Sample records for leptons leptons leptons

  1. Leptons in Composite MFV

    E-Print Network [OSTI]

    Michele Redi

    2014-07-21T23:59:59.000Z

    We study the lepton sector of composite Higgs models with partial compositeness. The standard anarchic scenario is in conflict with the absence of observable charged lepton flavor violation. This tension can be completely solved in MFV scenarios that require either left-handed or right-handed SM leptons to be equally composite. Constraints on this scenario are weak and the composite lepton partners could be as light as few hundreds GeVs with interesting LHC signatures. The contribution to the muon (g-2) in theories where the Higgs is a pseudo Nambu-Goldstone boson is also discussed.

  2. Neutrino and it's lepton

    E-Print Network [OSTI]

    G. Quznetsov

    2008-11-10T23:59:59.000Z

    In this paper I cite p.p. 100-117 of book G. Quznetsov, Probabilistic Treatment of Gauge Theories, in series Contemporary Fundamental Physics,ed. V. Dvoeglazov, Nova Sci. Publ., NY (2007). There I research a bound between neutrino and it's lepton.

  3. Lepton textures and neutrino oscillations

    E-Print Network [OSTI]

    Verma, Rohit

    2014-01-01T23:59:59.000Z

    Systematic analyses of the textures arising in lepton mass matrices have been carried out using unitary transformations and condition of naturalness for the Dirac and Majorana neutrino possibilities. It is observed that the recent three neutrino oscillation data together with the effective mass in neutrinoless double beta decay provide vital clues in predicting the general structures of these lepton mass matrices.

  4. Lepton textures and neutrino oscillations

    E-Print Network [OSTI]

    Rohit Verma

    2014-06-03T23:59:59.000Z

    Systematic analyses of the textures arising in lepton mass matrices have been carried out using unitary transformations and condition of naturalness for the Dirac and Majorana neutrino possibilities. It is observed that the recent three neutrino oscillation data together with the effective mass in neutrinoless double beta decay provide vital clues in predicting the general structures of these lepton mass matrices.

  5. On quark-lepton complementarity

    E-Print Network [OSTI]

    F. Gonzalez-Canales; A. Mondragon

    2006-06-16T23:59:59.000Z

    Recent measurements of the neutrino solar mixing angle and the Cabibbo angle satisfy the empirical relation theta_{sol} + theta_{C} ~ 45^{o}. This relation suggests the existence of a correlation between the mixing matrices of leptons and quarks, the so called quark-lepton complementarity. Here, we examine the possibility that this correlation originates in the strong hierarchy in the mass spectra of quarks and charged leptons, and the seesaw mechanism that gives mass to the Majorana neutrinos. In a unified treatment of quarks and leptons in which the mass matrices of all fermions have a similar Fritzsch texture, we calculate the mixing matrices V_{CKM} and U_{MNSP} as functions of quark and lepton masses and only two free parameters, in very good agreement with the latest experimental values on masses and mixings. Three essential ingredients to explain the quark-lepton complementarity relation are identified: the strong hierarchy in the mass spectra of quarks and charged leptons, the normal seesaw mechanism and the assumption of maximal CP violation in the lepton sector.

  6. On quark-lepton complementarity

    SciTech Connect (OSTI)

    Gonzalez Canales, F.; Mondragon, A. [Instituto de Fisica, UNAM, 04510, Mexico D.F. (Mexico)

    2006-09-25T23:59:59.000Z

    Recent measurements of the neutrino solar mixing angle and the Cabibbo angle satisfy the empirical relation {theta}{sub sol} + {theta}{sub C} {approx_equal} ({pi}/4). This relation suggests the existence of a correlation between the mixing matrices of leptons and quarks, the so called quark-lepton complementarity. Here, we examine the possibility that this correlation originates in the strong hierarchy in the mass spectra of quarks and charged leptons, and the seesaw mechanism that gives mass to the Majorana neutrinos. In a unified treatment of quarks and leptons in which the mass matrices of all fermions have a similar Fritzsch texture, we calculate the mixing matrices VCKM and UMNSP as functions of quark and lepton masses and only two free parameters, in very good agreement with the latest experimental values on masses and mixings. Three essential ingredients to explain the quark-lepton complementarity relation are identified: the strong hierarchy in the mass spectra of quarks and charged leptons, the normal seesaw mechanism and the assumption of maximal CP violation in the lepton sector.

  7. Seesaw enhancement of lepton mixing

    SciTech Connect (OSTI)

    Smirnov, A.Y. (Institute for Advanced Study, Princeton, New Jersey 08540 (United States) International Centre for Theoretical Physics, 34100 Trieste (Italy) Institute for Nuclear Research, 117312 Moscow (Russian Federation))

    1993-10-01T23:59:59.000Z

    The seesaw mechanism of neutrino mass generation may enhance lepton mixing up to maximal even if the Dirac mass matrices of leptons have a structure similar to that in the quark sector. Two sets of conditions for such an enhancement are found. The first one includes the seesaw generation of heavy Majorana masses for right-handed neutrinos and a universality of Yukawa couplings which can follow from the unification of neutrinos with new superheavy neutral leptons. The second set is related to the lepton number symmetry of the Yukawa interactions in the Dirac basis of neutrinos. Models which realize these conditions have a strong hierarchy or strong degeneration of Majorana masses of the right-handed neutrinos.

  8. Search for neutrinoless decays of the ? lepton

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-02-01T23:59:59.000Z

    We have searched for neutrinoless ? decays into three charged particles. Evidence of such decays would demonstrate nonconservation of lepton flavor and, in some cases, lepton number. We see no signal for any such neutrinoless ? decays and set upper...

  9. Lepton-flavored dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kile, Jennifer; Kobach, Andrew; Soni, Amarjit

    2015-05-01T23:59:59.000Z

    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV–1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. ? ? 3e, ? ? e??, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10–100 TeV), whereas the 3.6? deviation of the muon g – 2 from the standard model can be explained by a new physics scale lepton-flavor interaction that couples at tree level only to ?- and ?-flavored leptons and the dark sector. Dark matter thus interacts appreciably only with particles of ? and ? flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV–1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g – 2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e?e? colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables. (author)

  10. Lepton-flavored dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kile, Jennifer; Kobach, Andrew; Soni, Amarjit

    2015-05-01T23:59:59.000Z

    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV–1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. ? ? 3e, ? ? e??, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10–100 TeV), whereas the 3.6? deviation of the muon g – 2 from the standard model can be explained by a new physics scale more »TeV). Here, we suggest that it may not be a coincidence that both the muon g – 2 and the relic density can be satisfied by a new-physics scale ?1 TeV. We consider the possibility of a gauged lepton-flavor interaction that couples at tree level only to ?- and ?-flavored leptons and the dark sector. Dark matter thus interacts appreciably only with particles of ? and ? flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV–1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g – 2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e?e? colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables. (author)« less

  11. Natural fourth generation of leptons

    E-Print Network [OSTI]

    Oleg Antipin; Matti Heikinheimo; Kimmo Tuominen

    2009-09-14T23:59:59.000Z

    We consider implications of a fourth generation of leptons, allowing for the most general mass patterns for the fourth generation neutrino. We determine the constraints due to the precision electroweak measurements and outline the signatures to search for at the LHC experiments. As a concrete framework to apply these results we consider the minimal walking technicolor (MWTC) model where the matter content, regarding the electroweak quantum numbers, corresponds to a fourth generation.

  12. Search for lepton-family-number nonconservation

    SciTech Connect (OSTI)

    Hoffman, C.M.

    1986-01-01T23:59:59.000Z

    A review of the status of lepton-family-number nonconservation is given. After a brief historical and theoretical discussion, a description of how experimental searches for lepton-family-number nonconservation are performed is presented. Finally, a summary of the results from past experiments and prospects for future experiments is given.

  13. Symmetrical parametrizations of the lepton mixing matrix

    SciTech Connect (OSTI)

    Rodejohann, W. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, 69029 Heidelberg (Germany); Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

    2011-10-01T23:59:59.000Z

    Advantages of the original symmetrical form of the parametrization of the lepton mixing matrix are discussed. It provides a conceptually more transparent description of neutrino oscillations and lepton number violating processes like neutrinoless double beta decay, clarifying the significance of Dirac and Majorana phases. It is also ideal for parametrizing scenarios with light sterile neutrinos.

  14. Leptonic CP Violation from a New Perspective

    E-Print Network [OSTI]

    David Emmanuel-Costa; Nuno Rosa Agostinho; J. I. Silva-Marcos; Daniel Wegman

    2015-04-27T23:59:59.000Z

    We study leptonic CP violation from a new perspective. For Majorana neutrinos, a new parametrization for leptonic mixing of the form $V=O_{23} O_{12} K_{a}^{i}\\cdot O$ reveals interesting aspects that are less clear in the standard parametrization. We identify several important scenario-cases with mixing angles in agreement with experiment and leading to large leptonic CP violation. If neutrinos happen to be quasi-degenerate, this new parametrization might be very useful, e.g., in reducing the number of relevant parameters of models.

  15. Leptonic CP Violation from a New Perspective

    E-Print Network [OSTI]

    Emmanuel-Costa, David; Silva-Marcos, J I; Wegman, Daniel

    2015-01-01T23:59:59.000Z

    We study leptonic CP violation from a new perspective. For Majorana neutrinos, a new parametrization for leptonic mixing of the form $V=O_{23} O_{12} K_{a}^{i}\\cdot O$ reveals interesting aspects that are less clear in the standard parametrization. We identify several important scenario-cases with mixing angles in agreement with experiment and leading to large leptonic CP violation. If neutrinos happen to be quasi-degenerate, this new parametrization might be very useful, e.g., in reducing the number of relevant parameters of models.

  16. New textures for the lepton mass matrices

    E-Print Network [OSTI]

    P. M. Ferreira; L. Lavoura

    2014-12-02T23:59:59.000Z

    We study predictive textures for the lepton mass matrices in which the charged-lepton mass matrix has either four or five zero matrix elements while the neutrino Majorana mass matrix has, respectively, either four or three zero matrix elements. We find that all the viable textures of these two kinds share many predictions: the neutrino mass spectrum is inverted, the sum of the light-neutrino masses is close to 0.1 eV, the Dirac phase $\\delta$ in the lepton mixing matrix is close to either $0$ or $\\pi$, and the mass term responsible for neutrinoless double-beta decay lies in between 12 and 22 meV.

  17. Search for Lepton-Flavor and Lepton-Number Violation in the Decay tau to lhh'

    SciTech Connect (OSTI)

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /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

    2005-06-29T23:59:59.000Z

    A search for lepton-flavor and lepton-number violation in the decay of the tau lepton into one charged lepton and two charged hadrons is performed using 221.4 fb{sup -1} of data collected at an e{sup +}e{sup -} center-of-mass energy of 10.58 GeV with the BABAR detector at the PEP-II storage ring. In all 14 decay modes considered, the observed data are compatible with background expectations, and upper limits are set in the range {Beta}({tau} {yields} {ell}hh') < (0.7-4.8) x 10{sup -7} at 90% confidence level.

  18. Lepton Mass Hierarchy and Neutrino Oscillations

    E-Print Network [OSTI]

    H. Fritzsch; Z. Z Xing

    1995-09-26T23:59:59.000Z

    Starting from the symmetry of lepton flavor democracy, we propose and discuss a simple pattern for the mass generation and flavor mixing of the charged leptons and neutrinos. The three neutrino masses are nearly degenerate, and the flavor mixing angles can be calculated. The observed deficit of solar and atmospheric neutrinos can be interpreted as a consequence of the near degeneracy and large oscillations of $\

  19. The Lepton Sector of a Fourth Generation

    E-Print Network [OSTI]

    Gustavo Burdman; Leandro Da Rold; Ricardo D. Matheus

    2010-05-10T23:59:59.000Z

    In extensions of the standard model with a heavy fourth generation one important question is what makes the fourth-generation lepton sector, particularly the neutrinos, so different from the lighter three generations. We study this question in the context of models of electroweak symmetry breaking in warped extra dimensions, where the flavor hierarchy is generated by the localization of the zero-mode fermions in the extra dimension. In this setup the Higgs sector is localized near the infrared brane, whereas the Majorana mass term is localized at the ultraviolet brane. As a result, light neutrinos are almost entirely Majorana particles, whereas the fourth generation neutrino is mostly a Dirac fermion. We show that it is possible to obtain heavy fourth-generation leptons in regions of parameter space where the light neutrino masses and mixings are compatible with observation. We study the impact of these bounds, as well as the ones from lepton flavor violation, on the phenomenology of these models.

  20. Two-Higgs Leptonic Minimal Flavour Violation

    E-Print Network [OSTI]

    Botella, F J; Nebot, M; Rebelo, M N

    2011-01-01T23:59:59.000Z

    We construct extensions of the Standard Model with two Higgs doublets, where there are flavour changing neutral currents both in the quark and leptonic sectors, with their strength fixed by the fermion mixing matrices $V_{CKM}$ and $V_{PMNS}$. These models are an extension to the leptonic sector of the class of models previously considered by Branco, Grimus and Lavoura, for the quark sector. We consider both the cases of Dirac and Majorana neutrinos and identify the minimal discrete symmetry required in order to implement the models in a natural way.

  1. Probing lepton number violation on three frontiers

    SciTech Connect (OSTI)

    Deppisch, Frank F. [Department of Physics and Astronomy, University College London (United Kingdom)

    2013-12-30T23:59:59.000Z

    Neutrinoless double beta decay constitutes the main probe for lepton number violation at low energies, motivated by the expected Majorana nature of the light but massive neutrinos. On the other hand, the theoretical interpretation of the (non-)observation of this process is not straightforward as the Majorana neutrinos can destructively interfere in their contribution and many other New Physics mechanisms can additionally mediate the process. We here highlight the potential of combining neutrinoless double beta decay with searches for Tritium decay, cosmological observations and LHC physics to improve the quantitative insight into the neutrino properties and to unravel potential sources of lepton number violation.

  2. Limits on tau lepton flavor violating decays in three charged leptons

    SciTech Connect (OSTI)

    Cervelli, Alberto

    2010-04-29T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We measure the inclusive forward–backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton–antiproton collisions and decaying to final states that contain two charged leptons (electrons ...

  4. Universal Mass Texture, CP violation and Quark-Lepton Complementarity

    E-Print Network [OSTI]

    Canales, F Gonzalez; Barranco, J

    2010-01-01T23:59:59.000Z

    Recent measurements of the neutrino and quark mixing angles satisfy the empirical relations called quark-lepton complementarity. These empirical relations suggests the existence of a correlation between the mixing matrices of leptons and quarks. In this work, we examine the possibility that this correlation between the mixing angles of quarks and leptons originates in the similar hierarchy of quarks and charged lepton masses and the seesaw mechanism type I, that gives mass to the Majorana neutrinos. We asssume that the similar mass hierarchies of charged lepton and quark masses allows us to represent all the mass matrices of Dirac fermions in terms of a two zeroes Fritzsch texture.

  5. Universal mass matrix for quarks and leptons and CP violation

    SciTech Connect (OSTI)

    Barranco, J.; Gonzalez Canales, F.; Mondragon, A. [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Golm (Germany); Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510, Mexico D.F. (Mexico)

    2010-10-01T23:59:59.000Z

    The measurements of the neutrino and quark mixing angles satisfy the empirical relations called quark-lepton complementarity. These empirical relations suggest the existence of a correlation between the mixing matrices of leptons and quarks. In this work, we examine the possibility that this correlation between the mixing angles of quarks and leptons originates in the similar hierarchy of quarks and charged lepton masses and the seesaw mechanism type I, that gives mass to the Majorana neutrinos. We assume that the similar mass hierarchies of charged lepton and quark masses allows us to represent all the mass matrices of Dirac fermions in terms of a universal form with four texture zeroes.

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

    E-Print Network [OSTI]

    Istvan Danko; for the CLEO Collaboration

    2006-01-18T23:59:59.000Z

    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.

  7. Parallel hybrid textures of lepton mass matrices

    E-Print Network [OSTI]

    S. Dev; Shivani Gupta; Radha Raman Gautam

    2010-09-28T23:59:59.000Z

    We analyse the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total sixty parallel hybrid texture structures can be grouped into twelve classes, and all the hybrid textures in the same class have identical physical implications. We examine all the twelve classes under the assumption of non-factorizable phases in the neutrino mass matrix. Five out of the total twelve classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type $CP$ violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.

  8. Parallel hybrid textures of lepton mass matrices

    SciTech Connect (OSTI)

    Dev, S.; Gupta, Shivani; Gautam, Radha Raman [Department of Physics, Himachal Pradesh University, Shimla 171005 (India)

    2010-10-01T23:59:59.000Z

    We analyze the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total 60 parallel hybrid texture structures can be grouped into 12 classes, and all the hybrid textures in the same class have identical physical implications. We examine all 12 classes under the assumption of nonfactorizable phases in the neutrino mass matrix. Five out of the total 12 classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type CP violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.

  9. Parallel hybrid textures of lepton mass matrices

    E-Print Network [OSTI]

    Dev, S; Gautam, Radha Raman

    2010-01-01T23:59:59.000Z

    We analyse the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total sixty parallel hybrid texture structures can be grouped into twelve classes, and all the hybrid textures in the same class have identical physical implications. We examine all the twelve classes under the assumption of non-factorizable phases in the neutrino mass matrix. Five out of the total twelve classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type $CP$ violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.

  10. Lepton Flavor Violation in Flavored Gauge Mediation

    E-Print Network [OSTI]

    Lorenzo Calibbi; Paride Paradisi; Robert Ziegler

    2014-08-04T23:59:59.000Z

    We study the anatomy and phenomenology of Lepton Flavor Violation (LFV) in the context of Flavored Gauge Mediation (FGM). Within FGM, the messenger sector couples directly to the MSSM matter fields with couplings controlled by the same dynamics that explains the hierarchies in the SM Yukawas. Although the pattern of flavor violation depends on the particular underlying flavor model, FGM provides a built-in flavor suppression similar to wave function renormalization or SUSY Partial Compositeness. Moreover, in contrast to these models, there is an additional suppression of left-right (LR) flavor transitions by third-generation Yukawas that in particular provides an extra protection against flavor-blind phases. We exploit the consequences of this setup for lepton flavor phenomenology, assuming that the new couplings are controlled by simple U(1) flavor models that have been proposed to accommodate large neutrino mixing angles. Remarkably, it turns out that in the context of FGM these models can pass the impressive constraints from LFV processes and leptonic EDMs even for light superpartners, therefore offering the possibility of resolving the longstanding muon g-2 anomaly.

  11. Lepton sector of a fourth generation

    SciTech Connect (OSTI)

    Burdman, G. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil); Da Rold, L. [Centro Atomico Bariloche, Bariloche (Argentina); Matheus, R. D. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)

    2010-09-01T23:59:59.000Z

    In extensions of the standard model with a heavy fourth generation, one important question is what makes the fourth-generation lepton sector, particularly the neutrinos, so different from the lighter three generations. We study this question in the context of models of electroweak symmetry breaking in warped extra dimensions, where the flavor hierarchy is generated by choosing the localization of the zero-mode fermions in the extra dimension. In this setup the Higgs sector is localized near the infrared brane, whereas the Majorana mass term is localized at the ultraviolet brane. As a result, light neutrinos are almost entirely Majorana particles, whereas the fourth-generation neutrino is mostly a Dirac fermion. We show that it is possible to obtain heavy fourth-generation leptons in regions of parameter space where the light neutrino masses and mixings are compatible with observation. We study the impact of these bounds, as well as the ones from lepton flavor violation, on the phenomenology of these models.

  12. Lepton flavor violation as a probe of quark-lepton unification

    SciTech Connect (OSTI)

    Cheung, Kingman; Kang, Sin Kyu; Kim, C.S.; Lee, Jake [Department of Physics, Tsing Hua Univeristy, Hsinchu, Taiwan (China); School of Physics, Seoul National University, Seoul 151-741 (Korea, Republic of); Department of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2005-08-01T23:59:59.000Z

    The recent measurements of the solar neutrino mixing angle {theta}{sub sol} and the Cabibbo mixing angle {theta}{sub C} reveal a surprising relation, {theta}{sub sol}+{theta}{sub C}{approx_equal}({pi}/4), which has been interpreted as an evidence for quark-lepton unification. We show in realizations of quark-lepton unification that the PMNS mixing matrix can be decomposed into a CKM-like matrix and maximal mixing matrices. We explore a possibility to probe such implications by considering the relative sizes of branching ratios for the lepton flavor violating radiative decay processes, l{sub i}{yields}l{sub j}{gamma}, in the context of the supersymmetric standard model with heavy right-handed Majorana neutrinos.

  13. Electroweak phase transition in a model with gauged lepton number

    E-Print Network [OSTI]

    Alfredo Aranda; Enrique Jiménez; Carlos A. Vaquera-Araujo

    2015-01-16T23:59:59.000Z

    In this work we study the electroweak phase transition in a model with gauged lepton number. Here, a family of vector-like leptons is required in order to cancel the gauge anomalies. Furthermore, these leptons can play an important role in the transition process. We find that this framework is able to provide a strong transition, but only for a very limited number of cases.

  14. Testing solar lepton mixing sum rules in neutrino oscillation experiments

    E-Print Network [OSTI]

    Ballett, Peter; Luhn, Christoph; Pascoli, Silvia; Schmidt, Michael A

    2014-01-01T23:59:59.000Z

    Small discrete family symmetries such as S4, A4 or A5 may lead to simple leading-order predictions for the neutrino mixing matrix such as the bimaximal, tribimaximal or golden ratio mixing patterns, which may be brought into agreement with experimental data with the help of corrections from the charged-lepton sector. Such scenarios generally lead to relations among the parameters of the physical leptonic mixing matrix known as solar lepton mixing sum rules. In this article, we present a simple derivation of such solar sum rules, valid for arbitrary neutrino and charged lepton mixing angles and phases, assuming only {\\theta}13^{\

  15. Performance of ?q-lepton reconstruction and identification in CMS

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-01-01T23:59:59.000Z

    The performance of tau-lepton reconstruction and identification algorithms is studied using a data sample of proton-proton collisions at sqrt(s)=7 TeV, corresponding to an integrated luminosity of 36 inverse picobarns collected with the CMS detector at the LHC. The tau leptons that decay into one or three charged hadrons, zero or more short-lived neutral hadrons, and a neutrino are identified using final-state particles reconstructed in the CMS tracker and electromagnetic calorimeter. The reconstruction efficiency of the algorithms is measured using tau leptons produced in Z-boson decays. The tau-lepton misidentification rates for jets and electrons are determined.

  16. Leptonic CP Violation Phases, Quark-Lepton Similarity and Seesaw Mechanism

    E-Print Network [OSTI]

    Basudeb Dasgupta; Alexei Yu. Smirnov

    2014-05-20T23:59:59.000Z

    We explore generic features of the leptonic CP violation in the framework of the seesaw type I mechanism with similarity of the Dirac lepton and quarks mass matrices $m_D$. For this, we elaborate on the standard parametrization conditions which allow to simultaneously obtain the Dirac and Majorana phases. If the only origin of CP violation is the left-handed (LH) transformation which diagonalizes $m_D$ (similar to quarks), the leptonic CP violation is suppressed and the Dirac phase is close to $\\pi$ or to $0$ with $\\sin \\delta_{CP} \\approx (\\sin \\theta_{13}^q /\\sin \\theta_{13}) \\cos \\theta_{23} \\sin \\delta_q \\sim \\lambda^2 \\sin \\delta_q$. Here $\\lambda \\sim \\theta_C$, is the Cabibbo mixing angle, and $\\theta_{13}^q$ and $\\theta_{13}$ are the 1-3 mixing angles of quarks and leptons respectively. The Majorana phases $\\beta_1$ and $\\beta_2$ are suppressed as $\\lambda^3\\sin\\delta_q$. For Majorana neutrinos implied by seesaw, the right-handed (RH) transformations are important. We explore the simplest extension inspired by Left-Right (L-R) symmetry with small CKM-type CP violation. In this case, seesaw enhancement of the CP violation occurs due to strong hierarchy of the eigenvalues of $m_D$ leading to $\\delta_{CP} \\sim 1$. The enhancement is absent under the phase factorization conditions which require certain relations between parameters of the Majorana mass matrix of RH neutrinos.

  17. Unveiling neutrino mixing and leptonic CP violation

    SciTech Connect (OSTI)

    Mena, Olga; /Fermilab

    2005-01-01T23:59:59.000Z

    We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle {theta}{sub 13} and the CP-phase {delta}. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture.

  18. Phenomenology of a leptonic goldstino and invisible Higgs boson decays

    E-Print Network [OSTI]

    Ignatios Antoniadis; Marc Tuckmantel; Fabio Zwirner

    2005-03-23T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Aaltonen, Timo Antero; et al.,

    2014-07-23T23:59:59.000Z

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

  20. Renormalization group invariant of lepton Yukawa couplings

    E-Print Network [OSTI]

    Takanao Tsuyuki

    2015-04-20T23:59:59.000Z

    By using quark Yukawa matrices only, we can construct renormalization invariants that are exact at the one-loop level in the standard model. One of them $I^q$ is accidentally consistent with unity, even though quark masses are strongly hierarchical. We calculate a lepton version of the invariant $I^l$ for Dirac and Majorana neutrino cases and find that $I^l$ can also be close to unity. For the Dirac neutrino and inverted hierarchy case, if the lightest neutrino mass is 3.0 meV to 8.8 meV, an equality $I^q=I^l$ can be satisfied. These invariants are not changed even if new particles couple to the standard model particles, as long as those couplings are generation independent.

  1. Investigating texture six zero lepton mass matrices

    E-Print Network [OSTI]

    Mahajan, Neelu; Gupta, Manmohan; Gill, P S

    2013-01-01T23:59:59.000Z

    All possible hermitian texture 6 zero Fritzsch like as well as non Fritzsch like lepton mass matrices (144 combinations in all) have been investigated for both Majorana and Dirac neutrinos for their compatibility with the current neutrino oscillation data, keeping in mind the hierarchy of neutrino masses. All the combinations considered here are ruled out by the existing data in the case of inverted hierarchy and degenerate scenario of Majorana neutrino masses. For Majorana neutrinos with normal hierarchy, we find that out of 144 combinations, only 16 possibilities can accommodate the experimental data. Assuming neutrinos to be Dirac particles, normal hierarchy, inverted hierarchy as well as degenerate neutrinos are ruled out for all the combinations.

  2. Renormalization group invariant of lepton Yukawa couplings

    E-Print Network [OSTI]

    Tsuyuki, Takanao

    2015-01-01T23:59:59.000Z

    By using quark Yukawa matrices only, we can construct renormalization invariants that are exact at the one-loop level in the standard model. One of them $I^q$ is accidentally consistent with unity, even though quark masses are strongly hierarchical. We calculate a lepton version of the invariant $I^l$ for Dirac and Majorana neutrino cases and find that $I^l$ can be also close to unity. For the Dirac neutrino case, if we assume $I^q=I^l$, we can deduce that the hierarchy of neutrino masses is inverted, and the lightest neutrino mass is 3.0 meV to 8.8 meV.

  3. Little Flavor: Heavy Leptons, Z' and Higgs Phenomenology

    E-Print Network [OSTI]

    Sichun Sun

    2014-12-01T23:59:59.000Z

    The Little Flavor model is a close cousin of the Little Higgs theory which aims to generate flavor structure around TeV scale. While the original Little Flavor only included the quark sector, here we build the lepton part of the Little Flavor model and explore its phenomenology. The model produces the neutrino mixing matrix and Majorana masses of the Standard Model neutrinos through coupling to heavy lepton partners and Little Higgses. We combine the usual right-handed seesaw mechanism with global symmetry protection to suppress the Standard Model neutrino masses, and identify the TeV partners of leptons as right-handed Majorana neutrinos. The lepton masses and mixing matrix are calculated perturbatively in the theory. The TeV new gauge bosons have suppressed decay width in dilepton channels. Even assuming the Standard Model couplings, the branching ratios to normal dilepton channels are largely reduced in the model, to evade the bound from current $Z'$ search. It also opens up the new search channels for exotic gauge bosons, especially Z' -> E_{t missing} + multi L. The multiple lepton partners will create new chain decay signals in flavor related processes in colliders, which also give rise to flavor anomalies. The lepton flavor violation process can be highly suppressed in charged lepton sector and happens only through neutrinos.

  4. Isolated leptons in events with missing transverse momentum and the search for single top production

    E-Print Network [OSTI]

    Calorimeter · Optimised for precision measure- ment of the scattered lepton ZEUS · Depleted Uranium

  5. Lepton Number Violation and the Baryon Asymmetry of the Universe

    E-Print Network [OSTI]

    Harz, Julia; Päs, Heinrich

    2015-01-01T23:59:59.000Z

    Neutrinoless double beta decay, lepton number violating collider processes and the Baryon Asymmetry of the Universe (BAU) are intimately related. In particular lepton number violating processes at low energies in combination with sphaleron transitions will typically erase any pre-existing baryon asymmetry of the Universe. In this contribution we briefly review the tight connection between neutrinoless double beta decay, lepton number violating processes at the LHC and constraints from successful baryogenesis. We argue that far-reaching conclusions can be drawn unless the baryon asymmetry is stabilized via some newly introduced mechanism.

  6. Quark-lepton symmetric model at the LHC

    E-Print Network [OSTI]

    Jackson D. Clarke; Robert Foot; Raymond R. Volkas

    2012-02-04T23:59:59.000Z

    We investigate the quark-lepton symmetric model of Foot and Lew in the context of the Large Hadron Collider (LHC). In this `bottom-up' extension to the Standard Model, quark-lepton symmetry is achieved by introducing a gauged `leptonic colour' symmetry which is spontaneously broken above the electroweak scale. If this breaking occurs at the TeV scale, then we expect new physics to be discovered at the LHC. We examine three areas of interest: the Z$'$ heavy neutral gauge boson, charge $\\pm1/2$ exotic leptons, and a colour triplet scalar diquark. We find that the LHC has already explored and/or will explore new parameter space for these particles over the course of its lifetime.

  7. Texture 4 zero Fritzsch-like lepton mass matrices

    E-Print Network [OSTI]

    Gulsheen Ahuja; Sanjeev Kumar; Monika Randhawa; Manmohan Gupta; S. Dev

    2008-02-20T23:59:59.000Z

    For Majorana or Dirac neutrinos, using Fritzsch-like texture 4 zero mass matrices with parallel texture structures for the charged leptons and the Dirac neutrino mass matrix (M_{\

  8. Search for Lepton Flavor Violation in Upsilon Decays

    SciTech Connect (OSTI)

    Love, W.; Savinov, V. [University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Lopez, A.; Mehrabyan, S.; Mendez, H.; Ramirez, J. [University of Puerto Rico, Mayaguez, Puerto Rico 00681 (Puerto Rico); Huang, G. S.; Miller, D. H.; Pavlunin, V.; Sanghi, B.; Shipsey, I. P. J.; Xin, B. [Purdue University, West Lafayette, Indiana 47907 (United States); Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); He, Q. [University of Rochester, Rochester, New York 14627 (United States)] (and others)

    2008-11-14T23:59:59.000Z

    In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays {upsilon}(nS){yields}{mu}{tau} (n=1, 2, and 3) using the data collected with the CLEO III detector. We identify the {tau} lepton using its leptonic decay {nu}{sub {tau}}{nu}{sub e}e and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of {upsilon} mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

  9. Lepton flavor violation decays with the fourth generation neutrino

    E-Print Network [OSTI]

    Wu-Jun Huo; Tai-Fu Feng

    2002-03-22T23:59:59.000Z

    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, $\

  10. Survey of lepton number violation via effective operators

    SciTech Connect (OSTI)

    Gouvea, Andre de; Jenkins, James [Northwestern University, Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

    2008-01-01T23:59:59.000Z

    We survey 129 lepton number violating effective operators, consistent with the minimal standard model gauge group and particle content, of mass dimension up to and including 11. Upon requiring that each one radiatively generates the observed neutrino masses, we extract an associated characteristic cutoff energy scale which we use to calculate other observable manifestations of these operators for a number of current and future experimental probes, concentrating on lepton number violating phenomena. These include searches for neutrinoless double-beta decay and rare meson, lepton, and gauge boson decays. We also consider searches at hadron/lepton collider facilities in anticipation of the CERN LHC and the future ILC. We find that some operators are already disfavored by current data, while more are ripe to be probed by next-generation experiments. We also find that our current understanding of lepton mixing disfavors a subset of higher dimensional operators. While neutrinoless double-beta decay is the most promising signature of lepton number violation for the majority of operators, a handful is best probed by other means. We argue that a combination of constraints from various independent experimental sources will help to pinpoint the ''correct'' model of neutrino mass, or at least aid in narrowing down the set of possibilities.

  11. A Survey of Lepton Number Violation Via Effective Operators

    E-Print Network [OSTI]

    Andre de Gouvea; James Jenkins

    2007-08-09T23:59:59.000Z

    We survey 129 lepton number violating effective operators, consistent with the minimal Standard Model gauge group and particle content, of mass dimension up to and including eleven. Upon requiring that each one radiatively generates the observed neutrino masses, we extract an associated characteristic cutoff energy scale which we use to calculate other observable manifestations of these operators for a number of current and future experimental probes, concentrating on lepton number violating phenomena. These include searches for neutrinoless double-beta decay and rare meson, lepton, and gauge boson decays. We also consider searches at hadron/lepton collider facilities in anticipation of the LHC and the future ILC. We find that some operators are already disfavored by current data, while more are ripe to be probed by next-generation experiments. We also find that our current understanding of lepton mixing disfavors a subset of higher dimensional operators. While neutrinoless double-beta decay is the most promising signature of lepton number violation for the majority of operators, a handful is best probed by other means. We argue that a combination of constraints from various independent experimental sources will help to pinpoint the ``correct'' model of neutrino mass, or at least aid in narrowing down the set of possibilities.

  12. Nuclear PDF for neutrino and charged lepton data

    E-Print Network [OSTI]

    K. Kovarik

    2010-12-13T23:59:59.000Z

    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.

  13. Preon Trinity - a new model of leptons and quarks

    E-Print Network [OSTI]

    Jean-Jacques Dugne; Sverker Fredriksson; Johan Hansson; Enrico Predazzi

    1999-10-12T23:59:59.000Z

    A new model for the substructure of quarks, leptons and weak gauge bosons is discussed. It is based on three fundamental and absolutely stable spin-1/2 preons. Its preon flavour SU(3) symmetry leads to a prediction of nine quarks, nine leptons and nine heavy vector bosons. One of the quarks has charge $-4e/3$, and is speculated to be the top quark (whose charge has not been measured). The flavour symmetry leads to three conserved lepton numbers in all known weak processes, except for some neutrinos, which might either oscillate or decay. There is also a (Cabibbo) mixing of the $d$ and $s$ quarks due to an internal preon-antipreon annihilation channel. An identical channel exists inside the composite $Z^0$, leading to a relation between the Cabibbo and Weinberg mixing angles.

  14. Leptonic Decays of the Charged B Meson

    SciTech Connect (OSTI)

    Corwin, Luke A.; /Ohio State U.; ,

    2010-06-11T23:59:59.000Z

    The authors present a search for the decay B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}} ({ell} = {tau}, {mu}, or e) in (458.9 {+-} 5.1) x 10{sup 6} {Upsilon}(4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}X) is selected, and in the recoil a search for B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}} signal is performed. The {tau} is identified in the following channels: {tau}{sup +} {yields} e{sup +}{nu}{sub e}{bar {nu}}{sub {tau}}, {tau}{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{bar {nu}}{sub {tau}}, {tau}{sup +} {yields} {pi}{sup +}{bar {nu}}{sub {tau}}, and {tau}{sup +} {yields} {pi}{sup +}{pi}{sup 0}{bar {nu}}{sub {tau}}. The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. They determine from the dataset a preliminary measurement of {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (1.8 {+-} 0.8 {+-} 0.1) x 10{sup -4}, which excludes zero at 2.4{sigma}, and f{sub B} = 255 {+-} 58 MeV. Combination with the hadronically tagged measurement yields {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (1.8 {+-} 0.6) x 10{sup -4}. They also set preliminary limits on the branching fractions at {Beta}(B{sup +} {yields} e{sup +}{nu}{sub e}) < 7.7 x 10{sup -6} (90% C.L.), {Beta}(B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}) < 11 x 10{sup -6} (90% C.L.), and {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) < 3.2 x 10{sup -4} (90% C.L.).

