standard model the hypercharges of quarks and leptons are not determined by the gauge group SU(3){sub c}xSU(2){sub L}xU(1){sub Y} alone. We show that, if we choose the semidirect product group [SU(3){sub c}xSU(2){sub L}]xU(1){sub Y} as its gauge group, the hyperchages are settled to be n/6 mod Z(n=0,1,3,4). In addition, the conditions for gauge-anomaly cancellation give strong constraints. As a result, the ratios of the hypercharges are uniquely determined and the gravitational anomaly is automatically canceled. The standard charge assignment to quarks and leptons can be properly reproduced. For exotic matter fields their hypercharges are also discussed.

Hattori, Chuichiro [Science Division, General Education, Aichi Institute of Technology, Toyota 470-0392 (Japan); Matsunaga, Mamoru; Matsuoka, Takeo [Department of Physics Engineering, Mie University, Tsu 514-8507 (Japan)

2011-01-01T23:59:59.000Z

409

A4 models of tri-bimaximal-reactor mixing  

E-Print Network (OSTI)

Recent results from T2K, MINOS and Double CHOOZ all indicate a sizeable reactor angle theta_13 which would rule out conventional tri-bimaximal lepton mixing. However, it is possible to maintain the tri-bimaximal solar and atmospheric mixing angle predictions, theta_12 ~ 35 degrees, theta_23 ~ 45 degrees even for a quite sizeable reactor angle theta_13 ~ 8 degrees, using an ansatz called tri-bimaximal-reactor (TBR) mixing proposed by one of us some time ago. We propose an explicit A4 model of leptons based on the type I seesaw mechanism at both the effective and the renormalisable level which, together with vacuum alignment, leads to surprisingly accurate TBR neutrino mixing, with the second order corrections to mixing angles having small coefficients.

Stephen F. King; Christoph Luhn

2011-12-08T23:59:59.000Z

410

Search for a low mass Standard Model Higgs boson in the $\\tau-\\tau$ decay channel in $p\\bar{p}$ collisions at $\\sqrt{s}$ = 1.96 TeV  

Science Conference Proceedings (OSTI)

We report on a search for the standard model Higgs boson decaying into pairs of {tau} leptons in p{bar p} collisions produced by the Tevatron at {radical}s = 1.96 TeV. The analyzed data sample was recorded by the CDFII detector and corresponds to an integrated luminosity of 6.0 fb{sup -1}. The search is performed in the final state with one {tau} decaying leptonically and the second one identified through its semi-hadronic decay. Since no significant excess is observed, a 95% credibility level upper limit on the production cross section times branching ratio to the {tau}{tau} final state is set for hypothetical Higgs boson masses between 100 and 150 GeV/c{sup 2}. For a Higgs boson of 120 GeV/c{sup 2} the observed (expected) limit is 14.6 (15.3) the predicted value.

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

2012-01-01T23:59:59.000Z

411

HIggs Boson Mass in the Minimal Unified Subquark Model  

E-Print Network (OSTI)

In the original paper entitled, "Masses of Fundamental Particles"(arXiv:1109.3705v5, 10 Feb 2012), not only the masses of fundamental particles including the weak bosons, Higgs boson, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite models of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

Hidezumi Terazawa

2011-09-17T23:59:59.000Z

412

What Einstein Did Not Know  

SciTech Connect

This public lecture is about 100 years of research on elementary particles and fundamental forces, beginning with the identification of the electron about 1900 and extending to the astonishing discovery of Dark Matter in the late 1900s. The author talks about the elementary particle concept; the discoveries of leptons, quarks and force carrying particles; and some of the experimental technology used. The author tells of his own research, the discovery of the tau lepton, the long, inconclusive search for fractional charged particles and his new involvement in astronomical research on Dark Matter. He concludes by looking ahead to old unsolved puzzles and new questions on the fundamental nature of matter and force that face us in the 21st Century.

Perl, Martin L.; /SLAC

2007-02-02T23:59:59.000Z

413

New results for rare muon decays  

Science Conference Proceedings (OSTI)

Branching-ratio limits obtained with the Crystal Box detector are presented for the rare muon decays ..mu.. ..-->.. eee, ..mu.. ..-->.. e..gamma.., and ..mu.. ..-->.. e..gamma gamma... These decays, which violate the conservation of separate lepton-family numbers, are expected to occur in many extensions to the standard model. We found no candidates for the decay ..mu.. ..-->.. eee, yielding an upper limit for the branching ratio of B/sub ..mu..3e/ .. e..gamma.. candidates yields an upper limit of B/sub ..mu..e..gamma../ .. e..gamma gamma.. candidates gives an upper limit of B/sub ..mu..e..gamma gamma../ < 7.2 x 10/sup -11/. These results strengthen the constraints on models that allow transitions between lepton families.

Mischke, R.E.; Bolton, R.D.; Bowman, J.D.; Cooper, M.D.; Frank, J.S.; Hallin, A.L.; Heusi, P.A.; Hoffman, C.M.; Hogan, G.E.; Mariam, F.G.

1986-01-01T23:59:59.000Z

414

Probing TeV Left-Right Seesaw at Energy and Intensity Frontiers: a Snowmass White Paper  

E-Print Network (OSTI)

We discuss ways to probe the origin of neutrino masses at the Energy and Intensity frontiers, in TeV-scale left-right seesaw models where small neutrino masses arise via type-I seesaw mechanism. We consider generic ('vanilla') version of such models as well as a version which leads to 'large' light-heavy neutrino mixing while keeping the neutrino masses small in a natural manner. We point out specific observable implications of these classes of models at the LHC as well as in searches for lepton flavor violating processes such as $\\mu\\to e\\gamma$ and $\\mu\\to 3e$, and also in searches for lepton number violating neutrinoless double beta decay.

P. S. Bhupal Dev; R. N. Mohapatra

2013-08-09T23:59:59.000Z

415

A table-top laser-based source of femtosecond, collimated, ultra-relativistic positron beams  

E-Print Network (OSTI)

The generation of ultra-relativistic positron beams with short duration ($\\tau_{e^+} \\leq 30$ fs), small divergence ($\\theta_{e^+} \\simeq 3$ mrad), and high density ($n_{e^+} \\simeq 10^{14} - 10^{15}$ cm$^{-3}$) from a fully optical setup is reported. The detected positron beam propagates with a high-density electron beam and $\\gamma$-rays of similar spectral shape and peak energy, thus closely resembling the structure of an astrophysical leptonic jet. It is envisaged that this experimental evidence, besides the intrinsic relevance to laser-driven particle acceleration, may open the pathway for the small-scale study of astrophysical leptonic jets in the laboratory.

G. Sarri; W. Schumaker; A. Di Piazza; M. Vargas; B. Dromey; M. E. Dieckmann; V. Chvykov; A. Maksimchuk; V. Yanovsky; Z. H. He; B. X. Hou; J. A. Nees; A. G. R. Thomas; C. H. Keit; M. Zepf; K. Krushelnick

2013-04-19T23:59:59.000Z

416

Performance of the ATLAS tau trigger with 7 TeV collision data at the LHC  

E-Print Network (OSTI)

Tau leptons are a fundamental ingredient in the discovery of new physics at the LHC. The reconstruction of hadronic tau decays at the trigger level, although a very challenging task in proton-proton collision environments, allows us to double the sample of tau decays collected, and provides additional discovery power to final states which include tau leptons. In this contribution we show the understanding of the tau trigger system using data collected with the ATLAS detector at the LHC in proton-proton collisions at a center-of-mass energy of 7 TeV. We present the most relevant quantities used in the different stages of the trigger selection, and the trigger efficiencies as a function of ET using tau-like QCD events passing the offline reconstruction and identification selection.

Robinson, M; The ATLAS collaboration

2010-01-01T23:59:59.000Z

417

The CDF-II tau physics program triggers, tau ID and preliminary results  

SciTech Connect

The study of processes containing {tau} leptons in the final state will play an important role at Tevatron Run II. Such final states will be relevant both for electroweak studies and measurements as well as in searches for physics beyond the Standard Model. The present paper discusses the physics opportunities and challenges related to the implementation of new set of triggers able to select events containing tau candidates in the final state. They illustrate, in particular, the physics capabilities for a variety of new physics scenarios such as supersymmetry (SUSY), SUSY with Rp-parity violation, with Bilinear parity violation or models with the violation of lepton flavor. Finally, they present the first Run II results obtained using some of the described tau triggers.

C. Pagliarone et al.

2003-11-03T23:59:59.000Z

418

Minimal Neutrino Texture with Neutrino Mass Ratio and Cabibbo Angle  

E-Print Network (OSTI)

We present neutrino mass matrix textures in a minimal framework of the type-I seesaw mechanism where two right-handed Majorana neutrinos are introduced in order to reproduce experimental results of neutrino oscillations. The textures can lead to experimentally favored leptonic mixing angles described by the tri-bimaximal mixing with one additional rotation. We present minimal and next to minimal textures for the normal mass hierarchy case in a context of the texture zero. A minimal texture in the inverted hierarchy case is also constructed, which does not have any vanishing entries in a Dirac neutrino mass matrix. We also discuss some cases that model parameters in the textures are supposed to be a neutrino mass ratio and/or the Cabibbo angle. Predicted regions of mixing angles, a leptonic CP-violation parameter, and an effective mass for the neutrino-less double beta decay are presented in all textures.