  15. Particle Production Reactions in Laser-Boosted Lepton Collisions

    E-Print Network [OSTI]

    Sarah J. Müller; Christoph H. Keitel; Carsten Müller

    2014-12-28T23:59:59.000Z

    The need for ever higher energies in lepton colliders gives rise to the investigation of new accelerator schemes for elementary particle physics experiments. One perceivable way to increase the collision energy would be to combine conventional lepton acceleration with strong laser fields, making use of the momentum boost a charged particle experiences inside a plane electromagnetic wave. As an example for a process taking place in such a laser-boosted collision, Higgs boson creation is studied in detail. We further discuss other possible particle production processes that could be implemented in such a collider scheme and specify the required technical demands.

  16. Search for Low Mass Exotic leptonic or bosonic structures

    E-Print Network [OSTI]

    B. Tatischeff; E. Tomasi-Gustafsson

    2007-07-09T23:59:59.000Z

    Recently, several papers discussed the existence of a low mass leptonic structure. It was suggested that the $\\Sigma^{+}$ disintegration: $\\Sigma^{+}\\to$pP$^{0}$, P$^{0}\\to\\mu^{-}\\mu^{+}$ proceeds through an intermediate particle P$^{0}$ having a mass close to M$\\approx$~214.3 MeV. The present work intends to look at other available data, in order to observe the eventual existence of a small peak or shoulder, at a mass close to M=214.3 MeV, which can strengthen the existence of a state produced by two leptons of opposite electric charge.

  17. Lepton number violation and W ? chiral couplings at the LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Han, Tao; Lewis, Ian; Ruiz, Richard; Si, Zong-guo

    2013-02-01T23:59:59.000Z

    We study the observability for a heavy Majorana neutrino N along with a new charged gauge boson W' at the LHC. We emphasize the complementarity of these two particles in their production and decay to unambiguously determine their properties. We show that the Majorana nature of N can be verified by the lepton number violating like-sign dilepton process, and by polar and azimuthal angular distributions. The chirality of the W' coupling to leptons and to quarks can be determined by a polar angle distribution in the reconstructed frame and an azimuthal angle distribution.

  18. Particle Production Reactions in Laser-Boosted Lepton Collisions

    E-Print Network [OSTI]

    Müller, Sarah J; Müller, Carsten

    2014-01-01T23:59:59.000Z

    The need for ever higher energies in lepton colliders gives rise to the investigation of new accelerator schemes for elementary particle physics experiments. One perceivable way to increase the collision energy would be to combine conventional lepton acceleration with strong laser fields, making use of the momentum boost a charged particle experiences inside a plane electromagnetic wave. As an example for a process taking place in such a laser-boosted collision, Higgs boson creation is studied in detail. We further discuss other possible particle production processes that could be implemented in such a collider scheme and specify the required technical demands.

  19. Classification of lepton mixing patterns from finite flavour symmetries

    E-Print Network [OSTI]

    Renato M. Fonseca; Walter Grimus

    2014-10-15T23:59:59.000Z

    Flavour symmetries have been used to constrain both quark and lepton mixing parameters. In particular, they can be used to completely fix the mixing angles. For the lepton sector, assuming that neutrinos are Majorana particles, we have derived the complete list of mixing patterns achievable in this way, as well as the symmetry groups associated to each case. Partial computer scans done in the past have hinted that such list is limited, and this does indeed turn out to be the case. In addition, most mixing patterns are already 3-sigma excluded by neutrino oscillation data.

  20. Relating quarks and leptons with the T7 flavour group

    E-Print Network [OSTI]

    Bonilla, Cesar; Peinado, Eduardo; Valle, Jose W F

    2014-01-01T23:59:59.000Z

    In this letter we present a model for quarks and leptons based on T7 as flavour symmetry, predicting a canonical mass relation between charged leptons and down-type quarks proposed earlier. Neutrino masses are generated through a Type-I seesaw mechanism, with predicted correlations between the atmospheric mixing angle and neutrino masses. Compatibility with oscillation results lead to lower bounds for the lightest neutrino mass as well as for the neutrinoless double beta decay rates, even for normal neutrino mass hierarchy.

  1. Polarisation Observables in Antiproton Proton to Lepton Antilepton Reactions

    SciTech Connect (OSTI)

    Jennings, Elise [School of Mathematics, Trinity College Dublin (Ireland)

    2007-06-13T23:59:59.000Z

    The electromagnetic form factors of hadrons as measured both in the space like and time like domains provide fundamental information on the nucleon structure and internal dynamics. General expressions, including the lepton mass, for the spin averaged differential cross section for the annihilation reaction lepton antilepton to proton antiproton are given, as well as general formulae for the single and double spin asymmetries. The time reversed reaction would involve a kinematic factor. We also present general expressions for the helicity amplitudes for this reaction.

  2. Neutrinoless Double Beta Decay and Lepton Flavor Violation

    E-Print Network [OSTI]

    V. Cirigliano; A. Kurylov; M. J. Ramsey-Musolf; P. Vogel

    2004-06-17T23:59:59.000Z

    We point out that extensions of the Standard Model with low scale (~TeV) lepton number violation (LNV) generally lead to a pattern of lepton flavor violation (LFV) experimentally distinguishable from the one implied by models with GUT scale LNV. As a consequence, muon LFV processes provide a powerful diagnostic tool to determine whether or not the effective neutrino mass can be deduced from the rate of neutrinoless double beta decay. We discuss the role of \\mu -> e \\gamma and \\mu -> e conversion in nuclei, which will be studied with high sensitivity in forthcoming experiments.

  3. Bounds on R-parity violating supersymmetric couplings from leptonic and semileptonic meson decays

    SciTech Connect (OSTI)

    Dreiner, H. K.; Kraemer, M.; O'Leary, Ben [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany); S.U.P.A., School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom) and Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany)

    2007-06-01T23:59:59.000Z

    We present a comprehensive update of the bounds on R-parity violating supersymmetric couplings from lepton-flavor- and lepton-number-violating decay processes. We consider {tau} and {mu} decays as well as leptonic and semileptonic decays of mesons. We present several new bounds resulting from {tau}, {eta}, and kaon decays and correct some results in the literature concerning B meson decays.

  4. Tau decays into three charged leptons and two neutrinos

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1996-04-01T23:59:59.000Z

    We search for the radiative leptonic tau decays tau --> ee(+) e(-)nu(tau)nu(e) and tau --> mu e(+)e(-)nu(tau)nu(mu) using 3.60 fb(-1) of data collected by the CLEO-II experiment at the Cornell Electron Storage Ring. We present a first observation...

  5. Permutation symmetry for neutrino and charged-lepton mass matrices

    SciTech Connect (OSTI)

    Ma, Ernest [Physics Department, Univeristy of California, Riverside, California 92521 (United States)] [Physics Department, Univeristy of California, Riverside, California 92521 (United States)

    2000-02-01T23:59:59.000Z

    Permutation symmetry S{sub 3} is applied to obtain two equal Majorana neutrino masses, while maintaining three different charged-lepton masses and suppressing neutrinoless double beta decay. The resulting radiative splitting of the two neutrinos is shown to be suitable for solar neutrino vacuum oscillations. (c) 2000 The American Physical Society.

  6. Weak interactions of quarks and leptons: experimental status

    SciTech Connect (OSTI)

    Wojcicki, S.

    1984-09-01T23:59:59.000Z

    The present experimental status of weak interactions is discussed with emphasis on the problems and questions and on the possible lines of future investigations. Major topics include; (1) the quark mixing matrix, (2) CP violation, (3) rare decays, (4) the lepton sector, and (5) right handed currents. 118 references. (WHK)

  7. Detecting exotic heavy leptons at the large hadron collider.

    E-Print Network [OSTI]

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

    the cuts actually slightly increases with mass due to the longer time delays. 0.01 0.1 1 10 100 1000 100 200 300 400 500 600 700 800 900 1000 Cr os s se ct io n (fb ) Mass of heavy lepton (GeV) Before applying cuts After applying cuts Figure 5: Cross...

  8. Azimuthal asymmetry in lepton-proton scattering at high energies

    SciTech Connect (OSTI)

    Chay, J.; Ellis, S.D.; Stirling, W.J. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1992-01-01T23:59:59.000Z

    We consider the azimuthal angular dependence of the distribution of final-state hadrons in high-energy lepton-proton scattering. The distribution displays an azimuthal asymmetry due to both perturbative and nonperturbative effects. At the large momentum transfers attainable, for example, at the DESY {ital ep} collider HERA we expect the perturbative effects to dominate and constitute a clear test of QCD.

  9. U(2)? flavor symmetry and lepton universality violation in W?????

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Filipuzzi, Alberto; Portolés, Jorge; González-Alonso, Martín

    2012-06-01T23:59:59.000Z

    The seeming violation of universality in the ? lepton coupling to the W boson suggested by LEP-II data is studied using an effective field theory (EFT) approach. Within this framework we explore how this feature fits into the current constraints from electroweak precision observables using different assumptions about the flavor structure of New Physics, namely [U(2)×U(1)]? and U(2)?. We show the importance of leptonic and semileptonic tau decay measurements, giving 3–4 TeV bounds on the New Physics effective scale at 90% C.L. We conclude under very general assumptions that it is not possible to accommodate this deviation from universality inmore »the EFT framework, and thus such a signal could only be explained by the introduction of light degrees of freedom or New Physics strongly coupled at the electroweak scale.« less

  10. U(2)? flavor symmetry and lepton universality violation in W?????

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Filipuzzi, Alberto; Portolés, Jorge; González-Alonso, Martín

    2012-06-01T23:59:59.000Z

    The seeming violation of universality in the ? lepton coupling to the W boson suggested by LEP-II data is studied using an effective field theory (EFT) approach. Within this framework we explore how this feature fits into the current constraints from electroweak precision observables using different assumptions about the flavor structure of New Physics, namely [U(2)×U(1)]? and U(2)?. We show the importance of leptonic and semileptonic tau decay measurements, giving 3–4 TeV bounds on the New Physics effective scale at 90% C.L. We conclude under very general assumptions that it is not possible to accommodate this deviation from universality in the EFT framework, and thus such a signal could only be explained by the introduction of light degrees of freedom or New Physics strongly coupled at the electroweak scale.

  11. A minimal and predictive $T_7$ lepton flavor 331 model

    E-Print Network [OSTI]

    Hernández, A E Cárcamo

    2015-01-01T23:59:59.000Z

    We present a model based on the $SU(3)_{C}\\otimes SU(3)_{L}\\otimes U(1)_{X}$ gauge group having an extra $T_{7}\\otimes Z_{3}\\otimes Z_{14}$ flavor group, where the light active neutrino masses arise via double seesaw mechanism and the observed charged lepton mass hierarchy is a consequence of the $Z_{14}$ symmetry breaking at very high energy. In our minimal and predictive $T_7$ lepton flavor 331 model, the spectrum of neutrinos includes very light active neutrinos and heavy and very heavy sterile neutrinos. The obtained neutrino mixing parameters and neutrino mass squared splittings are compatible with the neutrino oscillation experimental data, for both normal and inverted hierarchies. The model predicts CP conservation in neutrino oscillations.

  12. Lepton Mixing Predictions from (Generalised) CP and Discrete Flavour Symmetry

    E-Print Network [OSTI]

    Thomas Neder

    2015-03-31T23:59:59.000Z

    An important class of flavour groups, that are subgroups of $U(3)$ and that predict experimentally viable lepton mixing parameters including Majorana phases, is the $\\Delta(6n^2)$ series. The most well-known member is $\\Delta(24)=S_4$. I present results of several extensive studies of lepton mixing predictions obtained in models with a $\\Delta(6n^2)$ flavour group that preserve either the full residual $Z_2\\times Z_2$ or a $Z_2$ subgroup for neutrinos and can include a generalised CP symmetry. Predictions include mixing angles and Dirac CP phase generally; and if invariance under a generalised CP symmetry is included, also Majorana phases. For this, the interplay of flavour group and generalised CP symmetry has to be studied carefully.

  13. Lepton Number Violation within the Conformal Inverse Seesaw

    E-Print Network [OSTI]

    Humbert, Pascal; Patra, Sudhanwa; Smirnov, Juri

    2015-01-01T23:59:59.000Z

    We present a novel framework within the conformal inverse seesaw scheme allowing large lepton number violation while the neutrino mass formula is still governed by the low-scale inverse seesaw mechanism. This model includes new contributions to rare low-energy lepton number violating processes like neutrinoless double beta decay. We find that the lifetime for this rare process due to heavy sterile neutrinos can saturate current experimental limits. The characteristic collider signature of the present conformal inverse seesaw scheme includes, same-sign dilepton plus two jets and same-sign dilepton plus four jets. Finally, we comment on the testability of the model at the Large Hadron Collider since there are new scalars, new fermions and an extra neutral gauge boson with masses around few 100 GeV to few TeV.

  14. Statistical Understanding of Quark and Lepton Masses in Gaussian Landscapes

    E-Print Network [OSTI]

    Lawrence J. Hall; Michael P. Salem; Taizan Watari

    2007-08-10T23:59:59.000Z

    The fundamental theory of nature may allow a large landscape of vacua. Even if the theory contains a unified gauge symmetry, the 22 flavor parameters of the Standard Model, including neutrino masses, may be largely determined by the statistics of this landscape, and not by any symmetry. Then the measured values of the flavor parameters do not lead to any fundamental symmetries, but are statistical accidents; their precise values do not provide any insights into the fundamental theory, rather the overall pattern of flavor reflects the underlying landscape. We investigate whether random selection from the statistics of a simple landscape can explain the broad patterns of quark, charged lepton, and neutrino masses and mixings. We propose Gaussian landscapes as simplified models of landscapes where Yukawa couplings result from overlap integrals of zero-mode wavefunctions in higher-dimensional supersymmetric gauge theories. In terms of just five free parameters, such landscapes can account for all gross features of flavor, including: the hierarchy of quark and charged lepton masses; small quark mixing angles, with 13 mixing less than 12 and 23 mixing; very light Majorana neutrino masses, with the solar to atmospheric neutrino mass ratio consistent with data; distributions for leptonic 12 and 23 mixings that are peaked at large values, while the distribution for 13 mixing is peaked at low values; and order unity CP violating phases in both the quark and lepton sectors. While the statistical distributions for flavor parameters are broad, the distributions are robust to changes in the geometry of the extra dimensions. Constraining the distributions by loose cuts about observed values leads to narrower distributions for neutrino measurements of 13 mixing, CP violation, and neutrinoless double beta decay.

  15. The vertex detector for the Lepton/Photon collaboration

    SciTech Connect (OSTI)

    Sullivan, J.P.; Boissevain, J.G.; Fox, D.; Hecke, H. van; Jacak, B.V.; Kapustinsky, J.S.; Leitch, M.J.; McGaughey, P.L.; Moss, J.M.; Sondheim, W.E. [Los Alamos National Lab., NM (United States)

    1991-12-31T23:59:59.000Z

    The conceptual design of the vertex detector for the Lepton/Photon Collaboration at RHIC is described, including simulations of its expected performance. The design consists of two con- centric layers of single-sided Si strips. The expected performance as a multiplicity detector and in measuring the pseudo-rapidity ({nu}) distribution is discussed as well as the expected vertex finding efficiency and accuracy. Various options which could be used to reduce the cost of the detector are also discussed.

  16. Electroweak Penguin and Leptonic Decays at BaBar

    SciTech Connect (OSTI)

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

    2005-08-26T23:59:59.000Z

    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}}.

  17. Lepton flavor violation two-body decays of quarkoniums

    E-Print Network [OSTI]

    W. J. Huo; T. F. Feng; Y. C. Xing

    2002-12-15T23:59:59.000Z

    In this paper we firstly study various model-independent bounds on lepton flavor violation (LFV) in processes of $J/\\Psi$, $\\Psi'$ and $\\Upsilon$ two-body decays, then calculate their branch ratios % By using the constraints from other ways, we obtain %the indirect bounds of ${\\rm Br} (J/\\Psi,\\Psi',\\Upsilon \\to ll')$ in models of the leptoquark, $R$ violating MSSM and topcolor assisted technicolor(TC2) models.

  18. Prospects of Heavy Neutrino Searches at Future Lepton Colliders

    E-Print Network [OSTI]

    Banerjee, Shankha; Ibarra, Alejandro; Mandal, Tanumoy; Mitra, Manimala

    2015-01-01T23:59:59.000Z

    We discuss the future prospects of heavy neutrino searches at next generation lepton colliders. In particular, we focus on the planned electron-positron colliders, operating in two different beam modes, namely, $e^+e^-$ and $e^-e^-$. In the $e^+e^-$ beam mode, we consider various production and decay modes of the heavy neutrino ($N$), and find that the final state with $e+2j+\\slashed{E}$, arising from the $e^+e^-\\to N\

  19. Kalman filter based tracker study for lepton flavor violation experiments

    E-Print Network [OSTI]

    Rashid M. Djilkibaev; Rostislav V. Konoplich

    2009-08-19T23:59:59.000Z

    A tracking detector is proposed for lepton flavor violation experiments ($\\mu \\to e$ conversion, $\\mu \\to e + \\gamma$, $\\mu \\to 3e $) consisting of identical chambers which can be reconfigured to meet the requirements for all three experiments. A pattern recognition and track reconstruction procedure based on the Kalman filter technique is presented for this detector. The pattern recognition proceeds in two stages. At the first stage only hit straw tube center coordinates, without drift time information, are used to reduce the background to a manageable level. At the second stage the drift time information is incorporated and a deterministic annealing filter is applied to reach the final level of background suppression. The final track momentum reconstruction is provided by a combinatorial drop filter which is effective in hit-to-track assignment. The momentum resolution of the tracker in measuring monochromatic leptons is found to be $\\sigma_{p}$ = 0.17 and 0.26 MeV for the $\\mu \\to e$ conversion and $\\mu^+ \\to e^+ + \\gamma$ processes, respectively. The tracker reconstruction resolution for the total scalar lepton momentum is $\\sigma_{p} = $ 0.33 MeV for the $\\mu \\to 3e$ process. The obtained tracker resolutions allow an increase in sensitivity to the branching ratios for these processes by a few orders of magnitude over current experimental limits.

  20. Lepton flavor violating Higgs boson decays from massive seesaw neutrinos

    SciTech Connect (OSTI)

    Arganda, Ernesto; Curiel, Ana M.; Herrero, Maria J.; Temes, David [Departamento de Fisica Teorica, Universidad Autonoma de Madrid (Spain); Laboratoire de Physique Theorique, LAPTH (France)

    2005-02-01T23:59:59.000Z

    Lepton flavor violating Higgs boson decays are studied within the context of seesaw models with Majorana massive neutrinos. Two models are considered: the SM-seesaw, with the standard model particle content plus three right-handed neutrinos, and the MSSM-seesaw, with the minimal supersymmetric standard model particle content plus three right-handed neutrinos and their supersymmetric partners. The widths for these decays are derived from a full one-loop diagrammatic computation in both models, and they are analyzed numerically in terms of the seesaw parameters, namely, the Dirac and Majorana mass matrices. Several possible scenarios for these mass matrices that are compatible with neutrino data are considered. In the SM-seesaw case, very small branching ratios are found for all studied scenarios. These ratios are explained as a consequence of the decoupling behavior of the heavy right-handed neutrinos. In contrast, in the MSSM-seesaw case, sizable branching ratios are found for some of the leptonic flavor violating decays of the MSSM neutral Higgs bosons and for some choices of the seesaw matrices and MSSM parameters. The relevance of the two competing sources of lepton flavor changing interactions in the MSSM-seesaw case is also discussed. The nondecoupling behavior of the supersymmetric particles contributing in the loop diagrams is finally shown.

  1. Clues for flavor from rare lepton and quark decays

    E-Print Network [OSTI]

    Varzielas, Ivo de Medeiros

    2015-01-01T23:59:59.000Z

    Flavor symmetries successfully explain lepton and quark masses and mixings yet it is usually hard to distinguish different models that predict the same mixing angles. Further experimental input could be available, if the agents of flavor breaking are sufficiently low in mass and detectable or if new physics with non-trivial flavor charges is sufficiently low in mass and detectable. The recent hint for lepton-nonuniversality in the ratio of branching fractions $B \\to K \\mu \\mu$ over $B \\to K e e$, $R_K$, suggests the latter, at least for indirect detection via rare decays. We demonstrate the discriminating power of the rare decay data on flavor model building taking into account viable leptonic mixings and show how correlations with other observables exist in leptoquark models. We give expectations for branching ratios $B \\to K \\ell \\ell^\\prime, B_{(s)} \\to \\ell \\ell^\\prime$ and $\\ell \\to \\ell^\\prime \\gamma$, and Higgs decays $h \\to \\ell \\ell^\\prime$.

  2. Electroweak model of lepton mass and mixing hierarchies

    E-Print Network [OSTI]

    E. M. Lipmanov

    2009-04-06T23:59:59.000Z

    Flavor physics, like cosmology, is likely in need of new basic ideas; the puzzles of elementary particle mass hierarchies and in particular the e-mu-tau and neutrino ones still remain mysteries. In this paper a new idea of dynamical connection between low energy 3-flavor particle mass hierarchies and electroweak charges is studied with restriction to the simplest case of lepton flavor phenomenology. The main inference is that it can be only two types of lepton 3-flavor particle-copy groups: 1) with large and strongly hierarchical mass ratios and 2) with close to 1 mass ratios. From experimental data definitely follows that the three charged leptons belong to the first type whereas the three neutrinos belong to the second type and so are quasi-degenerate. The inferences of QD-neutrinos with realistic small masses and oscillation hierarchy parameter and quark-QD-neutrino mixing angle complementarity follow from the fact of small EW charges and their relation to the concept of benchmark flavor pattern.

  3. Implications of theta_13 on Fritzsch-like lepton mass matrices

    E-Print Network [OSTI]

    Fakay, Priyanka; Verma, Rohit; Ahuja, Gulsheen; Gupta, Manmohan

    2013-01-01T23:59:59.000Z

    Implications of the lepton mixing angles, in particular of theta_13, have been investigated for minimal as well as non-minimal Fritzsch-like textures for the case of Majorana neutrinos. Both, in minimal texture (texture 6 zero lepton mass matrices) and non-minimal textures (two cases of texture 5 zero lepton mass matrices), inverted hierarchy and degenerate scenario of neutrino masses have been ruled out. The implications of theta_13 have been investigated on the lightest neutrino mass m_\

  4. Implications of theta_13 on Fritzsch-like lepton mass matrices

    E-Print Network [OSTI]

    Priyanka Fakay; Samandeep Sharma; Rohit Verma; Gulsheen Ahuja; Manmohan Gupta

    2013-01-25T23:59:59.000Z

    Implications of the lepton mixing angles, in particular of theta_13, have been investigated for minimal as well as non-minimal Fritzsch-like textures for the case of Majorana neutrinos. Both, in minimal texture (texture 6 zero lepton mass matrices) and non-minimal textures (two cases of texture 5 zero lepton mass matrices), inverted hierarchy and degenerate scenario of neutrino masses have been ruled out. The implications of theta_13 have been investigated on the lightest neutrino mass m_\

  5. Differentiating neutrino models on the basis of $\\theta_{13}$ and lepton flavor violation

    SciTech Connect (OSTI)

    Albright, Carl H.; /Northern Illinois U. /Fermilab

    2008-03-01T23:59:59.000Z

    The authors show how models of neutrino masses and mixings can be differentiated on the basis of their predictions for {theta}{sub 13} and lepton flavor violation in radiative charged lepton decays and {mu} - e conversion. They illustrate the lepton flavor violation results for five predictive SO(10) SUSY GUT models and point out the relative importance of their heavy right-handed neutrino mass spectra and {theta}{sub 13} predictions.

  6. Family number non-conservation induced by the supersymmetric mixing of scalar leptons

    SciTech Connect (OSTI)

    Levine, M.J.S.

    1987-08-01T23:59:59.000Z

    The most egregious aspect of (N = 1) supersymmetric theories is that each particle state is accompanied by a 'super-partner', a state with identical quantum numbers save that it differs in spin by one half unit. For the leptons these are scalars and are called ''sleptons'', or scalar leptons. These consist of the charged sleptons (selectron, smuon, stau) and the scalar neutrinos ('sneutrinos'). We examine a model of supersymmetry with soft breaking terms in the electroweak sector. Explicit mixing among the scalar leptons results in a number of effects, principally non-conservation of lepton family number. Comparison with experiment permits us to place constraints upon the model. 49 refs., 12 figs.

  7. Generalised CP and $\\Delta (6n^2)$ Family Symmetry in Semi-Direct Models of Leptons

    E-Print Network [OSTI]

    Ding, Gui-Jun; Neder, Thomas

    2014-01-01T23:59:59.000Z

    We perform a detailed analysis of $\\Delta (6n^2)$ family symmetry combined with a generalised CP symmetry in the lepton sector, breaking to different remnant symmetries $G_{\

  8. Muon g-2 Anomaly and Dark Leptonic Gauge Boson

    SciTech Connect (OSTI)

    Lee, Hye-Sung [W& M

    2014-11-01T23:59:59.000Z

    One of the major motivations to search for a dark gauge boson of MeV-GeV scale is the long-standing muon g-2 anomaly. Because of active searches such as fixed target experiments and rare meson decays, the muon g-2 favored parameter region has been rapidly reduced. With the most recent data, it is practically excluded now in the popular dark photon model. We overview the issue and investigate a potentially alternative model based on the gauged lepton number or U(1)_L, which is under different experimental constraints.

  9. Rephasing Invariants of Quark and Lepton Mixing Matrices

    E-Print Network [OSTI]

    Elizabeth Jenkins; Aneesh V. Manohar

    2007-11-14T23:59:59.000Z

    Rephasing invariants of quark and lepton mixing matrices are obtained in the standard model extended by the seesaw mechanism, and in its low-energy effective theory with the dimension-five Majorana mass operator. We classify the basic invariants, discuss non-trivial relations between them, and determine the independent invariants which characterize all the information in the mixing matrices in a basis-independent way. We also discuss the restrictions on the allowed ranges for the mixing phases, and on the rephasing invariants, which follow from a discrete invariance of the Majorana mass matrix.

  10. Higgs Boson Creation in Laser-Boosted Lepton Collisions

    E-Print Network [OSTI]

    Sarah J. Müller; Christoph H. Keitel; Carsten Müller

    2014-02-26T23:59:59.000Z

    Electroweak processes in high-energy lepton collisions are considered in a situation where the incident center-of-mass energy lies below the reaction threshold, but is boosted to the required level by subsequent laser acceleration. Within the framework of laser-dressed quantum field theory, we study the laser-boosted process $\\ell^+ \\ell^- \\to HZ^0$ in detail and specify the technical demands needed for its experimental realization. Further, we outline possible qualitative differences to field-free processes regarding the detection of the produced Higgs bosons.

  11. Lepton mixing under the lepton charge nonconservation, neutrino masses and oscillations and the 'forbidden' decay Micro-Sign {sup -} {yields} e{sup -} + {gamma}

    SciTech Connect (OSTI)

    Lyuboshitz, V. L.; Lyuboshitz, V. V., E-mail: Valery.Lyuboshitz@jinr.ru [Joint Institute for Nuclear Research (Russian Federation)

    2013-08-15T23:59:59.000Z

    The lepton-charge (L{sub e}, L{sub {mu}}, L{sub {tau}}) nonconserving interaction leads to the mixing of the electron, muon, and tau neutrinos, which manifests itself in spatial oscillations of a neutrino beam, and also to the mixing of the electron, negative muon, and tau lepton, which, in particular, may be the cause of the 'forbidden' radiative decay of the negative muon into the electron and {gamma} quantum. Under the assumption that the nondiagonal elements of the mass matrices for neutrinos and ordinary leptons, connected with the lepton charge nonconservation, are the same, and by performing the joint analysis of the experimental data on neutrino oscillations and experimental restriction for the probability of the decay Micro-Sign {sup -} {yields} e{sup -} + {gamma} per unit time, the following estimate for the lower bound of neutrino mass has been obtained: m{sup ({nu})} > 1.5 eV/c{sup 2}.

  12. Electric Dipole moments of charged leptons and lepton flavor violating interactions in the general two Higgs Doublet model

    E-Print Network [OSTI]

    E. O. Iltan

    2001-05-17T23:59:59.000Z

    We calculate the electric dipole moment of electron using the experimental result of muon electric dipole moment and upper limit of the BR(\\mu --> e\\gamma) in the framework of the general two Higgs doublet model. Our prediction is 10^{-32} e-cm, which lies in the experimental current limits. Further, we obtain constraints for the Yukawa couplings \\bar{\\xi}^{D}_{N,\\tau e} and \\bar{\\xi}^{D}_{N,\\tau\\mu}. Finally we present an expression which connects the BR(\\tau\\to \\mu\\gamma) and the electric dipole moment of \\tau-lepton and study the relation between these physical quantities.

  13. Leptogenesis within a generalized quark-lepton symmetry

    SciTech Connect (OSTI)

    Buccella, F.; Falcone, D.; Oliver, L. [Dipartimento di Scienze Fisiche, Universita di Napoli, Via Cintia, Naples (Italy) and INFN, Sezione di Napoli (Italy); Dipartimento di Scienze Fisiche, Universita di Napoli, Via Cintia, Naples (Italy); Laboratoire de Physique Theorique, Universite de Paris XI, Batiment 210, Orsay Cedex (France)

    2008-02-01T23:59:59.000Z

    We reexamine the question of baryogenesis via leptogenesis in schemes of the seesaw mechanism with quark-lepton symmetry. Within the phenomenological approach of textures, we propose to relax this strict symmetry and propose weaker conditions, namely, models of the neutrino Dirac mass matrix M{sub D} which have the same hierarchy as the matrix elements of M{sub u}. We call this guideline generalized hierarchical quark-lepton symmetry. We consider in detail particular cases in which the moduli of the matrix elements of M{sub D} are equal to those of M{sub u}. We try for the heavy Majorana mass matrix diagonal and off-diagonal forms. We find that an ansatz for M{sub D} preserving the hierarchy, together with an off-diagonal model for the heavy Majorana neutrino mass, is consistent with neutrino masses, neutrino mixing, and baryogenesis via leptogenesis for an intermediate mass scale m{sub R}{approx}10{sup 12} GeV. The preservation of the hierarchical structure could come from a possible symmetry scheme.

  14. Determination of the semi-leptonic weak interaction pseudoscalar coupling constant , g$_{P}$, using the reaction $\\mu^{-}$p --> $\

    E-Print Network [OSTI]

    Hasinoff, M D; Azuelos, Georges; Bertl, W; Blecher, M; Chen, C Q; Depommier, P; Doyle, B; Von Egidy, T; Gorringe, T P; Gumplinger, P; Henderson, R; Jonkmans, G; Larabee, A J; MacDonald, J A; McDonald, S C; Munro, M H; Poutissou, J M; Poutissou, R; Robertson, B C; Sample, D G; Schott, W; Taylor, G N; Veillette, S; Wright, D H

    1992-01-01T23:59:59.000Z

    Determination of the semi-leptonic weak interaction pseudoscalar coupling constant , g$_{P}$, using the reaction $\\mu^{-}$p --> $\

  15. Dirac Lepton Angle Matrix v.s. Majorana Lepton Angle Matrix and Their Renormalization Group Running Behaviours

    E-Print Network [OSTI]

    Shu Luo

    2011-12-14T23:59:59.000Z

    Enlightened by the idea of the 3 times 3 CKM angle matrix proposed recently by Harrison et al., we introduce the Dirac angle matrix Phi and the Majorana angle matrix Psi in the lepton sector for Dirac and Majorana neutrinos respectively. We show that in presence of the CP violation, the angle matrix Phi or Psi is entirely equivalent to the complex MNS matrix V itself, but has the advantage of being real, phase rephasing invariant, directly associated to the leptonic unitarity triangles (UTs) and do not depend on any particular parametrization of V. In this paper, we further analyzed how the angle matrices evolve with the energy scale. The one-loop Renormalization Group Equations (RGEs) of Phi, Psi and some other rephasing invariant parameters are derived and the numerical analysis is performed to compare between the case of Dirac and Majorana neutrinos. Different neutrino mass spectra are taken into account in our calculation. We find that apparently different from the case of Dirac neutrinos, for Majorana neutrinos the RG-evolutions of Phi, Psi and the Jarlskog strongly depend on the Majorana-type CP-violating parameters and are quite sensitive to the sign of Delta m^{2}_{31}. They may receive significant radiative corrections in the MSSM if three neutrino masses are nearly degenerate.

  16. Dirac Lepton Angle Matrix v.s. Majorana Lepton Angle Matrix and Their Renormalization Group Running Behaviours

    E-Print Network [OSTI]

    Luo, Shu

    2011-01-01T23:59:59.000Z

    Enlightened by the idea of the 3 times 3 CKM angle matrix proposed recently by Harrison et al., we introduce the Dirac angle matrix Phi and the Majorana angle matrix Psi in the lepton sector for Dirac and Majorana neutrinos respectively. We show that in presence of the CP violation, the angle matrix Phi or Psi is entirely equivalent to the complex MNS matrix V itself, but has the advantage of being real, phase rephasing invariant, directly associated to the leptonic unitarity triangles (UTs) and do not depend on any particular parametrization of V. In this paper, we further analyzed how the angle matrices evolve with the energy scale. The one-loop Renormalization Group Equations (RGEs) of Phi, Psi and some other rephasing invariant parameters are derived and the numerical analysis is performed to compare between the case of Dirac and Majorana neutrinos. Different neutrino mass spectra are taken into account in our calculation. We find that apparently different from the case of Dirac neutrinos, for Majorana ne...

  17. Classification of lepton mixing matrices from finite residual symmetries

    E-Print Network [OSTI]

    Renato M. Fonseca; Walter Grimus

    2014-08-19T23:59:59.000Z

    Assuming that neutrinos are Majorana particles, we perform a complete classification of all possible mixing matrices which are fully determined by residual symmetries in the charged-lepton and neutrino mass matrices. The classification is based on the assumption that the residual symmetries originate from a finite flavour symmetry group. The mathematical tools which allow us to accomplish this classification are theorems on sums of roots of unity. We find 17 sporadic cases plus one infinite series of mixing matrices associated with three-flavour mixing, all of which have already been discussed in the literature. Only the infinite series contains mixing matrices which are compatible with the data at the 3 sigma level.

  18. Texture-zero model for the lepton mass matrices

    E-Print Network [OSTI]

    Ferreira, P M

    2012-01-01T23:59:59.000Z

    We suggest a simple model, based on the type-I seesaw mechanism, for the lepton mass matrices. The model hinges on an Abelian symmetry which leads to mass matrices with some vanishing matrix elements. The model predicts one massless neutrino and $M_{e\\mu} = 0$ ($M$ is the effective light-neutrino Majorana mass matrix). We show that these predictions perfectly agree with the present experimental data if the neutrino mass spectrum is inverted, i.e. if $m_3 = 0$, provided the Dirac phase $\\delta$ is very close to maximal ($\\pm \\pi / 2$). In the case of a normal neutrino mass spectrum, i.e. when $m_1 = 0$, the agreement of our model with the data is less than optimal---the reactor mixing angle $\\theta_{13}$ is too small in our model. Minimal leptogenesis is not an option in our model due to the vanishing elements in the Yukawa-coupling matrices.

  19. Texture-zero model for the lepton mass matrices

    E-Print Network [OSTI]

    P. M. Ferreira; L. Lavoura

    2012-10-01T23:59:59.000Z

    We suggest a simple model, based on the type-I seesaw mechanism, for the lepton mass matrices. The model hinges on an Abelian symmetry which leads to mass matrices with some vanishing matrix elements. The model predicts one massless neutrino and $M_{e\\mu} = 0$ ($M$ is the effective light-neutrino Majorana mass matrix). We show that these predictions perfectly agree with the present experimental data if the neutrino mass spectrum is inverted, i.e. if $m_3 = 0$, provided the Dirac phase $\\delta$ is very close to maximal ($\\pm \\pi / 2$). In the case of a normal neutrino mass spectrum, i.e. when $m_1 = 0$, the agreement of our model with the data is less than optimal---the reactor mixing angle $\\theta_{13}$ is too small in our model. Minimal leptogenesis is not an option in our model due to the vanishing elements in the Yukawa-coupling matrices.