Yusuke Shimizu; Ryo Takahashi; Morimitsu Tanimoto

2012-12-24T23:59:59.000Z

419

Direct measurement of the mass difference between top and antitop quarks  

SciTech Connect

We present a direct measurement of the mass difference between top and antitop quarks ({Delta}m) in lepton+jets t{bar t} final states using the 'matrix element' method. The purity of the lepton+jets sample is enhanced for t{bar t} events by identifying at least one of the jet as originating from a b quark. The analyzed data correspond to 3.6 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV acquired by D0 in Run II of the Fermilab Tevatron Collider. The combination of the e+jets and m+jets channels yields {Delta}m = 0.8 {+-} 1.8 (stat) {+-} 0.5 (syst) GeV, which is in agreement with the standard model expectation of no mass difference.

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.

2011-06-01T23:59:59.000Z

420

Test of unparticle long range forces from perihelion precession of Mercury  

E-Print Network (OSTI)

Unparticle exchange gives rise to long range forces which deviate from the inverse square law due to non-canonical dimension of unparticles. It is well known that a potential of the form $r^{-n}$ where $n$ is not equal to one gives rise to a precession in the perihelion of planetary orbits. We calculate the constraints on unparticle couplings with baryons and leptons from the observations of perihelion advance of Mercury orbit.

Suratna Das; Subhendra Mohanty; Kumar Rao

2007-09-17T23:59:59.000Z

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421

Higgs boson interactions in supersymmetric theories with large tan beta  

E-Print Network (OSTI)

We show that radiative corrections to the Higgs potential in supersymmetric theories with large tan beta generically lead to large differences in the light Higgs boson decay branching fractions compared to those of the standard model Higgs boson. In contrast, the light Higgs boson production rates are largely unaffected. We identify W h associated production followed by Higgs boson decays to photons or to leptons via W W* as potential experimental probes of these theories.

Will Loinaz; James D. Wells

1998-08-10T23:59:59.000Z

422

Higgs boson coupling sensitivity at the LHC using H->tau tau decays  

E-Print Network (OSTI)

We investigate the potential for measuring the relative couplings of a low-mass Higgs boson at the Large Hadron Collider using WH, ZH, and ttbarH production, where the Higgs boson decays to tau-lepton pairs. With 100/fb of sqrt(s) = 14 TeV pp collision data we find that these modes can improve sensitivity to coupling-ratio measurements of a Higgs boson with a mass of about 125 GeV/c^2.

Boddy, Christopher; Hays, Christopher

2012-01-01T23:59:59.000Z

423

Discovery Potential of the Standard Model Higgs Boson Through $H\\to WW$ Decay Mode with the ATLAS Detector at LHC  

E-Print Network (OSTI)

We report results of a study of the Standard Model Higgs boson discovery potential through the W-pair leptonic decay modes with the ATLAS detector at LHC at 14 TeV center-of-mass energy. We used MC samples with full detector simulation and reconstruction of the ATLAS experiment to estimate the ATLAS detection sensitivity for the reaction of pp -> H -> WW -> e\

Yang, Hai-Jun

2009-01-01T23:59:59.000Z

424

CP violating phases in mu-e conversion  

E-Print Network (OSTI)

Experiments are planned to improve the sensitivity of mu-e conversion from the current ~ 10^{-12} to 10^{-16} - 10^{-18}. If the muon (bound to the nucleus) could be polarised, a spin asymmetry of the final state electron is sensitive to CP violating phases on lepton flavour violating operators. This is similar to extracting phases from asymmetries in the final state spin and phase space distributions of mu to 3e and mu to e gamma.

S Davidson

2008-09-01T23:59:59.000Z

425

EMC effect  

SciTech Connect

A review is presented of data and theoretical interpretations of the nuclear dependence of quark and antiquark distributions as observed in the deep inelastic scattering of neutrinos and charged leptons from nuclei. After a summary of the experimental situation and a survey of the broad spectrum of proposed explanations, I concentrate on the Q/sup 2/-rescaling approach and on interpretations in terms of conventional nuclear physics. The review concludes with a list of desirable future experiments. 31 refs., 4 figs.

Berger, E.L.

1986-06-01T23:59:59.000Z

426

EMC effect  

SciTech Connect

A review is presented of data and theoretical interpretations of the nuclear dependence of quark and antiquark distributions as observed in the deep inelastic scattering of neutrinos and charged leptons from nuclei. After a summary of the experimental situation and a survey of proposed explanations, the author concentrates on interpretations in terms of conventional nuclear physics and on the Q/sup 2/-rescaling approach. The review concludes with a list of desirable future experiments. 32 refs., 5 figs.

Berger, E.L.

1986-09-01T23:59:59.000Z

427

Spacetime as a topological insulator: Mechanism for the origin of the fermion generations  

E-Print Network (OSTI)

We suggest a mechanism whereby the three generations of quarks and leptons correspond to surface modes in a five-dimensional theory. These modes arise from a nonlinear fermion dispersion relation in the extra dimension, much in the same manner as fermion surface modes in a topological insulator or lattice implementation of domain wall fermions. We also show that the topological properties can persist in a deconstructed version of the model in four dimensions.

David B. Kaplan; Sichun Sun

2011-12-01T23:59:59.000Z

428

SOME ASPECTS OF THE PROSPECTIVE EXPERIMENTAL USE OF THE STANFORD TWO-MILE ACCELERATOR  

DOE Green Energy (OSTI)

Eleven papers dealing with photon beams from the accelerator, use of hydrogen bubble chambers and spark chambers, a storage ring for 10-Bev muons, muon beams and -p scattering experiments, mass analysis of highenergy accelerator beams, the search for intermediate bosons and heavy leptons, particle yields arising from decay of short-lived intermediate particles, and conjectures on the effects of Regge poles on Drell processes are included. Separate abstracts were prepared for the eleven papers. (D.C.W.)

Chinowsky, W.; DeWire, J.W.; Lichtenberg, D.B.; Masek, G.; Murray, J.J.; Perl, M.; Schwartz, M.; Tinlot, J.; Trilling, G.

1962-01-01T23:59:59.000Z

429

Doubly charged Higgsinos at the Tevatron  

Science Conference Proceedings (OSTI)

Several supersymmetric models with extended gauge structures, motivated by either grand unification or by neutrino mass generation, predict light doubly charged Higgsinos. In this work we study the signals of doubly charged Higgsinos at the Tevatron in both pair- and single-production modes, and show that it is possible, especially from the events containing same-sign same-flavor isolated leptons, to disentangle the effects of doubly charged Higgsinos in the Tevatron data.

Demir, Durmus A. [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir (Turkey); Frank, Mariana; Turan, Ismail [Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, H4B 1R6 (Canada); Ghosh, Dilip Kumar [Department of Theoretical Physics and Centre for Theoretical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Kolkata 700 032 (India); Huitu, Katri; Rai, Santosh Kumar [Department of Physics, University of Helsinki (Finland) and Helsinki Institute of Physics, Post Office Box 64, FIN-00014 University of Helsinki (Finland)

2009-05-01T23:59:59.000Z

430

Twist-4 Matrix Elements of the Nucleon from Recent DIS Data at CERN and SLAC  

E-Print Network (OSTI)

We analyse the recent precision measurements of the lepton-hadron deep inelastic scattering at CERN and SLAC to extract model independent constraints among the nucleon matrix elements of the twist-4 operators. We also study a parameterization of these matrix elements and point out the possibility that the matrix elements of the quark-gluon mixed operator has a negative value of the order of $- (400 \\pm 100\\ {\\rm MeV})^2$ at 5 GeV$^2$ renormalization scale.

S. Choi; T. Hatsuda; Y. Koike; Su H. Lee

1993-03-17T23:59:59.000Z

431

Quasielastic scattering with the Relativistic Green's Function approach  

E-Print Network (OSTI)

A relativistic model for quasielastic (QE) lepton-nucleus scattering is presented. The effects of final-state interactions (FSI) between the ejected nucleon and the residual nucleus are described in the relativistic Green's function (RGF) model where FSI are consistently described with exclusive scattering using a complex optical potential. The results of the model are compared with experimental results of electron and neutrino scattering.

Andrea Meucci; Carlotta Giusti

2013-04-08T23:59:59.000Z

432

R Parity Violating Decays of the Gluino  

E-Print Network (OSTI)

Assuming the lightest supersymmetric particle is the gluino, we treat the decays gluino->quark-antiquark-neutrino and gluino->gluon-neutrino. Such couplings can be induced by the R parity violating quark-squark-lepton interaction which can also be responsible for neutrino masses and mixings. These R parity violating gluino decays have the same final state structure (jets plus missing energy) as previously considered decays into quark-antiquark-photino and gluon-gravitino but with significantly different gluino lifetimes.