  20. Generalized lepton number and dark left-right gauge model

    SciTech Connect (OSTI)

    Khalil, Shaaban [Center for Theoretical Physics, British University in Egypt, El Sherouk City, Postal No. 11837, P.O. Box 43 (Egypt); Department of Mathematics, Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Lee, Hye-Sung; Ma, Ernest [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States)

    2009-02-15T23:59:59.000Z

    In a left-right gauge model of particle interactions, the left-handed fermion doublet ({nu},e){sub L} is connected to its right-handed counterpart (n,e){sub R} through a scalar bidoublet so that e{sub L} pairs with e{sub R}, and {nu}{sub L} with n{sub R} to form mass terms. Suppose the latter link is severed without affecting the former, then n{sub R} is not the mass partner of {nu}{sub L}, and as we show in this paper, becomes a candidate for dark matter which is relevant for the recent PAMELA and ATIC observations. We accomplish this in a specific nonsupersymmetric model, where a generalized lepton number can be defined, so that n{sub R} and W{sub R}{sup {+-}} are odd under R{identical_to}(-1){sup 3B+L+2j}. Fermionic leptoquarks are also predicted.

  1. Addition of First Generation Leptons to the External Flux Model

    E-Print Network [OSTI]

    Aaron J. Roy

    2009-11-28T23:59:59.000Z

    In an extra dimensional EW model in M_4 X S_1 there is no distinction mathematically with the standard model analog as far as the degrees of freedom of the two models along with the masses and more importantly the mass ratio relation in the zero mode limit. In this paper we present a theoretical construct of the same geometry but with the addition of an external magnetic flux permeating the extra coordinate. This will give all of the charged fields in the model an additional phase with nontrivial periodicity. This rather important addition leads to very interesting and mathematically rich physics. Here we will present the generalized theory for the addition of first generation leptons to this theory.

  2. Lepton flavor violating Higgs couplings and single production of the Higgs boson via e \\gamma collision

    E-Print Network [OSTI]

    Yue, Chong-Xing; Guo, Yu-Chen

    2015-01-01T23:59:59.000Z

    Taking into account of the constraints on the lepton flavor violation (LFV) couplings of the standard model (SM) Higgs boson H with leptons from low energy experiments and the recent CMS results, we investigate production of the SM Higgs boson associated with a lepton $\\tau$ via $e\\gamma$ collision at the ILC and LHeC experiments. The production cross sections are calculated, the LFV signals and the relevant SM backgrounds are examined. The LFV signals of the SM Higgs boson might be observed via $e\\gamma$ collision in future ILC experiments.

  3. Lepton flavor violating Higgs couplings and single production of the Higgs boson via e ?collision

    E-Print Network [OSTI]

    Chong-Xing Yue; Cong Pang; Yu-Chen Guo

    2015-05-08T23:59:59.000Z

    Taking into account of the constraints on the lepton flavor violation (LFV) couplings of the standard model (SM) Higgs boson H with leptons from low energy experiments and the recent CMS results, we investigate production of the SM Higgs boson associated with a lepton $\\tau$ via $e\\gamma$ collision at the ILC and LHeC experiments. The production cross sections are calculated, the LFV signals and the relevant SM backgrounds are examined. The LFV signals of the SM Higgs boson might be observed via $e\\gamma$ collision in future ILC experiments.

  4. Falsifying High-Scale Baryogenesis with Neutrinoless Double Beta Decay and Lepton Flavor Violation

    E-Print Network [OSTI]

    Deppisch, Frank F; Hirsch, Martin; Huang, Wei-Chih; Päs, Heinrich

    2015-01-01T23:59:59.000Z

    Interactions that manifest themselves as lepton number violating processes at low energies in combination with sphaleron transitions typically erase any pre-existing baryon asymmetry of the universe. In this letter, we discuss the constraints obtained from an observation of neutrinoless double beta decay in this context. If a new physics mechanism of neutrinoless double beta decay is observed, typical scenarios of high-scale baryogenesis will be excluded unless the baryon asymmetry is stabilized via some new mechanism. We also sketch how this conclusion can be extended beyond the first lepton generation by incorporating lepton flavor violating processes.

  5. Falsifying High-Scale Baryogenesis with Neutrinoless Double Beta Decay and Lepton Flavor Violation

    E-Print Network [OSTI]

    Frank F. Deppisch; Julia Harz; Martin Hirsch; Wei-Chih Huang; Heinrich Päs

    2015-03-16T23:59:59.000Z

    Interactions that manifest themselves as lepton number violating processes at low energies in combination with sphaleron transitions typically erase any pre-existing baryon asymmetry of the universe. In this letter, we discuss the constraints obtained from an observation of neutrinoless double beta decay in this context. If a new physics mechanism of neutrinoless double beta decay is observed, typical scenarios of high-scale baryogenesis will be excluded unless the baryon asymmetry is stabilized via some new mechanism. We also sketch how this conclusion can be extended beyond the first lepton generation by incorporating lepton flavor violating processes.

  6. Impact of Lepton Number Violation at the LHC on Models of Leptogenesis

    E-Print Network [OSTI]

    Frank F. Deppisch; Julia Harz

    2014-08-22T23:59:59.000Z

    The discovery of lepton number violation (LNV) at the LHC would have profound consequences for the viability of high-scale leptogenesis models. As an example, we discuss the case of observing a signal with two same-sign leptons, two jets and no missing energy. This would imply a large washout factor for the lepton number density in the early Universe, which leads to a significant constraint on any high-scale model for the generation of the observed baryon asymmetry. In a standard leptogenesis scenario, the corresponding washout factor would strongly decrease a pre-existing lepton asymmetry and thus would render leptogenesis models that generate a (B-L) asymmetry far above the LHC scale ineffective. Therefore, LHC searches focused on LNV processes without missing energy are powerful probes for high-scale leptogenesis models and correspondingly shed light on the nature of baryogenesis and neutrino masses.

  7. Upper limits on electric dipole moments of tau-lepton, heavy quarks, and W-boson

    E-Print Network [OSTI]

    A. G. Grozin; I. B. Khriplovich; A. S. Rudenko

    2009-03-04T23:59:59.000Z

    We discuss upper limits on the electric dipole moments (EDM) of the tau-lepton, heavy quarks, and W-boson, which follow from the precision measurements of the electron and neutron EDM.

  8. Upper limits on electric dipole moments of tau-lepton, heavy quarks, and W-boson

    E-Print Network [OSTI]

    Grozin, A G; Rudenko, A S

    2009-01-01T23:59:59.000Z

    We discuss upper limits on the electric dipole moments (EDM) of the tau-lepton, heavy quarks, and W-boson, which follow from the precision measurements of the electron and neutron EDM.

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

    Office of Scientific and Technical Information (OSTI)

    Search for the Higgs boson in lepton, tau and jets final states Re-direct Destination: Abstract Not Provided U.S. Department of Energy U.S. Department of Energy Office of Science...

  10. Nucleon binding corrections to lepton-nucleus deep inelastic scattering: Use of a realistic spectral function

    SciTech Connect (OSTI)

    Dieperink, A.E.L.; Miller, G.A. (Department of Physics, FM-15, University of Washington, Seattle, Washington (USA))

    1991-08-01T23:59:59.000Z

    Nuclear spectral functions computed with realistic nuclear forces are used to compute mean separation energies and to estimate the binding corrections to lepton-nucleus deep inelastic scattering. The separation energies are large and significant binding effects are obtained.

  11. Calculation of conventional and prompt lepton fluxes at very high energy

    E-Print Network [OSTI]

    Fedynitch, Anatoli; Gaisser, Thomas K; Riehn, Felix; Stanev, Todor

    2015-01-01T23:59:59.000Z

    An efficient method for calculating inclusive conventional and prompt atmospheric leptons fluxes is presented. The coupled cascade equations are solved numerically by formulating them as matrix equation. The presented approach is very flexible and allows the use of different hadronic interaction models, realistic parametrizations of the primary cosmic-ray flux and the Earth's atmosphere, and a detailed treatment of particle interactions and decays. The power of the developed method is illustrated by calculating lepton flux predictions for a number of different scenarios.

  12. Search for quark-lepton compositeness using the Drell-Yan process at D-Zero

    SciTech Connect (OSTI)

    NONE

    1998-09-01T23:59:59.000Z

    We present preliminary results on the search for quark-lepton compositeness using the Drell-Yan process in p{anti p} collisions at {radical}s = 1.8 TeV. If quarks and leptons were composite with common substructure, the dielectron mass spectrum would show an excess in the high mass region relative to the Standard model. We observe no such excess. We set a 95% confidence level lower limit on the compositness scale using a contact interaction model.

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

    E-Print Network [OSTI]

    C. Lazzeroni et al.

    2011-03-01T23:59:59.000Z

    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.

  14. Almost Maximal Lepton Mixing with Large T Violation in Neutrino Oscillations and Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Zhi-zhong Xing

    2001-07-02T23:59:59.000Z

    We point out two simple but instructive possibilities to construct the charged lepton and neutrino mass matrices, from which the nearly bi-maximal neutrino mixing with large T violation can naturally emerge. The two lepton mixing scenarios are compatible very well with current experimental data on solar and atmospheric neutrino oscillations, and one of them may lead to an observable T-violating asymmetry between \

  15. Higgs boson decay into four leptons at NLOPS electroweak accuracy

    E-Print Network [OSTI]

    Boselli, Stefano; Montagna, Guido; Nicrosini, Oreste; Piccinini, Fulvio

    2015-01-01T23:59:59.000Z

    In view of precision studies of the Higgs sector at the Run II of the LHC, the improvement of the accuracy of the theoretical prediction is becoming a pressing issue. In this framework, we detail a calculation of the full Next-to-Leading Order (NLO) electroweak corrections to Higgs boson decay into four charged leptons, by considering the gold-plated channel H -> Z(*) Z(*) -> 2l 2l', l,l' = e, mu. We match the NLO corrections with a QED Parton Shower (PS), in order to simulate exclusive multiple photon emission and provide novel results at NLOPS electroweak accuracy. We compare our NLO predictions to those of the program Prophecy4f and present NLOPS phenomenological results relevant for Higgs physics studies, with particular attention to precision measurements of the Higgs boson mass, spin-parity assignment and tests of the Standard Model. Our calculation is implemented in a new code, Hto4l, which can be easily interfaced to any generator describing Higgs boson production. As an example, we provide illustrati...

  16. Lepton Flavor Violation in Predictive SUSY-GUT Models

    SciTech Connect (OSTI)

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

    2008-02-01T23:59:59.000Z

    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.

  17. Top Quark Mass in Events with two Charged Leptons at the D0 Experiment

    SciTech Connect (OSTI)

    Boline, Daniel Dooley; /Boston U.

    2010-01-01T23:59:59.000Z

    The top quark is the most massive observed fundamental subatomic particle, and at the Tevatron accelerator is produced mostly in top-antitop (t{bar t}) quark pairs from the collisions of protons and anti-protons. Each top quark decays into a bottom quark and a W boson. The W boson can then decay into a pair of quarks, or into a charged lepton and a neutrino. The various decays can be broken up into three different channels based on the number of leptons from the decay of the W bosons: all-jets (with no leptons), lepton+jets (with one lepton), and dilepton (with two leptons). This dissertation will present a measurement of the top quark mass in the dilepton channel. The dilepton channel is characterized by two leptons, two neutrinos and two b-quarks. The neutrinos are not directly observed, but their absence is felt as missing transverse momentum (p{sub T}) in the detector. The combination of two leptons and large p{sub T} produces an easily isolated signal, giving the dilepton channel a high signal over background ratio. Having two neutrinos means that we cannot know what the transverse momenta of either neutrino is. This means that even if we knew the momenta of the leptons and b-quarks perfectly, we would be unable to reconstruct the mass of the top quark. This measurement gets around this problem by scanning over all possible values of the top mass, finding all consistent t{bar t} combinations, assigning a kinematic weight to each, and then adding the weights for each combination at a given possible top mass. The lepton momenta, jet momenta, and p{sub T} are only known to within some finite precision, so for a given top mass, I also vary each of these momenta within their resolutions and add the weights for a given possible top mass. After scanning over possible top masses, I choose the top mass with the largest sum of weights m{sub t}{sup max} as an observable for the event. I then perform a template based likelihood fit of m{sub t} using m{sub t}{sup max}. I analyze 322 candidate events collected by the D0 detector, and obtain a top quark mass of: m{sub t} = 174.8 {+-} 3.1 GeV.

  18. LFV decays and anomalous magnetic (electric) moments in a lepton mass matrices ansatz induced by SUSY GUT

    E-Print Network [OSTI]

    W. J. Huo

    2003-01-27T23:59:59.000Z

    By using the anomalous magnetic and electric dipole moments of the $\\tau$ lepton in an effective lagrangian approach to the new physics, we investigate the lepton flavor violation (LFV) decays, $l\\to l'\\gamma$, and $\\mu,\\tau$ anomalous magnetic and electric dipole moments in a lepton mass matrices ansatz which induced by SUSY GUT. We put very stringent constraints LFV decays and $\\tau$ anomalous magnetic and electric dipole moments.

  19. Perturbations to $?-?$ Symmetry, Leptogenesis and Lepton Flavour Violation with Type II Seesaw

    E-Print Network [OSTI]

    Manikanta Borah; Debasish Borah; Mrinal Kumar Das; Sudhanwa Patra

    2014-10-17T23:59:59.000Z

    We study the possibility of generating non-zero reactor mixing angle $\\theta_{13}$ by perturbing the $\\mu-\\tau$ symmetric neutrino mass matrix. The leading order $\\mu-\\tau$ symmetric neutrino mass matrix originates from type I seesaw mechanism whereas the perturbations to $\\mu-\\tau$ symmetry originate from type II seesaw term. We consider four different realizations of $\\mu-\\tau$ symmetry: Bimaximal Mixing(BM), Tri-bimaximal Mixing (TBM), Hexagonal Mixing (HM) and Golden Ratio Mixing (GRM) all giving rise to $\\theta_{13} = 0, \\theta_{23} = \\frac{\\pi}{4}$ but different non-zero values of solar mixing angle $\\theta_{12}$. We assume a minimal $\\mu-\\tau$ symmetry breaking type II seesaw mass matrix as a perturbation and calculate the neutrino oscillation parameters as a function of type II seesaw strength. We then consider the origin of non-trivial leptonic CP phase in the charged lepton sector and calculate the lepton asymmetry arising from the lightest right handed neutrino decay by incorporating the presence of both type I and type II seesaw. We constrain the type II seesaw strength as well as leptonic CP phase (and hence the charged lepton sector) by comparing our results with experimental neutrino oscillation parameters as well as Planck bound on baryon to photon ratio. Finally, we extend our analysis on lepton flavour violating decays like $\\mu \\to e \\gamma$ and $\\mu \\to eee$ due to exchange of TeV scale Higgs triplet scalar within the low scale type II seesaw framework. The branching ratios for these lepton flavour processes are examined with the small type II perturbation term $\\omega$ and the estimated values are very close to the experimental bound coming from current search experiments.

  20. Quasidegeneracy of Majorana Neutrinos and the Origin of Large Leptonic Mixing

    E-Print Network [OSTI]

    G. C. Branco; M. N. Rebelo; J. I. Silva-Marcos; Daniel Wegman

    2015-02-20T23:59:59.000Z

    We propose that the observed large leptonic mixing may just reflect a quasidegeneracy of three Majorana neutrinos. The limit of exact degeneracy of Majorana neutrinos is not trivial, as leptonic mixing and even CP violation may occur. We conjecture that the smallness of $|U_{13}|$, when compared to the other elements of $U_{PMNS}$, may just reflect the fact that, in the limit of exact mass degeneracy, the leptonic mixing matrix necessarily has a vanishing element. We show that the lifting of the mass degeneracy can lead to the measured value of $|U_{13}|$ while at the same time accommodating the observed solar and atmospheric mixing angles. In the scenario we consider for the breaking of the mass degeneracy there is only one CP violating phase, already present in the limit of exact degeneracy, which upon the lifting of the degeneracy generates both Majorana and Dirac-type CP violation in the leptonic sector. We analyse some of the correlations among physical observables and point out that in most of the cases considered, the implied strength of leptonic Dirac-type CP violation is large enough to be detected in the next round of experiments.

  1. Leptogenesis in a seesaw model with Fritzsch-type lepton mass matrices

    SciTech Connect (OSTI)

    Ahn, Y. H.; Kim, C. S.; Lee, Jake [Department of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Kang, Sin Kyu [School of Liberal Arts, Seoul National University of Technology, Seoul 139-743 (Korea, Republic of)

    2008-04-01T23:59:59.000Z

    We investigate how the baryon asymmetry of our Universe via leptogenesis can be achieved within the framework of the seesaw model with Fritzsch-type lepton mass matrices proposed by Fukugita et al. We study the cases with CP-violating phases in charged-lepton Yukawa matrix, however, with and without Dirac neutrino Yukawa phases. We consider both flavor-independent and flavor-dependent leptogenesis, and demonstrate how they lead to different amounts of lepton asymmetries in detail. In particular, it is shown that flavor-dependent leptogenesis in this model can be achieved only for very tiny or zero values of CP phases in Dirac neutrino Yukawa matrix at the grand unified theory scale. In addition to the CP phases, for successful leptogenesis in the model it is required that the degeneracy of the heavy Majorana neutrino mass spectrum should be broken and we also show that the breakdown of the degeneracy can be radiatively induced.

  2. Anomalous magnetic and electric moments of $?$ and lepton flavor mixing matrix in effective lagrangian approach

    E-Print Network [OSTI]

    J. Q. Zhang; X. C. Song; W. J. Huo; T. F. Feng

    2002-06-17T23:59:59.000Z

    In an effective lagrangian approach [EM97] to new physics, the authors in ref. [HL99] pushed tau anomalous magnetic and electric dipole moments (AMDM and EDM) down to $10^{-11}$ and $10^{-25} e cm$ by using a Fritzsch-Xing lepton mass matrix ansatz. In this note, we find that, in this approach, there exists the connection between $\\tau$ AMDM and EDM and the lepton flavor mixing matrix. By using the current neutrino oscillation experimental results, we investigate the parameter space of lepton mixing angles to $\\tau$ AMDM and EDM. We can obtain the same or smaller bounds of $\\delta a_\\tau$ and $d_\\tau$ acquired in ref. [HL99] and constrain $\\theta_l$ (the mixing angle obtained by long-baseline neutrino oscillation experiments) from $\\tau$ AMDM and EDM.

  3. Preon Trinity - A Schematic Model of Leptons, Quarks and Heavy Vector Bosons

    E-Print Network [OSTI]

    Jean-Jacques Dugne; Sverker Fredriksson; Johan Hansson

    2002-08-14T23:59:59.000Z

    Quarks, leptons and heavy vector bosons are suggested to be composed of stable spin-1/2 preons, existing in three flavours, combined according to simple rules. Straightforward consequences of an SU(3) preon-flavour symmetry are the conservation of three lepton numbers, oscillations and decays between some neutrinos, and the mixing of the d and s quarks, as well as of the vector fields W^0 and B^0. We find a relation between the Cabibbo and Weinberg mixing angles, and predict new (heavy) leptons, quarks and vector bosons, some of which might be observable at the Fermilab Tevatron and the future CERN LHC. A heavy neutrino might even be visible in existing data from the CERN LEP facility.

  4. Measurements of Four-Lepton Production at the Z Resonance in pp Collisions at ?s = 7 and 8 TeV with ATLAS

    E-Print Network [OSTI]

    Taylor, Frank E.

    Measurements of four-lepton (4?, ? = e,?) production cross sections at the Z resonance in pp collisions at the LHC with the ATLAS detector are presented. For dilepton and four-lepton invariant mass regions m[subscript ?+??] ...

  5. Updated values of running quark and lepton masses at GUT scale in SM, 2HDM and MSSM

    E-Print Network [OSTI]

    Kalpana Bora

    2012-06-26T23:59:59.000Z

    Updated values of running quark and lepton masses at GUT (Grand unified theories) scales are important for fermion mass model building, and to calculate neutrino masses, in GUTs . We present their values at GUT scales, in SM, MSSM and 2HDM theories, using the latest values of running quark and lepton masses.

  6. Texture Zero Mass Matrices and Flavor Mixing of Quarks and Leptons

    E-Print Network [OSTI]

    Fritzsch, Harald

    2015-01-01T23:59:59.000Z

    We discuss mass matrices with four texture zeros for the quarks and leptons. The three mixing angles for the quarks and leptons are functions of the fermion masses. The results agree with the experimental data. The ratio of the masses of the first two neutrinos is given by the solar mixing angle. The neutrino masses are calculated: $m_1$ $\\approx$ 0.003 eV , $m_2$ $\\approx$ 0.012 eV , $m_3$ $\\approx$ 0.048 eV.

  7. Confronting predictive texture zeros in lepton mass matrices with current data

    E-Print Network [OSTI]

    Luís M. Cebola; David Emmanuel-Costa; Ricardo González Felipe

    2015-04-24T23:59:59.000Z

    Several popular Ans\\"atze of lepton mass matrices that contain texture zeros are confronted with current neutrino observational data. We perform a systematic $\\chi^2$-analysis in a wide class of schemes, considering arbitrary Hermitian charged lepton mass matrices and symmetric mass matrices for Majorana neutrinos or Hermitian mass matrices for Dirac neutrinos. Our study reveals that several patterns are still consistent with all the observations at 68.27% confidence level, while some others are disfavored or excluded by the experimental data. The well-known Frampton-Glashow-Marfatia two-zero textures, hybrid textures and parallel structures, among others, are considered.

  8. Confronting predictive texture zeros in lepton mass matrices with current data

    E-Print Network [OSTI]

    Cebola, Luís M; Felipe, Ricardo González

    2015-01-01T23:59:59.000Z

    Several popular Ans\\"atze of lepton mass matrices that contain texture zeros are confronted with current neutrino observational data. We perform a systematic $\\chi^2$-analysis in a wide class of schemes, considering arbitrary Hermitian charged lepton mass matrices and symmetric mass matrices for Majorana neutrinos or Hermitian mass matrices for Dirac neutrinos. Our study reveals that several patterns are still consistent with all the observations at 68.27% confidence level, while some others are disfavored or excluded by the experimental data. The well-known Frampton-Glashow-Marfatia two-zero textures, hybrid textures and parallel structures, among others, are considered.

  9. Neutrino Mixing Angles from Texture Zeros of the Lepton Mass Matrices

    E-Print Network [OSTI]

    Fritzsch, Harald

    2012-01-01T23:59:59.000Z

    Taking into account the latest neutrino oscillation data, we study texture zeros of the lepton mass matrices. Assuming the Dirac neutrino mass matrix M_D, the charged-lepton mass matrix M_l and the mass matrix of heavy right-handed Majorana neutrinos M_R to have three texture zeros, we show that the observed neutrino mixing angles can naturally be obtained. The phenomenological implications for the neutrino mass spectrum, the CP-violating phases, the tritium beta decay and the neutrinoless double-beta decay are explored.

  10. Neutrino Mixing Angles from Texture Zeros of the Lepton Mass Matrices

    E-Print Network [OSTI]

    Harald Fritzsch; Shun Zhou

    2012-12-03T23:59:59.000Z

    Taking into account the latest neutrino oscillation data, we study texture zeros of the lepton mass matrices. Assuming the Dirac neutrino mass matrix M_D, the charged-lepton mass matrix M_l and the mass matrix of heavy right-handed Majorana neutrinos M_R to have three texture zeros, we show that the observed neutrino mixing angles can naturally be obtained. The phenomenological implications for the neutrino mass spectrum, the CP-violating phases, the tritium beta decay and the neutrinoless double-beta decay are explored.

  11. Leptogenesis from right-handed neutrino decays to right-handed leptons

    E-Print Network [OSTI]

    Thomas Hambye

    2006-06-16T23:59:59.000Z

    We investigate what would be the consequences for leptogenesis of the existence of a charged SU(2)_L singlet scalar delta^+. If such a scalar particle exists, it allows the right-handed neutrinos to couple not only to left-handed lepton and Higgs doublets as in ordinary leptogenesis, but also to a right-handed charged lepton and a delta^+. This provides a new source of leptogenesis which can be successful in a non-resonant way at scales as low as TeV. The incorporation of this scenario in left-right symmetric and unified models is discussed.

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

    E-Print Network [OSTI]

    Khotilovich, Vadim Gennadyevich

    2009-05-15T23:59:59.000Z

    ~t1 decays into a tau lepton and a b quark, with branching ratio B, 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...

  13. Drell-Yan Lepton pair production at NNLO QCD with parton showers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hoeche, Stefan [SLAC National Accelerator Lab., Menlo Park, CA (United States); Li, Ye [SLAC National Accelerator Lab., Menlo Park, CA (United States); Prestel, Stefan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-04-01T23:59:59.000Z

    We present a simple approach to combine NNLO QCD calculations and parton showers, based on the UNLOPS technique. We apply the method to the computation of Drell-Yan lepton-pair production at the Large Hadron Collider. We comment on possible improvements and intrinsic uncertainties.

  14. Forschung an Lepton Collidern Abbildung 49: Perspektivische Ansicht des TESLA-Detektors.

    E-Print Network [OSTI]

    Forschung an Lepton Collidern Abbildung 49: Perspektivische Ansicht des TESLA-Detektors. 86 #12An- strengung vieler Gruppen und Institute der ,,Tech- nical Design Report" für TESLA veröffentlicht wer- den von TESLA, besonders in Bereichen, die im TDR nicht ausreichend behandelt werden konnten, und die

  15. Non-perturbative Heavy Quark Effective Theory: An application to semi-leptonic B-decays

    E-Print Network [OSTI]

    Michele Della Morte; Jochen Heitger; Hubert Simma; Rainer Sommer

    2015-01-14T23:59:59.000Z

    We review a lattice strategy how to non-perturbatively determine the coefficients in the HQET expansion of all components of the heavy-light axial and vector currents, including 1/m_h-corrections. We also discuss recent preliminary results on the form factors parameterizing semi-leptonic B-decays at the leading order in 1/m_h.

  16. Higher twist contributions to lepton-pair production and other QCD processes

    SciTech Connect (OSTI)

    Brodsky, S.J.; Berger, E.L.; Lepage, G.P.

    1982-12-01T23:59:59.000Z

    A general discussion of the calculations and phenomenological consequences of power-law suppressed QCD processes is given with emphasis on tests in massive lepton pair production. Absolutely normalized predictions are given for the leading twist (transverse current) and higher twist (longitudinal current) contributions to the meson structure function in the region of large x.

  17. Search for WW and WZ production in lepton plus jets final state at CDF

    E-Print Network [OSTI]

    Xie, Si

    We present a search for WW and WZ production in final states that contain a charged lepton (electron or muon) and at least two jets, produced in ?s=1.96??TeV pp? collisions at the Fermilab Tevatron, using data corresponding ...

  18. Search for Associated Production of a Single Top Quark and a Higgs Boson in Leptonic Channels

    E-Print Network [OSTI]

    CMS Collaboration

    2015-01-01T23:59:59.000Z

    A search for the production of a Higgs boson in association with a single top quark is presented, focusing on leptonic signatures provided by the $\\mathrm{H}\\rightarrow\\mathrm{W}\\mathrm{W}$ and $\\mathrm{H}\\rightarrow\\tau\\tau$ decay modes.

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

    E-Print Network [OSTI]

    Evelyne Delmeire

    2007-05-15T23:59:59.000Z

    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.

  20. A wave equation including leptons and quarks for the standard model of quantum physics in

    E-Print Network [OSTI]

    Boyer, Edmond

    A wave equation including leptons and quarks for the standard model of quantum physics in Clifford-m@orange.fr August 27, 2014 Abstract A wave equation with mass term is studied for all particles and an- tiparticles of color and antiquarks u and d. This wave equation is form invariant under the Cl 3 group generalizing

  1. Measurement of leptonic asymmetries and top-quark polarization in tt-bar production

    E-Print Network [OSTI]

    Baringer, Philip S.; Bean, Alice; Chen, G.; Clutter, Justace Randall; Sekaric, Jadranka; Wilson, Graham Wallace; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Askew, A.; Atkins, S.

    2013-01-24T23:59:59.000Z

    We present measurements of lepton (?) angular distributions in top-quark (t) pair production and tt-bar?W+bW?b-bar??+?b???-b-ar b-bar decays produced in pp-bar collisions at a center-of-mass energy of s?=1.96??TeV, where ...

  2. A measurement of the Michel parameters in leptonic decays of the tau

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1997-06-01T23:59:59.000Z

    We have measured the spectral shape Michel parameters rho and eta using leptonic decays of the tau, recorded by the CLEO II detector. Assuming e-mu universality in the vectorlike couplings, we find rho(e mu) = 0.735 +/- 0.013 +/- 0.008 and eta(e mu...

  3. The anomalous lepton magnetic moment, LFV decays and the fourth generation

    E-Print Network [OSTI]

    W. J. Huo; T. F. Feng

    2003-01-20T23:59:59.000Z

    We investigate the lepton flavor violation (LFV) decays, $\\tau\\to l\\gamma$ ($l=\\mu, e$) and $\\mu\\to e\\gamma$, and the newly observed muon $g-2$ anomaly in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\

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

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    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 ...

  5. Evidence for the 125 GeV Higgs boson decaying to a pair of ? leptons

    E-Print Network [OSTI]

    Apyan, Aram

    A search for a standard model Higgs boson decaying into a pair of ? leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 ...

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

    SciTech Connect (OSTI)

    Fedorko, Wojciech T.; /Chicago U.

    2008-09-01T23:59:59.000Z

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

  7. Searches for the baryon- and lepton-number violating decays B 0 ? ? c + l ? , B ? ? ? l ? , and B ? ? ? ¯ l ?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Jasper, H.; Petzold, A.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Volk, A.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Perez, A.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Anderson, J.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Sciolla, G.; Zhao, M.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kass, R.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Prendki, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Renga, F.; Buenger, C.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Allen, M. T.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.

    2011-05-01T23:59:59.000Z

    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 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)×10?? are set on the branching fractions at the 90% confidence level.

  8. Search for new physics in final states with a lepton and missing transverse energy in pp collisions at the LHC

    E-Print Network [OSTI]

    Apyan, Aram

    This Letter describes the search for an enhanced production rate of events with a charged lepton and a neutrino in high-energy pp collisions at the LHC. The analysis uses data collected with the CMS detector, with an ...

  9. Search for new physics in final states with a lepton and missing transverse energy in pp collisions at the LHC

    E-Print Network [OSTI]

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

    2013-04-08T23:59:59.000Z

    This Letter describes the search for an enhanced production rate of events with a charged lepton and a neutrino in high-energy pp collisions at the LHC. The analysis uses data collected with the CMS detector, with an ...

  10. A Search for Prompt Lepton-Jets in pp Collisions at ?s = 7 TeV with the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    We present a search for a light (<2 GeV) boson predicted by Hidden Valley supersymmetric models that decays into a final state consisting of collimated muons or electrons, denoted “lepton-jets”. The analysis uses 5 ...

  11. A model of leptons, quarks and bosons as composites of spinons

    E-Print Network [OSTI]

    Eckart Marsch

    2010-04-20T23:59:59.000Z

    A model is presented of the leptons, quarks and bosons as non-elementary particles being composed of spinons. They are defined as massless fermions obeying the Weyl equations, but in addition are charged and assumed to have two internal degrees of freedom (weak colour charges). The corresponding total Lagrangian density of the quantized fields has a fermionic part and a gauge-field part, which leads to the interaction of the charged spinons. They are bound together by the gauge fields of the non-Abelian SU(2) symmetry group, and three of them can combine to a triple state forming the well known first generation of left- and right-handed leptons and quarks, including their proper electric charges (fractional for the quarks). The neutral and charged vector bosons of the weak interactions or the Higgs bosons can be constructed as binaries of two spinons.

  12. An infrared origin of leptonic mixing and its test at DeepCore

    E-Print Network [OSTI]

    F. Terranova

    2011-10-10T23:59:59.000Z

    Fermion mixing is generally believed to be a low-energy manifestation of an underlying theory whose energy scale is much larger than the electroweak scale. In this paper we investigate the possibility that the parameters describing lepton mixing actually arise from the low-energy behavior of the neutrino interacting fields. In particular, we conjecture that the measured value of the mixing angles for a given process depends on the number of unobservable flavor states at the energy of the process. We provide a covariant implementation of such conjecture, draw its consequences in a two neutrino family approximation and compare these findings with current experimental data. Finally we show that this infrared origin of mixing will be manifest at the Ice Cube DeepCore array, which measures atmospheric oscillations at energies much larger than the tau lepton mass; it will hence be experimentally tested in a short time scale.

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

    E-Print Network [OSTI]

    D0 Collaboration

    2012-05-16T23:59:59.000Z

    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^{-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.

  14. Measurement of J/psi leptonic width with the KEDR detector

    E-Print Network [OSTI]

    Anashin, V V; Baldin, E M; Barladyan, A K; Barnyakov, A Yu; Barnyakov, M Yu; Baru, S E; Basok, I Yu; Beloborodova, O L; Blinov, A E; Blinov, V E; Bobrov, A V; Bobrovnikov, V S; Bogomyagkov, A V; Bondar, A E; Buzykaev, A R; Eidelman, S I; Grigoriev, D N; Glukhovchenko, Yu M; Gulevich, V V; Gusev, D V; Karnaev, S E; Karpov, G V; Karpov, S V; Kharlamova, T A; Kiselev, V A; Kolmogorov, V V; Kononov, S A; Kotov, K Yu; Kravchenko, E A; Kudryavtsev, V N; Kulikov, V F; Kurkin, G Ya; Kuper, E A; Levichev, E B; Maksimov, D A; Malyshev, V M; Maslennikov, A L; Medvedko, A S; Meshkov, O I; Mishnev, S I; Morozov, I I; Muchnoi, N Yu; Neufeld, V V; Nikitin, S A; Nikolaev, I B; Okunev, I N; Onuchin, A P; Oreshkin, S B; Orlov, I O; Osipov, A A; Peleganchuk, S V; Pivovarov, S G; Piminov, P A; Petrov, V V; Poluektov, A O; Prisekin, V G; Ruban, A A; Sandyrev, V K; Savinov, G A; Shamov, A G; Shatilov, D N; Shwartz, B A; Simonov, E A; Sinyatkin, S V; Skrinsky, A N; Smaluk, V V; Sokolov, A V; Sukharev, A M; Starostina, E V; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Yu; Tumaikin, G M; Usov, Yu V; Vorobiov, A I; Yushkov, A N; Zhilich, V N; Zhulanov, V V; Zhuravlev, A N

    2011-01-01T23:59:59.000Z

    We report a new precise determination of the leptonic widths of the J/psi meson performed with the KEDR detector at the VEPP-4M $e^{+}e^{-}$ collider. The measured values of the J/psi parameters are: \\Gamma_{ee}\\times\\Gamma_{ee}/\\Gamma = 0.3323 \\pm 0.0064 (stat.) \\pm 0.0048 (syst.) keV \\Gamma_{ee}\\times\\Gamma_{\\mu\\mu}/\\Gamma=0.3318 \\pm 0.0052 (stat.) \\pm 0.0063 (syst.) keV. Assuming $e\\mu$ universality and using the table value of the branching ratios the leptonic \\Gamma_{ll}= 5.59 \\pm 0.12 keV width and the total \\Gamma=94.1 \\pm 2.7 keV widths were obtained. We also discuss in detail a method to calculate radiative corrections at a narrow resonance.

  15. A complete survey of texture zeros in the lepton mass matrices

    E-Print Network [OSTI]

    Ludl, Patrick Otto

    2014-01-01T23:59:59.000Z

    We perform a systematic and complete analysis of texture zeros in the lepton mass matrices and identify all viable and maximally restrictive cases of pairs (M_\\ell, M_D) and (M_\\ell, M_L), where M_\\ell, M_D and M_L are the charged-lepton, Dirac neutrino and Majorana neutrino mass matrices, respectively. To this end, we perform a thorough analysis of textures which are equivalent through weak-basis permutations. Furthermore, we introduce numerical measures for the predictivity of textures and apply them to the viable and maximally restrictive texture zero models. It turns out that for Dirac neutrinos these models can at most predict the smallest neutrino mass and the CKM-type phase of the mixing matrix. For Majorana neutrinos most models can, in addition, predict the effective neutrino mass for neutrinoless double beta decay.

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

    E-Print Network [OSTI]

    D0 Collaboration

    2013-01-28T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Vieira, J; Mori, W B; Silva, L O; Muggli, P

    2015-01-01T23:59:59.000Z

    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 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 differ when the blowout is reached. Seeding the self-modulation instability suppresses 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.

  18. Small mixing angle {theta}{sub 13} and the lepton asymmetry

    SciTech Connect (OSTI)

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

    2005-05-01T23:59:59.000Z

    We present the correlation of low-energy CP phases, both Dirac and Majorana, and the lepton asymmetry for the baryon asymmetry in the universe, with a certain class of Yukawa matrices that consist of two right-handed neutrinos whose mass ratio is about 2x10{sup -4} and include one texture zero in themselves. For cases in which the amount of the lepton asymmetry Y{sub L} turns out to be proportional to {theta}{sub 13}{sup 2}, we consider the constraint between two types of CP phases and the relation of Y{sub L} versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as {theta}{sub 13} varies.

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

    SciTech Connect (OSTI)

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

    2012-04-10T23:59:59.000Z

    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}.

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

    SciTech Connect (OSTI)

    Abazov, Victor Mukhamedovich; et al.

    2012-08-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Abazov, V. M.; et al.

    2013-09-01T23:59:59.000Z

    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 ? ? ? 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.

  2. CPT and lepton number violation in neutrino sector: Modified mass matrix and oscillation due to gravity

    E-Print Network [OSTI]

    Monika Sinha; Banibrata Mukhopadhyay

    2007-11-21T23:59:59.000Z

    We study the consequences of CPT and lepton number violation in neutrino sector. For CPT violation we take gravity with which neutrino and antineutrino couple differently. Gravity mixes neutrino and antineutrino in an unequal ratio to give two mass eigenstates. Lepton number violation interaction together with CPT violation gives rise to neutrino-antineutrino oscillation. Subsequently, we study the neutrino flavor mixing and oscillation under the influence of gravity. It is found that gravity changes flavor oscillation significantly which influences the relative abundance of different flavors in present universe. We show that the neutrinoless double beta decay rate is modified due to presence of gravity- the origin of CPT violation, as the mass of the flavor state is modified.

  3. Lepton-flavor-violating decay {tau}{yields}{mu}{mu}{mu} at the CERN LHC

    SciTech Connect (OSTI)

    Giffels, M.; Stahl, A. [III. Physikalisches Institut, RWTH Aachen, 52056 Aachen (Germany); Kallarackal, J. [Institut fuer Theoretische Physik, RWTH Aachen, 52074 Aachen (Germany); Institut fuer Physik, Humboldt-Universitaet zu Berlin, 12489 Berlin (Germany); Kraemer, M.; O'Leary, B. [Institut fuer Theoretische Physik, RWTH Aachen, 52074 Aachen (Germany)

    2008-04-01T23:59:59.000Z

    Lepton-flavor-violating {tau} decays are predicted in many extensions of the standard model at a rate observable at future collider experiments. In this article we focus on the decay {tau}{yields}{mu}{mu}{mu}, which is a promising channel to observe lepton-flavor violation at the CERN Large Hadron Collider (LHC). We present analytic expressions for the differential decay width derived from a model-independent effective Lagrangian with general four-fermion operators, and estimate the experimental acceptance for detecting the decay {tau}{yields}{mu}{mu}{mu} at the LHC. Specific emphasis is given to decay angular distributions and how they can be used to discriminate new physics models. We provide specific predictions for various extensions of the standard model, including supersymmetric, little Higgs, and technicolor models.

  4. Precision Measurement of the Ratio of the Charged Kaon Leptonic Decay Rates

    E-Print Network [OSTI]

    The NA62 collaboration

    2013-01-29T23:59:59.000Z

    A precision measurement of the ratio RK of the rates of kaon leptonic decays K+- --> e nu and K+- --> mu nu with the full data sample collected by the NA62 experiment at CERN in 2007-2008 is reported. The result, obtained by analysing ~150000 reconstructed K+- --> e nu candidates with 11% background contamination, is RK = (2.488+-0.010)*10^{-5}, in agreement with the Standard Model expectation.

  5. On leptonic decay of a heavy quarkonium with a Higgs-boson emission

    E-Print Network [OSTI]

    G. A. Kozlov

    2005-06-27T23:59:59.000Z

    A leptonic $(\\bar l l)$ decay of a heavy quark-antiquark bound state $T(\\bar QQ)$ with a Higgs-boson $H$ emission is investigated. The applying of the well-known low-energy theorem to meson-Higgs coupling allows one to estimate the probability of the decay $T(\\bar QQ)\\to \\bar ll H$. The only a simple version of the Standard Model extension containing two-Higgs doublet is considered.

  6. Search for the associated production of chargino and neutralino in the final state with three leptons

    SciTech Connect (OSTI)

    Canepa, Anadi; /Purdue U.

    2006-02-01T23:59:59.000Z

    Supersymmetry, if realized in nature, predicts the existence of new particles, as chargino and neutralino, which might manifest themselves with peculiar signatures. Three leptons and large missing transverse energy in the event could signal their associated production. They report the latest results of the search performed by the CDF Collaboration in {radical}s = 1.96 TeV proton-antiproton collisions at Tevatron Run II.

  7. Semi-leptonic Decay of Lambda-b in the Standard Model and with New Physics

    E-Print Network [OSTI]

    Wanwei Wu

    2015-05-13T23:59:59.000Z

    Heavy quark decays provide a very advantageous investigation to test the Standard Model (SM). Recently, promising experiments with \\textit{b} quark, as well as the analysis of the huge data sets produced at the B factories, have led to an increasing study and sensitive measurements of relative \\textit{b} quark decays. In this thesis, I calculate various observables in the semi-leptonic decay process $\\Lambda_{b}\\to \\Lambda_{c}\\tau\\bar{\

  8. PHYSICAL REVIEW D VOLUME 53,NUMBER 1 Measurement of the mass of the T lepton

    E-Print Network [OSTI]

    Olsen, Stephen L.

    PHYSICAL REVIEW D VOLUME 53,NUMBER 1 Measurement of the mass of the T lepton 1JANUARY 1996 J. Z,4 .I. Chen,5 S. J. Chen,l S. M. Chen,l Y. Chen,' Y. B. Chen,' Y. Q. Chen,' B. S. Cheng,' R. F. Cowan,e H. C. Cu&l X. Z. Cui,' H. L. Ding,' Z. Z. Du,' W. Dunwoodie,e X. L. Fan,' J. Fang, 1 C. S. Gao,' M

  9. Neutrino masses and mixing, quark-lepton symmetry, and strong right-handed neutrino hierarchy

    SciTech Connect (OSTI)

    Dermisek, Radovan [Davis Institute for High Energy Physics, University of California, Davis, California 95616 (United States)

    2004-10-01T23:59:59.000Z

    Assuming the same form of all mass matrices as motivated by quark-lepton symmetry, we discuss conditions under which bilarge mixing in the lepton sector can be obtained with a minimal amount of fine-tuning requirements for possible models. We assume hierarchical mass matrices, dominated by the 3-3 element, with off-diagonal elements much smaller than the larger neighboring diagonal element. Characteristic features of this scenario are strong hierarchy in masses of right-handed neutrinos, and comparable contributions of both lighter right-handed neutrinos to the resulting left-handed neutrino Majorana mass matrix. Because of obvious quark-lepton symmetry, this approach can be embedded into grand unified theories. The mass of the lightest neutrino does not depend on details of a model in the leading order. The right-handed neutrino scale can be identified with the GUT scale in which case the mass of the lightest neutrino is given as (m{sub top}{sup 2}/M{sub GUT}) vertical bar U{sub {tau}}{sub 1} vertical bar{sup 2}.

  10. Search for new light gauge boson in Higgs boson decays to four-lepton events in pp collisions at 8 TeV with the ATLAS detector

    E-Print Network [OSTI]

    Paredes Hernandez, Daniela; The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    Search for new light gauge boson in Higgs boson decays to four-lepton events in pp collisions at 8 TeV with the ATLAS detector

  11. Neutrino mixings and leptonic CP violation from CKM matrix and Majorana phases

    SciTech Connect (OSTI)

    Agarwalla, Sanjib Kumar; Parida, M. K.; Mohapatra, R. N.; Rajasekaran, G. [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Institute of Mathematical Sciences, Chennai 600113 (India)

    2007-02-01T23:59:59.000Z

    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 quasidegenerate 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 quasidegenerate neutrinos could, within this framework, be interpreted as being consistent with 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 Pontecorvo-Maki-Nakagawa-Sakata matrix is identical to the Cabibbo-Kobayashi-Maskawa quark-mixing matrix at the seesaw scale, with a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to be ({approx_equal}0.3 deg.) and leptonic CP-violation parameter J{sub CP}{approx_equal}(4-8)x10{sup -5} and {theta}{sub 13}=3.5 deg. If on the other hand, the Pontecorvo-Maki-Nakagawa-Sakata matrix is assumed to also have non-negligible Majorana phase(s) 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}{sub 13}=3.5 deg. -10 deg. and vertical bar J{sub CP} vertical bar as large as 0.02-0.04 which are accessible to long baseline neutrino oscillation experiments.

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

    E-Print Network [OSTI]

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

    2007-04-11T23:59:59.000Z

    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.

  13. New precise determination of the $\\tau$ lepton mass at KEDR detector

    E-Print Network [OSTI]

    Anashin, V V; Baldin, E M; Barladyan, A K; Barnyakov, A Y; Barnyakov, M Y; Baru, S E; Bedny, I V; Beloborodova, O L; Blinov, A E; Blinov, V E; Bobrov, A B; Bobrovnikov, V S; Bogomyagkov, A V; Bondar, A E; Bondarev, D V; Buzykaev, A R; Cherepanov, V P; Eidelman, S I; Glukhovchenko, Yu M; Gulevich, V V; Karnaev, S E; Karpov, G V; Karpov, S V; Kiselev, V A; Kononov, S A; Kotov, K Yu; Kravchenko, E A; Kremyanskaya, E V; Kulikov, V F; Kurkin, G Ya; Kuper, E A; Levichev, E B; Maksimov, D A; Malyshev, V M; Maslennikov, A L; Medvedko, A S; Meshkov, O I; Mishnev, S E; Morozov, I I; Muchnoi, N Yu; Neufeld, V V; Nikitin, S A; Nikolaev, I B; Onuchin, A P; Oreshkin, S B; Orlov, I O; Osipov, A A; Peleganchuk, S V; Petrosyan, S S; Pivovarov, S G; Piminov, P; Petrov, V V; Poluektov, A O; Pospelov, G E; Prisekin, V G; Ruban, A A; Sandyrev, V K; Savinov, G A; Shamov, A G; Shatilov, D N; Shubin, E I; Shwartz, B A; Sidorov, V A; Simonov, E A; Sinyatkin, S V; Skovpen, Y I; Skrinsky, A N; Smaluk, V V; Soukharev, A M; Struchalin, M V; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Y; Tumaikin, G M; Usov, Yu V; Vorobiov, A I; Yushkov, A N; Zhilich, V N; Zhuravlev, A N

    2007-01-01T23:59:59.000Z

    The status of the experiment on the precise $\\tau$ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the $\\tau^+\\tau^-$ cross section behaviour around the production threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is $m_{\\tau}=1776.80^{+0.25}_{-0.23} \\pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data collected at the $\\psi'$ peak the preliminary result is also obtained: $\\Gamma_{ee}B_{\\tau\\tau}(\\psi') = 7.2 \\pm 2.1$ eV.

  14. Effect of steriles states on lepton magnetic moments and neutrinoless double beta decay

    E-Print Network [OSTI]

    Abada, A; Teixeira, A M

    2014-01-01T23:59:59.000Z

    We address the impact of sterile fermion states on the anomalous magnetic moment of charged leptons, as well as their contribution to neutrinoless double beta decays. We illustrate our results in a minimal, effective extension of the Standard Model by one sterile fermion state, and in a well-motivated framework of neutrino mass generation, embedding the Inverse Seesaw into the Standard Model. The simple "3+1" effective case succeeds in alleviating the tension related to the muon anomalous magnetic moment, albeit only at the 3$\\sigma$ level, and for light sterile states (corresponding to a }cosmologically disfavoured regime). Interestingly, our analysis shows that a future $0 \

  15. Further Evidence of Narrow Baryonic Structures with Hadronic as Well as Leptonic Probes

    E-Print Network [OSTI]

    B. Tatischeff; E. Tomasi-Gustafsson

    2004-11-22T23:59:59.000Z

    Although extracted from several experiments using hadronic probes \\cite{bor1}, narrow baryonic structures have been sometimes met with disbelief. New signatures are presented, which appear from already published data, obtained with hadronic probes as well as with leptonic probes. The authors of these results did not take into account the possibility to associate the discontinuities of their spectra with the topic of narrow baryonic low mass structures. The stability of the observed narrow structure masses, represents a confirmation of their genuine existence.

  16. Neutrino mass hierarchy and the origin of leptonic flavor mixing from the righthanded sector

    E-Print Network [OSTI]

    Leser, Philipp

    2011-01-01T23:59:59.000Z

    We consider a neutrino mass model where all leptonic mixing is induced by a heavy Majorana sector through the seesaw type I mechanism, while the Dirac mass matrices are diagonal. Such a pattern occurs naturally in Grand Unified Theories (GUTs). Constraints on the parameters of the models are considered and it is shown that a normal neutrino mass hierarchy is preferred. The lightest neutrino mass is typically small, leading to non-observable rates for neutrinoless double beta decay in the normal hierarchy case.

  17. Search for Lepton Flavor Violation in the Decay tau -> electron gamma

    SciTech Connect (OSTI)

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /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

    2005-08-26T23:59:59.000Z

    A search for the non-conservation of lepton flavor in the decay {tau}{sup {+-}} {yields} e{sup {+-}}{gamma} has been performed with 2.07 x 10{sup 8} e{sup +}e{sup -} {yields} {tau}{sup +}{tau}{sup -} events collected by the BABAR detector at the PEP-II storage ring at a center-of-mass energy near 10.58 GeV. They find no evidence for a signal and set an upper limit on the branching ratio of {Beta}({tau}{sup {+-}} {yields} e{sup {+-}}{gamma}) < 1.1 x 10{sup -7} at 90% confidence level.

  18. AN in inclusive lepton-proton collisions: TMD and twist-3 approaches

    SciTech Connect (OSTI)

    Prokudin, Alexey [JLAB

    2015-01-01T23:59:59.000Z

    We consider the inclusive production of hadrons in lepton-nucleon scattering. For a transversely polarized nucleon this reaction shows a left-right azimuthal asymmetry, which we compute this asymmetry in both TMD and in twist-3 collinear factorization formalisms. All non-perturbative parton correlators of the calculation are fixed through information from other hard processes. Our results for the left-right asymmetry agree in sign with recent data for charged pion production from the HERMES Collaboration and from Jefferson Lab. We discuss similarities and differences of two formalisms.

  19. Dark Matter and Lepton Flavour Violation in a Hybrid Neutrino Mass Model

    E-Print Network [OSTI]

    Deppisch, Frank F

    2014-01-01T23:59:59.000Z

    We describe a hybrid model in which the light neutrino mass matrix receives both tree-level seesaw and loop-induced contributions. An additional U(1) gauge symmetry is used to stabilize the lightest right-handed neutrino as the Dark Matter candidate. After fitting the experimental neutrino data, we analyze and correlate the phenomenological consequences of the model, namely its impact on electroweak precision measurements, the Dark Matter relic abundance, lepton flavour violating rare decays and neutrinoless double beta decay. We find that natural realizations of the model characterized by large Yukawa couplings are compatible with and close to the current experimental limits.

  20. Updated fit to three neutrino mixing: status of leptonic CP violation

    E-Print Network [OSTI]

    M. C. Gonzalez-Garcia; Michele Maltoni; Thomas Schwetz

    2014-12-16T23:59:59.000Z

    We present a global analysis of solar, atmospheric, reactor and accelerator neutrino data in the framework of three-neutrino oscillations based on data available in summer 2014. We provide the allowed ranges of the six oscillation parameters and show that their determination is stable with respect to uncertainties related to reactor neutrino and solar neutrino flux predictions. We find that the maximal possible value of the Jarlskog invariant in the lepton sector is $0.0329 \\pm 0.0009$ ($\\pm 0.0027$) at the $1\\sigma$ ($3\\sigma$) level and we use leptonic unitarity triangles to illustrate the ability of global oscillation data to obtain information on CP violation. We discuss "tendencies and tensions" of the global fit related to the octant of $\\theta_{23}$ as well as the CP violating phase $\\delta_\\mathrm{CP}$. The favored values of $\\delta_\\mathrm{CP}$ are around $3\\pi/2$ while values around $\\pi/2$ are disfavored at about $\\Delta\\chi^2 \\simeq 6$. We comment on the non-trivial task to assign a confidence level to this $\\Delta\\chi^2$ value by performing a Monte Carlo study of T2K data.

  1. NLO QCD and electroweak corrections to W+? production with leptonic W-boson decays

    E-Print Network [OSTI]

    Ansgar Denner; Stefan Dittmaier; Markus Hecht; Christian Pasold

    2014-12-23T23:59:59.000Z

    We present a calculation of the next-to-leading-order electroweak corrections to W+\\gamma\\ production, including the leptonic decay of the W boson and taking into account all off-shell effects of the W boson, where the finite width of the W boson is implemented using the complex-mass scheme. Corrections induced by incoming photons are fully included and find particular emphasis in the discussion of phenomenological predictions for the LHC. The corresponding next-to-leading-order QCD corrections are reproduced as well. In order to separate hard photons from jets, a quark-to-photon fragmentation function a la Glover and Morgan is employed. Our results are implemented into Monte Carlo programs allowing for the evaluation of arbitrary differential cross sections. We present integrated cross sections for the LHC at 7TeV, 8TeV, and 14TeV as well as differential distributions at 14TeV for bare muons and dressed leptons. Finally, we discuss the impact of anomalous WW\\gamma\\ couplings.

  2. Neutrino Masses, Lepton Flavor Mixing and Leptogenesis in the Minimal Seesaw Model

    E-Print Network [OSTI]

    Wan-lei Guo; Zhi-zhong Xing; Shun Zhou

    2006-12-05T23:59:59.000Z

    We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as $\\mu \\to e + \\gamma$, are also discussed in the supersymmetric extension of the MSM.

  3. Horizon-Scale Lepton Acceleration in Jets: Explaining the Compact Radio Emission in M87

    E-Print Network [OSTI]

    Tchekhovskoy, Alexander

    2015-01-01T23:59:59.000Z

    It has now become clear that the radio jet in the giant elliptical galaxy M87 must turn on very close to the black hole. This implies the efficient acceleration of leptons within the jet at scales much smaller than feasible by the typical dissipative events usually invoked to explain jet synchrotron emission. Here we show that the stagnation surface, the separatrix between material that falls back into the black hole and material that is accelerated outward forming the jet, is a natural site of pair formation and particle acceleration. This occurs via an inverse-Compton pair catastrophe driven by unscreened electric fields within the charge-starved region about the stagnation surface and substantially amplified by a post-gap cascade. For typical estimates of the jet properties in M87, we find excellent quantitive agreement between the predicted relativistic lepton densities and those required by recent high-frequency radio observations of M87. This mechanism fails to adequately fill a putative jet from Sagitt...

  4. A complete survey of texture zeros in the lepton mass matrices

    E-Print Network [OSTI]

    Patrick Otto Ludl; Walter Grimus

    2014-10-16T23:59:59.000Z

    We perform a systematic and complete analysis of texture zeros in the lepton mass matrices and identify all viable and maximally restrictive cases of pairs (M_\\ell, M_D) and (M_\\ell, M_L), where M_\\ell, M_D and M_L are the charged-lepton, Dirac neutrino and Majorana neutrino mass matrices, respectively. To this end, we perform a thorough analysis of textures which are equivalent through weak-basis permutations. Furthermore, we introduce numerical measures for the predictivity of textures and apply them to the viable and maximally restrictive texture zero models. It turns out that for Dirac neutrinos these models can at most predict the smallest neutrino mass and the CKM-type phase of the mixing matrix. For Majorana neutrinos most models can, in addition, predict the effective neutrino mass for neutrinoless double beta decay. Apart from one model, which has marginal predictive power with respect to sin^2(theta_23), no other model can predict any of the already measured observables.

  5. Charged-Lepton-Flavour Violation in the Light of the Super-Kamiokande Data

    E-Print Network [OSTI]

    John Ellis; M. E. Gomez; G. K. Leontaris; S. Lola; D. V. Nanopoulos

    1999-12-18T23:59:59.000Z

    Motivated by the data from Super-Kamiokande and elsewhere indicating oscillations of atmospheric and solar neutrinos, we study charged-lepton-flavour violation, in particular the radiative decays mu -> e gamma and tau -> mu gamma, but also commenting on mu -> 3e and tau -> 3 mu/e decays, as well as mu - e conversion on nuclei. We first show how the renormalization group may be used to calculate flavour-violating soft supersymmetry-breaking masses for charged sleptons and sneutrinos in models with universal input parameters. Subsequently, we classify possible patterns of lepton-flavour violation in the context of phenomenological neutrino mass textures that accommodate the Super-Kamiokande data, giving examples based on Abelian flavour symmetries. Then we calculate in these examples rates for mu -> e gamma and tau ->mu gamma, which may be close to the present experimental upper limits, and show how they may distinguish between the different generic mixing patterns. The rates are promisingly large when the soft supersymmetry-breaking mass parameters are chosen to be consistent with the cosmological relic-density constraints. In addition, we discuss mu -> e conversion on Titanium, which may also be accessible to future experiments.

  6. Effective Hamiltonian for non-leptonic |Delta F| = 1 decays at NNLO in QCD

    SciTech Connect (OSTI)

    Gorbahn, Martin; /Durham U., IPPP; Haisch, Ulrich; /Fermilab

    2004-11-01T23:59:59.000Z

    The authors compute the effective hamiltonian for non-leptonic |{Delta}F| = 1 decays in the standard model including next-to-next-to-leading order QCD corrections. In particular, they present the complete three-loop anomalous dimension matrix describing the mixing of current-current and QCD penguin operators. The calculation is performed in an operator basis which allows to consistently use fully anticommuting {gamma}{sub 5} in dimensional regularization at an arbitrary number of loops. The renormalization scheme dependences and their cancellation in physical quantities is discussed in detail. Furthermore, they demonstrate how the results are transformed to a different basis of effective operators which is frequently adopted in phenomenological applications. They give all necessary two-loop constant terms which allow to obtain the three-loop anomalous dimensions and the corresponding initial conditions of the two-loop Wilson coefficients in the latter scheme. Finally, they solve the renormalization group equation and given the analytic expressions for the low-energy Wilson coefficients relevant for non-leptonic B meson decays beyond next-to-leading order in both renormalization schemes.

  7. Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions

    SciTech Connect (OSTI)

    Khachatryan, V. [Yerevan Physics Institute (Armenia); et al.,

    2014-10-01T23:59:59.000Z

    A search for neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM) decaying to tau-lepton pairs in pp collisions is performed, using events recorded by the CMS experiment at the LHC. The dataset corresponds to an integrated luminosity of 24.6 fb$^{?1}$, with 4.9 fb$^{?1}$ at 7 TeV and 19.7 fb$^{?1}$ at 8 TeV. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes the case where the Higgs boson is produced in association with a b-quark jet. No excess is observed in the tau-lepton-pair invariant mass spectrum. Exclusion limits are presented in the MSSM parameter space for different benchmark scenarios, m$_{h}^{max}$ , m$_{h}^{mod?+}$ , m$_{h}^{mod??}$ , light-stop, light-stau, ?-phobic, and low-m$_{H}$. Upper limits on the cross section times branching fraction for gluon fusion and b-quark associated Higgs boson production are also given.

  8. Low and high energy phenomenology of quark-lepton complementarity scenarios

    SciTech Connect (OSTI)

    Hochmuth, Kathrin A. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, D-80805 Munich (Germany); Rodejohann, Werner [Physik-Department, Technische Universitaet Muenchen, James-Franck-Strasse, D-85748 Garching (Germany)

    2007-04-01T23:59:59.000Z

    We conduct a detailed analysis of the phenomenology of two predictive seesaw scenarios leading to quark-lepton complementarity. In both cases we discuss the neutrino mixing observables and their correlations, neutrinoless double beta decay and lepton flavor violating decays such as {mu}{yields}e{gamma}. We also comment on leptogenesis. The first scenario is disfavored on the level of one to two standard deviations, in particular, due to its prediction for |U{sub e3}|. There can be resonant leptogenesis with quasidegenerate heavy and light neutrinos, which would imply sizable cancellations in neutrinoless double beta decay. The decays {mu}{yields}e{gamma} and {tau}{yields}{mu}{gamma} are typically observable unless the SUSY masses approach the TeV scale. In the second scenario leptogenesis is impossible. It is, however, in perfect agreement with all oscillation data. The prediction for {mu}{yields}e{gamma} is in general too large, unless the SUSY masses are in the range of several TeV. In this case {tau}{yields}e{gamma} and {tau}{yields}{mu}{gamma} are unobservable.

  9. On the ambiguities in the tri-bimaximal mixing matrix and corresponding charged lepton corrections

    E-Print Network [OSTI]

    Duarah, Chandan

    2015-01-01T23:59:59.000Z

    Two negative signs naturally appear in the $U_{\\mu 1}$ and $U_{\\tau 2}$ elements of the Tri-bimaximal (TBM) matrix for positive values of the mixing angles $\\theta_{12}$ and $\\theta_{23}$. Apart from this, in other TBM matrices negative signs are shifted to other elements in each case. They account for positive as well as negative values of $\\theta_{12}$ and $\\theta_{23}$. We discuss the sign ambiguity in the TBM matrix and find that the TBM matrices, in fact, can be divided into two groups under certain circumstances. Interestingly, this classification of TBM matrices is accompanied by two different $\\mu-\\tau$ symmetric mass matrices which can separately be related to the groups. To accommodate non-zero value of $\\theta_{13}$ and deviate $\\theta_{23}$ towards first octant, we then perturb the TBM mixing ansatz with the help of charged lepton correction. The diagonalizing matrices for charged lepton mass matrices also possess sign ambiguity and respect the grouping of TBM matrices. They are parametrized in te...

  10. Evidence for Higgs boson decays to tau leptons with the ATLAS detector and prospects for future measurements

    E-Print Network [OSTI]

    Tuna, Alexander Naip; The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    Recent results on the search for Higgs boson decays to tau leptons with the ATLAS detector are presented based on approximately 25 $\\text{fb}^{-1}$ of proton-proton collision data collected at $\\sqrt{s}=$ 7 and 8 TeV. Prospects of future measurements with proposed ATLAS upgrades at the High Luminosity LHC are also presented.

  11. Giant Liquid Argon Observatory for Proton Decay, Neutrino Astrophysics and CP-violation in the Lepton Sector (GLACIER)

    E-Print Network [OSTI]

    Badertscher, A; Degunda, U; Epprecht, L; Horikawa, S; Knecht, L; Lazzaro, C; Lussi, D; Marchionni, A; Natterer, G; Otiougova, P; Resnati, F; Rubbia, A; Strabel, C; Ulbricht, J; Viant, T

    2010-01-01T23:59:59.000Z

    GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) is a large underground observatory for proton decay search, neutrino astrophysics and CP-violation studies in the lepton sector. Possible underground sites are studied within the FP7 LAGUNA project (Europe) and along the JPARC neutrino beam in collaboration with KEK (Japan). The concept is scalable to very large masses.

  12. Search for Top Squarks in R-Parity-Violating Supersymmetry Using Three or More Leptons and b-Tagged Jets

    E-Print Network [OSTI]

    Apyan, Aram

    A search for anomalous production of events with three or more isolated leptons and bottom-quark jets produced in pp collisions at ?s = 8??TeV is presented. The analysis is based on a data sample corresponding to an ...

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

    E-Print Network [OSTI]

    Fermilab

    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

  14. Search for New Physics in Lepton + Photon + Missing Transverse Energy + b-jets Events and tt Cross-Section measurement

    E-Print Network [OSTI]

    Quigg, Chris

    V collected using CDF II detector at the Fermilab Tevatron. We find 15 ETb events versus an expectation of 14 production of ETb events, and the results of a search for t¯t events in a semi-leptonic channel using 929 pb

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

    SciTech Connect (OSTI)

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

    2011-08-09T23:59:59.000Z

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

  16. Electroweak corrections to lepton pair production in association with two hard jets at the LHC

    E-Print Network [OSTI]

    Ansgar Denner; Lars Hofer; Andreas Scharf; Sandro Uccirati

    2014-11-04T23:59:59.000Z

    We compute the next-to-leading order corrections of $O(\\alpha_s^2\\alpha^3)$ to the hadronic production of two oppositely charged leptons and two hard jets, $p p \\to j j l^- l^+$, using Recola and Collier. We include electroweak and QCD corrections at the given order and all off-shell effects. We provide detailed predictions for the LHC operating at 13 TeV and obtain per-cent-level corrections for the total cross section. For differential distributions we find significant non-uniform distortions in high-energy tails at the level of several ten per cent due to electroweak Sudakov logarithms and deformations at the level of a few per cent for angular variables.

  17. Chiral sum rules and vacuum condensates from tau-lepton decay data

    E-Print Network [OSTI]

    C. A. Dominguez; L. A. Hernandez; K. Schilcher; H. Spiesberger

    2015-02-16T23:59:59.000Z

    QCD finite energy sum rules, together with the latest updated ALEPH data on hadronic decays of the tau-lepton are used in order to determine the vacuum condensates of dimension $d=2$ and $d=4$. These data are also used to check the validity of the Weinberg sum rules, and to determine the chiral condensates of dimension $d=6$ and $d=8$, as well as the chiral correlator at zero momentum, proportional to the counter term of the ${\\cal{O}}(p^4)$ Lagrangian of chiral perturbation theory, $\\bar{L}_{10}$. Suitable (pinched) integration kernels are introduced in the sum rules in order to suppress potential quark-hadron duality violations. We find no compelling indications of duality violations in the kinematic region above $s \\simeq 2.2$ GeV$^2$ after using pinched integration kernels.

  18. Events with Isolated Leptons and Missing Transverse Momentum in ep Collisions at HERA

    E-Print Network [OSTI]

    G. Brandt

    2007-01-28T23:59:59.000Z

    The analysis of events with isolated leptons and missing transverse momentum in the H1 experiment is discussed for the electron, muon and tau channels. In the Standard Model (SM) framework, production of real W-bosons gives rise to such topologies. Contributions to the background are dominated by QCD processes. An excess of observed signal over background presents a chance of the discovery of new physics. The results using the HERA 1994-2006 data set corresponding to 341 pb^-1 are presented. While the e- p sample shows good agreement between data and SM expectation, in e+ p collisions an excess over the SM expectation with 3.4 sigma significance is observed at high hadronic transverse momentum.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D; Alkhazov, Georgiy D; Alton, Andrew K; Alverson, George O; Alves, Gilvan Augusto; et al

    2011-08-09T23:59:59.000Z

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

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2011-08-09T23:59:59.000Z

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

  1. Leptonic dark matter annihilation in the evolving universe: constraints and implications

    E-Print Network [OSTI]

    Yuan, Qiang; Bi, Xiaojun; Chen, Xuelei; Zhang, Xinmin

    2009-01-01T23:59:59.000Z

    The cosmic electron and positron excesses have been explained as possible dark matter (DM) annihilation products. In this work we investigate the possible effects of such kind of DM annihilation scenario during the evolution history of the Universe. We first calculate the extragalactic $\\gamma$-ray background (EGRB) produced through electrons/positrons inverse Compton scattering with the cosmic microwave background and the final state radiation. %by adopting a generic structure formation scenario. The DM halo profile and the minimal halo mass, which are not yet well determined from the current N-body simulations, are constrained by the EGRET data of EGRB. The preliminary EGRB data from the Fermi satellite are expected to set much stronger constraints. Then we discuss the impact of such leptonic DM model on cosmic evolution, such as the reionization and heating of intergalactic medium, neutral hydrogen 21 cm signal and suppression on structure formation. In some cases the 21 cm signal could be altered signific...

  2. Search for a Narrow Resonance in e e- to Four Lepton Final States

    SciTech Connect (OSTI)

    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.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G. /LBL, Berkeley /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 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 /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., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2009-10-17T23:59:59.000Z

    Motivated by recent models proposing a hidden sector with {approx} GeV scale force carriers, we present a search for a narrow dilepton resonance in 4 lepton final states using 536 fb{sup -1} collected by the BABAR detector. We search for the reaction, e{sup +}e{sup -} {yields} W{prime}W{prime} {yields} (l{sup +}l{sup -})(l{prime}{sup +}l{prime}{sup -}), where the leptons carry the full 4-momentum and the two dilepton pair invariant masses are equal. We do not observe a significant signal and we set 90% upper limits of {sigma}(e{sup +}e{sup -} {yields} W{prime}W{prime} {yields} e{sup +}e{sup -}e{sup +}e{sup -}) < (15-70) ab, {sigma}(e{sup +}e{sup -} {yields} W{prime}W{prime} {yields} e{sup +}e{sup -}{mu}{sup +}{mu}{sup -} < (15-40) ab, and {sigma}(e{sup +}e{sup -} {yields} W{prime}W{prime} {yields} {mu}{sup +}{mu}{sup -}{mu}{sup +}{mu}{sup -}) < 11-17) ab in the W{prime} mass range between 0.24 and 5.3GeV/c{sup 2}. Under the assumption that the W{prime} coupling to electrons and muons is the same, we obtain a combined upper limit of {sigma}e{sup +}e{sup -} {yields} W{prime}W{prime} {yields} l{sup +}l{sup -}l{prime}{sup +}l{prime}{sup -} < (25-60) ab. Using these limits, we constrain the product of the SM-dark sector mixing and the dark coupling constant in the case of a non-Abelian Higgsed dark sector.

  3. Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at ?s = 7 TeV

    E-Print Network [OSTI]

    Bauer, Gerry P.

    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a ...

  4. Study of top quark production and decays involving a tau lepton at CDF and limits on a charged Higgs boson contribution

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We present an analysis of top-antitop quark production and decay into a tau lepton, tau neutrino, and bottom quark using data from 9??fb[superscript ?1] of integrated luminosity at the Collider Detector at Fermilab. Dilepton ...

  5. Search for the Lepton-Flavor-Violating Decays B[0 over s] ? e[superscript ±]?[superscript ?] and B[superscript 0] ? e[superscript ±]?[superscript ?

    E-Print Network [OSTI]

    Williams, Michael

    A search for the lepton-flavor-violating decays B[0 over s] ? e[superscript ±]?[superscript ?] and B[superscript 0] ? e[superscript ±]?[superscript ?] is performed with a data sample, corresponding to an integrated luminosity ...

  6. Measurement of Angular Correlations in Drell–Yan Lepton Pairs to Probe Z/?[superscript ?] Boson Transverse Momentum at ?s = 7 TeV with the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A measurement of angular correlations in Drell–Yan lepton pairs via the ?[* over ?] observable is presented. This variable probes the same physics as the Z/?[superscript ?] boson transverse momentum with a better experimental ...

  7. Measurement of the Mass of the W Boson in $e^+ e^-$ collisions using the Fully Leptonic Channel

    E-Print Network [OSTI]

    Abbiendi, G; Åkesson, P F; Alexander, Gideon; Allison, J; Anagnostou, G; Anderson, K J; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Bloodworth, Ian J; Boeriu, O; Bock, P; Bonacorsi, D; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Büsser, K; Burckhart, H J; Cammin, J; Campana, S; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Cohen, I; Csilling, Akos; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Fürtjes, A; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harder, K; Harel, A; Harin-Dirac, M; Hauschild, M; Hauschildt, J; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Homer, R James; Horváth, D; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Kokott, T P; Komamiya, S; Kormos, L L; Kowalewski, R V; Krämer, T; Kress, T; Krieger, P; Von Krogh, J; Krop, D; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Layter, J G; Leins, A; Lellouch, Daniel; Letts, J; Levinson, L; Lillich, J; Littlewood, C; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Masetti, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Patrick, G N; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Pooth, O; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Rick, Hartmut; Roney, J M; Rosati, S; Rozen, Y; Runge, K; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Spanó, F; Stahl, A; Stephens, K; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Taylor, R J; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trefzger, T M; Tricoli, A; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vachon, B; Vollmer, C F; Vannerem, P; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D

    2003-01-01T23:59:59.000Z

    A novel method of determining the mass of the W boson in the W+W- -> lnu lnu channel is presented and applied to 667pb^-1 of data recorded at the center-of- mass energies in the range 183-207 GeV with the OPAL detector at LEP. The Measured energies of charged leptons and the results of a new procedure based on an approximate kinematic reconstruction of the events are combined to give: Mw=80.41+-0.41+-0.13 GeV, when the first error is statistical and the second is systematic. The systematic error is dominated by the uncertainty on the lepton energy, which is calibrated using data, and the parameterization of the variables used in the fitting, which is obtained using Monte Carlo events. Both of these are limited by statistics.