L. Clavelli; H. Stremnitzer

2003-08-27T23:59:59.000Z

433

Search for pair production of the scalar top quark in the electron-muon final state  

E-Print Network (OSTI)

We report the result of a search for the pair production of the lightest supersymmetric partner of the top quark ($\\tilde{t}_1$) in $p\\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider corresponding to an integrated luminosity of 5.4 fb$^{-1}$. The scalar top quarks are assumed to decay into a $b$ quark, a charged lepton, and a scalar neutrino ($\\tilde{\

V. M. Abazov; B. Abbott; M. Abolins; B. S. Acharya; M. Adams; T. Adams; G. D. Alexeev; G. Alkhazov; A. Altona; G. Alverson; G. A. Alves; L. S. Ancu; M. Aoki; Y. Arnoud; M. Arov; A. Askew; B. sman; O. Atramentov; C. Avila; J. BackusMayes; F. Badaud; L. Bagby; B. Baldin; D. V. Bandurin; S. Banerjee; E. Barberis; P. Baringer; J. Barreto; J. F. Bartlett; U. Bassler; V. Bazterra; S. Beale; A. Bean; M. Begalli; M. Begel; C. Belanger-Champagne; L. Bellantoni; S. B. Beri; G. Bernardi; R. Bernhard; I. Bertram; M. Besanon; R. Beuselinck; V. A. Bezzubov; P. C. Bhat; V. Bhatnagar; G. Blazey; S. Blessing; K. Bloom; A. Boehnlein; D. Boline; T. A. Bolton; E. E. Boos; G. Borissov; T. Bose; A. Brandt; O. Brandt; R. Brock; G. Brooijmans; A. Bross; D. Brown; J. Brown; X. B. Bu; D. Buchholz; M. Buehler; V. Buescher; V. Bunichev; S. Burdinb; T. H. Burnett; C. P. Buszello; B. Calpas; E. Camacho-Prez; M. A. Carrasco-Lizarraga; B. C. K. Casey; H. Castilla-Valdez; S. Chakrabarti; D. Chakraborty; K. M. Chan; A. Chandra; G. Chen; S. Chevalier-Thry; D. K. Cho; S. W. Cho; S. Choi; B. Choudhary; T. Christoudias; S. Cihangir; D. Claes; J. Clutter; M. Cooke; W. E. Cooper; M. Corcoran; F. Couderc; M. -C. Cousinou; A. Croc; D. Cutts; M. ?wiok; A. Das; G. Davies; K. De; S. J. de Jong; E. De La Cruz-Burelo; F. Dliot; M. Demarteau; 47 R. Demina; D. Denisov; S. P. Denisov; S. Desai; K. DeVaughan; H. T. Diehl; M. Diesburg; A. Dominguez; T. Dorland; A. Dubey; L. V. Dudko; D. Duggan; A. Duperrin; S. Dutt; A. Dyshkant; M. Eads; D. Edmunds; J. Ellison; V. D. Elvira; Y. Enari; S. Eno; H. Evans; A. Evdokimov; V. N. Evdokimov; G. Facini; T. Ferbel; F. Fiedler; F. Filthaut; W. Fisher; H. E. Fisk; M. Fortner; H. Fox; S. Fuess; T. Gadfort; A. Garcia-Bellido; V. Gavrilov; P. Gay; W. Geist; W. Geng; D. Gerbaudo; C. E. Gerber; Y. Gershtein; G. Ginther; G. Golovanov; A. Goussiou; P. D. Grannis; S. Greder; H. Greenlee; Z. D. Greenwood; E. M. Gregores; G. Grenier; Ph. Gris; J. -F. Grivaz; A. Grohsjean; S. Grnendahl; M. W. Grnewald; F. Guo; J. Guo; G. Gutierrez; P. Gutierrez; A. Haasc; S. Hagopian; J. Haley; L. Han; K. Harder; A. Harel; J. M. Hauptman; J. Hays; T. Head; T. Hebbeker; D. Hedin; H. Hegab; A. P. Heinson; U. Heintz; C. Hensel; I. Heredia-De La Cruz; K. Herner; G. Hesketh; M. D. Hildreth; R. Hirosky; T. Hoang; J. D. Hobbs; B. Hoeneisen; M. Hohlfeld; S. Hossain; Z. Hubacek; N. Huske; V. Hynek; I. Iashvili; R. Illingworth; A. S. Ito; S. Jabeen; M. Jaffr; S. Jain; D. Jamin; R. Jesik; K. Johns; M. Johnson; D. Johnston; A. Jonckheere; P. Jonsson; J. Joshi; A. Justed; K. Kaadze; E. Kajfasz; D. Karmanov; P. A. Kasper; I. Katsanos; R. Kehoe; S. Kermiche; N. Khalatyan; A. Khanov; A. Kharchilava; Y. N. Kharzheev; D. Khatidze; M. H. Kirby; J. M. Kohli; A. V. Kozelov; J. Kraus; A. Kumar; A. Kupco; T. Kur?a; V. A. Kuzmin; J. Kvita; S. Lammers; G. Landsberg; P. Lebrun; H. S. Lee; S. W. Lee; W. M. Lee; J. Lellouch; L. Li; Q. Z. Li; S. M. Lietti; J. K. Lim; D. Lincoln; J. Linnemann; V. V. Lipaev; R. Lipton; Y. Liu; Z. Liu; A. Lobodenko; M. Lokajicek; P. Love; H. J. Lubatti; R. Luna-Garciae; A. L. Lyon; A. K. A. Maciel; D. Mackin; R. Madar; R. Magaa-Villalba; S. Malik; V. L. Malyshev; Y. Maravin; J. Martnez-Ortega; R. McCarthy; C. L. McGivern; M. M. Meijer; A. Melnitchouk; D. Menezes; P. G. Mercadante; M. Merkin; A. Meyer; J. Meyer; N. K. Mondal; G. S. Muanza; M. Mulhearn; E. Nagy; M. Naimuddin; M. Narain; R. Nayyar; H. A. Neal; J. P. Negret; P. Neustroev; S. F. Novaes; T. Nunnemann; G. Obrant; J. Orduna; N. Osman; J. Osta; G. J. Otero y Garzn; M. Owen; M. Padilla; M. Pangilinan; N. Parashar; V. Parihar; S. K. Park; J. Parsons; R. Partridgec; N. Parua; A. Patwa; B. Penning; M. Perfilov; K. Peters; Y. Peters; G. Petrillo; P. Ptroff; R. Piegaia; J. Piper; M. -A. Pleier; P. L. M. Podesta-Lermaf; V. M. Podstavkov; M. -E. Pol; P. Polozov; A. V. Popov; M. Prewitt; D. Price; S. Protopopescu; J. Qian; A. Quadt; B. Quinn; M. S. Rangel; K. Ranjan; P. N. Ratoff; I. Razumov; P. Renkel; P. Rich; M. Rijssenbeek; I. Ripp-Baudot; F. Rizatdinova; M. Rominsky; C. Royon; P. Rubinov; R. Ruchti; G. Safronov; G. Sajot; A. Snchez-Hernndez; M. P. Sanders; B. Sanghi; A. S. Santos; G. Savage; L. Sawyer; T. Scanlon; R. D. Schamberger; Y. Scheglov; H. Schellman; T. Schliephake; S. Schlobohm; C. Schwanenberger; R. Schwienhorst; J. Sekaric; H. Severini; E. Shabalina; V. Shary; A. A. Shchukin; R. K. Shivpuri; V. Simak; V. Sirotenko; P. Skubic; P. Slattery; D. Smirnov; K. J. Smith; G. R. Snow; J. Snow; S. Snyder; S. Sldner-Rembold; L. Sonnenschein; A. Sopczak; M. Sosebee; K. Soustruznik; B. Spurlock; J. Stark; V. Stolin; D. A. Stoyanova; E. Strauss; M. Strauss; D. Strom; L. Stutte; P. Svoisky; M. Takahashi; A. Tanasijczuk; W. Taylor; M. Titov; V. V. Tokmenin; D. Tsybychev; B. Tuchming; C. Tully; P. M. Tuts; L. Uvarov

2010-09-29T23:59:59.000Z

434

The Anomalous Magnetic Moment of the Muon and Higgs-Mediated Flavor Changing Neutral Currents  

E-Print Network (OSTI)

In the two-Higgs doublet extension of the standard model, flavor-changing neutral couplings arise naturally. In the lepton sector, the largest such coupling is expected to be $\\mu-\\tau-\\phi#. We consider the effects of this coupling on the anomalous magnetic moment of the muon. The resulting bound on the coupling, unlike previous bounds, is independent of the value of other unknown couplings. It will be significantly improved by the upcoming E821 experiment at Brookhaven National Lab.

Shuquan Nie; Marc Sher

1998-05-19T23:59:59.000Z

435

Tracing Very High Energy Tau Neutrinos from Cosmological Distances in Ice  

E-Print Network (OSTI)

Astrophysical sources of ultrahigh energy neutrinos yield tau neutrino fluxes due to neutrino oscillations. We study in detail the contribution of tau neutrinos with energies above $10^6$ GeV relative to the contribution of the other flavors. We consider several different initial neutrino fluxes and include tau neutrino regeneration in transit through the Earth and energy loss of charged leptons. We discuss signals of tau neutrinos in detectors such as IceCube, RICE and ANITA.

J. Jones; I. Mocioiu; I. Sarcevic; M. H. Reno

2004-08-04T23:59:59.000Z

436

Discovery Potential of the Standard Model Higgs Boson Through H -> WW Decay Mode with the ATLAS Detector at LHC  

E-Print Network (OSTI)

We report results of a study of the Standard Model Higgs boson discovery potential through the W-pair leptonic decay modes with the ATLAS detector at LHC at 14 TeV center-of-mass energy. We used MC samples with full detector simulation and reconstruction of the ATLAS experiment to estimate the ATLAS detection sensitivity for the reaction of pp -> H -> WW -> e\

Hai-Jun Yang; for the ATLAS Collaboration

2009-10-01T23:59:59.000Z

437

TASI 2004 Lecture Notes: Higgs Boson Physics  

E-Print Network (OSTI)

In these lectures I briefly review the Higgs mechanism of spontaneous symmetry breaking and focus on the most relevant aspects of the phenomenology of the Standard Model and of the Minimal Supersymmetric Standard Model Higgs bosons at both hadron and lepton colliders. Some emphasis is put on the perturbative calculation of both Higgs boson branching ratios and production cross sections, including the most important radiative corrections.

L. Reina

2005-12-30T23:59:59.000Z

438

Tau longitudinal polarization in B{yields}D{tau}{nu} and its role in the search for the charged Higgs boson  

Science Conference Proceedings (OSTI)

We study the longitudinal polarization of the tau lepton in B{yields}D{tau}{nu} decay. After discussing possible sensitivities of {tau} decay modes to the {tau} polarization, we examine the effect of charged Higgs boson on the {tau} polarization in B{yields}D{tau}{nu}. We find a relation between the decay rate and the {tau} polarization, and clarify the role of the {tau} polarization measurement in the search for the charged Higgs boson.

Tanaka, Minoru; Watanabe, Ryoutaro [Department of Physics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2010-08-01T23:59:59.000Z

439

The light pseudoscalar Higgs boson in NMSSM  

E-Print Network (OSTI)

We study the associated production of a very light pseudoscalar Higgs boson with a pair of charginos. The novel signature involves a pair of charged leptons from chargino decays and a pair of photons from the pseudoscalar Higgs boson decay, plus large missing energy at the LHC and ILC. The signal may help us to distinguish the NMSSM from MSSM, provided that the experiment can resolve the two photons from the decay of the pseudoscalar Higgs boson.

Abdesslam Arhrib; Kingman Cheung; Tie-Jiun Hou; Kok-Wee Song

2006-11-16T23:59:59.000Z

440

The Unification and Cogeneration of Dark Matter and Baryonic Matter  

E-Print Network (OSTI)

In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

S. M. Barr

2011-09-12T23:59:59.000Z

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441

The Unification and Cogeneration of Dark Matter and Baryonic Matter  

E-Print Network (OSTI)

In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

Barr, S M

2011-01-01T23:59:59.000Z

442

Search for the Higgs boson produced in association with a W boson at CDF Run II  

SciTech Connect

We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (p{bar p} {yields} W{sup {+-}}H {yields} {ell}{nu}b{bar b}) at a center of mass energy of 1.96 TeV. WH candidate events have a signature of a single lepton (E{sup {+-}}/{mu}{sup {+-}}), missing transverse energy, and two jets. The search looks for candidate events in approximately 2.7 fb{sup -1} of data recorded with the CDF II detector. The high-p{sub T} lepton (e,{mu}) in the events provides a distinct signature for triggering and most of the events in the dataset come from high-p{sub t} lepton triggers. Our analysis improves on prior searches by including events recorded on the E{sub T} + 2 Jets trigger with a lepton reconstructed as an isolated high-p{sub T} charged particle. We increase the sample purity by identifying ('tagging') long-lived b-hadrons in jets. A neural network combines distinguishing kinematic information into a function optimized for WH sensitivity. The neural network output distributions are consistent with the standard model background expectations and we set limits upper limits on the rate of Higgs production. We set 95% confidence level upper limits on the WH production cross section times branching ratio for Higgs masses from 100 to 150 GeV/c{sup 2} and express our results as a ratio of the experimental limit to the theoretical Standard Model production rate. Our limits range from 3.6 (4.3 expected) to 61.1 (43.2 expected) for Higgs masses from 100 to 150 GeV/c{sup 2}, respectively.

Slaunwhite, Jason Michael; /Ohio State U.

2009-01-01T23:59:59.000Z

443

Higgs decay to bottom quarks at the Tevatron  

SciTech Connect

We study the production and detection of the standard-model Higgs boson at the Fermilab Tevatron. The most promising mode is WH and ZH associated production followed by leptonic decay of the weak vector bosons and H {yields} b{bar b}. It may be possible to detect a Higgs boson of mass m{sub H} = 60--80 GeV with 1000 pb{sup {minus}1} of integrated luminosity.

Stange, A.; Marciano, W. [Brookhaven National Lab., Upton, NY (United States); Willenbrock, S. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Brookhaven National Lab., Upton, NY (United States)

1993-10-01T23:59:59.000Z

444

Searches for Exotic Decays of the Upsilon(3S) at BaBar  

SciTech Connect

In this paper we present two searches for new physics in {Upsilon}(3S) decays collected by the BABAR detector. We search for charged lepton-flavour violating decays of the {Upsilon}(3S), which are unobservable in the Standard Model but are predicted to occur in several beyond-the-Standard Model scenarios. We also search for production of a light Higgs or Higgs-like state produced in radiative decays of the {Upsilon}(3S) and decaying to muon pairs.

Hooberman, Benjamin; /LBL, Berkeley /Heidelberg U.

2011-12-01T23:59:59.000Z

445

W ? production in vector boson fusion at NLO in QCD  

E-Print Network (OSTI)

The next-to-leading order QCD corrections to W gamma production in association with two jets via vector boson fusion are calculated, including the leptonic decay of the W with full off-shell effects and spin correlations. The process lends itself to a test of quartic gauge couplings. The next-to-leading order corrections reduce the scale uncertainty significantly and show a non-trivial phase space dependence.

Francisco Campanario; Nicolas Kaiser; Dieter Zeppenfeld

2013-09-27T23:59:59.000Z

446

Tools for top physics at CDF  

SciTech Connect

The authors describe here the different tools used for top physics analysis in the CDF Collaboration. In particular, they discuss how the jet energy scale, lepton identification, b tagging algorithms and the neural networks help to improve the signal to background ratio of the top sample in some cases and to reduce the dominant uncertainties in other. Results using each one of these tools are also presented.

Palencia, E.; /Fermilab

2008-07-01T23:59:59.000Z

447

Searches for long-lived charged particles in pp collisions at sqrt(s) = 7 and 8 TeV  

E-Print Network (OSTI)

Results of searches for heavy stable charged particles produced in pp collisions at sqrt(s) = 7 and 8 TeV are presented corresponding to an integrated luminosity of 5.0 inverse femtobarns and 18.8 inverse femtobarns, respectively. Data collected with the CMS detector are used to study the momentum, energy deposition, and time-of-flight of signal candidates. Leptons with an electric charge between e/3 and 8e, as well as bound states that can undergo charge exchange with the detector material, are studied. Analysis results are presented for various combinations of signatures in the inner tracker only, inner tracker and muon detector, and muon detector only. Detector signatures utilized are long time-of-flight to the outer muon system and anomalously high (or low) energy deposition in the inner tracker. The data are consistent with the expected background, and upper limits are set on the production cross section of long-lived gluinos, scalar top quarks, and scalar tau leptons, as well as pair produced long-lived leptons. Corresponding lower mass limits, ranging up to 1322 GeV for gluinos, are the most stringent to date.

CMS Collaboration

2013-05-02T23:59:59.000Z

448

strucfun.dvi  

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

1.1. 1.1. Deep inelastic scattering High-energy lepton-nucleon scattering (deep inelastic scattering) plays a key role in determining the partonic structure of the proton. The process ℓN → ℓ ' X is illustrated in Fig. 1.1. The filled circle in this figure represents the internal structure of the proton which can be expressed in terms of structure functions. k k q P, M W Figure 1.1: Kinematic quantities for the description of deep inelastic scattering. The quantities k and k ' are the four-momenta of the incoming and outgoing leptons, P is the four-momentum of a nucleon with mass M , and W is the mass of the recoiling system X. The exchanged particle is a γ, W ± , or Z; it transfers four-momentum q = k - k ' to the nucleon. Invariant quantities: ν = q · P M = E - E ' is the lepton's energy loss in the nucleon rest frame (in earlier literature sometimes ν = q · P ). Here, E and E ' are the initial and final

449

Beyond the Standard Model  

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

allá del Modelo Standard allá del Modelo Standard Avanzar Volver Principal ESTOY PERDIDO!!! El modelo standard explica muchas de las preguntas acerca de la estructura y la estabilidad de la materia, con sus seis tipos de quarks, sus seis tipos de leptones, y sus cuatro fuerzas fundamentales. Sin embargo, el modelo standard es una teoría incompleta porque todavía no puede explicar la naturaleza del mundo en forma completa. ¿Por qué hay tres generaciones de quarks y leptones? ¿Los quarks y leptones son realmente fundamentales, o están constituidos a su vez por partículas aún más fundamentales? ¿Por qué no puede el modelo standard predecir la masa de una partícula? De acuerdo con nuestros experimentos, las cantidades de materia y antimateria en el universo deberían ser iguales; pero, ¿por qué hemos