  8. Search for the associated production of the Higgs boson with a top quark pair in multi-lepton final states with the ATLAS detector

    E-Print Network [OSTI]

    The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    A search for the associated production of the Higgs boson with a top quark pair is performed in multi-lepton final states using 20.3 fb$^{-1}$ of proton-proton collision data recorded by the ATLAS experiment at $\\sqrt{s}=8$ TeV at the Large Hadron Collider. Five final states, targeting the decays $H\\to WW^*$, $\\tau\\tau$, and $ZZ^*$, are examined for the presence of the Standard Model (SM) Higgs boson: two same-charged light leptons ($e$ or $\\mu$) without an additional hadronically decaying tau; three light leptons; two same-charged light leptons with an additional hadronically decaying tau; four light leptons; and one light lepton and two hadronically decaying taus. No significant excess of events is observed above the background expectation. The best fit for the $t\\bar t H$ production cross section, assuming a Higgs boson mass of 125 GeV, is $2.1 ^{+1.4}_{-1.2}$ times the SM expectation, and the observed (expected) upper limit at the 95% confidence level is 4.7 (2.4) times the SM rate. The $p$-value for comp...

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

    SciTech Connect (OSTI)

    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

    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.

  10. CDF/PHYS/TOP/PUBLIC/7245 Top Quark Mass Measurement in Non-tagged Lepton+Jets Events at CDF

    E-Print Network [OSTI]

    Quigg, Chris

    CDF/PHYS/TOP/PUBLIC/7245 Top Quark Mass Measurement in Non-tagged Lepton+Jets Events at CDF The CDF of the top quark mass in non-tagged sample of lep- ton+4 jet events from p#22;p collisions at p s=1.96 Te as a superposition of top and W+jet events. The signal-constrained #12;t imposing a signal of 15.5#6;3.2 events

  11. Neutrino Mass, Sneutrino Dark Matter and Signals of Lepton Flavor Violation in the MRSSM

    E-Print Network [OSTI]

    Kumar, Abhishek; Weiner, Neal

    2009-01-01T23:59:59.000Z

    We study the phenomenology of mixed-sneutrino dark matter in the Minimal R-Symmetric Supersymmetric Standard Model (MRSSM). Mixed sneutrinos fit naturally within the MRSSM, as the smallness (or absence) of neutrino Yukawa couplings singles out sneutrino A-terms as the only ones not automatically forbidden by R-symmetry. We perform a study of randomly generated sneutrino mass matrices and find that (i) the measured value of $\\Omega_{DM}$ is well within the range of typical values obtained for the relic abundance of the lightest sneutrino, (ii) with small lepton-number-violating mass terms $m_{nn}^{2} {\\tilde n} {\\tilde n}$ for the right-handed sneutrinos, random matrices satisfying the $\\Omega_{DM}$ constraint have a decent probability of satisfying direct detection constraints, and much of the remaining parameter space will be probed by upcoming experiments, (iii) the $m_{nn}^{2} {\\tilde n} {\\tilde n}$ terms radiatively generate appropriately small Majorana neutrino masses, with neutrino oscillation data favo...

  12. Running Effects on Lepton Mixing Angles in Flavour Models with Type I Seesaw

    E-Print Network [OSTI]

    Yin Lin; Luca Merlo; Alessio Paris

    2009-11-27T23:59:59.000Z

    We study renormalization group running effects on neutrino mixing patterns when a (type I) seesaw model is implemented by suitable flavour symmetries. We are particularly interested in mass-independent mixing patterns to which the widely studied tribimaximal mixing pattern belongs. In this class of flavour models, the running contribution from neutrino Yukawa coupling, which is generally dominant at energies above the seesaw threshold, can be absorbed by a small shift on neutrino mass eigenvalues leaving mixing angles unchanged. Consequently, in the whole running energy range, the change in mixing angles is due to the contribution coming from charged lepton sector. Subsequently, we analyze in detail these effects in an explicit flavour model for tribimaximal neutrino mixing based on an A4 discrete symmetry group. We find that for normally ordered light neutrinos, the tribimaximal prediction is essentially stable under renormalization group evolution. On the other hand, in the case of inverted hierarchy, the deviation of the solar angle from its TB value can be large depending on mass degeneracy.

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

    SciTech Connect (OSTI)

    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

    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.

  14. Lepton number violating processes mediated by Majorana neutrinos at hadron colliders

    SciTech Connect (OSTI)

    Kovalenko, Sergey; Lu Zhun; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico, Santa Maria, Casilla 110-V, Valparaiso (Chile) and Center of Subatomic Physics, Valparaiso (Chile)

    2009-10-01T23:59:59.000Z

    We study the lepton number violating like-sign dilepton processes h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}jjX and h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}W{sup {+-}}X, mediated by heavy GeV scale Majorana neutrinos. We focus on the resonantly enhanced contributions with a nearly on-mass-shell Majorana neutrino in the s channel. We study the constraints on like-sign dilepton production at the Tevatron and the LHC on the basis of the existing experimental limits on the masses of heavy neutrinos and their mixings U{sub {alpha}}{sub N} with {alpha}={nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}. Special attention is paid to the constraints from neutrinoless double beta decay. We note that searches for like-sign e{sup {+-}}e{sup {+-}} events at Tevatron and LHC may provide evidence of CP violation in the neutrino sector. We also discuss the conditions under which it is possible to extract individual constraints on the mixing matrix elements in a model independent way.

  15. Probing long-range leptonic forces with solar and reactor neutrinos

    E-Print Network [OSTI]

    González-Garciá, M C; Massó, E; Zukanovich-Funchal, R

    2007-01-01T23:59:59.000Z

    In this work we study the phenomenological consequences of the existence of long-range forces coupled to lepton flavour numbers in solar neutrino oscillations. We study electronic forces mediated by scalar, vector or tensor neutral bosons and analyze their effect on the propagation of solar neutrinos as a function of the force strength and range. Under the assumption of one mass scale dominance, we perform a global analysis of solar and KamLAND neutrino data which depends on the two standard oscillation parameters, \\Delta m^2_{21} and \\tan^2\\theta_{12}, the force coupling constant, its range and, for the case of scalar-mediated interactions, on the neutrino mass scale as well. We find that, generically, the inclusion of the new interaction does not lead to a very statistically significant improvement on the description of the data in the most favored MSW LMA (or LMA-I) region. It does, however, substantially improve the fit in the high-\\Delta m^2 LMA (or LMA-II) region which can be allowed for vector and scal...

  16. Lepton Generation Problem, Some Properties and Implications of the Curved Spacetime Dirac Equation -- (II)

    E-Print Network [OSTI]

    G. G. Nyambuya

    2010-01-22T23:59:59.000Z

    This reading is a continuation of the earlier reading Nyambuya (2008); where three new Curved Spacetime Dirac Equations have been derived mainly to try and account in a natural way for the observed anomalous gyromagnetic ratio of fermions and the suggestions is that particles including the Electron, which is thought to be a point particle, do have a finite spatial size and this is one of the reasons for the observed anomalous gyromagnetic ratio. Combining the idea in Nyambuya (2008) which lead to the derivation of the three new Curved Spacetime Dirac Equations, and the proposed Unified Field Theory (Nyambuya 2007), a total of 12 equations each with 16 sub-components are generated thus leading to a total of 192 equations for the Curved Spacetime Dirac Equation. Some symmetries of these equations are investigated, i.e., the Lorentz symmetry, charge conjugation symmetry (C), time reversal symmetry (T), Space reversal (P) and a combination of the C, P and T - symmetries. It is shown that these equations are Lorentz invariant, obey C-symmetry and that some violate T and P-symmetry while others do not and that they all obey PT-symmetry. These symmetries show (or modestly said -- seem to suggest) that anti-particles have positive mass and energy but a negative rest-mass and the opposite sign in electronic charge. Through the inspection of these symmetries, a suggestion is (here) made to the effect that the rest-mass of a particle must be related to the electronic charge of that particle thus leading us to a possible resolution of whether or not Neutrinos do have a none-zero rest-mass. Additionally, we demonstrate that these equations have the potency to explain naturally the observed lepton generation phenomena.

  17. Identification and energy calibration of hadronically decaying tau leptons with the ATLAS experiment in $pp$ collisions at $\\sqrt{s}$=8 TeV

    E-Print Network [OSTI]

    ATLAS Collaboration

    2014-12-22T23:59:59.000Z

    This paper describes the trigger and offline reconstruction, identification and energy calibration algorithms for hadronic decays of tau leptons employed for the data collected from $pp$ collisions in 2012 with the ATLAS detector at the LHC center-of-mass energy $\\sqrt{\\mathrm{s}} = 8$ TeV. The performance of these algorithms is measured in most cases with Z decays to tau leptons using the full 2012 dataset, corresponding to an integrated luminosity of 20.3 fb$^{-1}$. An uncertainty on the offline reconstructed tau energy scale of 2% to 4%, depending on transverse energy and pseudorapidity, is achieved using two independent methods. The offline tau identification efficiency is measured with a precision of 2.5% for hadronically decaying tau leptons with one associated track, and of 4% for the case of three associated tracks, inclusive in pseudorapidity and for a visible transverse energy greater than $20$ GeV. For hadronic tau lepton decays selected by offline algorithms, the tau trigger identification efficiency is measured with a precision of 2% to 8%, depending on the transverse energy. The performance of the tau algorithms, both offline and at the trigger level, is found to be stable with respect to the number of concurrent proton--proton interactions and has supported a variety of physics results using hadronically decaying tau leptons at ATLAS.

  18. Lepton masses, mixings, and flavor-changing neutral currents in a minimal S{sub 3}-invariant extension of the standard model

    SciTech Connect (OSTI)

    Mondragon, A.; Mondragon, M.; Peinado, E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 Mexico D.F. (Mexico)

    2007-10-01T23:59:59.000Z

    The mass matrices of the charged leptons and neutrinos, previously derived in a minimal S{sub 3}-invariant extension of the standard model, were reparametrized in terms of their eigenvalues. We obtained explicit, analytical expressions for all entries in the neutrino mixing matrix, V{sub PMNS}, the neutrino mixing angles, and the Majorana phases as functions of the masses of charged leptons and neutrinos in excellent agreement with the latest experimental values. The resulting V{sub PMNS} matrix is very close to the tribimaximal form of the neutrino mixing matrix. We also derived explicit, analytical expressions for the matrices of the Yukawa couplings and computed the branching ratios of some selected flavor-changing neutral current processes as functions of the masses of the charged leptons and the neutral Higgs bosons. We find that the S{sub 3}xZ{sub 2} flavor symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector well below the present experimental upper bounds by many orders of magnitude.

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

    SciTech Connect (OSTI)

    Mills, Corrinne Elaine; /UC, Santa Barbara

    2007-06-01T23:59:59.000Z

    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.

  20. Averages of B-Hadron, C-Hadron, and tau-lepton properties as of early 2012

    SciTech Connect (OSTI)

    Amhis, Y.; et al.

    2012-07-01T23:59:59.000Z

    This article reports world averages of measurements of b-hadron, c-hadron, and tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG) using results available through the end of 2011. In some cases results available in the early part of 2012 are included. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays and CKM matrix elements.

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

    SciTech Connect (OSTI)

    Chaden Djalali

    2011-12-01T23:59:59.000Z

    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.

  2. The effect of the Gaussian profile of the new Higgs doublet on the radiative lepton flavor violating decay

    E-Print Network [OSTI]

    E. O. Iltan

    2006-02-19T23:59:59.000Z

    We study the branching ratios of the lepton flavor violating processes \\mu -> e\\gamma, \\tau -> e\\gamma and \\tau -> \\mu\\gamma by considering that the new Higgs scalars localize with Gaussian profile in the extra dimension. We see that the BRs of the LFV decays \\mu -> e \\gamma, \\tau -> e \\gamma and \\tau -> \\mu\\gamma are at the order of the magnitude of 10^{-12}, 10^{-16} and 10^{-12} in the considered range of the free parameters. These numerical values are slightly suppressed in the case that the localization points of new Higgs scalars are different than origin.

  3. Search for Top Squarks in R-Parity-Violating Supersymmetry Using Three or More Leptons and b-Tagged Jets

    E-Print Network [OSTI]

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

    2013-11-25T23:59:59.000Z

    are in good agree- ment with the SM predictions everywhere. See the Supplemental Material [43] for additional ST distributions. We demonstrate natural SUSY with RPV couplings in a stop RPV model where the light stop decays to a top quark and intermediate on... naturalness, searches for all possible decay chains should be carried out. These can be broadly categorized as R-parity conserving (RPC) or violating (RPV) [5], where R-parity is defined by R ¼ ð#1;1Þ3BþLþ2s, with B and L the baryon and lepton numbers...

  4. Can the four-zero-texture mass matrix model reproduce the observed quark and lepton mixing angles and CP-violating phases?

    SciTech Connect (OSTI)

    Matsuda, Koichi; Nishiura, Hiroyuki [Center for High Energy Physics, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Faculty of Information Science and Technology, Osaka Institute of Technology, Hirakata, Osaka 573-0196 (Japan)

    2006-08-01T23:59:59.000Z

    We reconsider a universal mass matrix model which has a seesaw-invariant structure with four-zero texture common to all quarks and leptons. The Cabibbo-Kobayashi-Maskawa (CKM) quark and Maki-Nakagawa-Sakata (MNS) lepton mixing matrices of the model are analyzed analytically. We show that the model can be consistent with all the experimental data of neutrino oscillation and quark mixings by tuning free parameters of the model. It is also shown that the model predicts a relatively large value for the (1, 3) element of the MNS lepton mixing matrix (U{sub MNS}){sub 13}{sup 2}{approx_equal}(0.041-9.6)x10{sup -2}. Using the seesaw mechanism, we also discuss the conditions for the components of the Dirac and the right-handed Majorana neutrino mass matrices which lead to the neutrino mass matrix consistent with the experimental data.

  5. arXiv:0708.1344v1[hep-ph]9Aug2007 NUHEP-TH/07-10 A Survey of Lepton Number Violation Via Effective Operators

    E-Print Network [OSTI]

    number violating phenomena. These include searches for neutrinoless double-beta decay and rare meson understanding of lepton mixing disfavors a subset of higher dimensional operators. While neutrinoless double-beta decay is the most promising signature of lepton number violation for the majority of operators

  6. Lepton number violation and W ? chiral couplings at the LHC

    SciTech Connect (OSTI)

    Han, Tao; Lewis, Ian; Ruiz, Richard; Si, Zong-guo

    2013-02-01T23:59:59.000Z

    We study the observability for a heavy Majorana neutrino N along with a new charged gauge boson W' at the LHC. We emphasize the complementarity of these two particles in their production and decay to unambiguously determine their properties. We show that the Majorana nature of N can be verified by the lepton number violating like-sign dilepton process, and by polar and azimuthal angular distributions. The chirality of the W' coupling to leptons and to quarks can be determined by a polar angle distribution in the reconstructed frame and an azimuthal angle distribution.

  7. Aspects of Neutrino Masses and Lepton-Number Violation in the light of the Super-Kamiokande data

    E-Print Network [OSTI]

    Smaragda Lola

    1999-03-01T23:59:59.000Z

    We discuss aspects of neutrino masses and lepton-number violation, in the light of the observations of Super-Kamiokande. As a first step, we use the data from various experiments, in order to obtain a phenomenological understanding of neutrino mass textures. We then investigate how the required patterns of neutrino masses and mixings are related to the flavour structure of the underlying theory. In supersymmetric extensions of the Standard Model, renormalisation group effects can have important implications: for small tanb, bottom-tau unification indicates the presence of significant muon-tau flavour mixing. The evolution of the neutrino mixing may be described by simple semi-analytic expressions, which confirm that, for large tanb, very small mixing at the GUT scale may be amplified to maximal mixing at low energies, and vice versa. Passing to specific models, we first discuss the predictions for neutrino masses in different GUT models (including superstring-embedded solutions). Imposing the requirement for successful leptogenesis may give additional constraints on the generic structure of the neutrino mass textures. Finally, we discuss direct ways to look for lepton-number violation in ultra-high energy neutrino interactions.

  8. NLO QCD corrections to off-shell top-antitop production with leptonic decays in association with a Higgs boson at the LHC

    E-Print Network [OSTI]

    Denner, Ansgar

    2015-01-01T23:59:59.000Z

    We compute the hadronic production of top-antitop pairs in association with a Higgs boson at next-to-leading-order QCD, including the decay of the top and antitop quark into bottom quarks and leptons. Our computation is based on full leading and next-to-leading-order matrix elements for $e^+ \

  9. /CDF/PHYS/TOP/PUBLIC/8133 Measurement of the Top Quark Mass in the Lepton+Jets channel using the Decay

    E-Print Network [OSTI]

    Quigg, Chris

    /CDF/PHYS/TOP/PUBLIC/8133 Measurement of the Top Quark Mass in the Lepton+Jets channel using present an updated measurement of the top quark mass using the transverse decay length of b- hadrons from top decays. This technique relies solely on tracking and thus avoids the jet energy scale uncertainty

  10. /CDF/PHYS/TOP/PUBLIC/7781 First Measurement of the Top Quark Mass in the Lepton+Jets channel using the

    E-Print Network [OSTI]

    Quigg, Chris

    /CDF/PHYS/TOP/PUBLIC/7781 First Measurement of the Top Quark Mass in the Lepton+Jets channel using a novel method to measure the top quark mass using the transverse decay length of b-hadrons from top a competitive measurement of the top quark mass by itself, since the decay length technique is uncorrelated

  11. Test of QED to fourth order by study of four-lepton final states in e(+)e(?) interactions at 29 GeV with the HRS detector

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-10-01T23:59:59.000Z

    Data taken with the High Resolution Spectrometer detector at the SLAC storage ring PEP were used to test QED to fourth order in the coupling constant ?. The experiment studied four-lepton final states produced at high Q(2) in e(+)e(?) interactions...

  12. 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]

    Gomez-Ceballos, Guillelmo

    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 ...

  13. Search for new phenomena in events with three charged leptons at sqrt[s]=7??TeV with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A generic search for anomalous production of events with at least three charged leptons is presented. The search uses a pp-collision data sample at a center-of-mass energy of ?s=7??TeV corresponding to 4.6??fb-1 of integrated ...

  14. Flavor symmetry L{sub e}-L{sub {mu}}-L{sub {tau}}, atmospheric neutrino mixing, and CP violation in the lepton sector

    SciTech Connect (OSTI)

    Petcov, S.T.; Rodejohann, W. [Scuola Internazionale Superiore di Studi Avanzati, Via Beirut 2-4, I-34014 Trieste, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34014 Trieste (Italy)

    2005-04-01T23:59:59.000Z

    The Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing matrix is given, in general, by the product of two unitary matrices associated with the diagonalization of the charged lepton and neutrino mass matrices. Assuming that the active flavor neutrinos possess a Majorana mass matrix which is diagonalized by a bimaximal mixing matrix, we give the allowed forms of the charged lepton mixing matrix and the corresponding implied forms of the charged lepton mass matrix. We then assume that the origin of bimaximal mixing is a weakly broken flavor symmetry corresponding to the conservation of the nonstandard lepton charge L{sup '}=L{sub e}-L{sub {mu}}-L{sub {tau}}. The latter does not predict, in general, the atmospheric neutrino mixing to be maximal. We study the impact of this fact on the allowed forms of the charged lepton mixing matrix and on the neutrino mixing observables, analyzing the case of CP violation in detail. When compared with the case of exact bimaximal mixing, the deviations from zero U{sub e3} and from maximal atmospheric neutrino mixing are typically more sizable if one assumes just L{sup '} conservation. In fact, |U{sub e3}|{sup 2} can be as small as 0.007 and atmospheric neutrino mixing can take any value inside its currently allowed range. We discuss under which conditions the atmospheric neutrino mixing angle is larger or smaller than {pi}/4. We present also a simple seesaw realization of the implied light neutrino Majorana mass matrix and consider leptogenesis in this scenario.

  15. SU(3) Gauge Family Symmetry and Prediction for the Lepton-Flavor Mixing and Neutrino Masses with Maximal Spontaneous CP Violation

    E-Print Network [OSTI]

    Yue-Liang Wu

    2012-07-12T23:59:59.000Z

    A model for the lepton-flavor mixing and CP violation is proposed based on the SU$_F$(3) gauge family symmetry and the Majorana feature of neutrinos. A consistent prediction for the lepton-flavor mixing and masses is shown to be resulted from the appropriate vacuum structure of SU$_F$(3) gauge symmetry breaking. By choosing the SU$_F$(3) gauge fixing condition to possess a residual $Z_2$ symmetry and requiring the vacuum structure of spontaneous symmetry breaking to have approximate global U(1) family symmetries, we obtain naturally the tri-bimaximal mixing matrix and largely degenerate neutrino masses in the neutrino sector and the small mixing matrix in the charged-lepton sector. With a simple ansatz that all the smallness due to the approximate global U(1) family symmetries is characterized by a single Wolfenstein parameter $\\lambda \\simeq 0.22$, and the charged-lepton mixing matrix has a similar hierarchy structure as the CKM quark mixing matrix, we arrive at a consistent prediction for the MNSP lepton-flavor mixing with a maximal spontaneous CP violation: $\\delta =\\pi/2$, $\\sin^2\\theta_{13} \\simeq 1/2\\lambda^2 \\simeq 0.024$ ($\\sin^22\\theta_{13} \\simeq 0.094$), $\\sin^2\\theta_{12} \\simeq 1/3{3}(1 - 2\\lambda^3) \\simeq 0.326$ and $\\sin^2\\theta_{23} \\simeq 1/2(1 - \\lambda^2) \\simeq 0.48$, which agree well with the current experimental data. The CP-violating Jarlskog-invariant is obtained to be $J_{CP} \\simeq 1/6\\lambda(1-\\lambda^2/2-\\lambda^3)\\sin\\delta \\simeq 0.035$, which is detectable in next generation neutrino experiment. The largely degenerate neutrino masses with the normal hierarchy and inverse hierarchy are discussed and found be at the order $m_{\

  16. B -> K1 gamma and tests of factorization for two-body non leptonic Bdecays with axial-vector mesons

    E-Print Network [OSTI]

    G. Nardulli; T. N. Pham

    2005-07-30T23:59:59.000Z

    The large branching ratio for B-> K1 gamma recently measured at Belle implies a large B -> K1 transition form factor and large branching ratios for non leptonic B decays involving an axial-vector meson. In this paper we present an analysis of two-body B decays with an axial-vector meson in the final state using naive factorization and the B -> K1 form factors obtained from the measured radiative decays. We find that the predicted B -> J/psi K1 branching ratio is in agreement with experiment. We also suggest that the decay rates of B -> K1 pi, B -> a1 K and B -> b1 K could be used to test the factorization ansatz.

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

    SciTech Connect (OSTI)

    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

    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.

  18. Double-Spin Asymmetry in the Cross Section for Exclusive rho^0 Production in Lepton-Proton Scattering

    E-Print Network [OSTI]

    Airapetian, A; Amarian, M; Arrington, J; Aschenauer, E C; Avakian, H; Avakian, R; Avetisian, A; Avetissian, E; Bailey, P; Bains, B; Baumgarten, C; Beckmann, M; Belostotskii, S; Bernreuther, S; Bianchi, N; Böttcher, Helmut B; Borisov, A; Bouwhuis, M; Brack, J; Brauksiepe, S; Braun, B; Brückner, W; Brüll, A; Budz, P; Bulten, H J; Capitani, G P; Carter, P; Chumney, P; Cisbani, E; Court, G R; Dalpiaz, P F; De Leo, R; De Nardo, L; De Sanctis, E; De Schepper, D; Devitsin, E G; De Witt-Huberts, P K A; Di Nezza, P; Dzhordzhadze, V; Düren, M; Dvoredsky, A P; Elbakian, G M; Ely, J; Fantoni, A; Feshchenko, A; Felawka, L; Ferro-Luzzi, M; Fiedler, K; Filippone, B W; Fischer, H; Fox, B; Franz, J; Frullani, S; Gärber, Y; Garibaldi, F; Garutti, E; Gavrilov, G E; Karibian, V; Golendukhin, A; Graw, G; Grebenyuk, O; Green, P W; Greeniaus, L G; Gute, A; Haeberli, W; Hartig, M; Hasch, D; Heesbeen, D; Heinsius, F H; Henoch, M; Hertenberger, R; Hesselink, W H A; Hofman, G J; Holler, Y; Holt, R J; Hommez, B; Iarygin, G; Iodice, M; Izotov, A A; Jackson, H E; Jgoun, A; Jung, P; Kaiser, R; Kanesaka, J; Kinney, E R; Kiselev, A; Kitching, P; Kobayashi, H; Koch, N; Königsmann, K C; Kolster, H; Korotkov, V A; Kotik, E; Kozlov, V; Krivokhizhin, V G; Kyle, G S; Lagamba, L; Laziev, A; Lenisa, P; Lindemann, T; Lorenzon, W; Makins, N C R; Martin, J W; Marukyan, H O; Masoli, F; McAndrew, M; McIlhany, K; McKeown, R D; Meissner, F; Menden, F; Metz, A; Meyners, N; Miklukho, O; Miller, C A; Milner, R; Muccifora, V; Mussa, R; Nagaitsev, A P; Nappi, E; Naryshkin, Yu; Nass, A; Negodaeva, K; Nowak, Wolf-Dieter; Oganesyan, K A; O'Neill, T G; Openshaw, R; Ouyang, J; Owen, B R; Pate, S F; Potashov, S Yu; Potterveld, D H; Rakness, G; Rappoport, V; Redwine, R P; Reggiani, D; Reolon, A R; Ristinen, R; Rith, K; Robinson, D; Rostomyan, A; Ruh, M; Ryckbosch, D; Sakemi, Y; Sato, F; Savin, I A; Scarlett, C; Schäfer, A; Schill, C; Schmidt, F; Schnell, G; Schüler, K P; Schwind, A; Seibert, J; Seitz, B; Shibata, T A; Shin, T; Shutov, V B; Simani, C; Simon, A; Sinram, K; Steffens, E; Steijger, J J M; Stewart, J; Stösslein, U; Suetsugu, K; Sutter, M F; Szymanowski, L; Taroian, S P; Terkulov, A R; Teryaev, O V; Tessarin, S; Thomas, E; Tipton, B; Tytgat, M; Urciuoli, G M; Van den Brand, J F J; van der Steenhoven, G; Van de Vyver, R; Van Hunen, J J; Vetterli, Martin C; Vikhrov, V V; Vincter, M G; Visser, J; Volk, E; Weiskopf, C; Wendland, J; Wilbert, J; Wise, T; Yen, S; Yoneyama, S; Zohrabyan, H G

    2001-01-01T23:59:59.000Z

    Evidence for a positive longitudinal double-spin asymmetry = 0.24 +-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive rho^0(770) vector meson production in polarised lepton-proton scattering was observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA positron beam was scattered off a longitudinally polarised pure hydrogen gas target. The average invariant mass of the photon-proton system has a value of = 4.9 GeV, while the average negative squared four-momentum of the virtual photon is = 1.7 GeV^2. The ratio of the present result to the corresponding spin asymmetry in inclusive deep-inelastic scattering is in agreement with an early theoretical prediction based on the generalised vector meson dominance model.

  19. Upper Limits on Electric and Weak Dipole Moments of Tau-Lepton and Heavy Quarks from e+e- Annihilation

    E-Print Network [OSTI]

    A. E. Blinov; A. S. Rudenko

    2009-03-23T23:59:59.000Z

    The total cross-sections measured at LEP for e+e- annihilation into tau+tau-, c\\bar{c} and b\\bar{b} at 2E ~ 200 GeV are used to derive the upper limits 3*10^{-17}, 5*10^{-17}, 2*10^{-17} e*cm for the electric dipole moments and 4*10^{-17}, 7*10^{-17}, 2.5*10^{-17} e*cm for the weak dipole moments of the tau-lepton, c-, and b-quarks, respectively. Some of the existing limits on these moments are improved and for the b-quark the improvement is rather significant.

  20. Search for Nucleon Decay into Charged Anti-lepton plus Meson in Super-Kamiokande I and II

    E-Print Network [OSTI]

    Nishino, H; Hayato, Y; Iida, T; Ikeda, M; Kameda, J; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Sekiya, H; Shiozawa, M; Suzuki, Y; Takeda, A; Takenaga, Y; Takeuchi, Y; Ueno, K; Ueshima, K; Watanabe, H; Yamada, S; Hazama, S; Higuchi, I; Ishihara, C; Kaji, H; Kajita, T; Kaneyuki, K; Mitsuka, G; Okumura, K; Tanimoto, N; Dufour, F; Kearns, E; Litos, M; Raaf, J L; Stone, J L; Sulak, L R; Goldhaber, M; Bays, K; Cravens, J P; Kropp, W R; Mine, S; Regis, C; Smy, M B; Sobel, H W; Ganezer, K S; Hill, J; Keig, W E; Jang, J S; Kim, J Y; Lim, I T; Albert, J B; Scholberg, K; Walter, C W; Wendell, R; Ishizuka, T; Tasaka, S; Learned, J G; Matsuno, S; Watanabe, Y; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Nishikawa, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Minamino, A; Nakaya, T; Yokoyama, M; Fukuda, Y; Itow, Y; Tanaka, T; Jung, C K; Lopez, G; McGrew, C; Yanagisawa, C; Tamura, N; Idehara, Y; Sakuda, M; Kuno, Y; Yoshida, M; Kim, S B; Yang, B S; Okazawa, H; Choi, Y; Seo, H K; Furuse, Y; Nishijima, K; Yokosawa, Y; Koshiba, M; Totsuka, Y; Vagins, M R; Chen, S; Heng, Y; Liu, J; Yang, Z; Zhang, H; Kielczewska, D; Connolly, K; Thrane, E; Wilkes, R J

    2012-01-01T23:59:59.000Z

    Searches for a nucleon decay into a charged anti-lepton (e^+ or {\\mu}^+) plus a light meson ({\\pi}^0, {\\pi}^-, {\\eta}, {\\rho}^0, {\\rho}^-, {\\omega}) were performed using the Super-Kamiokande I and II data. Twelve nucleon decay modes were searched for. The total exposure is 140.9 kiloton \\cdot years, which includes a 91.7 kiloton \\cdot year exposure (1489.2 live days) of Super-Kamiokande-I and a 49.2 kiloton \\cdot year exposure (798.6 live days) of Super-Kamiokande-II. The number of candidate events in the data was consistent with the atmospheric neutrino background expectation. No significant evidence for a nucleon decay was observed in the data. Thus, lower limits on the nucleon partial lifetime at 90% confidence level were obtained. The limits range from 3.6 \\times 10^31 to 8.2 \\times 10^33 years, depending on the decay modes.

  1. Search for Nucleon Decay into Charged Anti-lepton plus Meson in Super-Kamiokande I and II

    E-Print Network [OSTI]

    Super-Kamiokande Collaboration; :; H. Nishino; K. Abe; Y. Hayato; T. Iida; M. Ikeda; J. Kameda; Y. Koshio; M. Miura; S. Moriyama; M. Nakahata; S. Nakayama; Y. Obayashi; H. Sekiya; M. Shiozawa; Y. Suzuki; A. Takeda; Y. Takenaga; Y. Takeuchi; K. Ueno; K. Ueshima; H. Watanabe; S. Yamada; S. Hazama; I. Higuchi; C. Ishihara; H. Kaji; T. Kajita; K. Kaneyuki; G. Mitsuka; K. Okumura; N. Tanimoto; F. Dufour; E. Kearns; M. Litos; J. L. Raaf; J. L. Stone; L. R. Sulak; M. Goldhaber; K. Bays; J. P. Cravens; W. R. Kropp; S. Mine; C. Regis; M. B. Smy; H. W. Sobel; K. S. Ganezer; J. Hill; W. E. Keig; J. S. Jang; J. Y. Kim; I. T. Lim; J. B. Albert; K. Scholberg; C. W. Walter; R. Wendell; T. Ishizuka; S. Tasaka; J. G. Learned; S. Matsuno; Y. Watanabe; T. Hasegawa; T. Ishida; T. Ishii; T. Kobayashi; T. Nakadaira; K. Nakamura; K. Nishikawa; Y. Oyama; K. Sakashita; T. Sekiguchi; T. Tsukamoto; A. T. Suzuki; A. Minamino; T. Nakaya; M. Yokoyama; Y. Fukuda; Y. Itow; T. Tanaka; C. K. Jung; G. Lopez; C. McGrew; C. Yanagisawa; N. Tamura; Y. Idehara; M. Sakuda; Y. Kuno; M. Yoshida; S. B. Kim; B. S. Yang; H. Okazawa; Y. Choi; H. K. Seo; Y. Furuse; K. Nishijima; Y. Yokosawa; M. Koshiba; Y. Totsuka; M. R. Vagins; S. Chen; Y. Heng; J. Liu; Z. Yang; H. Zhang; D. Kielczewska; K. Connolly; E. Thrane; R. J. Wilkes

    2012-06-22T23:59:59.000Z

    Searches for a nucleon decay into a charged anti-lepton (e^+ or {\\mu}^+) plus a light meson ({\\pi}^0, {\\pi}^-, {\\eta}, {\\rho}^0, {\\rho}^-, {\\omega}) were performed using the Super-Kamiokande I and II data. Twelve nucleon decay modes were searched for. The total exposure is 140.9 kiloton \\cdot years, which includes a 91.7 kiloton \\cdot year exposure (1489.2 live days) of Super-Kamiokande-I and a 49.2 kiloton \\cdot year exposure (798.6 live days) of Super-Kamiokande-II. The number of candidate events in the data was consistent with the atmospheric neutrino background expectation. No significant evidence for a nucleon decay was observed in the data. Thus, lower limits on the nucleon partial lifetime at 90% confidence level were obtained. The limits range from 3.6 \\times 10^31 to 8.2 \\times 10^33 years, depending on the decay modes.

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

    SciTech Connect (OSTI)

    Adelman, Jahred A.; /Chicago U.

    2008-05-01T23:59:59.000Z

    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}.

  3. Calorimeter-Based Triggers at the ATLAS Detector for Searches for Supersymmetry in Zero-Lepton Final States

    E-Print Network [OSTI]

    Alexander Mann

    2012-05-22T23:59:59.000Z

    This thesis consists of three closely related parts. An analysis of data recorded by the ATLAS detector in 2010 in proton-proton collisions at a center-of-mass energy of 7 TeV with an integrated luminosity of 33.4/pb is performed, searching for supersymmetric final states containing jets and missing transverse energy and no electrons or muons (zero-lepton channel). No excess over the Standard Model background expectation is observed. Using the CLs and PLR methods, exclusion limits are set in two different supergravity models. These considerably extend the excluded parameter ranges from earlier experiments. The rates and efficiencies of triggers based on combined signatures with jets plus missing transverse energy in ATLAS are studied, which are the primary triggers for the search for Supersymmetry in the zero-lepton channel. For the measurement of the efficiencies in data collected in 2010 and 2011, the bootstrap method is applied. Different sample triggers based on jets and missing transverse energy are compared and their efficiencies are measured. A reweighting approach is used to correct for the bias from the propagation of the uncertainties in the bootstrap method. A universal model is developed to describe the contribution of fake missing transverse energy from resolution effects to the rates of missing transverse energy triggers as function of the level of in-time pile-up, i.e. the number of concurrent proton-proton interactions. The input parameters are tuned to the properties of the ATLAS trigger system, and the model predictions are compared to measurements of trigger rates in ATLAS. Good agreement is found for low thresholds for which the rates are dominated by resolution effects, whereas the rates for higher thresholds are underestimated due to additional sources of fake and real missing transverse energy, which are not incorporated in the model.