450

zprime_s056215-web.dvi  

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

May May 2012 by G. Brooijmans (Columbia University), M.-C. Chen (UC Irvine), and B.A. Dobrescu (Fermilab). The Z ' boson is a hypothetical massive, electrically-neutral and color-singlet particle of spin 1. This particle is predicted in many extensions of the Standard Model, and has been the object of extensive phenomenological studies [1]. Z ' boson couplings to quarks and leptons. The couplings of a Z ' boson to the first-generation fermions are given by Z ' µ ( g L u u L γ µ u L + g L d d L γ µ d L + g R u u R γ µ u R + g R d d R γ µ d R + g L ν ν L γ µ ν L + g L e e L γ µ e L + g R e e R γ µ e R , (1) where u, d, ν and e are the quark and lepton fields in the mass eigenstate basis, and the coefficients g L u , g L d , g R u , g R d , g L ν , g L e , g R e are real dimensionless parameters. If the Z ' couplings to quarks and leptons are generation-independent, then these seven parameters describe the couplings of the Z ' boson to all Standard

451

Probing Color Octet Electrons at the LHC  

E-Print Network (OSTI)

Models with quark and lepton compositeness predict the existence of colored partners of the Standard Model leptons. In this paper we study the LHC phenomenology of a charged colored lepton partner, namely the color octet electron, $e_8$ in an effective theory framework. We explore various mechanisms for resonant production of $e_8$'s. With the pair production channel the 14 TeV LHC can probe $e_8$'s with masses up to 2.5 TeV (2.8 TeV) with 100 fb$^{-1}$ (300 fb$^{-1}$) of integrated luminosity. A common feature in all the resonant production channels is the presence of two high $p_T$ electrons and at least one high $p_T$ jet in the final state. Using this feature, we implement a search method where the signal is a combination of pair and single production events. This method has potential to increase the LHC reach significantly. Using the combined signal we estimate the LHC discovery potential for the $e_8$'s. Our analysis shows that the LHC with 14 TeV center-of-mass energy and 100 fb$^{-1}$ (300 fb$^{-1}$) of integrated luminosity can probe $e_8$'s with masses up to 3.4 TeV (4 TeV) for the compositeness scale of 5 TeV.

Tanumoy Mandal; Subhadip Mitra

2012-11-27T23:59:59.000Z

452

Forward-Backward Asymmetry at High Mass in $t\\bar{t}$ Production in $p\\bar{p}$ Collisions at $\\sqrt{s} = 1.96$ TeV  

SciTech Connect

Current understanding of particle physics postulates that there are 17 fundamental particles that interact via four fundamental forces - gravity, the strong force, the weak force, and the electromagnetic force. These fundamental particles can be classified by their spins into bosons, which are the force-carrying particles with integer spins, and fermions, which have half-integer spins. Fermions can be further divided into quarks and leptons. The particles and three of the four forces - all but gravity - are described by the Standard Model, a local SU(3) x SU(2) x U(1) gauge theory. Electromagnetic and weak interactions as described by Electroweak Theory or Quantum Electrodynamics, SU(2) x U(1). Strong interactions are described by Quantum Chromodynamics or QCD, SU(3). Fermions are grouped into three generations as shown in Table 1.1. Each generation consists of a leptonic doublet containing a charged and a neutral lepton and a weak isospin doublet containing two quarks. The first generation, containing the electron, the electron neutrino, the up quark, and the down quark, is the lightest generation and is thus the most frequently found in nature. The second generation contains the muon, the muon neutrino, the strange quark, and the charm quark. The third generation contains the tau, the tau neutrino, the bottom quark, and the top quark.

Eppig, Andrew; /Michigan U.

2011-04-01T23:59:59.000Z

453

Phenomenological constraints on broken R parity symmetry in supersymmetry models  

E-Print Network (OSTI)

The R parity odd renormalizable Yukawa interactions of quarks and leptons with the scalar superpartners have the ability to violate the baryon and lepton numbers, change the hadron and lepton flavors and make the lightest supersymmetric particle unstable. The existence of an approximate R parity symmetry would thus affect in a deep way the conventional framework of the Minimal Supersymmetric Standard Model where an exact R parity symmetry is built-in by assumption. The purpose of the present review is to survey in a systematic way the direct experimental constraints set on the R parity violating couplings by the low and intermediate energy physics processes. We consider first the option of bilinear R parity violation and spontaneously broken R parity symmetry and proceed next to the trilinear R parity violating interactions. The discussion aims at surveying the indirect coupling constant bounds derived from fundamental tests of the Standard Model and the variety of scattering and rare decay processes. We also discuss the constraints imposed by the renormalization group scale evolution and the cosmological and astrophysical phenomenology.

Marc Chemtob

2004-06-02T23:59:59.000Z

454

Neutrino Mass and Mixing with Discrete Symmetry  

E-Print Network (OSTI)

This is a review article about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of seesaw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mec...

King, Stephen F

2013-01-01T23:59:59.000Z

455

A Search for  

E-Print Network (OSTI)

We search for the decay B \\Gamma ! \\Gamma in a sample of over 2 million charged B decays using the CLEO detector. We use the channel in which the tau decays leptonically, and combine this lepton with the missing energy and momentum in the event to form a B candidate. A fit to the mass and energy distribution of these B candidates yields \\Gamma14 \\Sigma 46 signal events. This value corresponds to an upper limit of B(B \\Gamma ! \\Gamma ) ! 2:2 \\Theta 10 \\Gamma3 at the 90% confidence level. Permanent address: University of Hawaii at Manoa 1 I. INTRODUCTION The purely leptonic decays of mesons are perhaps the simplest of all known decays of hadrons. Unlike all other decays, the final state is unaffected by strong interactions. As a consequence, the rate for these decays can be predicted by many models of particle interactions, and measurement of the rate can provide information about a particular model that can be interpreted easily. In this paper we report on a new ...

Alexander Bebek Berkelman; Ichep Ref; Gls Cleo Conf; K. Bloom

1994-01-01T23:59:59.000Z

456

Gamma-Ray Lines from Radiative Dark Matter Decay  

E-Print Network (OSTI)

The decay of dark matter particles which are coupled predominantly to charged leptons has been proposed as a possible origin of excess high-energy positrons and electrons observed by cosmic-ray telescopes PAMELA and Fermi LAT. Even though the dark matter itself is electrically neutral, the tree-level decay of dark matter into charged lepton pairs will generically induce radiative two-body decays of dark matter at the quantum level. Using an effective theory of leptophilic dark matter decay, we calculate the rates of radiative two-body decays for scalar and fermionic dark matter particles. Due to the absence of astrophysical sources of monochromatic gamma rays, the observation of a line in the diffuse gamma-ray spectrum would constitute a strong indication of a particle physics origin of these photons. We estimate the intensity of the gamma-ray line that may be present in the energy range of a few TeV if the dark matter decay interpretation of the leptonic cosmic-ray anomalies is correct and comment on observational prospects of present and future Imaging Cherenkov Telescopes, in particular the CTA.

Mathias Garny; Alejandro Ibarra; David Tran; Christoph Weniger

2010-11-16T23:59:59.000Z

457

Dipole Moment Bounds on Scalar Dark Matter Annihilation  

E-Print Network (OSTI)

We consider a scalar dark matter annihilations to light leptons mediated by charged exotic fermions. The interaction of this model also adds a correction to dipole moments of light leptons. In the simplified model, these processes will depend upon the same coupling constants. The tight experimental bounds on the dipole moments of light leptons will constrain the coupling constants. Consequently, this bound will then limit the annihilations. We will produce this dipole moment bounds on the annihilation. From this analysis, we report that the bound on annihilation to the electrons is $4.0\\times10^{-7}\\pb$ (g-2) + $8.8\\times 10^{-15}\\pb$ (EDM) and the muons is $5.6\\times 10^{-4}\\pb$ (g-2) + $180\\pb$ (EDM), in the limit where the mediator is much heavier than dark matter. The parentheses indicate the dipole moment used to obtain the values. We note that only the annihilation to muons through a CP-violating (EDM) coupling is not excluded from indirect detection experiments.

Keita Fukushima

2013-10-07T23:59:59.000Z

458

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV  

SciTech Connect

We present the measurement of the t{bar t} cross section in the lepton plus jets channel with {ge} 1 and {ge} 2 secondary vertex tags. We use the scalar sum of transverse energies of the event (H{sub T}) to discriminate t{bar t} from the other backgrounds. We also use the transverse mass of the leptonic W-boson (M{sub T}{sup W}) to further reduce the Non-W backgrounds. We use a combination of data and Monte Carlo to estimate the backgrounds from electroweak processes, single top, fake leptons, W+ Light Flavor fake tags, and real W+ Heavy Flavor production. We obtain a value of {sigma} {sub {ge}1} = 8.7{sub -0.9}{sup +0.9}(stat){sub -0.9}{sup +1.2}(sys) pb for the {ge}1 tag cross section, and {sigma}{sub {ge}2} = 8.7{sub -1.6}{sup +1.8}(stat){sub -1.3}{sup +1.9}(sys) pb for the {ge}2 tag cross section. The authors also present a measurement of the t{bar t} cross section by fitting the N{sub jet} spectrum. They combine the =1 and {ge}2 tag cross sections to obtain {sigma}{sub t{bar t}} = 8.9{sub -0.9}{sup +0.9}(stat){sub -1.3}{sup +1.4}(syst)pb.

Rappoccio, Salvatore Rocco; /Harvard U.