  4. Double Beta Decay, Lepton Flavour Violation and Collider Signatures of Left-Right Symmetric Models with Spontaneous D Parity Breaking

    E-Print Network [OSTI]

    Frank F. Deppisch; Tomas E. Gonzalo; Sudhanwa Patra; Narendra Sahu; Utpal Sarkar

    2014-10-23T23:59:59.000Z

    We propose a class of left-right symmetric models (LRSMs) with spontaneous D parity breaking, where SU(2)_R breaks at the TeV scale while discrete left-right symmetry breaks around 10^9 GeV. By embedding this framework in a non-supersymmetric SO(10) Grand Unified Theory (GUT) with Pati-Salam symmetry as the highest intermediate breaking step, we obtain g_R / g_L ~ 0.6 between the right- and left-handed gauge couplings at the TeV scale. This leads to a suppression of beyond the Standard Model phenomena induced by the right-handed gauge coupling. Here we focus specifically on the consequences for neutrinoless double beta decay, low energy lepton flavour violation and LHC signatures due to the suppressed right handed currents. Interestingly, the reduced g_R allows us to interpret an excess of events observed recently in the range of 1.9 TeV to 2.4 TeV by the CMS group at the LHC as the signature of a right handed gauge boson in LRSMs with spontaneous D parity breaking. Moreover, the reduced right-handed gauge coupling also strongly suppresses the non-standard contribution of heavy states to the neutrinoless double beta decay rate as well as the amplitude of low energy lepton flavour violating processes. In a dominant type-II Seesaw mechanism of neutrino mass generation, we find that both sets of observables provide stringent and complimentary bounds which make it challenging to observe the scenario at the LHC.

  5. Light Vector Meson Photoproduction off of 1H at Jefferson Lab and p-w Interference in the Leptonic Decay Channel

    SciTech Connect (OSTI)

    Djalali, Chaden [University of Iowa; Paolone, Michael [Temple University, JLAB; Weygand, Dennis; Wood, Mike H. [USC LA, JLAB

    2014-09-01T23:59:59.000Z

    Although the phenomena of r – w interference has been studied at great length in pionic decay channel over the past 50 years, a study of the interference in a purely electromagnetic production and decay channel has never been performed on an elementary proton target until now. The only published photo-production data of the r - w leptonic decay channel was obtained in the early seventies on C and Be. An investigation of the r - w interference on a Hydrogen was recently completed at Jefferson Lab with the CLAS detector. The di-lepton spectra was fit with two inter- fering relativistic Breit-Wigner functions, and the interference phase was extracted. Preliminary results will be compared to the previous experimental studies in nuclei.

  6. Search for anomalous production of events with three or more leptons in pp collisions at sqrt(s) = 8 TeV

    SciTech Connect (OSTI)

    Chatrchyan, S. [Yerevan Physics Institute (Armenia); et al.,

    2014-08-01T23:59:59.000Z

    A search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5 inverse femtobarns of proton-proton collisions with center-of-mass energy sqrt(s) = 8 TeV, was collected by the CMS experiment at the LHC during 2012. The data are divided into exclusive categories based on the number of leptons and their flavor, the presence or absence of an opposite-sign, same-flavor lepton pair (OSSF), the invariant mass of the OSSF pair, the presence or absence of a tagged bottom-quark jet, the number of identified hadronically decaying tau leptons, and the magnitude of the missing transverse energy and of the scalar sum of jet transverse momenta. The numbers of observed events are found to be consistent with the expected numbers from standard model processes, and limits are placed on new-physics scenarios that yield multilepton final states. In particular, scenarios that predict Higgs boson production in the context of supersymmetric decay chains are examined. We also place a 95% confidence level upper limit of 1.3% on the branching fraction for the decay of a top quark to a charm quark and a Higgs boson (t to c H), which translates to a bound on the left- and right-handed top-charm flavor-violating Higgs Yukawa couplings, lambda[H, tc] and lambda[H, ct], respectively, of sqrt(abs(lambda[H, tc])^2 + abs(lambda[H, ct])^2) < 0.21.

  7. Double Beta Decay, Lepton Flavour Violation and Collider Signatures of Left-Right Symmetric Models with Spontaneous D Parity Breaking

    E-Print Network [OSTI]

    Deppisch, Frank F; Patra, Sudhanwa; Sahu, Narendra; Sarkar, Utpal

    2014-01-01T23:59:59.000Z

    We propose a class of left-right symmetric models (LRSMs) with spontaneous D parity breaking, where SU(2)_R breaks at the TeV scale while discrete left-right symmetry breaks around 10^9 GeV. By embedding this framework in a non-supersymmetric SO(10) Grand Unified Theory (GUT) with Pati-Salam symmetry as the highest intermediate breaking step, we obtain g_R / g_L ~ 0.6 between the right- and left-handed gauge couplings at the TeV scale. This leads to a suppression of beyond the Standard Model phenomena induced by the right-handed gauge coupling. Here we focus specifically on the consequences for neutrinoless double beta decay, low energy lepton flavour violation and LHC signatures due to the suppressed right handed currents. Interestingly, the reduced g_R allows us to interpret an excess of events observed recently in the range of 1.9 TeV to 2.4 TeV by the CMS group at the LHC as the signature of a right handed gauge boson in LRSMs with spontaneous D parity breaking. Moreover, the reduced right-handed gauge co...

  8. Measurement of the Top Quark Mass in the Di-lepton Channel using the Dalitz-Goldstein Method

    SciTech Connect (OSTI)

    Hare, Matthew Frederick; /Tufts U.

    2010-10-01T23:59:59.000Z

    This dissertation describes a measurement of the mass of the top quark using a method developed by G. Goldstein and R.H. Dalitz. It is based on 2.0 fb{sup -1} of data collected by the Collider Detector Facility at Fermi National Accelerator Laboratories. Di-lepton events were observed from colliding protons with anti-protons with {radical}s = 1.96 TeV in the Tevatron Collider. A total of 145 candidate events were observed with 49 expected to be from background. These events include two neutrinos which elude detection. The method begins by assuming an initial top quark mass and solves for the neutrino momenta using a geometrical construction. The method samples over a range of likely top quark masses choosing the most consistent mass via a likelihood function. An important distinguishing feature of this method from others is its lack of dependence on the missing transverse energy, a quantity that is poorly measured by the experiment. This analysis determines the top quark mass to be M{sub top} = 172.3 {+-} 3.4(stat.) {+-} 2.0(syst.) GeV/c{sup 2} (M{sub top} = 170.5 {+-} 3.7(stat.) {+-} 1.8(syst.) GeV/c{sup 2} with b-tagging).

  9. Dynamical evolution of neutrino--cooled accretion disks: detailed microphysics, lepton-driven convection, and global energetics

    E-Print Network [OSTI]

    William H. Lee; Enrico Ramirez-Ruiz; Dany Page

    2005-06-06T23:59:59.000Z

    We present a detailed, two dimensional numerical study of the microphysical conditions and dynamical evolution of accretion disks around black holes when neutrino emission is the main source of cooling. Such structures are likely to form after the gravitational collapse of massive rotating stellar cores, or the coalescence of two compact objects in a binary (e.g., the Hulse--Taylor system). The physical composition is determined self consistently by considering two regimes: neutrino--opaque and neutrino--transparent, with a detailed equation of state which takes into account neutronization, nuclear statistical equilibrium of a gas of free nucleons and alpha particles, blackbody radiation and a relativistic Fermi gas of arbitrary degeneracy. Various neutrino emission processes are considered, with electron/positron capture onto free nucleons providing the dominant contribution to the cooling rate. We find that important temporal and spatial scales, related to the optically thin/optically thick transition are present in the disk, and manifest themselves clearly in the energy output in neutrinos. This transition produces an inversion of the lepton gradient in the innermost regions of the flow which drives convective motions, and affects the density and disk scale height radial profiles. The electron fraction remains low in the region close to the black hole, and if preserved in an outflow, could give rise to heavy element nucleosynthesis. Our specific initial conditions arise from the binary merger context, and so we explore the implications of our results for the production of gamma ray bursts.

  10. Baryogenesis via leptogenesis from quark-lepton symmetry and a compact heavy N{sub R} spectrum

    SciTech Connect (OSTI)

    Buccella, F.; Falcone, D.; Oliver, L. [Dipartimento di Scienze Fisiche, Universita di Napoli, Via Cintia, Napoli (Italy); INFN, Sezione di Napoli (Italy); Dipartimento di Scienze Fisiche, Universita di Napoli, Via Cintia, Napoli (Italy); Laboratoire de Physique Theorique Universite de Paris XI, Batiment 210, 91405 Orsay Cedex (France)

    2011-05-01T23:59:59.000Z

    By demanding a compact spectrum for the right-handed neutrinos and an approximate quark-lepton symmetry inspired from SO(10) gauge unification (assuming a Dirac neutrino mass matrix close to the up quark mass matrix), we construct a fine-tuning scenario for baryogenesis via leptogenesis. We find two solutions with a normal hierarchy, with the lightest neutrino mass m{sub 1} different from zero, providing an absolute scale for the spectrum. In the approximations of the model, there are three independent CP phases: {delta}{sub L} (that we take of the order of the quark Kobayashi-Maskawa phase) and the two light neutrino Majorana phases {alpha} and {beta}. A main conclusion is that, although this general scheme is rather flexible, in some regions of parameter space we find that the necessary baryogenesis with its sign is given in terms of the {delta}{sub L} phase alone. The light Majorana phases can also be computed, and they turn out to be close to {pi}/2 or very small. Moreover, SO(10) breaks down to the Pati-Salam group SU(4)xSU(2)xSU(2) at the expected natural intermediate scale of about 10{sup 10}-10{sup 11} GeV. A prediction is made for the effective mass in ({beta}{beta}){sub 0{nu}} decay, the {nu}{sub e} mass, and the sum of all light neutrino masses.

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

    DOE Data Explorer [Office of Scientific and Technical Information (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.

  12. Search for events with leptonic jets and missing transverse energy in $\\mathbf{p\\bar{p}}$ collisions at $\\mathbf{\\sqrt{s}=1.96}$ TeV

    SciTech Connect (OSTI)

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

    2010-08-01T23:59:59.000Z

    We present the first search for pair production of isolated jets of charged leptons in association with a large imbalance in transverse energy in p{bar p} collisions using 5.8 fb{sup -1} of integrated luminosity collected by the D0 detector at the Fermilab Tevatron Collider. No excess is observed above Standard Model background, and the result is used to set upper limits on the production cross section of pairs of supersymmetric chargino and neutralino particles as a function of 'dark-photon' mass, where the dark photon is produced in the decay of the lightest supersymmetric particle.

  13. Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\\sqrt{s} with the ATLAS Detector

    SciTech Connect (OSTI)

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; /Freiburg U. /Oklahoma U. /Barcelona, IFAE /Geneva U. /Oxford U. /Baku, Inst. Phys. /Oklahoma State U. /Michigan State U. /Tel Aviv U. /Orsay, LAL /INFN, Milan /Milan U. /INFN, Udine /ICTP, Trieste /Brookhaven /Hampton U. /Yale U. /Heidelberg, Max Planck Inst. /Munich U. /Queen Mary, U. of London /Rutherford

    2012-06-20T23:59:59.000Z

    The ATLAS detector is used to search for high-mass states, such as heavy charged gauge bosons (W{prime},W*), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of ppcollisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 36 pb{sup -1}. No excess beyond standard model expectations is observed. A W{prime} with sequential standard model couplings is excluded at 95% confidence level for masses below 1.49 TeV, and a W* (charged chiral boson) for masses below 1.35 TeV.

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

    SciTech Connect (OSTI)

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

    2011-10-14T23:59:59.000Z

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

  15. Leptonic decay of the phi(1020) meson in Au+Au collisions at $\\sqrt{s_{\\rm NN}}$ = 200 GeV measured with the STAR experiment

    E-Print Network [OSTI]

    STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; A. Aparin; D. Arkhipkin; E. C. Aschenauer; G. S. Averichev; A. Banerjee; R. Bellwied; A. Bhasin; A. K. Bhati; P. Bhattarai; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; J. Bouchet; A. V. Brandin; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calder'on de la Barca S'anchez; J. M. Campbell; D. Cebra; M. C. Cervantes; I. Chakaberia; P. Chaloupka; Z. Chang; S. Chattopadhyay; J. H. Chen; X. Chen; J. Cheng; M. Cherney; W. Christie; M. J. M. Codrington; G. Contin; H. J. Crawford; S. Das; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; A. A. Derevschikov; B. di Ruzza; L. Didenko; C. Dilks; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; J. Engelage; G. Eppley; R. Esha; O. Evdokimov; O. Eyser; R. Fatemi; S. Fazio; P. Federic; J. Fedorisin; Feng; P. Filip; Y. Fisyak; C. E. Flores; L. Fulek; C. A. Gagliardi; D. Garand; F. Geurts; A. Gibson; M. Girard; L. Greiner; D. Grosnick; D. S. Gunarathne; Y. Guo; A. Gupta; S. Gupta; W. Guryn; A. Hamad; A. Hamed; R. Haque; J. W. Harris; L. He; S. Heppelmann; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; X. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; H. Jang; K. Jiang; E. G. Judd; S. Kabana; D. Kalinkin; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; Z. H. Khan; D. P. Kikola; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; L. K. Kosarzewski; L. Kotchenda; A. F. Kraishan; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; R. A. Kycia; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; Z. M. Li; Y. Li; X. Li; C. Li; W. Li; X. Li; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; M. Lomnitz; R. S. Longacre; X. Luo; Y. G. Ma; R. Ma; G. L. Ma; L. Ma; N. Magdy; R. Majka; A. Manion; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; K. Meehan; N. G. Minaev; S. Mioduszewski; B. Mohanty; M. M. Mondal; D. A. Morozov; M. K. Mustafa; B. K. Nandi; Md. Nasim; T. K. Nayak; G. Nigmatkulov; L. V. Nogach; S. Y. Noh; J. Novak; S. B. Nurushev; G. Odyniec; A. Ogawa; K. Oh; V. Okorokov; D. L. Olvitt Jr.; B. S. Page; R. Pak; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; A. Peterson; P. Pile; M. Planinic; J. Pluta; N. Poljak; K. Poniatowska; J. Porter; M. Posik; A. M. Poskanzer; N. K. Pruthi; J. Putschke; H. Qiu; A. Quintero; S. Ramachandran; S. Raniwala; R. Raniwala; R. L. Ray; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; A. Roy; L. Ruan; J. Rusnak; O. Rusnakova; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; W. B. Schmidke; N. Schmitz; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; P. V. Shanmuganathan; M. Shao; B. Sharma; M. K. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. Sikora; M. Simko; M. J. Skoby; N. Smirnov; D. Smirnov; D. Solanki; L. Song; P. Sorensen; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; M. Stepanov; R. Stock; M. Strikhanov; B. Stringfellow; M. Sumbera; B. J. Summa; Y. Sun; X. M. Sun; X. Sun; Z. Sun; B. Surrow; D. N. Svirida; M. A. Szelezniak; A. H. Tang; Z. Tang; T. Tarnowsky; A. N. Tawfik; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; S. K. Tripathy; B. A. Trzeciak; O. D. Tsai; T. Ullrich; D. G. Underwood; I. Upsal; G. Van Buren; G. van Nieuwenhuizen; M. Vandenbroucke; R. Varma; A. N. Vasiliev; R. Vertesi; F. Videbaek; Y. P. Viyogi; S. Vokal; S. A. Voloshin; A. Vossen; J. S. Wang; G. Wang; F. Wang; Y. Wang; Y. Wang; H. Wang; G. Webb; J. C. Webb; L. Wen; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; Q. H. Xu; Z. Xu; Y. F. Xu; N. Xu; H. Xu; Y. Yang; S. Yang; Q. Yang; Y. Yang; C. Yang; Z. Ye; P. Yepes; L. Yi; K. Yip; I. -K. Yoo; N. Yu; H. Zbroszczyk; W. Zha; X. P. Zhang; J. B. Zhang; Y. Zhang; J. Zhang; Z. Zhang; J. L. Zhang; S. Zhang; J. Zhao; F. Zhao; C. Zhong; L. Zhou; X. Zhu; Y. Zoulkarneeva; M. Zyzak

    2015-03-13T23:59:59.000Z

    We report the measurement of the phi(1020) meson production via the leptonic decay channel in Au+Au collisions at $\\sqrt{s_{\\rm NN}}$ = 200 GeV from the STAR (Solenoidal Tracker at RHIC) experiment. The transverse momentum ($p_{\\rm T}$) spectrum is measured for 0.1 $\\le p_{\\rm T} \\le 2.5$ GeV/$c$ at mid-rapidity ($|y|\\le1$) with a similar detector setup of corresponding measurements via the hadronic decay channel. We obtain the $p_{\\rm T}$-integrated phi(1020) mass $M_{\\phi}=1017.7\\pm0.8 (\\rm {stat.}) \\pm0.9 (\\rm {sys.})$ MeV/$c^{2}$ and width $\\Gamma_{\\phi} = 8.0\\pm 2.5(\\rm {stat.}) \\pm 2.3(\\rm {sys.}) \\textrm{MeV/}c^{2}$, which are within 1.5 $\\sigma$ and 1.1 $\\sigma$ of the vacuum values, respectively. No significant difference is observed in the reconstructed phi(1020) $p_{\\rm T}$ spectrum, $dN/dy$, or $\\left$ between the leptonic and hadronic decay channels. The experimental results are compared to a theoretical model including the medium-modified phi(1020).

  16. Search for tt¯ resonances in the lepton plus jets final state with ATLAS using 4.7 fb?¹ of pp collisions at ?s=7 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behar Harpaz, S.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Bertella, C.; Bertin, A.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bittner, B.; Black, C. W.; Black, J. E.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brown, G.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.

    2013-07-01T23:59:59.000Z

    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?¹ of proton–proton (pp ) collision data collected at a center-of-mass energy ?s =7 TeV . In the tt¯ ?WbWb decay, the lepton plus jets final state is used, where one W boson decays leptonically and the other hadronically. The tt¯ system is reconstructed using both small-radius and large-radius jets, the latter being supplemented by a jet substructure analysis. A search for local excesses in the number of data events compared to the Standard Model expectation in the tt¯ invariant mass spectrum is performed. No evidence for a tt¯ resonance is found and 95% credibility-level limits on the production rate are determined for massive states predicted in two benchmark models. The upper limits on the cross section times branching ratio of a narrow Z' resonance range from 5.1 pb for a boson mass of 0.5 TeV to 0.03 pb for a mass of 3 TeV. A narrow leptophobic topcolor Z' resonance with a mass below 1.74 TeV is excluded. Limits are also derived for a broad color-octet resonance with ?/m=15.3% . A Kaluza–Klein excitation of the gluon in a Randall–Sundrum model is excluded for masses below 2.07 TeV.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2011-10-14T23:59:59.000Z

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

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2011-10-14T23:59:59.000Z

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

  19. # Leptons at HERA DISSERTATION

    E-Print Network [OSTI]

    , Alessandro Montanari, Mayuko Kataoka, Detlef Bartsch, Eileen Heaphy, Xi­ ang Liu and Heuijin Lim. My special

  20. 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]

    Fermilab

    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

  1. Search for the standard model Higgs boson in the decay channel $H$ to $Z Z$ to 4 leptons in $pp$ collisions at $\\sqrt{s}=7$ TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-03-01T23:59:59.000Z

    A search for a Higgs boson in the four-lepton decay channel H to ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range 110 < mH < 600 GeV. The analysis uses data corresponding to an integrated luminosity of 4.7 inverse femtobarns recorded by the CMS detector in pp collisions at sqrt(s) = 7 TeV from the LHC. Seventy-two events are observed with four-lepton invariant mass m[4 leptons] > 100 GeV (with thirteen below 160 GeV), while 67.1 +/- 6.0 (9.5 +/-1.3) events are expected from background. The four-lepton mass distribution is consistent with the expectation of standard model background production of ZZ pairs. Upper limits at 95% confidence level exclude the standard model Higgs boson in the ranges 134-158 GeV, 180-305 GeV, and 340 -465 GeV. Small excesses of events are observed around masses of 119, 126, and 320 GeV, making the observed limits weaker than expected in the absence of a signal.

  2. Search for direct slepton and gaugino production in final states with two leptons and missing transverse momentum with the ATLAS detector in pp collisions at ?s = 7 TeV

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search for the electroweak pair production of charged sleptons and weak gauginos decaying into final states with two leptons is performed using 4.7 fb[superscript ?1] of proton–proton collision data at ?s = 7 TeV recorded ...

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan [Yerevan Physics Inst. (YerPhI) (Armenia)

    2014-11-01T23:59:59.000Z

    A search is presented for standard model (SM) production of four top quarks (t?tt?t) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6?¹ recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM (t?tt?t) production is ?SM(t?tt?t). A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence level on the cross section for producing four top quarks in the SM, where a limit of 32 ± 17 fb is expected.

  4. A new map of neutrino cosmology - revised bounds on the number of neutrino species and the cosmological lepton asymmetry from WMAP data

    E-Print Network [OSTI]

    Hannestad, S

    2003-01-01T23:59:59.000Z

    We have performed a thorough analysis of the constraints which can be put on neutrino parameters from cosmological observations, most notably those from the WMAP satellite and the 2dF galaxy survey. In terms of the relativistic energy density in neutrinos or other weakly interacting species we find, in units of equivalent number of neutrino species, N_nu, that N_nu = 2.1+1.6-1.8 (95% conf.). This limit on relativistic energy density can be translated into a bound on the neutrino lepton asymmetry of |eta| 5% conf), assuming that the asymmetry is entirely in one flavour. When BBN constraints are added, the bound on N_nu is 2.5 +- 0.5 (95% conf), suggesting that N_nu could possibly be lower than the standard model value of 3. this can for instance be the case in models with very low reheating temperature and incomplete neutrino thermalization.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan

    2014-11-01T23:59:59.000Z

    A search is presented for standard model (SM) production of four top quarks (t?tt?t) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6?¹ recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM (t?tt?t) production is ?SM(t?tt?t). A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence levelmore »on the cross section for producing four top quarks in the SM, where a limit of 32 ± 17 fb is expected.« less

  6. Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan; et al.,

    2014-09-01T23:59:59.000Z

    Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and $\\mathrm{W}$ , $\\mathrm{Z}$ , and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy $\\sqrt{s}=8\\,\\mathrm{TeV}$ with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 $\\,\\text {fb}^\\text {-1}$ . The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 $\\,\\text {GeV}$ , and sleptons up to 260 $\\,\\text {GeV}$ , depending on the modelmore »details.« less

  7. Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan [Yerevan Physics Institute (Armenia); et al.,

    2014-09-01T23:59:59.000Z

    Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and $\\mathrm{W}$ , $\\mathrm{Z}$ , and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy $\\sqrt{s}=8\\,\\mathrm{TeV}$ with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 $\\,\\text {fb}^\\text {-1}$ . The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 $\\,\\text {GeV}$ , and sleptons up to 260 $\\,\\text {GeV}$ , depending on the model details.

  8. Search for supersymmetry in pp collisions at sqrt(s)=7 TeV in events with a single lepton, jets, and missing transverse momentum

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2011-08-01T23:59:59.000Z

    Results are reported from a search for physics beyond the standard model in proton-proton collisions at a center-of-mass energy of 7 TeV, focusing on the signature with a single, isolated, high-transverse-momentum lepton (electron or muon), energetic jets, and large missing transverse momentum. The data sample comprises an integrated luminosity of 36 inverse picobarns, recorded by the CMS experiment at the LHC. The search is motivated by models of new physics, including supersymmetry. The observed event yields are consistent with standard model backgrounds predicted using control samples obtained from the data. The characteristics of the event sample are consistent with those expected for the production of t t-bar and W +jets events. The results are interpreted in terms of limits on the parameter space for the constrained minimal supersymmetric extension of the standard model.

  9. Search for supersymmetry in events with a lepton, a photon, and large missing transverse energy in pp collisions at sqrt(s) = 7 TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2011-06-01T23:59:59.000Z

    A search is performed for an excess of events, over the standard model expectations, with a photon, a lepton, and large missing transverse energy in pp collisions at sqrt(s) = 7 TeV. Such events are expected in many new physics models, in particular a supersymmetric theory that is broken via a gauge-mediated mechanism, when the lightest charged and neutral gauginos are mass degenerate. The data sample used in this search corresponds to an integrated luminosity of 35 inverse picobarns collected with the CMS detector at the LHC. No evidence of such an excess above the standard model backgrounds, dominated by W-gamma production, is found. The results are presented as 95% confidence level upper limits on the cross section for a benchmark gauge-mediated scenario, and are then converted into exclusion limits on the squark, gluino, and wino masses.

  10. SEARCH FOR NEW LIGHT GAUGE BOSONS IN HIGGS DECAYS TO FOUR-LEPTON EVENTS AT $\\sqrt{s}=8$~TEV WITH THE ATLAS DETECTOR

    E-Print Network [OSTI]

    Paredes Hernandez, Daniela; The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    This study presents a search for Higgs bosons decaying to four leptons via one or two light exotic gauge bosons $Z_d$, $H\\rightarrow ZZ_d\\rightarrow4\\ell$ and $H\\rightarrow Z_dZ_d\\rightarrow4\\ell$. The search uses the data taken in $pp$ collisions with the ATLAS detector at the LHC at $\\sqrt{s}=8$~TeV. The observed data are well described by the Standard Model prediction. Upper bounds on the branching ratios of $H\\rightarrow ZZ_d\\rightarrow4\\ell$ and $H\\rightarrow Z_dZ_d\\rightarrow4\\ell$, relative to the branching ratio of $H\\rightarrow 4\\ell$ and to the Standard Model branching ratio of $H\\rightarrow ZZ^*\\rightarrow4\\ell$ respectively, are set as a function of the mass of the exotic vector boson at 95\\% confidence level.

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

    SciTech Connect (OSTI)

    Khachatryan, Vardan [Yerevan Physics Inst. (YerPhI) (Armenia)

    2014-11-01T23:59:59.000Z

    A search is presented for standard model (SM) production of four top quarks (t?tt?t) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6?¹ recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM (t?tt?t) production is ?SM(t?tt?t). A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence level on the cross section for producing four top quarks in the SM, where a limit of 32 ± 17 fb is expected.

  12. Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at ?s = 8 TeV with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O.?S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B.?S.; Adamczyk, L.; Adams, D.?L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A.?A.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J.?A.; Agustoni, M.; Ahlen, S.?P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T.?P.?A.; Akimoto, G.; Akimov, A.?V.; Alberghi, G.?L.; Albert, J.; Albrand, S.; Alconada Verzini, M.?J.; Aleksa, M.; Aleksandrov, I.?N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Alkire, S.?P.; Allbrooke, B.?M.?M.; Allport, P.?P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M.?G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S.?P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L.?S.; Andari, N.; Andeen, T.; Anders, C.?F.; Anders, G.; Anderson, K.?J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.?V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J.?P.; Arce, A.?T.?H.; Arduh, F.?A.; Arguin, J-F.; Argyropoulos, S.; Arik, M.; Armbruster, A.?J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N.?B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Ayoub, M.?K.; Azuelos, G.; Baak, M.?A.; Baas, A.?E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J.?T.; Baker, O.?K.; Balek, P.; Balestri, T.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A.?A.?E.; Bansil, H.?S.; Barak, L.; Baranov, S.?P.; Barberio, E.?L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S.?L.; Barnett, B.?M.; Barnett, R.?M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A.?J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A.?E.; Bartos, P.; Bassalat, A.; Basye, A.; Bates, R.?L.; Batista, S.?J.; Batley, J.?R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H.?S.; Beacham, J.?B.; Beattie, M.?D.; Beau, T.; Beauchemin, P.?H.; Beccherle, R.; Bechtle, P.; Beck, H.?P.; Becker, K.; Becker, M.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A.?J.; Beddall, A.; Bednyakov, V.?A.; Bee, C.?P.; Beemster, L.?J.; Beermann, T.?A.; Begel, M.; Behr, J.?K.; Belanger-Champagne, C.; Bell, P.?J.; Bell, W.?H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J.?A.; Benjamin, D.?P.; Bensinger, J.?R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N.?R.; Bernius, C.; Bernlochner, F.?U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M.?I.; Besjes, G.?J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A.?J.; Bhimji, W.; Bianchi, R.?M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S.?P.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C.?W.; Black, J.?E.; Black, K.?M.; Blackburn, D.; Blair, R.?E.; Blanchard, J.-B.; Blanco, J.?E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G.?J.; Bobrovnikov, V.?S.; Bocchetta, S.?S.; Bocci, A.; Bock, C.; Boehler, M.; Bogaerts, J.?A.; Bogdanchikov, A.?G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A.?S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E.?V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boveia, A.; Boyd, J.; Boyko, I.?R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J.?E.; Braun, H.?M.; Brazzale, S.?F.; Brendlinger, K.; Brennan, A.?J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T.?M.; Britton, D.; Britzger, D.; Brochu, F.?M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W.?K.; Brosamer, J.; Brost, E.; Brown, J.

    2015-06-01T23:59:59.000Z

    A search has been performed for pair production of heavy vectorlike down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising from b quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3??fb?¹. No significant excess of events is observed above the expected background. Limits are set on vectorlike B production, as a function of the B branching ratios, assuming the allowable decay modes are B ? Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B ? Wt, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 810 GeV (760 GeV). In the case where the vectorlike B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T5/3, with subsequent decay T5/3 ? Wt, sets an observed (expected) 95% C.L. lower limit on the T5/3 mass of 840 GeV (780 GeV).

  13. Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at ?s = 8 TeV with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O.?S.; Abramowicz, H.; Abreu, H.; Abreu, R.; et al

    2015-06-01T23:59:59.000Z

    A search has been performed for pair production of heavy vectorlike down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising from b quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8more »TeV, corresponding to an integrated luminosity of 20.3 fb?¹. No significant excess of events is observed above the expected background. Limits are set on vectorlike B production, as a function of the B branching ratios, assuming the allowable decay modes are B ? Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B ? Wt, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 810 GeV (760 GeV). In the case where the vectorlike B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T5/3, with subsequent decay T5/3 ? Wt, sets an observed (expected) 95% C.L. lower limit on the T5/3 mass of 840 GeV (780 GeV).« less

  14. Measurement of the production and lepton charge asymmetry of $\\textit{W}$ bosons in Pb+Pb collisions at $\\sqrt{s_{\\mathrm{\\mathbf{NN}}}}=$ 2.76 TeV with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-01-26T23:59:59.000Z

    A measurement of $\\textit{W}$ boson production in lead-lead collisions at $\\sqrt{s_{\\mathrm{NN}}}=$2.76 TeV is presented. It is based on the analysis of data collected with the ATLAS detector at the LHC in 2011 corresponding to an integrated luminosity of 0.14 $\\mathrm{nb}^{-1}$ and 0.15 $\\mathrm{nb}^{-1}$ in the muon and electron decay channels, respectively. The differential production yields and lepton charge asymmetry are each measured as a function of the average number of participating nucleons $$ and absolute pseudorapidity of the charged lepton. The results are compared to predictions based on next-to-leading-order QCD calculations. These measurements are, in principle, sensitive to possible nuclear modifications to the parton distribution functions and also provide information on scaling of $\\textit{W}$ boson production in multi-nucleon systems.

  15. 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 [Office of Scientific and Technical Information (OSTI)]

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

    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 functionsö 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://hepdata.cedar.ac.uk/reaction

  16. Measurements of the Higgs boson mass and width in the four-lepton final state and electron reconstruction in the CMS experiment at the LHC

    E-Print Network [OSTI]

    Dalchenko, Mykhailo; Charlot, Claude

    This thesis document reports measurements of the mass and width of the new boson re- cently discovered at the Large Hadron Collider (LHC), candidating to be the Standard Model Higgs boson. The analysis uses proton-proton collision data recorded by the Compact Muon Solenoid (CMS) detector at the LHC, corresponding to integrated luminosities of $5.1~fb^{?1}$ at $7~$TeV center of mass energy and $19.7~fb^{?1}$ at $8~$TeV center of mass energy. Set of events selecting Higgs boson via the $H\\to ZZ$ decay channel, where both $Z$ bosons decay to electron or muon lepton pairs, is used for the Higgs boson properties measurements. A precise measurement of its mass has been performed and gives $125.6\\pm0.4\\mbox{(stat)}\\pm0.2\\mbox{(syst)}~$GeV. Constraints on the Higgs boson width were established using its off-shell production and decay to a pair of $Z$ bosons, where one $Z$ boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The obtained result is an upper limit on the Hi...

  17. Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at $\\sqrt{s} =$ 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan [Yerevan Phys. Inst. (Armenia); et al.,

    2014-08-01T23:59:59.000Z

    A search for new resonances decaying to WW, ZZ, or WZ is presented. Final states are considered in which one of the vector bosons decays leptonically and the other hadronically. Results are based on data corresponding to an integrated luminosity of 19.7 inverse femtobarns recorded in proton-proton collisions at $\\sqrt{s}$ = 8 TeV with the CMS detector at the CERN LHC. Techniques aiming at identifying jet substructures are used to analyze signal events in which the hadronization products from the decay of highly boosted W or Z bosons are contained within a single reconstructed jet. Upper limits on the production of generic WW, ZZ, or WZ resonances are set as a function of the resonance mass and width. We increase the sensitivity of the analysis by statistically combining the results of this search with a complementary study of the all-hadronic final state. Upper limits at 95% confidence level are set on the bulk graviton production cross section in the range from 700 to 10 femtobarns for resonance masses between 600 and 2500 GeV, respectively. These limits on the bulk graviton model are the most stringent to date in the diboson final state.

  18. Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing transverse momentum in pp collisions at 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan; et al.,

    2015-04-01T23:59:59.000Z

    The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton-proton collisions collected at center-of-mass energy $\\sqrt{s}$ = 8 TeV with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 inverse femtobarns. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in which SUSYmore »is approximately conserved. The data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation, and the results are used to set limits on squark pair production in the stealth SUSY framework.« less

  19. UHE Leptons and Neutrons feeding Precessing gamma Jet in GRBs - SGRs: A SGR 1806-20 link to EeV C.R.?

    E-Print Network [OSTI]

    D. Fargion; M. Grossi

    2005-05-09T23:59:59.000Z

    Soft Gamma Repeaters are widely believed to occur as isotropic Magnetar explosion. We suggest on the contrary that they may be described by thin collimated spinning and precessing Gamma Jets flashing and blazing along the line of sight. The Jet (for SGRs) maybe powered by an accretion disk in binary system and it reproduces huge outflow and oscillating blazing mode as the observed ones in Giant Flare SGR 1806-20. The precessing and spinning blazing nature reflects at smaller intensity the same behavior observed in brief GRBs Jetted Supernova, as well as re-brightening and bumps in afterglows. The SGR gamma beam maybe powered by Inverse Compton Scattering or by Synchrotron Radiation of electron pair beam respectively at GeVs or PeVs energies. In the latter case tens PeVs leptons (muons and later decaying PeVs electrons) might be originated while EeV nucleons Jets (protons-neutrons) are in photo-pion equilibrium with infrared photons surrounding the source. The neutron Jet might survive and remain collimated. It maybe already detected as an EeV cosmic ray anisotropy in present AGASA map pointing toward known (North Hemisphere) SGRs : SGR 1900 +14 and SGR 1806-20. If the SGR-EeV connection is correct a parasite traces of PeVs neutrino as well PeV-TeVs gamma rays might be found in present or future data records, among the others C.R. array detectors, inside the Amanda and Milagro volumes.

  20. Masses and Mixing Matrices of Families of Quarks and Leptons Within the Spin-Charge-Family theory, predictions beyond the tree level

    E-Print Network [OSTI]

    Hernandez-Galeana, A

    2011-01-01T23:59:59.000Z

    The {\\it theory unifying spin and charges and predicting families}, proposed by N.S.M.B., predicts at the low energy regime two (in the mixing matrix elements decoupled) groups of four families. There are two kinds of contributions to mass matrices in this theory. One kind distinguishes on the tree level only among the members of one family, that is among the $u$-quark, $d$-quark, neutrino and electron, the left and right handed, while the other kind distinguishes only among the families. Mass matrices for $d$-quarks and electrons are on the tree level correspondingly strongly correlated and so are mass matrices for $u$-quarks and neutrinos, up to the term, the Majorana term, which is nonzero only for right handed neutrinos. Beyond the tree level both kinds of contributions start to contribute coherently and it is expected that a detailed study of properties of mass matrices beyond the tree level explains drastic differences in masses and mixing matrices between quarks and leptons. We report in this paper on ...