2005-08-01T23:59:59.000Z

459

Herwig++ Physics and Manual  

E-Print Network (OSTI)

In this paper we describe Herwig++ version 2.3, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron collisions. A number of important hard scattering processes are available, together with an interface via the Les Houches Accord to specialized matrix element generators for additional processes. The simulation of Beyond the Standard Model (BSM) physics includes a range of models and allows new models to be added by encoding the Feynman rules of the model. The parton-shower approach is used to simulate initial- and final-state QCD radiation, including colour coherence effects, with special emphasis on the correct description of radiation from heavy particles. The underlying event is simulated using an eikonal multiple parton-parton scattering model. The formation of hadrons from the quarks and gluons produced in the parton shower is described using the cluster hadronization model. Hadron decays are simulated using matrix elements, where possible including spin correlations and off-shell effects.

M. Bahr; S. Gieseke; M. A. Gigg; D. Grellscheid; K. Hamilton; O. Latunde-Dada; S. Platzer; P. Richardson; M. H. Seymour; A. Sherstnev; J. Tully; B. R. Webber

2008-03-06T23:59:59.000Z

460

Search for the Higgs Boson Using High-pT Isolated Like-Sign Dil Events in 1.96-TeV Proton-Antiproton Collisions  

SciTech Connect

Our physics objective is to search for the neutral on using events containing a like-sign dilepton pair in the following reaction: q{bar q} {yields} W{sup {+-}} H {yields} W{sup {+-}} W*W* {yields} {ell}{sup {+-}}{ell}{sup {+-}} + X. The relevant Higgs boson mass region is above 160 GeV/c{sup 2} for the Standard Model Higgs boson where the branching fraction of H {yields} W*W* supersedes that of H {yields} b{bar b}. The search for this signature in the region at low mass (less than 135 GeV/c{sup 2}) is, however, still important because we need to investigate various Higgs boson couplings as an essential test to convince that signals are attributed to the Higgs boson production. This channel also covers the case beyond the Standard Model that the Higgs boson couples only to the gauge bosons, which is referred to as the bosophilic or fermiophobic Higgs boson. The corresponding mass region suitable to our signature is above 110 GeV/c{sup 2} where the branching fraction of H {yields} {gamma}{gamma} is overtaken by this channel. On the experimental side, the like-sign dilepton event is one of the cleanest signature in hadron collisions. This analysis exploiting such a distinctive signature is therefore expected to have a high potential of the sensitivity for the search of the Higgs boson. The data were collected with the CDF II detector between March 2002 and September 2003, corresponding to an integrated luminosity of 193.5 pb{sup -1}. At off-line, the central region (|{eta}| < 1.1) is considered for the lepton detection. We require at least one electron with E{sub T} > 20 GeV or muon with p{sub T} > 20 GeV/c which is considered to be responsible for firing the corresponding trigger, and at least one other electron with E{sub T} > 6 GeV or muon with p{sub T} > 6 GeV/c. The leptons are required to be isolated in terms of the calorimeter cone-isolation with a cone size of R = 0.4. We require that the isolation is less than 2 GeV for each lepton. For the events with like-sign two or more leptons that pass our selection above, we apply a cosmic-ray veto, dilepton mass cut (M{sub {ell}{ell}} > 12 GeV/c{sup 2}), and a Z-decay removal to clean up the sample. We also explicitly require that the leptons must be consistent with coming from the same vertex, which is an important requirement for multi-lepton signatures especially in a high-luminosity situation. The selection cuts identifies high-p{sub T}, isolated leptons with almost ''standard'' identification criteria. We observed 45 like-sign dilepton events in data.

Kobayashi, Hirokazu; /Tsukuba U.

2005-03-01T23:59:59.000Z

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461

Modified Higgs Sectors and NLO Associated Production  

E-Print Network (OSTI)

Many beyond the Standard Model (BSM) scenarios involve Higgs couplings to additional electroweak fields. It is well established that these new fields may modify Higgs gamma-gamma and gamma-Z decays at one-loop. However, one unexplored aspect of such scenarios is that by electroweak symmetry one should also expect modifications to the Higgs Z-Z coupling at one-loop and, more generally, modifications to Higgs production and decay channels beyond tree-level. In this paper we investigate the full BSM modified electroweak corrections to associated Higgs production at both the LHC and a future lepton collider in two simple SM extensions. From both inclusive and differential NLO associated production cross sections we find BSM-NLO corrections can be as large as O(>10%) when compared to the SM expectation, consistent with other precision electroweak measurements, even in scenarios where modifications to the Higgs diphoton rate are not significant. At the LHC such corrections are comparable to the involved QCD uncertainties. At a lepton collider the Higgs associated production cross section can be measured to high accuracy (O(1%) independent of uncertainties in total width and other couplings), and such a deviation could be easily observed even if the new states remain beyond kinematic reach. This should be compared to the expected accuracy for a model-independent determination of the Higgs diphoton coupling at a lepton collider, which is O(15%). This work demonstrates that precision measurements of the Higgs associated production cross section constitute a powerful probe of modified Higgs sectors and will be valuable for indirectly exploring BSM scenarios.

Christoph Englert; Matthew McCullough

2013-03-06T23:59:59.000Z

462

The pair production of Charged and Neutral Higgs bosons in W and Z gauge boson fusion process  

E-Print Network (OSTI)

We study the signatures of a two Higgs doublet model of Davidson and Logan. The model includes an extra Higgs doublet with the vacuum expectation value (VEV) much smaller than the one of the standard model like Higgs. The smaller VEV is related to the origin of the small neutrino mass in the two Higgs doublet model. In the model, a single non-standard model like Higgs production of weak gauge boson fusion is suppressed due to the smallness of the vacuum expectation value. In contrast to the single Higgs production, the cross section of the Higgs pair production due to gauge boson fusion is not suppressed. Using the model, we compute the charged Higgs and neutral Higgs pair production cross section in W Z annihilation channel. In the two Higgs doublet model, the charged Higgs H^+ decays into a pair of the charged anti-lepton and right-handed neutrino. The neutral Higgs boson decays into right-handed neutrino and left-handed anti-neutrino pair which is invisible. A single charged anti-lepton and three neutrinos are the products of the subsequent decays of the charged Higgs and the neutral Higgs. W Z pair production gives the background for the signal through the decays W^+ ->nu l^+ and Z -> nu nubar. By multiplying the charged and neutral Higgses production cross section with the lepton flavor specific decay branching fractions of charged Higgs, we define a measurement which characterizes the present model. We numerically compute the measurement and find the sizable deviation from the standard model prediction.

Takuya Morozumi; Kotaro Tamai

2012-12-10T23:59:59.000Z

463

Santa Cruz Institute for Particle Physics (SCIPP)  

Science Conference Proceedings (OSTI)

Work for the coming year is a logical continuation of the efforts of the past year. Some special highlights of this past year which are discusses in more detail in this report are: (1) The move onto beamline and start of ZEUS data taking. (2) The completion of the SDC technical proposal including a detailed long-term plan for construction. (3) Continuing publication of very detailed physics results from ALEPH concerning [tau] and b physics, and a precision measurement of electroweak and QCD parameters. (4) Completion of very successful data taking for E-791 at Fermilab, with nearly twice as many events recorded as initially proposed. (5) First measurement of beam polarization at the SLC. These efforts have led to about 15 physics publications this past year centered mainly on topics related to QCD, couplings of flavors to the Z[degrees], and heavy flavor decays. Taken as a whole, the results in jets from LEP, the ratio of hadronic to leptonic decays of the [tau] the leptonic branching fraction of the J/[psi], and the charmonium mass spectrum provide a very consistent set of values of [alpha][sub s] at a variety of scales. In particular, they show the running of [alpha][sub s] by a factor of about three from m[sub r] to m[sub z]. Results from LEP also provide evidence of the triple gluon vertex. Similarly, the measurement of the b[bar b] fraction of Z[degrees] decays, from the MARK II as well as LEP, provide increasingly better measurements of the Z[degree] coupling to b quarks. Combined with earlier precision measurements of the Z[degrees] mass, width, and leptonic branching fractions, the Z[degrees] decays continue to provide a very precise verification of the Standard Model.

Burchat, P.; Dorfan, D.; Litke, A.; Heusch, C.; Sadrozinski, H.; Schalk, T.; Seiden, A.

1992-01-01T23:59:59.000Z

464

Positive muon and the positron as probes of defects  

SciTech Connect

The positive muon and the positron are each being used nowadays to investigate defects in condensed matter. A brief summary of the experimental methods employed with each particle is given in this paper. Similarities and differences between the behavior of the two leptons when implanted in consensed matter are pointed out, and by means of a comparison between muon and positron data in Al it is shown that the combination of muon and positron experiments can serve as a useful new probe of defects in solids.

Lynn, K G

1980-01-01T23:59:59.000Z

465

Weinberg Angle and Integer Electric Charges of Quarks  

E-Print Network (OSTI)

Orthogonality between photon and Z boson involves the Weinberg angle and a scheme for assignments of electric charge and weak isospin to leptons and quarks coupling to photon and Z. The Han-Nambu scheme, with integer electric charges for quarks, satisfies photon-Z orthogonality with sin^2(theta_W)= 0.25 in leading order. Experimental results for photon-photon fusion into charm-anticharm and bottom-antibottom pairs provide further support for assigning integer electric charges to quarks.