  1. Masses and Mixing Matrices of Families of Quarks and Leptons Within the Spin-Charge-Family theory, predictions beyond the tree level

    E-Print Network [OSTI]

    A. Hernandez-Galeana; N. S. Mankoc Borstnik

    2011-12-19T23:59:59.000Z

    The {\\it theory unifying spin and charges and predicting families}, proposed by N.S.M.B., predicts at the low energy regime two (in the mixing matrix elements decoupled) groups of four families. There are two kinds of contributions to mass matrices in this theory. One kind distinguishes on the tree level only among the members of one family, that is among the $u$-quark, $d$-quark, neutrino and electron, the left and right handed, while the other kind distinguishes only among the families. Mass matrices for $d$-quarks and electrons are on the tree level correspondingly strongly correlated and so are mass matrices for $u$-quarks and neutrinos, up to the term, the Majorana term, which is nonzero only for right handed neutrinos. Beyond the tree level both kinds of contributions start to contribute coherently and it is expected that a detailed study of properties of mass matrices beyond the tree level explains drastic differences in masses and mixing matrices between quarks and leptons. We report in this paper on analysis of one loop corrections to the tree level fermion masses and mixing matrices. Loop diagrams are mediated by the gauge bosons and the two kinds of scalar fields. A detailed numerical analysis of fermion masses and mixing, including neutrinos, within this scenario is in progress and preparation.

  2. Measurement of the Top Quark Mass by Dynamical Likelihood Method using the Lepton + Jets Events with the Collider Detector at Fermilab

    SciTech Connect (OSTI)

    Kubo, Taichi; /Tsukuba U.

    2008-02-01T23:59:59.000Z

    We have measured the top quark mass with the dynamical likelihood method. The data corresponding to an integrated luminosity of 1.7fb{sup -1} was collected in proton antiproton collisions at a center of mass energy of 1.96 TeV with the CDF detector at Fermilab Tevatron during the period March 2002-March 2007. We select t{bar t} pair production candidates by requiring one high energy lepton and four jets, in which at least one of jets must be tagged as a b-jet. In order to reconstruct the top quark mass, we use the dynamical likelihood method based on maximum likelihood method where a likelihood is defined as the differential cross section multiplied by the transfer function from observed quantities to parton quantities, as a function of the top quark mass and the jet energy scale(JES). With this method, we measure the top quark mass to be 171.6 {+-} 2.0 (stat.+ JES) {+-} 1.3(syst.) = 171.6 {+-} 2.4 GeV/c{sup 2}.

  3. Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing transverse momentum in pp collisions at 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan [Yerevan Physics Institute (Armenia); et al.,

    2015-04-01T23:59:59.000Z

    The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton-proton collisions collected at center-of-mass energy $\\sqrt{s}$ = 8 TeV with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 inverse femtobarns. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in which SUSY is approximately conserved. The data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation, and the results are used to set limits on squark pair production in the stealth SUSY framework.

  4. Leptonic decay constants fK, fD and fDs with Nf = 2+1+1 twisted-mass lattice QCD

    E-Print Network [OSTI]

    N. Carrasco; P. Dimopoulos; R. Frezzotti; P. Lami; V. Lubicz; F. Nazzaro; E. Picca; L. Riggio; G. C. Rossi; F. Sanfilippo; S. Simula; C. Tarantino

    2015-02-25T23:59:59.000Z

    We present a lattice QCD calculation of the pseudoscalar decay constants fK, fD and fDs performed using the gauge configurations produced by the European Twisted Mass Collaboration with Nf = 2 + 1 + 1 dynamical quarks, which include in the sea, besides two light mass degenerate quarks, also the strange and charm quarks with masses close to their values in the real world. The simulations are based on a unitary setup for the two light mass-degenerate quarks and on a mixed action approach for the strange and charm quarks. We use data simulated at three different values of the lattice spacing in the range 0.06 - 0.09 fm and at pion masses in the range 210 - 450 MeV. Our main results are: fK+ / fpi+ = 1.184 (16), fK+ = 154.4 (2.0) MeV, which incorporate the leading strong isospin breaking correction due to the up- and down-quark mass difference, and fK = 155.0 (1.9) MeV, fD = 207.4 (3.8) MeV, fDs = 247.2 (4.1) MeV, fDs / fD = 1.192 (22) and (fDs / fD) / (fK / fpi) = 1.003 (14) obtained in the isospin symmetric limit of QCD. Combined with the experimental measurements of the leptonic decay rates of kaon, pion, D- and Ds-mesons our results lead to the following determination of the CKM matrix elements: |Vus| = 0.2269 (29), |Vcd| = 0.2221 (67) and |Vcs| = 1.014 (24). Using the latest value of |Vud| from superallowed nuclear beta decays the unitarity of the first row of the CKM matrix is fulfilled at the permille level.

  5. A Meaurement of the W+- production cross section in p anti-p collisions at sqroot(s)=1.96 TeV in the DiLepton channel and limits on anomalous WWZ/gamma couplings

    SciTech Connect (OSTI)

    McGivern, Dustin; /University Coll. London

    2005-12-01T23:59:59.000Z

    Measurements of the production cross section of W{sup +}W{sup -} pairs in p{bar p} collisions at 1.96 TeV and limits on trilinear gauge boson coupling (TGC) parameters are presented. The data were recorded with the CDF experiment at Tevatron during the 2001 and 2002 data taking periods in which a total integrated luminosity of 184 pb{sup -1} was collected. The data sample was filtered for events with two leptonic w boson decays where the charged leptons can be either electrons or muons. 17 events are observed against an expected background of 5.0{sub -0.8}{sup +2.2} events. The resulting cross-section is found to be {sigma}(p{bar p} {yields} W{sup +}W{sup -}) = 14.5{sub -5.1}{sup +5.8}(stat){sub -3.0}{sup +1.8}(syst) {+-} 0.9(lum) pb and agrees well with the Standard Model expectation. Limits on the TGC parameters {Delta}{kappa} and {lambda} are set under both the equal coupling scheme, that assumes the W boson couples identically to the Z and {gamma}, and the HISZ coupling scheme, that requires the couplings to respect SU(2){sub L} x &(1){sub Y} gauge symmetry. In both cases this is achieved by using a likelihood fit to the lepton-P{sub T} distribution of the 17 candidate events. The resulting limits are found to be: -0.4 < {Delta}{kappa} < +0.6({lambda} = 0); -0.3 < {lambda} < +0.4 ({Delta}{kappa} = 0) for the EQUAL couplings and -0.7 < {Delta}{kappa} < +0.9 ({lambda} = 0); -0.4 < {lambda} < +0.4 ({Delta}{kappa} = 0) for the HISZ couplings.

  6. Search for High-Mass Resonances Decaying into Leptons of Different Flavor (e mu, e tau, mu tau) in p anti-p Collisions at sqrt(s) = 1.96 TeV

    SciTech Connect (OSTI)

    Tu, Yanjun; /Pennsylvania U.

    2008-10-01T23:59:59.000Z

    We present a search for high-mass resonances decaying into two leptons of different flavor: e{mu}, e{tau}, and {mu}{tau}. These resonances are predicted by several models beyond the standard model, such as the R-parity-violating MSSM. The search is based on 1 fb{sup -1} of data collected at the Collider Detector at Fermilab (CDF II) in proton anti-proton collisions. Our observations are consistent with the standard model expectations. The results are interpreted to set 95% C.L. upper limits on {sigma} x BR of {tilde {nu}}{sub {tau}} {yields} e{mu}, e{tau}, {mu}{tau}.

  7. 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 (OSTI)

    Buzatu, Adrian; /McGill U.

    2011-08-01T23:59:59.000Z

    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

  8. Measurement of the Single Top Quark Cross Section in the Lepton Plus Jets Final State in Proton-Antiproton Collisions at a Center of Mass Energy of 1.96 TeV Using the CDF II Detector

    SciTech Connect (OSTI)

    Wu, Zhenbin

    2012-01-01T23:59:59.000Z

    We present a measurement of the single top quark cross section in the lepton plus jets final state using an integrated luminosity corresponding to 7.5~\\text{fb}^{-1} of p\\bar p collision data collected by the Collider Detector at Fermilab. The single top candidate events are identified by the signature of a charged lepton, large missing transverse energy, and two or three jets with at least one of them identified as originating from a bottom quark. A new Monte Carlo generator \\textsc{powheg} is used to model the single top quark production processes, which include {s}-channel, {t}-channel, and {Wt}-channel. A neural network multivariate method is exploited to discriminate the single top quark signal from the comparatively large backgrounds. We measure a single top production cross section of $3.04^{+0.57}_{-0.53}$ (\\mathrm{stat.~+~syst.}) pb assuming $m_{\\rm top}=172.5$~GeV/$c^2$. In addition, we extract the CKM matrix element value $|V_{tb}|=0.96\\pm 0.09~(\\mathrm{stat.~+~syst.})\\pm 0.05~(\\mathrm{theory})$ and set a lower limit of |V_{tb}|>0.78 at the 95\\% credibility level.

  9. Search for Lepton Flavour Violating Decays of Heavy Resonances and Quantum Black Holes to electron/muon Pairs in pp Collisions at a centre of mass energy of 8 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    2015-01-01T23:59:59.000Z

    A search for heavy states decaying into the e$\\mu$ final state has been performed using an integrated luminosity of $19.7~\\text{fb}^{-1}$ of $8\\,\\text{TeV}$ proton-proton collision data recorded with the CMS detector at the LHC. No evidence for physics beyond the Standard Model is observed in the invariant mass spectrum of selected e$\\mu$ pairs. 95$\\%$ CL upper limits are set on the cross section times branching ratio of different signals arising in theories of new physics with lepton flavour violation in interactions involving charged leptons. In the framework of TeV-scale quantum gravity from a renormalization of Newton's constant, exclusion limits are set on the production threshold of quantum black holes for threshold masses below $1.99\\,\\text{TeV}$, and in extra-dimensional models the bounds range from $2.36\\,\\text{TeV}$ for one extra dimension to $3.63\\,\\text{TeV}$ for six extra dimensions. Scenarios of resonant tau sneutrino LSP production in R-parity violating supersymmetry are excluded for LSP masses...

  10. 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 lifetime b-tagging

    SciTech Connect (OSTI)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G.A.; Anastasoaie, M.; Andeen, T.; Anderson, S.; Andrieu, B.; Arnoud, Y.; Askew, A.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao

    2005-04-01T23:59:59.000Z

    We present a measurement of the top quark pair (t{bar t}) production cross section ({sigma}{sub t{bar t}}) in p{bar p} collisions at {radical}s = 1.96 TeV using 230 pb{sup -1} of data collected by the D0 experiment at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), missing transverse energy, and jets in the final state. We employ lifetime-based b-jet identification techniques to further enhance the t{bar t} purity of the selected sample. For a top quark mass of 175 GeV, we measure {sigma}{sub t{bar t}} = 8.6{sub -1.5}{sup +1.6}(stat. + syst.) {+-} 0.6 (lumi.) pb, in agreement with the standard model expectation.

  11. Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96 = TeV using kinematic characteristics of lepton + jets events

    SciTech Connect (OSTI)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G.A.; Anastasoaie, M.; Andeen, T.; Anderson, S.; Andrieu, B.; Arnoud, Y.; Askew, A.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao

    2005-04-01T23:59:59.000Z

    We present a measurement of the top quark pair (t{bar t}) production cross section ({sigma}{sub t{bar t}}) in p{bar p} collisions at a center-of-mass energy of 1.96 TeV using 230 pb{sub -1} of data collected by the D0 detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the t{bar t} content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure {sigma}{sub t{bar t}} = 6.7{sub -1.3}{sup +1.4}(stat){sub -1.1}{sup +1.6}(syst) {+-} 0.4(lumi)pb, in good agreement with the standard model prediction.

  12. Search for the standard model Higgs boson decaying to a $W$ pair in the fully leptonic final state in $pp$ collisions at $\\sqrt{s}=7$ TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-03-01T23:59:59.000Z

    A search for the standard model Higgs boson decaying to W+W- in pp collisions at sqrt(s) = 7 TeV is reported. The data are collected at the LHC with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. The W+W- candidates are selected in events with two charged leptons and large missing transverse energy. No significant excess of events above the standard model background expectations is observed, and upper limits on the Higgs boson production relative to the standard model Higgs expectation are derived. The standard model Higgs boson is excluded in the mass range 129-270 GeV at 95% confidence level.

  13. A search for $t\\bar{t}$ resonances using lepton-plus-jets events in proton-proton collisions at $\\sqrt{s} = 8$ TeV with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-05-26T23:59:59.000Z

    A search for new particles that decay into top quark pairs is reported. The search is performed with the ATLAS experiment at the LHC using an integrated luminosity of 20.3 fb$^{-1}$ of proton-proton collision data collected at a centre-of-mass energy of $\\sqrt{s}=8$ TeV. The lepton-plus-jets final state is used, where the top pair decays to $W^+bW^-\\bar{b}$, with one $W$ boson decaying leptonically and the other hadronically. The invariant mass spectrum of top quark pairs is examined for local excesses or deficits that are inconsistent with the Standard Model predictions. No evidence for a top quark pair resonance is found, and 95% confidence-level limits on the production rate are determined for massive states in benchmark models. The upper limits on the cross-section times branching ratio of a narrow $Z'$ boson decaying to top pairs range from 4.2 pb to 0.03 pb for resonance masses from 0.4 TeV to 3.0 TeV. A narrow leptophobic topcolour $Z'$ boson with mass below 1.8 TeV is excluded. Upper limits are set on the cross-section times branching ratio for a broad colour-octet resonance with $\\Gamma/m =$ 15% decaying to $t\\bar{t}$. These range from 2.5 pb to 0.03 pb for masses from 0.4 TeV to 3.0 TeV. A Kaluza-Klein excitation of the gluon in a Randall-Sundrum model is excluded for masses below 2.2 TeV.

  14. 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 (OSTI)

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

    2006-12-01T23:59:59.000Z

    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}}.

  15. Search for new light gauge bosons in Higgs boson decays to four-lepton final states in $pp$ collisions at $\\sqrt{s}=8~$TeV with the ATLAS detector at the LHC.

    E-Print Network [OSTI]

    The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    This paper presents a search for Higgs bosons decaying to four leptons via one or two light exotic gauge bosons $Z_d$, $H\\to Z Z_d \\to 4\\ell$ and $H \\to Z_dZ_d \\to 4\\ell$ ($\\ell=e$ or $\\mu$). The search is performed using $pp$ collision data corresponding to an integrated luminosity of about 20~\\ifb\\ at the center-of-mass energy of $\\sqrt{s}=8~$TeV recorded with the ATLAS detector at the Large Hadron Collider. The observed data are well described by the Standard Model prediction. Upper bounds at 95\\% confidence level are set on the relative branching ratios $BR(H \\to ZZ_d\\to 4\\ell)$ to $BR(H \\to 4\\ell)$ for the exotic vector boson masses between 15 and 55~GeV, and $BR(H \\to Z_dZ_d \\to 4\\ell)$ to $BR(H \\to ZZ^* \\to 4\\ell)$ for the exotic vector boson masses between 15 and 60~GeV.

  16. Search for new light gauge bosons in Higgs boson decays to four-lepton final states in $pp$ collisions at $\\sqrt{s}=8$TeV with the ATLAS detector at the LHC

    E-Print Network [OSTI]

    Aad, Georges; ATLAS Collaboration; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Maurice; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet

    2015-01-01T23:59:59.000Z

    This paper presents a search for Higgs bosons decaying to four leptons, either electrons or muons, via one or two light exotic gauge bosons $Z_d$, $H\\to Z Z_d \\to 4\\ell$ or $H\\to Z_d Z_d \\to 4\\ell$. The search was performed using $pp$ collision data corresponding to an integrated luminosity of about 20 fb$^{-1}$ at the center-of-mass energy of $\\sqrt{s}=8 $TeV recorded with the ATLAS detector at the Large Hadron Collider. The observed data are well described by the Standard Model prediction. Upper bounds on the branching ratio of $H\\to Z Z_d \\to 4\\ell$ and on the kinetic mixing parameter between the $Z_d$ and the Standard Model hypercharge gauge boson are set in the range $(1$--$9)\\times10^{-5}$ and $(4$--$17)\\times10^{-2}$ respectively, at 95% confidence level assuming the Standard Model branching ratio of $H\\to Z Z^* \\to 4\\ell$, for $Z_d$ masses between 15 and 55 GeV. Upper bounds on the effective mass mixing parameter between the $Z$ and the $Z_d$ are also set using the branching ratio limits in the $H \\to...

  17. 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

    SciTech Connect (OSTI)

    Aaltonen, Timo Antero; et al,

    2013-11-01T23:59:59.000Z

    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.

  18. Search for anomalous production of prompt same-sign lepton pairs and pair-produced doubly charged Higgs bosons with $\\sqrt{s} = 8$ TeV $pp$ collisions using the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-03-16T23:59:59.000Z

    A low-background inclusive search for new physics in events with same-sign dileptons is presented. The search uses proton-proton collisions corresponding to 20.3 fb$^{-1}$ of integrated luminosity taken in 2012 at a centre-of-mass energy of 8 TeV with the ATLAS detector at the LHC. Pairs of isolated leptons with the same electric charge and large transverse momenta of the type $e^{\\pm}e^{\\pm}, e^{\\pm}\\mu^{\\pm}$, and $\\mu^{\\pm}\\mu^{\\pm}$ are selected and their invariant mass distribution is examined. No excess of events above the expected level of Standard Model background is found. The results are used to set upper limits on the cross-sections for processes beyond the Standard Model. Limits are placed as a function of the dilepton invariant mass within a fiducial region corresponding to the signal event selection criteria. Exclusion limits are also derived for a specific model of doubly charged Higgs boson production.

  19. Search for WW and WZ production in lepton, neutrino plus jets final states at CDF Run II and Silicon module production and detector control system for the ATLAS SemiConductor Tracker

    SciTech Connect (OSTI)

    Sfyrla, Anna; /Geneva U.

    2008-03-01T23:59:59.000Z

    In the first part of this work, we present a search for WW and WZ production in charged lepton, neutrino plus jets final states produced in p{bar p} collisions with {radical}s = 1.96 TeV at the Fermilab Tevatron, using 1.2 fb{sup -1} of data accumulated with the CDF II detector. This channel is yet to be observed in hadron colliders due to the large singleWplus jets background. However, this decay mode has a much larger branching fraction than the cleaner fully leptonic mode making it more sensitive to anomalous triple gauge couplings that manifest themselves at higher transverse W momentum. Because the final state is topologically similar to associated production of a Higgs boson with a W, the techniques developed in this analysis are also applicable in that search. An Artificial Neural Network has been used for the event selection optimization. The theoretical prediction for the cross section is {sigma}{sub WW/WZ}{sup theory} x Br(W {yields} {ell}{nu}; W/Z {yields} jj) = 2.09 {+-} 0.14 pb. They measured N{sub Signal} = 410 {+-} 212(stat) {+-} 102(sys) signal events that correspond to a cross section {sigma}{sub WW/WZ} x Br(W {yields} {ell}{nu}; W/Z {yields} jj) = 1.47 {+-} 0.77(stat) {+-} 0.38(sys) pb. The 95% CL upper limit to the cross section is estimated to be {sigma} x Br(W {yields} {ell}{nu}; W/Z {yields} jj) < 2.88 pb. The second part of the present work is technical and concerns the ATLAS SemiConductor Tracker (SCT) assembly phase. Although technical, the work in the SCT assembly phase is of prime importance for the good performance of the detector during data taking. The production at the University of Geneva of approximately one third of the silicon microstrip end-cap modules is presented. This collaborative effort of the university of Geneva group that lasted two years, resulted in 655 produced modules, 97% of which were good modules, constructed within the mechanical and electrical specifications and delivered in the SCT collaboration for assembly on the end-cap disks. The SCT end-caps and barrels consist of 4088 silicon modules, with a total of 6.3 million readout channels. The coherent and safe operation of the SCT during commissioning and subsequent operation is the essential task of the Detector Control System (DCS). The main building blocks of the DCS are the cooling system, the power supplies and the environmental system. The DCS has been initially developed for the SCT assembly phase and this system is described in the present work. Particular emphasis is given in the environmental hardware and software components, that were my major contributions. Results from the DCS testing during the assembly phase are also reported.

  20. 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 (OSTI)

    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,

    2005-12-01T23:59:59.000Z

    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}.

  1. Supersymmetric Dark Matter and Lepton Flavor Violation

    E-Print Network [OSTI]

    Soleimani, Ali

    2010-05-07T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1.5 Notation and Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 1.6 Flavor violation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 1.6.1 Quark sector flavor....3) LHiggs = |Dµ?|2 +µ2?†???(?†?)2, (1.4) and LYukawa = summationdisplay generations bracketleftBig ?fe¯L·?eR ?fd ¯Q·?dR ?fuepsilon1ab ¯Qa?†buR + h.c. bracketrightBig . (1.5) Here, Gµ?A , Wµ?A , Bµ? are the color, weak isospin and hypercharge field tensors...

  2. DECAYS OF THE HEAVY LEPTON, TAU (1785)

    E-Print Network [OSTI]

    Blocker, Craig Alan

    2010-01-01T23:59:59.000Z

    G. S. Abrams et. a_K , PRL 4_3, 1555 (1979) W. Davies-WhiteL. v. C. Perl L. e t al_. , PRL 3 5 , al_. , et 63B, f,f^l. , Cavalli-Sforza J. Felinan PRL _3f r 558 H" (197

  3. Martin Perl and the Tau Lepton

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilAElectronicCurves | SciTech ConnectLow-Cycle-FatigueofDeptOffice ofDeptMartin

  4. Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States using a Topological Multivariate Technique as well as Lifetime b-Tagging in Proton - Anti-proton Collisions at s**(1/2)=1.96 TeV with the D0 Detector at the Tevatron

    SciTech Connect (OSTI)

    Golling, Tobias F

    2005-01-01T23:59:59.000Z

    Two alternative measurements of the t{bar t} production cross section at {radical}s = 1.96 TeV in proton-antiproton collisions in the lepton+jets channel are presented. The t{bar t} production cross section is extracted by combining the kinematic event information in a multivariate discriminant. The measurement yields {sigma}{sub p{bar p} {yields} t{bar t} + x} = 5.13{sub -1.57}{sup +1.76}(stat){sub -1.10}{sup +0.96}(syst) {+-} 0.33 (lumi) pb in the muon+jets channel, using 229.1 pb{sup -1}, and in the combination with the electron+jets channel 226.3 pb{sup -1} {sigma}{sub p{bar p} {yields} t{bar t} + x} = 6.60{sub -1.28}{sup +1.37}(stat){sub -1.11}{sup +1.25}(syst) {+-} 0.43 (lumi) pb. The second measurement presented reconstructs explicitly secondary vertices to d lifetime b-tagging. The measurement combines the muon+jets and the electron+jets channel, using 158.4 pb{sup -1} and 168.8 pb{sup -1}, respectively: {sigma}{sub p{bar p} {yields} t{bar t} + x} = 8.24{sub -1.25}{sup +1.34}(stat){sub -1.63}{sup +1.89}(syst) {+-} 0.54 (lumi) pb.

  5. TESLA*HERA as Lepton (Photon)-Hadron Collider

    E-Print Network [OSTI]

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

    2000-04-11T23:59:59.000Z

    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.

  6. A 233 km tunnel for lepton and hadron colliders

    SciTech Connect (OSTI)

    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

    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.

  7. Neutrino mass, lepton number, and the origin of matter

    E-Print Network [OSTI]

    antiparticles? And many other things% Do neutrinos violate CP? #12;Neutrinoless Double Beta Decay W. Rodejohann? #12;Neutrinoless Double Beta Decay 1 sigma W. Rodejohann, 1206.2560 #12;14 F. Iachello #12;15 Regions

  8. Non-leptonic decays of charmed mesons into two Pseudoscalars

    E-Print Network [OSTI]

    Biswas, Aritra; Abbas, Gauhar

    2015-01-01T23:59:59.000Z

    We examine the role of resonant coupled channel final state interactions (FSI), as well as weak annihilation and exchange contributions in explaining all the two body hadronic $D\\rightarrow PP$ decay modes data. In the un-unitarized amplitudes we include modified Wilson coefficients with non-factorizable corrections as parameters. For the hadronic form factors the z-series expansion method is used to get the $q^2$ dependence. The FSI effects are incorporated via a phenomenological approach with widths of resonances to various channels taken from observations where available, and others as additional parameters to be determined from fits of all the theoretical rates to the measured ones. Our results for the rather hard to explain $D^0\\rightarrow K^+K^-, \\pi^+\\pi^- $ are in agreement with measured values. We demonstrate that both weak exchange as well as FSI effects are required to get the correct branching ratio for the $D^0\\rightarrow K^0\\bar{K^0}$ mode. Using our unitarized amplitudes we evaluate the strong ...

  9. Phenomenology of Maximal and Near-Maximal Lepton Mixing

    E-Print Network [OSTI]

    M. C. Gonzalez-Garcia; C. Peña-Garay; Y. Nir; A. Yu. Smirnov

    2000-09-18T23:59:59.000Z

    We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other ($x$=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter $\\epsilon\\equiv1-2\\sin^2\\theta_{ex}$ and quantify the present experimental status for $|\\epsilon|<0.3$. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for $10^{-8}$ eV$^2\\lsim\\Delta m^2\\lsim2\\times10^{-7}$ eV$^2$. In the mass ranges $\\Delta m^2\\gsim 1.5\\times10^{-5}$ eV$^2$ and $4\\times10^{-10}$ eV$^2\\lsim\\Delta m^2\\lsim2\\times10^{-7}$ eV$^2$ the full interval $|\\epsilon|<0.3$ is allowed within 4$\\sigma$(99.995 % CL). We suggest ways to measure $\\epsilon$ in future experiments. The observable that is most sensitive to $\\epsilon$ is the rate [NC]/[CC] in combination with the Day-Night asymmetry in the SNO detector. With theoretical and statistical uncertainties, the expected accuracy after 5 years is $\\Delta \\epsilon\\sim 0.07$. We also discuss the effects of maximal and near-maximal $\

  10. Search for neutrinoless decays of the tau lepton

    E-Print Network [OSTI]

    Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Lam, H.

    1994-10-01T23:59:59.000Z

    . The upper limits obtained for 22 decay branching fractions are several times more stringent than those set previously....

  11. Non-leptonic decays of Charmed mesons into two Pseudoscalars

    E-Print Network [OSTI]

    Aritra Biswas; Nita Sinha; Gauhar Abbas

    2015-04-20T23:59:59.000Z

    We examine the role of resonant coupled channel final state interactions (FSI), as well as weak annihilation and exchange contributions in explaining all the two body hadronic $D\\rightarrow PP$ decay modes data. In the un-unitarized amplitudes we include modified Wilson coefficients with non-factorizable corrections as parameters. For the hadronic form factors, the z-series expansion method is used to get the $q^2$ dependence. The FSI effects are incorporated via a phenomenological approach with widths of resonances to various channels taken from observations where available, and others as additional parameters to be determined from fits of all the theoretical rates to the measured ones. Our results for the rather hard to explain $D^0\\rightarrow K^+K^-, \\pi^+\\pi^- $ are in agreement with measured values. We demonstrate that both weak exchange as well as FSI effects are required to get the correct branching ratio for the $D^ \\rightarrow K^0\\bar{K^0}$ mode. Using our unitarized amplitudes we evaluate the strong phase difference between the amplitudes for $D^0\\rightarrow K^-\\pi^+$ and $D^0\\rightarrow K^+\\pi^-$ and find it to be in complete agreement with the recent BES III result.

  12. Leptonic and Semileptonic Decays of D and Ds Mesons

    E-Print Network [OSTI]

    · backgrounds from Ds semileptonic decays · Consistent results 7 PRL 100, 161801 (2008) #12;M. R. Shepherd PANIC08, Eilat November 11, 2008 Ds(,) and fDs Summary 8 (Preliminary) (Preliminary) (PRL 100, 161801 11, 2008 9 Belle (63% of current data) PRL 100, 241801 (2008) BaBar (47% of data) PRL 98, 141801

  13. Measurement of di-lepton widths and branching fractions

    E-Print Network [OSTI]

    -- bb (Y) and cc () states Bottominia: ­ B(Y) = B((nS)+-) for n=1,2,3 PRL 94, 012001 (2005) ­ ee(Y) = ((nS)e+e-) for n=1,2,3 PRL 96, 092003 (2006) Charmonia: ­ B(J/) = B(J/+-) for =e, PRD 71, 111103(R) (2005) ­ ee(J/) = (J/e+e-) PRD 73, 051103(R) (2006) ­ ee[(2S)] = ((2S)e+e-) PRL 96, 082004 (2006) ­ ee

  14. Prediction of Leptonic CP Phase in $A_4$ symmetric model

    E-Print Network [OSTI]

    Sin Kyu Kang; Morimitsu Tanimoto

    2015-01-29T23:59:59.000Z

    We consider minimal modifications to tribimaximal (TBM) mixing matrix which accommodate non-zero mixing angle $\\theta_{13}$ and CP violation. We derive four possible forms for the minimal modifications to TBM mixing in a model with $A_4$ flavor symmetry by incorporating symmetry breaking terms appropriately. We show how possible values of the Dirac-type CP phase $\\delta_D$ can be predicted with regards to two neutrino mixing angles in the standard parametrization of the neutrino mixing matrix. Carrying out numerical analysis based on the recent updated experimental results for neutrino mixing angles, we predict the values of the CP phase for all possible cases. We also confront our predictions of the CP phase with the updated fit.

  15. Lepton flavour violation and flavour changing neutral current

    E-Print Network [OSTI]

    Discriminant defined by thethe density ofdensity of bgbg andand signal eventsignal event inin the 6the 6--dim phasedim

  16. Subluminal and Superluminal Electromagnetic Waves and the Lepton Mass Spectrum

    E-Print Network [OSTI]

    Rodríguez, W A

    1996-01-01T23:59:59.000Z

    Maxwell equation $\\dirac F = 0$ for $F \\in \\sec \\bwe^2 M \\subset \\sec \\clif (M)$, where $\\clif (M)$ is the Clifford bundle of differential forms, have subluminal and superluminal solutions characterized by $F^2 \

  17. Hadron attenuation in deep inelastic lepton-nucleus scattering

    SciTech Connect (OSTI)

    Falter, T.; Cassing, W.; Gallmeister, K.; Mosel, U. [Institut fuer Theoretische Physik, Universitaet Giessen, D-35392 Giessen (Germany)

    2004-11-01T23:59:59.000Z

    We present a detailed theoretical investigation of hadron attenuation in deep inelastic scattering off complex nuclei in the kinematic regime of the HERMES experiment. The analysis is carried out in the framework of a probabilistic coupled-channel transport model based on the Boltzmann-Uehling-Uhlenbeck equation, which allows for a treatment of the final-state interactions beyond simple absorption mechanisms. Furthermore, our event-by-event simulations account for the kinematic cuts of the experiments as well as the geometrical acceptance of the detectors. We calculate the multiplicity ratios of charged hadrons for various nuclear targets relative to deuterium as a function of the photon energy {nu}, the hadron energy fraction z{sub h}=E{sub h}/{nu}, and the transverse momentum p{sub T}. We also confront our model results on double-hadron attenuation with recent experimental data. Separately, we compare the attenuation of identified hadrons ({pi}{sup {+-}}, {pi}{sup 0}, K{sup {+-}}, p, and p) on {sup 20}Ne and {sup 84}Kr targets with the data from the HERMES Collaboration and make predictions for a {sup 131}Xe target. At the end we turn towards hadron attenuation on {sup 63}Cu nuclei at EMC energies. Our studies demonstrate that (pre-)hadronic final-state interactions play a dominant role in the kinematic regime of the HERMES experiment while our present approach overestimates the attenuation at EMC energies.

  18. Neutron observables from inclusive lepton scattering on nuclei

    SciTech Connect (OSTI)

    Rinat, A. S.; Taragin, M. F. [Weizmann Institute of Science, Department of Particle Physics, Rehovot 76100 (Israel)

    2010-07-15T23:59:59.000Z

    We analyze new data from Thomas Jefferson National Accelerator Facility (JLab) for inclusive electron scattering on various targets. Computed and measured total inclusive cross sections in the range 0.3 < or approx. x < or approx. 0.95 show reasonable agreement on a logarithmic scale for all targets. However, closer inspection of the quasielastic components reveals serious discrepancies. European Muon Collaboration (EMC) ratios with conceivably smaller systematic errors fare the same. As a consequence, the new data do not enable the extraction of the magnetic form factor G{sub M}{sup n} and the structure function F{sub 2}{sup n} of the neutron, although the application of exactly the same analysis to older data had been successful. We incorporate in the above analysis older CLAS Collaboration data on F{sub 2}{sup 2H}. Removal of some scattered points from those makes it appear possible to obtain the desired neutron information. We compare our results with others from alternative sources. Special attention is paid to the A=3 isodoublet cross sections and EMC ratios. Present data exist only for {sup 3}He, but the available input in combination with charge symmetry enables computations for {sup 3}H. Their average is the computed isoscalar part and is compared with the empirical modification of {sup 3}He EMC ratios toward a fictitious A=3 isosinglet.

  19. TeV Scale Lepton Number Violation and Baryogenesis

    E-Print Network [OSTI]

    Dev, P S Bhupal; Mohapatra, R N

    2015-01-01T23:59:59.000Z

    Contrary to the common lore based on naive dimensional analysis, the seesaw scale for neutrino masses can be naturally in the TeV range, with small parameters coming from radiative corrections. We present one such class of type-I seesaw models, based on the left-right gauge group $SU(2)_L\\times SU(2)_R\\times U(1)_{B-L}$ realized at the TeV scale, which fits the observed neutrino oscillation parameters as well as other low energy constraints. We discuss how the small parameters of this scenario can arise naturally from one loop effects. The neutrino fits in this model use quasi-degenerate heavy Majorana neutrinos, as also required to explain the matter-antimatter asymmetry in our Universe via resonant leptogenesis mechanism. We discuss the constraints implied by the dynamics of this mechanism on the mass of the right-handed gauge boson in this class of models with enhanced neutrino Yukawa couplings compared to the canonical seesaw model and find a lower bound of $m_{W_R}\\geq 9.9$ TeV for successful leptogenesi...

  20. R. Tayloe, Indiana University Lepton-Photon '07 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70COMMUNITYResponses: Question 1:Office ofBoersNNuInt07

  1. Exploring the Role of Lepton Mass in the Hydrogen Atom Frank Rioux

    E-Print Network [OSTI]

    Rioux, Frank

    kinetic energy. Substitution of the deBroglie relation ( = h/mv) into the classical expression for kinetic energy yields a quantum mechanical expression for kinetic energy. It is of utmost importance general and versatile quantum mechanical expression for kinetic energy is the differential operator shown

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

    E-Print Network [OSTI]

    LeBourgeois, Matthew; LeBourgeois, Matthew

    2012-01-01T23:59:59.000Z

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

  3. Lattice study of the leptonic decay constant of the pion and its excitations

    SciTech Connect (OSTI)

    Mastropas, Ekaterina; Richard, David

    2014-11-01T23:59:59.000Z

    We present a calculation of the decay constant of the pion, and its lowest-lying three excitations, at three values of the pion mass between around 400 and 700 MeV, using anisotropic clover lattices. We use the variational method to determine an optimal interpolating operator for each of the states. We find that the decay constant of the first excitation, and more notably of the second, is suppressed with respect to that of the ground-state pion, but that the suppression shows little dependence on the quark mass.

  4. Numerical Implementation of lepton-nucleus interactions and its effect on neutrino oscillation analysis

    E-Print Network [OSTI]

    C. -M. Jen; A. Ankowski; O. Benhar; A. P. Furmanski; L. N. Kalousis; C. Mariani

    2014-10-13T23:59:59.000Z

    We discuss the implementation of the nuclear model based on realistic nuclear spectral functions in the GENIE neutrino interaction generator. Besides improving on the Fermi gas description of the nuclear ground state, our scheme involves a new prescription for $Q^2$ selection, meant to efficiently enforce energy momentum conservation. The results of our simulations, validated through comparison to electron scattering data, have been obtained for a variety of target nuclei, ranging from carbon to argon, and cover the kinematical region in which quasi elastic scattering is the dominant reaction mechanism. We also analyse the influence of the adopted nuclear model on the determination of neutrino oscillation parameters.

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

    E-Print Network [OSTI]

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

    -space factorization d?3n+1?(P1 + P2; k1, . . . , k2n, r1, . . . , rn, x) = d?n+1?(P1 + P2; p1, . . . , pn, x) n ? i=1 d?3(pi; k2i?1, k2i, ri) dp2i 2pi , (2.13) with the three-body phase spaces on the r.h.s. accounting for the decays ti(pi) ?? Wi(qi) + bi(ri) ?? li(k2i...