Martin A. Faessler

2013-08-22T23:59:59.000Z

466

New Physics at the LHC: A Les Houches Report. Physics at Tev Colliders 2007 - New Physics Working Group  

SciTech Connect

We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. The signatures are organized according to the experimental objects that appear in the final state, and in particular the number of high p{sub T} leptons. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the 'New Physics' working group for the 'Physics at TeV Colliders' workshop (Les Houches, France, 11-29 June, 2007).

Brooijmans, Gustaaf H.; /Columbia U.; Delgado, A.; /Notre Dame U.; Dobrescu, Bogdan A.; /Fermilab; Grojean, C.; /CERN /Saclay, SPhT; Narain, Meenakshi; /Brown U.; Alwall, Johan; /SLAC; Azuelos, Georges; /Montreal U. /TRIUMF; Black, K.; /Harvard U.; Boos, E.; /SINP, Moscow; Bose, Tulika; /Brown U.; Bunichev, V.; /SINP, Moscow; Chivukula, R.S.; /Michigan State U.; Contino, R.; /CERN; Djouadi, A.; /Louis Pasteur U., Strasbourg I /Orsay, LAL; Dudko, Lev V.; /Durham U.; Ferland, J.; /Montreal U.; Gershtein, Yuri S.; /Florida State U.; Gigg, M.; /Durham U.; Gonzalez de la Hoz, S.; /Valencia U., IFIC; Herquet, M.; /Louvain U.; Hirn, J.; /Yale U. /Brown U. /Boston U. /Annecy, LAPTH /INFN, Turin /Valencia U., IFIC /Yale U. /Arizona U. /Louis Pasteur U., Strasbourg I /Orsay, LAL /KEK, Tsukuba /Moscow State U. /Lisbon, LIFEP /CERN /Durham U. /Valencia U., IFIC /Sao Paulo, IFT /Fermilab /Zurich, ETH /Boston U. /DESY /CERN /Saclay, SPhT /Durham U. /Cambridge U. /Michigan State U. /Louis Pasteur U., Strasbourg I /Orsay, LAL /Annecy, LAPTH /Fermilab /CERN /Arizona U. /Northwestern U. /Argonne /Kyoto U. /Valencia U., IFIC /UC, Berkeley /LBL, Berkeley

2011-12-05T23:59:59.000Z

467

Kinematics in Vector Boson Fusion  

E-Print Network (OSTI)

The vector boson fusion process leads to two forward/backward jets (tag jets) and the produced state, a Higgs boson in this case, moving slowly in the p-p C.M. frame at the LHC. For the case of Higgs decaying to W+W (W*) with Higgs mass below 180 GeV, the W bosons have low momentum in the Higgs C.M. For the case of W leptonic decays, this fact allows for an approximate reconstruction of the two final state neutrinos. In turn, those solutions then provide additional kinematic cuts against background.

D. Green

2006-03-02T23:59:59.000Z

468

QED peripheral mechanism of pair production at colliders  

Science Conference Proceedings (OSTI)

Cross sections of the processes of production of neutral pions and pairs of charged fermions and bosons in peripheral interaction of leptons and photons are calculated in the main logarithmic approximation. We investigate the phase volumes and differential cross sections. The differential cross sections of production of a few neutral pions and a few pairs are written down explicitly. Considering the academic problem of summation over a number of pairs for massless particles we reproduce the known results obtained in the 1970s. The possibility of constructing the generator for Monte Carlo modeling of these processes based on these results is discussed.

Ahmadov, A. I.; Galynskii, M. V.; Bystritskiy, Yu. M.; Kuraev, E. A.; Shatnev, M. G. [Joint Institute for Nuclear Research, Dubna, Russia, and Institute of Physics, Azerbaijan National Academy of Sciences, Baku (Azerbaijan); Institute of Physics, Minsk (Belarus); Joint Institute for Nuclear Research, Dubna (Russian Federation); Kharkov Institute of Physics and Technology, Kharkov, 61108 (Ukraine)

2008-10-01T23:59:59.000Z

469

Gravity wraps Higgs boson  

E-Print Network (OSTI)

It is shown that, by rescaling the matter fields and metric tensor with appropriate powers of the Higgs field, the Higgs boson can be wholly transferred from material sector to the gravity sector in which it possesses only gravitational interactions and escapes detection in collider experiments. The Higgs boson gets buried in a scalar-tensor theory of gravity wherein it might be of relevance for Dark Energy. It is absent from the electroweak spectrum yet leptons, quarks and vector bosons possess their already known properties. The Higgs boson can contact with the matter sector via only the higher-dimensional operators suppressed by a cutoff scale.

Demir, Durmus A

2011-01-01T23:59:59.000Z

470

Magninos: Experimental consequences and constraints  

SciTech Connect

A stable weakly interacting massive particle can simultaneously solve both the solar neutrino and missing mass problems. We have identified this particle with a neutral lepton with mass of order 5 to 15 GeV and an anomalous magnetic moment of order 10/sup -2/ (in the natural units). We call this new particle a (magnino). In one scenario, the magnino is the neutral component of an electroweak doublet. It has a charged partner with mass a few GeV heavier. In this talk the experimental consequences of the magnino, its charged partner and associated Higgs are discussed. 25 refs., 9 figs.

Raby, S.; West, G.B.

1987-01-01T23:59:59.000Z

471

Search for Higgs boson production in oppositely charged dilepton and missing energy events in ${p\\bar{p}}$ collisions at ${\\sqrt{s} =}$1.96 TeV}  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson using events with two oppositely charged leptons and large missing transverse energy as expected in $H\\rightarrow WW$ decays. The events are selected from data corresponding to 8.6 \\ifb\\ of integrated luminosity in $p \\bar{p}$ collisions at $\\sqrt{s}=1.96$ TeV collected with the D0 detector at the Fermilab Tevatron Collider. No significant excess above the standard model background expectation in the Higgs boson mass range this search is sensitive to is observed, and upper limits on the Higgs boson production cross section are derived.

D0 Collaboration

2012-07-04T23:59:59.000Z

472

Neutrino mixings and grand unification: SU(5) GUT with anomaly free U(1){sub F}  

Science Conference Proceedings (OSTI)

The model of supersymmetric SU(5) GUT augmented with anomaly free U(1){sub F} flavor symmetry is presented. The field content and the U(1){sub F} charge assignment is obtained by specific embedding of SU(5) Multiplication-Sign U(1){sub F} in larger non-Abelian group. We focus on a particular case which gives very economical field content with the U(1){sub F} charges fixed in such a way that for quarks and leptons appealing texture zero Yukawa couplings are generated. The model gives realistic fermion masses and mixings and predict inverted hierarchical neutrino mass scenario with interesting implications.

Tavartkiladze, Zurab [Center for Elementary Particle Physics, ITP, Ilia State University, 0162 Tbilisi (Georgia)

2013-05-23T23:59:59.000Z

473

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics  

E-Print Network (OSTI)

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.

The ATLAS Collaboration; G. Aad; E. Abat; B. Abbott; J. Abdallah; A. A. Abdelalim; A. Abdesselam; O. Abdinov; B. Abi; M. Abolins; H. Abramowicz; B. S. Acharya; D. L. Adams; T. N. Addy; C. Adorisio; P. Adragna; T. Adye; J. A. Aguilar-Saavedra; M. Aharrouche; S. P. Ahlen; F. Ahles; A. Ahmad; H. Ahmed; G. Aielli; T. Akdogan; T. P. A. Akesson; G. Akimoto; M. S. Alam; M. A. Alam; J. Albert; S. Albrand; M. Aleksa; I. N. Aleksandrov; F. Alessandria; C. Alexa; G. Alexander; G. Alexandre; T. Alexopoulos; M. Alhroob; G. Alimonti; J. Alison; M. Aliyev; P. P. Allport; S. E. Allwood-Spiers; A. Aloisio; R. Alon; A. Alonso; J. Alonso; M. G. Alviggi; K. Amako; P. Amaral; C. Amelung; V. V. Ammosov; A. Amorim; G. Amoros; N. Amram; C. Anastopoulos; C. F. Anders; K. J. Anderson; A. Andreazza; V. Andrei; M-L. Andrieux; X. S. Anduaga; F. Anghinolfi; A. Antonaki; M. Antonelli; S. Antonelli; B. Antunovic; F. A. Anulli; G. Arabidze; I. Aracena; Y. Arai; A. T. H. Arce; J. P. Archambault; S. Arfaoui; J-F. Arguin; T. Argyropoulos; E. Arik; M. Arik; A. J. Armbruster; O. Arnaez; C. Arnault; A. Artamonov; D. Arutinov; M. Asai; S. Asai; S. Ask; B. Asman; D. Asner; L. Asquith; K. Assamagan; A. Astbury; A. Astvatsatourov; T. Atkinson; G. Atoian; B. Auerbach; E. Auge; K. Augsten; M. A. Aurousseau; N. Austin; G. Avolio; R. Avramidou; A. Axen; C. Ay; G. Azuelos; Y. Azuma; M. A. Baak; G. Baccaglioni; C. Bacci; H. Bachacou; K. Bachas; M. Backes; E. Badescu; P. Bagnaia; Y. Bai; D. C. Bailey; J. T. Baines; O. K. Baker; F. Baltasar Dos Santos Pedrosa; E. Banas; S. Banerjee; D. Banfi; A. Bangert; V. Bansal; S. P. Baranov; S. Baranov; A. Barashkou; T. B. Barber; E. L. Barberio; D. Barberis; M. B. Barbero; D. Y. Bardin; T. Barillari; M. Barisonzi; T. Barklow; N. B. Barlow; B. M. Barnett; R. M. Barnett; S. Baron; A. Baroncelli; A. J. Barr; F. Barreiro; J. Barreiro Guimaraes da Costa; P. Barrillon; R. Bartoldus; D. Bartsch; J. Bastos; R. L. Bates; J. R. Batley; A. Battaglia; M. Battistin; F. Bauer; M. Bazalova; B. Beare; P. H. Beauchemin; R. B. Beccherle; N. Becerici; P. Bechtle; G. A. Beck; H. P. Beck; M. Beckingham; K. H. Becks; I. Bedajanek; A. J. Beddall; A. Beddall; P. Bednar; V. A. Bednyakov; C. Bee; S. Behar Harpaz; P. K. Behera; M. Beimforde; C. Belanger-Champagne; P. J. Bell; W. H. Bell; G. Bella; L. Bellagamba; F. Bellina; M. Bellomo; A. Belloni; K. Belotskiy; O. Beltramello; S. Ben Ami; O. Benary; D. Benchekroun; M. Bendel; B. H. Benedict; N. Benekos; Y. Benhammou; G. P. Benincasa; D. P. Benjamin; M. Benoit; J. R. Bensinger; K. Benslama; S. Bentvelsen; M. Beretta; D. Berge; E. Bergeaas Kuutmann; N. Berger; F. Berghaus; E. Berglund; J. Beringer; K. Bernardet; P. Bernat; R. Bernhard; C. Bernius; T. Berry; A. Bertin; N. Besson; S. Bethke; R. M. Bianchi; M. Bianco; O. Biebel; J. Biesiada; M. Biglietti; H. Bilokon; S. Binet; A. Bingul; C. Bini; C. Biscarat; M. Bischofberger; U. Bitenc; K. M. Black; R. E. Blair; G. Blanchot; C. Blocker; J. Blocki; A. Blondel; W. Blum; U. Blumenschein; C. Boaretto; G. J. Bobbink; A. Bocci; B. Bodine; J. Boek; N. Boelaert; S. Boeser; J. A. Bogaerts; A. Bogouch; C. Bohm; J. Bohm; V. Boisvert; T. Bold; V. Boldea; V. G. Bondarenko; M. Bondioli; M. Boonekamp; C. N. Booth; P. S. L. Booth; J. R. A. Booth; A. Borisov; G. Borissov; I. Borjanovic; S. Borroni; K. Bos; D. Boscherini; M. Bosman; M. Bosteels; H. Boterenbrood; J. Bouchami; J. Boudreau; E. V. Bouhova-Thacker; C. Boulahouache; C. Bourdarios; J. Boyd; I. R. Boyko; A. Braem; P. Branchini; G. W. Brandenburg; A. Brandt; O. Brandt; U. Bratzler; J. E. Brau; H. M. Braun; B. Brelier; J. Bremer; R. Brenner; S. Bressler; D. Breton; N. D. Brett; D. Britton; F. M. Brochu; I. Brock; R. Brock; E. Brodet; F. Broggi; G. Brooijmans; W. K. Brooks; E. Brubaker; P. A. Bruckman de Renstrom; D. Bruncko; R. Bruneliere; S. Brunet; A. Bruni; G. Bruni; M. Bruschi; T. Buanes; F. B. Bucci; P. Buchholz; A. G. Buckley; I. A. Budagov; V. Buescher; L. Bugge; F. Bujor; O. Bulekov; M. Bunse; T. Buran; H. Burckhart; S. Burdin; S. Burke; E. Busato; C. P. Buszello; F. Butin; B. Butler; J. M. Butler; C. M. Buttar; J. M. Butterworth; T. Byatt; S. Cabrera Urban; D. Caforio; O. Cakir; P. Calafiura; G. Calderini; R. Calkins; L. P. Caloba; R. Caloi; D. Calvet; P. Camarri; M. Cambiaghi; D. Cameron; F. Campabadal Segura; S. Campana; M. Campanelli; V. Canale; J. Cantero; M. D. M. Capeans Garrido; I. Caprini; M. Caprini; M. Capua; R. Caputo; C. Caramarcu; R. Cardarelli; T. Carli; G. Carlino; L. Carminati; B. Caron; S. Caron; S. Carron Montero; A. A. Carter; J. R. Carter; J. Carvalho; D. Casadei; M. P. Casado; M. Cascella; C. Caso; A. M. Castaneda Hernadez; E. Castaneda Miranda; V. Castillo Gimenez; N. F. Castro; G. Cataldi; A. Catinaccio; J. R. Catmore; A. Cattai; G. Cattani; S. Caughron; D. Cauz; P. Cavalleri; D. Cavalli; M. Cavalli-Sforza

2008-12-28T23:59:59.000Z

474

Heavy Quarkonium Production in Single Transverse Polarized HighEnergy Scattering  

Science Conference Proceedings (OSTI)

We formulate the single transverse spin asymmetry in heavyquarkoniumproduction in lepton-nucleon and nucleon-nucleon collisionsinthe non-relativistic limit. We findthat the asymmetry is very sensitiveto the production mechanism. The finalstate interactions with the heavyquark and antiquark cancel out among themselves whenthe pair are producedin a color-single configuration, or cancel out with the initialstateinteraction in pp scattering when they are in color-octet. As aconsequence, the asymmetry is nonzero in ep collisions only in thecolor-octet model, whereas in pp collisions only in the color-singletmodel.

Yuan, Feng

2008-01-17T23:59:59.000Z

475

MEIC Design Progress  

SciTech Connect

This paper will report the recent progress in the conceptual design of MEIC, a high luminosity medium energy polarized ring-ring electron-ion collider at Jefferson lab. The topics and achievements that will be covered are design of the ion large booster and the ERL-circulator-ring-based electron cooling facility, optimization of chromatic corrections and dynamic aperture studies, schemes and tracking simulations of lepton and ion polarization in the figure-8 collider ring, and the beam-beam and electron cooling simulations. A proposal of a test facility for the MEIC electron cooler will also be discussed.

Zhang, Y; Douglas, D; Hutton, A; Krafft, G A; Li, R; Lin, F; Morozov, V S; Nissen, E W; Pilat, F C; Satogata, T; Tennant, C; Terzic, B; Yunn, C; Barber, D P; Filatov, Y; Hyde, C; Kondratenko, A M; Manikonda, S L; Ostroumov, P N

2012-07-01T23:59:59.000Z

476

Gravity wraps Higgs boson  

E-Print Network (OSTI)

It is shown that, under a conformal transformation with reference to the Higgs field, the Higgs boson can be completely decoupled from electroweak interactions with no apparent change in known properties of leptons, quarks and vector bosons. Higgs boson becomes part of a scalar-tensor gravity which can be relevant for Dark Energy. It interacts with matter sector via higher-dimensional terms (e.g. neutrino Majorana mass), and via the fields (of new physics) whose masses are not generated by the Higgs mechanism. Dark Matter and two-Higgs-doublet model are the simplest examples.

Durmus A. Demir

2011-10-17T23:59:59.000Z

477

Associated Higgs-W-Boson Production at Hadron Colliders: A Fully Exclusive QCD Calculation at NNLO  

SciTech Connect

We consider QCD radiative corrections to standard model Higgs-boson production in association with a W boson in hadron collisions. We present a fully exclusive calculation up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. To perform this NNLO computation, we use a recently proposed version of the subtraction formalism. Our calculation includes finite-width effects, the leptonic decay of the W boson with its spin correlations, and the decay of the Higgs boson into a bb pair. We present selected numerical results at the Tevatron and the LHC.

Ferrera, Giancarlo [Dipartimento di Fisica e Astronomia, Universita di Firenze and INFN, Sezione di Firenze, I-50019 Sesto Fiorentino, Florence (Italy); Grazzini, Massimiliano [Institut fuer Theoretische Physik, Universitaet Zuerich, CH-8057 Zuerich (Switzerland); Tramontano, Francesco [Theory Group, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)

2011-10-07T23:59:59.000Z

478

Search for the standard model Higgs boson in $\\bm{\\ell?}$+jets final states in 9.7~fb$\\bm{^{-1}}$ of $\\bm{p\\bar{p}}$ collisions with the D0 detector  

E-Print Network (OSTI)

We present, in detail, a search for the standard model Higgs boson, $H$, in final states with a charged lepton (electron or muon), missing energy, and two or more jets in data corresponding to 9.7 fb$^{-1}$ of integrated luminosity collected at a center of mass energy of $\\sqrt{s}$ = 1.96 TeV with the D0 detector at the Fermilab Tevatron $p\\bar{p}$ Collider. The search uses $b$-jet identification to categorize events for improved signal versus background separation and is sensitive to associated production of the $H$ with a $W$ boson, $WH\\to\\ell\

D0 Collaboration

2013-01-25T23:59:59.000Z

479

Polarized deeply inelastic scattering (DIS) structure functions for nucleons and nuclei  

Science Conference Proceedings (OSTI)

We extract parton distribution functions (PDFs) and structure functions from recent experimental data of polarized lepton-deeply inelastic scattering (DIS) on nucleons at next-to-leading order (NLO) quantum chromodynamics. We apply the Jacobi polynomial method to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution as this is numerically efficient. Having determined the polarized proton and neutron spin struc