  6. Measurement of the Higgs Boson Mass in Decays into Four Leptons with the ATLAS Detector

    E-Print Network [OSTI]

    Röhrig, Rainer

    This master thesis presents a measurement of the mass of the observed Higgs boson candidate in the decay channel $H \\rightarrow ZZ^* \\rightarrow \\ell^+\\ell^-\\ell^{'+}\\ell^{'-}$, with $\\ell,\\ell' = e$ or $\\mu$. The result is based on the full 2011 and 2012 proton-proton collision dataset recorded with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of $4.5~\\mathrm{fb}^{-1}$ and $20.3~\\mathrm{fb}^{-1}$ at a center-of-mass energy of $\\sqrt{s} = 7~\\mathrm{TeV}$ and $8~\\mathrm{TeV}$, respectively. The mass is measured to be $m_H = 124.58 ^{+0.53}_{-0.47}{\\rm{~(stat)~}}\\pm0.06{\\rm{~(syst)~}} ~\\mathrm{GeV}$ using an analytical parametrization of the expected mass distribution on an event-by-event basis.

  7. Production cross section and topological decay branching fractions of the ? lepton

    E-Print Network [OSTI]

    Baringer, Philip S.

    1989-08-01T23:59:59.000Z

    (+)e(?) colliding-beam facility PEP. The measured cross section yields R??=1.044±0.014±0.030 [where the first (second) error is statistical (systematic)], consistent with QED and corresponding to QED cutoff parameters of ?+>129 GeV and ??>284 GeV at the 95% C...

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

    E-Print Network [OSTI]

    Chan, Matthew Hans

    2013-01-01T23:59:59.000Z

    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 ...

  9. Higher-dimensional effective-potential model of quarks and leptons

    E-Print Network [OSTI]

    Wirjawan, Johannes Vincentius Djoko

    1993-01-01T23:59:59.000Z

    bosonic fields as vector-isovector weak-bosonic fields and a vector-isoscalar B-field, and ignore the Cab'bbo- Kobayash' Maskawa mixing, then we can show that through the electro-weak interaction, weak isospin, chirality, particle- type, color...

  10. Accumulating evidence for nonstandard leptonic decays of D_s mesons

    E-Print Network [OSTI]

    Bogdan A. Dobrescu; Andreas S. Kronfeld

    2008-07-14T23:59:59.000Z

    The measured rate for D_s -> l nu decays, where l is a muon or tau, is larger than the standard model prediction, which relies on lattice QCD, at the 3.8 sigma level. We discuss how robust the theoretical prediction is, and we show that the discrepancy with experiment may be explained by a charged Higgs boson or a leptoquark.

  11. DESY 98063 ISSN 04189833 Observation of Events with an Isolated High Energy Lepton

    E-Print Network [OSTI]

    . KrË?amerkË?amper 8 , M.W. Krasny 29 , H. Krehbiel 11 , D. KrË?ucker 26 , A. KË?upper 34 , H. KË?uster 21

  12. CDF note 7113 Search for t # #W q Using Lepton Plus Jets Events

    E-Print Network [OSTI]

    Quigg, Chris

    be accomodated in two­Higgs­doublet scenarios and N = 2 SUSY models, and possibly remove the requirement anomalous results from LEP on the b forward­backward asymmetry are accomodated naturally

  13. Observation and examination of a Higgs boson in the ZZ to four lepton channel

    E-Print Network [OSTI]

    Ralph, Duncan (Duncan Kelley)

    2014-01-01T23:59:59.000Z

    Results are presented on 5.1 fb- 1 of proton-proton collisions at a center of mass energy of 7 TeV and 19.7 fb- 1 at 8 TeV in a search for decays of the Standard Model (SM) Higgs boson to two Z bosons to four charged ...

  14. Electron generation of leptons and hadrons with reciprocal -quantized lifetimes and masses

    E-Print Network [OSTI]

    generation occurs via an initial "-leap" from an electron pair to a "platform state" M, and then subsequent in modern physics has been the theory of quantum electrodynamics (QED). This is the theory for the much stronger had- ron interactions is quantum chromodynamics (QCD), which was patterned after QED

  15. Higher-dimensional effective-potential model of quarks and leptons 

    E-Print Network [OSTI]

    Wirjawan, Johannes Vincentius Djoko

    1993-01-01T23:59:59.000Z

    bosonic fields as vector-isovector weak-bosonic fields and a vector-isoscalar B-field, and ignore the Cab'bbo- Kobayash' Maskawa mixing, then we can show that through the electro-weak interaction, weak isospin, chirality, particle- type, color...

  16. Decays of ? leptons to final states containing K(0)S mesons

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1996-06-01T23:59:59.000Z

    present branching fractions for decays to five final states: t 2!K0h2n t , t 2!K0h2p0n t , t 2!K0K2n t , t 2!K0K2p0n t , and t2!KS0KS0h2nt , where K0h2 de- notes the sum of the processes involving K¯0p2 and K0K2 particle combinations. Substructure and mass... of the candidate KS 0) divided by the known KS0 lifetime for events in the t2!KS0h2nt sample. The distribution de- viates only slightly from an exponential, and agrees well with the Monte Carlo prediction. The selection of t2!KS0h2p0nt events proceeds as that for t...

  17. Top quark mass measurement in the lepton plus jets channel using a modified matrix element method

    E-Print Network [OSTI]

    Xie, Si

    We report a measurement of the top quark mass, m_t, obtained from pp? collisions at ?s=1.96??TeV at the Fermilab Tevatron using the CDF II detector. We analyze a sample corresponding to an integrated luminosity of ...

  18. Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states

    E-Print Network [OSTI]

    Apyan, Aram

    A search for the standard model Higgs boson decaying to a W-boson pair at the LHC is reported. The event sample corresponds to an integrated luminosity of 4.9 fb[superscript ?1] and 19.4 fb[superscript ?1] collected with ...

  19. arXiv:hepph/0201284 Large lepton avor violating signals in supersymmetric particle

    E-Print Network [OSTI]

    masses and mixings, e.g. by the see-saw mechanism and by introducing heavy right-handed Majorana decays. Assuming the most general mass matrices for sleptons and sneutrinos, we demonstrate that large are 3 #2; 3 matrices. They are given by M 2 LL;ij = M 2 L;ij + v 2 d Y E#3; ki Y E kj 2 + g 0 2 g 2 #1

  20. Properties of twice four families of quarks and leptons, of scalars and gauge fields

    E-Print Network [OSTI]

    matrices. The families are identical with respect to the charges and spin. There are two kinds of fields properties discussed, including the one which enables the existence of the Majorana neutrinos. The discussed relation of the scalar fields and mass matrices following from the spin

  1. LC-TH-2003-030 Large lepton avor violating signals in supersymmetric particle

    E-Print Network [OSTI]

    -saw mechanism and by introducing heavy right-handed Majorana neutrinos [6]. In general, a gauge matrices for sleptons and sneutrinos, we demonstrate that large signals are expected. The most general @ M 2 LL M 2y LR M 2 LR M 2 RR 1 A ; (1) 2 #12; where the entries are 3 #2; 3 matrices. They are given

  2. Supersymmetric Froggatt-Nielsen Models with Baryon- and Lepton-Number Violation

    E-Print Network [OSTI]

    Dreiner, Herbi K.

    2009-01-01T23:59:59.000Z

    handed neutrino Majorana mass matrix. The latter depends onthe Dirac and Majorana neutrino mass matrices to be without

  3. Top Quark Mass Measurement in the 2 fb -1 Tight Lepton and Isolated Track Sample using

    E-Print Network [OSTI]

    Quigg, Chris

    have been specified (see below). y Part of this work was supported by DARA grant WE2 50 OR 9411. 1 #12

  4. Observable T{sub 7} Lepton Flavor Symmetry at the Large Hadron Collider

    SciTech Connect (OSTI)

    Cao Qinghong [High Energy Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Khalil, Shaaban [Centre for Theoretical Physics, British University in Egypt, El Sherouk City, Postal No. 11837, P.O. Box 43 (Egypt); Department of Mathematics, Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Ma, Ernest [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Okada, Hiroshi [Centre for Theoretical Physics, British University in Egypt, El Sherouk City, Postal No. 11837, P.O. Box 43 (Egypt)

    2011-04-01T23:59:59.000Z

    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.

  5. t-tbar cross-section at Tevatron Lepton + jets channel

    E-Print Network [OSTI]

    : isolated EM clusters in CEM matching XFT track ­ Jets use cone: 0.4 Standard jet energy corrections Jet energy resolution: ­ Muons are of two types: ­ CMX ­ eta = 0.6..1.0 ­ CMUP ­ eta; veto cosmics III-c. W+Jets selection (1) #12; Neutrino: ­ Missing ET from calo towers > 20 Ge

  6. Search for VH ? leptons + b¯b with the ATLAS experiment at the LHC 

    E-Print Network [OSTI]

    Debenedetti, Chiara

    2014-11-27T23:59:59.000Z

    The search for a Higgs boson decaying to a b¯b pair is one of the key analyses ongoing at the ATLAS experiment. Despite being the largest branching ratio decay for a Standard Model Higgs boson, a large dataset is necessary ...

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

    SciTech Connect (OSTI)

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

    2008-12-01T23:59:59.000Z

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

  8. From Clifford Algebra of Nonrelativistic Phase Space to Quarks and Leptons of the Standard Model

    E-Print Network [OSTI]

    Piotr ?enczykowski

    2015-05-11T23:59:59.000Z

    We review a recently proposed Clifford-algebra approach to elementary particles. We start with: (1) a philosophical background that motivates a maximally symmetric treatment of position and momentum variables, and: (2) an analysis of the minimal conceptual assumptions needed in quark mass extraction procedures. With these points in mind, a variation on Born's reciprocity argument provides us with an unorthodox view on the problem of mass. The idea of space quantization suggests then the linearization of the nonrelativistic quadratic form ${\\bf p}^2 +{\\bf x}^2$ with position and momentum satisfying standard commutation relations. This leads to the 64-dimensional Clifford algebra ${Cl}_{6,0}$ of nonrelativistic phase space within which one identifies the internal quantum numbers of a single Standard Model generation of elementary particles (i.e. weak isospin, hypercharge, and color). The relevant quantum numbers are naturally linked to the symmetries of macroscopic phase space. It is shown that the obtained phase-space-based description of elementary particles gives a subquark-less explanation of the celebrated Harari-Shupe rishon model. Finally, the concept of additivity is used to form novel suggestions as to how hadrons are constructed out of quarks and how macroscopically motivated invariances may be restored at the hadron level.

  9. Application of nuclear density functionals to lepton number violating weak processes

    SciTech Connect (OSTI)

    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

    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.

  10. Exclusion of an Exotic Top Quark with-4/3 Electric Charge Using Soft Lepton Tagging

    E-Print Network [OSTI]

    Paus, Christoph M. E.

    We present a measurement of the electric charge of the top quark using pp[over-bar] collisions corresponding to an integrated luminosity of 2.7??fb[superscript -1] at the CDF II detector. We reconstruct tt[over-bar] events ...

  11. Search for exotic particles with correlated leptons in the final state with the ATLAS detector

    E-Print Network [OSTI]

    Deliyergiyev, Maksym

    2015-02-19T23:59:59.000Z

    The Large Hadron Collider (LHC) – the world’s highest-energy particle accelerator at CERN, Geneva is pushing High Energy Physics into a brand new territory. It presents an unprecedented opportunity to probe the realm of New Physics in the TeV region, shed light on some of the core unresolved issues of Particle Physics, and go further in search of understanding. These issues include the possible constituent of dark matter, the possible existence of extra gauge groups. The current era may bring discoveries of unprecedented magnitude, delivering validation or extreme disappointment to the Physics theories of the previous decades. LHC aims to produce particles in the center-of-mass energy up to 14 TeV – above those that are already known. At the same time, there are exciting possibilities for new physics in the low-mass range that may have gone unnoticed until now. Many models of new physics beyond the Standard Model contain a ‘light’ hidden sector (dark sector) with a colorful spectrum of new particles...

  12. NEUTRON IZATI ON, LEPTON ESCAPE,AND STELLAR HYDRODYNAMICS* W. David Arnett

    E-Print Network [OSTI]

    Boyer, Edmond

    in kinetic and bin- ding energy, PdV the work done by pressure forces and dQ the net energy carried out of the system. This simply states that energy is conserved. With the possibility of composi- tion changing of species i. With these variables the E in eq. (1) becomes energy per mole of nucleons and the Q becomes

  13. Measurement of leptonic and hadronic decays of omega- and phi-mesons at RHIC by PHENIX

    E-Print Network [OSTI]

    Yu. Riabov

    2007-02-09T23:59:59.000Z

    The PHENIX experiment at RHIC measured production of the \\omega- and \\phi- mesons in p+p, d+Au and Au+Au collisions at \\sqrt{s_NN} = 63 and 200 GeV. Particle properties were studied using hadronic and di-electron decay channels. Transverse momentum (mass) spectra measured in different decay modes are found to be in agreement with each other within the errors. Nuclear modification factors R_{AA} measured for both mesons are consistent with results previously obtained for other neutral mesons. Position of the meson mass peaks and their widths reconstructed in hadronic decay channels are in agreement with their properties measured in vacuum.

  14. Measurement of the properties of a Higgs boson in the four-lepton final state

    E-Print Network [OSTI]

    Apyan, Aram

    The properties of a Higgs boson candidate are measured in the H ? ZZ ? 4? decay channel, with ? = e, ?, using data from pp collisions corresponding to an integrated luminosity of 5.1??fb[superscript ?1] at the center-of-mass ...

  15. THE STATUS OF HEAVY-LEPTON SEARCHES*+ Martin L. Per1 Stanford Linear Accelerator Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructureProposed Action(InsertAboutSTRUCTUREDTaskPHYSICS OFSTATUS OF

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70COMMUNITYResponses:December 11, 2014WD2 MAY2REVIEW OF HEAVY

  17. A wave equation including leptons and quarks for the standard model of quantum physics in Clifford Algebra

    E-Print Network [OSTI]

    Claude Daviau; Jacques Bertrand

    2014-08-27T23:59:59.000Z

    A wave equation with mass term is studied for all particles and antiparticles of the first generation: electron and its neutrino, positron and antineutrino, quarks $u$ and $d$ with three states of color and antiquarks $\\overline{u}$ and $\\overline{d}$. This wave equation is form invariant under the $Cl_3^*$ group generalizing the relativistic invariance. It is gauge invariant under the $U(1)\\times SU(2) \\times SU(3)$ group of the standard model of quantum physics. The wave is a function of space and time with value in the Clifford algebra $Cl_{1,5}$. All features of the standard model, charge conjugation, color, left waves, Lagrangian formalism, are linked to the geometry of this extended space-time.

  18. Status of the measurement of K S -> ?e? branching ratio and lepton charge asymmetry with the KLOE detector

    E-Print Network [OSTI]

    D. Kami?ska on behalf of the KLOE-2 collaboration

    2015-07-03T23:59:59.000Z

    We present the current status of the analysis of about 1.7 billion K_S K_L pair events collected at DA{\\Phi}NE with the KLOE detector to determine the branching ratio of K_S -> {\\pi}e{\

  19. Measurement of the top quark mass using the invariant mass of lepton pairs in soft muon b-tagged events

    E-Print Network [OSTI]

    Bauer, Gerry P.

    We present the first measurement of the mass of the top quark in a sample of tt? ???? bb? qq? events (where ?=e,?) selected by identifying jets containing a muon candidate from the semileptonic decay of heavy-flavor hadrons ...

  20. Measurement of the Top Pair Production Cross Section in the Lepton + Jets Channel Using a Jet Flavor Discriminant

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.

    2011-08-01T23:59:59.000Z

    We present a new method to measure the top quark pair production cross section and the background rates with data corresponding to an integrated luminosity of 2.7 fb-1 from p p? collisions at ?s = 1.96 TeV collected with the CDF II Detector. We select events with a single electron or muon candidate, missing transverse energy, and at least one b-tagged jet. We perform a simultaneous fit to a jet flavor discriminant across nine samples defined by the number of jets and b-tags. An advantage of this approach is that many systematic uncertainties are measured in situ and inversely scale with integrated luminosity. We measure a top cross section of ?tt? = 7.64 ± 0.57 (stat + syst) ± 0.45 (luminosity) pb.

  1. A model independent search for new physics in final states containing leptons at the D0 experiment

    SciTech Connect (OSTI)

    Piper, Joel Michael; /Michigan State U.

    2009-12-01T23:59:59.000Z

    The standard model is known to be the low energy limit of a more general theory. Several consequences of the standard model point to a strong probability of new physics becoming experimentally visible in high energy collisions of a few TeV, resulting in high momentum objects. The specific signatures of these collisions are topics of much debate. Rather than choosing a specific signature, this analysis broadly searches the data, preferring breadth over sensitivity. In searching for new physics, several different approaches are used. These include the comparison of data with standard model background expectation in overall number of events, comparisons of distributions of many kinematic variables, and finally comparisons on the tails of distributions that sum the momenta of the objects in an event. With 1.07 fb{sup -1} at the D0 experiment, we find no evidence of physics beyond the standard model. Several discrepancies from the standard model were found, but none of these provide a compelling case for new physics.

  2. Complete off-shell effects in top quark pair hadroproduction with leptonic decay at next-to-leading order

    E-Print Network [OSTI]

    Giuseppe Bevilacqua; Michal Czakon; Andreas van Hameren; Costas G. Papadopoulos; Malgorzata Worek

    2011-02-18T23:59:59.000Z

    Results for next-to-leading order QCD corrections to the pp(p\\bar{p}) -> t \\bar{t} -> W^+W^- b\\bar{b} -> e^{+} \

  3. DESY 98-063 ISSN 0418-9833 Observation of Events with an Isolated High Energy Lepton

    E-Print Network [OSTI]

    .W. Krasny ¢¦© , H. Krehbiel §¨§ , D. Kr¨ucker ¢¦ , A. K¨upper ¡ , H. K¨uster ¢!§ , M. Kuhlen ¢¦ , T. Kurca

  4. Identifying fake leptons in ATLAS while hunting SUSY in 8 TeV proton-proton collisions

    E-Print Network [OSTI]

    Gillam, Thomas P. S.

    2015-04-28T23:59:59.000Z

    of those installed at the LHC, weighing in at around 7000 tonnes. Although it is presently, in the public eye at least, very much associated with the 2012 discovery of the Higgs boson, it is designed to be a multi-purpose detector. The other such detector...

  5. Measurement of the Top Pair Production Cross Section in the Lepton + Jets Channel Using a Jet Flavor Discriminant

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; et al

    2011-08-01T23:59:59.000Z

    We present a new method to measure the top quark pair production cross section and the background rates with data corresponding to an integrated luminosity of 2.7 fb-1 from p p? collisions at ?s = 1.96 TeV collected with the CDF II Detector. We select events with a single electron or muon candidate, missing transverse energy, and at least one b-tagged jet. We perform a simultaneous fit to a jet flavor discriminant across nine samples defined by the number of jets and b-tags. An advantage of this approach is that many systematic uncertainties are measured in situ and inversely scalemore »with integrated luminosity. We measure a top cross section of ?tt? = 7.64 ± 0.57 (stat + syst) ± 0.45 (luminosity) pb.« less

  6. Construction and testing of a large scale prototype of a silicon tungsten electromagnetic calorimeter for a future lepton collider

    E-Print Network [OSTI]

    Rouëné,J

    2013-01-01T23:59:59.000Z

    The CALICE collaboration is preparing large scale prototypes of highly granular calorimeters for detectors to be operated at a future linear electron positron collider. After several beam campaigns at DESY, CERN and FNAL, the CALICE collaboration has demonstrated the principle of highly granular electromagnetic calorimeters with a first prototype called physics prototype. The next prototype, called technological prototype, addresses the engineering challenges which come along with the realisation of highly granular calorimeters. This prototype will comprise 30 layers where each layer is composed of four 9_9 cm2 silicon wafers. The front end electronics is integrated into the detector layers. The size of each pixel is 5_5 mm2. This prototype enter sits construction phase. We present results of the first layers of the technological prototype obtained during beam test campaigns in spring and summer 2012. According to these results the signal over noise ratio of the detector exceeds the R&D goal of10:1.

  7. Study of the Rare Decay B Mesons Decaying to X Mesons Positive And Negative Leptons at BABAR

    SciTech Connect (OSTI)

    Koptchev, Ventzislav B.; /Massachusetts U., Amherst

    2005-08-30T23:59:59.000Z

    Flavor-changing neutral current transitions are forbidden at tree level in the Standard Model and can only occur via higher order diagrams. Since the amplitudes for such loops are dominated by the heaviest known particles, and non-SM effects are expected to contribute at the same order as the SM, such processes are an ideal place to look for new physics. We present a measurement of the inclusive branching fraction for the flavor-changing neutral current process B {yields} X{sub s}{ell}{sup +}{ell}{sup -} with a sample of 81.9 fb{sup -1}, collected with the BABAR detector at the Stanford Linear Accelerator Center. The final state is reconstructed from e{sup +}e{sup -} or {mu}{sup +}{mu}{sup -} pairs and a hadronic system consisting of one K{sup {+-}} or K{sub s} and up to two pions, with at most one {pi}{sup 0}. They observe a signal of 40 {+-} 10(stat) {+-} 2(syst) events and extract a branching fraction {Beta}(B {yields} X{sub s}{ell}{sup +}{ell}{sup -}) = (5.6 {+-} 1.5(stat) {+-} 0.6(exp. syst) {+-} 1.1(model syst)) x 10{sup -6} for m{sub ll} > 0.2 GeV.

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

    SciTech Connect (OSTI)

    Freeman, John; /Fermilab

    2004-12-01T23:59:59.000Z

    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.

  9. Measurement of ZZ Production in Leptonic Final States at ?s of 1.96 TeV at CDF

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    In this Letter, we present a precise measurement of the total ZZ production cross section in pp? collisions at ?s=1.96??TeV, using data collected with the CDF II detector corresponding to an integrated luminosity of ...

  10. Measurement of the WW plus WZ Production Cross Section Using the lepton plus jets Final State at CDF II

    E-Print Network [OSTI]

    Paus, Christoph M. E.

    We report two complementary measurements of the WW+WZ cross section in the final state consisting of an electron or muon, missing transverse energy, and jets, performed using pp[over-bar] collision data at [sqrt]s=1.96??TeV ...

  11. Measurement of the top pair production cross section in the lepton+jets channel using a jet flavor discriminant

    E-Print Network [OSTI]

    Bauer, Gerry P.

    We present a new method to measure the top quark pair production cross section and the background rates with data corresponding to an integrated luminosity of 2.7??fb[superscript -1] from pp? collisions at ?s=1.96??TeV ...

  12. The Signature Lepton + Photon + b-jet with Missing Transverse Energy and a Measurement of the tt Cross-Section

    E-Print Network [OSTI]

    Quigg, Chris

    pair production with an additional radiated photon, t¯t + . We find 28 ETb events versus of ETb events using 1850 pb-1 of in- tegrated luminosity from ¯pp collisions at s = 1.96 TeV collected

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

    E-Print Network [OSTI]

    Mark S. Neubauer; for the ATLAS Collaboration

    2011-10-11T23:59:59.000Z

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

  14. abbildung einfacher informationsverarbeitungsprozesse: Topics...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    und Univ 10 Forschung an Lepton Collidern Abbildung 49: Perspektivische Ansicht des TESLA-Detektors. Physics Websites Summary: Forschung an Lepton Collidern Abbildung 49:...

  15. abbildung evozierter regionaler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    und Univ 8 Forschung an Lepton Collidern Abbildung 49: Perspektivische Ansicht des TESLA-Detektors. Physics Websites Summary: Forschung an Lepton Collidern Abbildung 49:...

  16. 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]

    Gomez-Ceballos, Guillelmo

    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 ...

  17. 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]

    CDF Collaboration

    2012-07-27T23:59:59.000Z

    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.

  18. Search for WZ resonances in the fully leptonic channel using pp collisions at ?s = 8 TeV with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search for resonant WZ production in the ???[superscript ?]?[superscript ?] (?,?[superscript ?] =e,?) decay channel using 20.3 fb[superscript ?1] of ?s = 8 TeV collision data collected by the ATLAS experiment at LHC is ...

  19. Search for Quantum Black Hole Production in High-Invariant-Mass Lepton + Jet Final States Using pp Collisions at ?s = 8 TeV and the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    This Letter presents a search for quantum black-hole production using 20.3??fb[superscript ?1] of data collected with the ATLAS detector in pp collisions at the LHC at ?s = 8??TeV. The quantum black holes are assumed to ...

  20. Measurement of the top quark mass at CDF using the "neutrino phi weighting" template method on a lepton plus isolated track sample

    E-Print Network [OSTI]

    Choudalakis, Georgios

    We present a measurement of the top quark mass with tt? dilepton events produced in pp? collisions at the Fermilab Tevatron (?s=1.96??TeV) and collected by the CDF II detector. A sample of 328 events with a charged ...

  1. Search for Maximal Flavor Violating Scalars in Same-Charge Lepton Pairs in pp-bar Collisions at sqrt[s]=1.96 TeV

    E-Print Network [OSTI]

    Miles, Christopher J.

    Models of maximal flavor violation (MxFV) in elementary particle physics may contain at least one new scalar SU(2) doublet field ?FV=(?[superscript 0],?[superscript +]) that couples the first and third generation quarks ...

  2. Search for Events with Leptonic Jets and Missing Transverse Energy in pp-bar Collisions at s?=1.96??TeV

    E-Print Network [OSTI]

    Baringer, Philip S.; Bean, Alice; Clutter, Justace Randall; McGivern, Carrie Lynne; Sekaric, Jadranka; Wilson, Graham Wallace; Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.

    2010-11-19T23:59:59.000Z

    ,2 J. F. Bartlett,47 U. Bassler,18 S. Beale,6 A. Bean,55 M. Begalli,3 M. Begel,71 C. Belanger-Champagne,40 L. Bellantoni,47 J. A. Benitez,62 S. B. Beri,27 G. Bernardi,17 R. Bernhard,22 I. Bertram,41 M. Besanc¸on,18 R. Beuselinck,42 V.A. Bezzubov,38 P.... Zhao,80 B. Zhou,61 J. Zhu,61 M. Zielinski,69 D. Zieminska,51 and L. Zivkovic68 (The D0 Collaboration) 1Universidad de Buenos Aires, Buenos Aires, Argentina 2LAFEX, Centro Brasileiro de Pesquisas F?´sicas, Rio de Janeiro, Brazil 3Universidade do Estado...

  3. 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]

    Elagin, Andrey

    2012-02-14T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Khotilovich, Vadim Gennadyevich

    2009-05-15T23:59:59.000Z

    of matter. It also contains four kinds of vector gauge bosons which serve as interaction carriers: gluons for the strong interactions, the W and Z bosons for the weak interactions, and photon for the electromagnetic. The scalar Higgs boson is the only SM... really independent and arbitrarily de ned in nature? Choice and structure of the gauge group: why do we have three independent symmetry groups? 6 How is the electroweak symmetry broken? Is the Higgs boson, which was put into the theory as a \\convenient...

  5. Search for displaced muonic lepton jets from light Higgs boson decay in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector

    E-Print Network [OSTI]

    The ATLAS Collaboration

    2012-10-01T23:59:59.000Z

    A search is performed for collimated muon pairs displaced from the primary vertex produced in the decay of long-lived neutral particles in proton-proton collisions at sqrt(s) = 7 TeV centre-of-mass energy, with the ATLAS detector at the LHC. In a 1.9 fb-1 event sample collected during 2011, the observed data are consistent with the Standard Model background expectations. Limits on the product of the production cross section and the branching ratio of a Higgs boson decaying to hidden-sector neutral long-lived particles are derived as a function of the particles' mean lifetime.

  6. Measurement of the WZ and ZZ production cross sections using leptonic final states in 8.6 fb?¹ of pp? collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Åsman, B.; Atkins, S.; Atramentov, O.; Augsten, K.; 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.; Bean, A.; Begalli, M.; Belanger-Champagne, C.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; 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-Pérez, E.; Carrasco-Lizarraga, M. A.; Casey, B. C. K.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, 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 Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; 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.; García-Guerra, G. 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.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; 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.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jamin, D.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, M.; 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.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-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.; Orduna, J.; Osman, N.; Osta, J.; Oteroy y Garzón, G. J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Piegaia, R.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Polozov, P.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Rijssenbeek, M.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Safronov, G.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schliephake, T.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Sirotenko, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.

    2012-06-01T23:59:59.000Z

    We study the processes pp??WZ?l±?l?l? and pp??ZZ?l?l???¯, where l=e or ?. Using 8.6 fb?¹ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider, we measure the WZ production cross section to be 4.50+0.63–0.66 pb which is consistent with, but slightly larger than, the prediction of the standard model. The ZZ cross section is measured to be 1.64±0.46 pb, in agreement with a prediction of the standard model. Combination with an earlier analysis of the ZZ?l?l?l?l? channel yields a ZZ cross section of 1.44+0.35–0.34 pb.

  7. Search for $W'\\rightarrow t\\bar{b}$ in the lepton plus jets final states with the ATLAS detector at the LHC

    E-Print Network [OSTI]

    Geoffrey Gilles

    2014-11-28T23:59:59.000Z

    This document presents a search for a $W'$ boson, decaying to a top quark and a $b$ quark in an effective coupling approach, using a multivariate method based on boosted decision trees. It reports exclusion limits on the $W'\\rightarrow tb$ cross-section times branching ratio and effective couplings as a function of the $W'$-boson mass. The search covers $W'$-boson masses between 0.5 and 3.0 TeV, for right-handed or left-handed $W'$-boson, with 20.3 fb$^{-1}$ of proton-proton collision data produced by the LHC in 2012, at a center-of-mass energy of 8 TeV and collected by the ATLAS detector.

  8. 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]

    Elagin, Andrey

    2012-02-14T23:59:59.000Z

    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...

  9. Search for physics beyond the standard model in final states with a lepton and missing transverse energy in proton-proton collisions at s = 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, V.; Sirunyan, A.?M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V.?M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E.?A.; Janssen, X.; Knutsson, A.; Luyckx, S.; Ochesanu, S.; Roland, B.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D’Hondt, J.; Daci, N.; Heracleous, N.; Kalogeropoulos, A.; Keaveney, J.; Kim, T.?J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G.?P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A.?P.?R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Dildick, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A.?A.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G.?G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jez, P.; Komm, M.; Lemaitre, V.; Liao, J.; Nuttens, C.; Pagano, D.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J.?M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G.?H.; Aldá Júnior, W.?L.; Alves, G.?A.; Correa Martins Junior, M.; Dos Reis Martins, T.; Pol, M.?E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E.?M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Malek, M.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W.?L.; Santaolalla, J.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E.?J.; Vilela Pereira, A.; Bernardes, C.?A.; Dias, F.?A.; Fernandez Perez Tomei, T.?R.; Gregores, E.?M.; Mercadante, P.?G.; Novaes, S.?F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J.?G.; Chen, G.?M.; Chen, H.?S.; Chen, M.; Du, R.; Jiang, C.?H.; Liang, D.; Liang, S.; Plestina, R.; Tao, J.; Wang, X.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, Q.; Li, W.; Liu, S.; Mao, Y.; Qian, S.?J.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Chaparro Sierra, L.?F.; Florez, C.; Gomez, J.?P.; Gomez Moreno, B.; Sanabria, J.?C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P.?A.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Mahmoud, M.?A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M.?J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J.?L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Busson, P.; Charlot, C.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Mastrolorenzo, L.; Miné, P.; Mironov, C.; Naranjo, I.?N.; Nguyen, M.; Ochando, C.; Paganini, P.; Salerno, R.; Sauvan, J.?B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E.?C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Boudoul, G.; Brochet, S.; Carrillo Montoya, C.?A.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Ruiz Alvarez, J.?D.; Sabes, D.; Sgandurra, L.

    2015-05-01T23:59:59.000Z

    A search for new physics in proton-proton collisions having final states with an electron or muon and missing transverse energy is presented.

  10. Improving estimates of the number of fake leptons and other mis-reconstructed objects in hadron collider events: BoB's your UNCLE

    E-Print Network [OSTI]

    Gillam, Thomas P.S.; Lester, Christopher G.

    2014-11-06T23:59:59.000Z

    .2671] [INSPIRE]. [36] B. Mistlberger and F. Dulat, Limit setting procedures and theoretical uncertainties in Higgs boson searches, arXiv:1204.3851 [INSPIRE]. [37] BIPM, IEC, IFCC, ISO, IUPAC, IUPAP and OIML, Guide to the expression of uncertainty in measurement...

  11. Measurement of the ttbar production cross section in ppbar collisions at sqrt{s} = 1.96 TeV using kinematic characteristics of lepton + jets events

    E-Print Network [OSTI]

    Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, C; Clement, B; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; de Jong, P; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutíerrez, P; Gutíerrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A I; Kharzheev, Yu M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kühl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G L; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perea, P M; Peters, K; Peters, Y; Petroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E

    2007-01-01T23:59:59.000Z

    We present a measurement of the top quark pair production cross section in ppbar collisions at sqrt(s)=1.96 TeV utilizing 425 pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-pT electron or muon and at least four jets. We exploit specific kinematic features of ttbar events to extract the cross section. For a top quark mass of 175 GeV, we measure sigma_ttbar = 6.4 +1.3-1.2(stat} +/- 0.7(syst)+/- 0.4(lum) pb in good agreement with the standard model prediction.

  12. Measurement of the t[bar over t] Production Cross Section in pp Collisions at ?s = 7 TeV with Lepton + jets Final States

    E-Print Network [OSTI]

    Apyan, Aram

    A measurement of the t[bar over t] production cross section in pp collisions at ?s = 7 TeV is presented. The results are based on data corresponding to an integrated luminosity of 2.3 fb[superscript ?1] collected by the ...

  13. A measurement of the $WZ$ and $ZZ$ production cross sections using leptonic final states in 8.6 fb$^{-1}$ of $p\\bar{p}$ collisions

    SciTech Connect (OSTI)

    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

    We study the processes p{bar p} {yields} WZ {yields} {ell}{nu}{ell}{sup +}{ell}{sup -} and p{bar p} {yields} ZZ {yields} {ell}{sup +}{ell}{sup -}{nu}{bar {nu}}, where {ell} = e or {mu}. Using 8.6 fb{sup -1} of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider, we measure the WZ production cross section to be 4.50{sub -0.66}{sup +0.63} pb which is consistent with, but slightly above a prediction of the standard model. The ZZ cross section is measured to be 1.64 {+-} 0.46 pb, in agreement with a prediction of the standard model. Combination with an earlier analysis of the ZZ {yields} {ell}{sup +}{ell}{sup -}{ell}{sup +}{ell}{sup -} channel yields a ZZ cross section of 1.44{sub -0.34}{sup +0.35} pb.

  14. Nonzero {theta}{sub 13} for neutrino mixing in a supersymmetric B-L gauge model with T{sub 7} lepton flavor symmetry

    SciTech Connect (OSTI)

    Cao Qinghong [Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, U.S.A (United States); Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Khalil, Shaaban [Centre for Theoretical Physics, The British University in Egypt, El Sherouk City, Postal No. 11837, P.O. Box 43 (Egypt); Department of Mathematics, Ain Shams University, Faculty of Science, Cairo 11566 (Egypt); Ma, Ernest [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Okada, Hiroshi [School of Physics, KIAS, Seoul 130-722 (Korea, Republic of)

    2011-10-01T23:59:59.000Z

    We discuss how {theta}{sub 13}{ne}0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T{sub 7} in the context of a supersymmetric extension of the standard model with gauged U(1){sub B-L}. We predict a correlation between {theta}{sub 13} and {theta}{sub 23}, as well as the effective neutrino mass m{sub ee} in neutrinoless double beta decay.

  15. Top Quark Mass Measurement in the lepton plus jets Channel Using a Matrix Element Method and in situ Jet Energy Calibration

    E-Print Network [OSTI]

    Bauer, Gerry P.

    A precision measurement of the top quark mass mt [m subscript t] is obtained using a sample of tt? events from pp? collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, ...

  16. 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]

    Gomez-Ceballos, Guillelmo

    We present a measurement of the top-quark pair production cross section in proton-antiproton collisions at ?s = 1.96??TeV. The data were collected at the Fermilab Tevatron by the CDF II detector and correspond to an ...

  17. Search for new charged bosons and dark matter in final states with one lepton and missing transverse energy with the ATLAS detector at the LHC

    E-Print Network [OSTI]

    Bugge, Magnar Kopangen; Read, Alexander Lincoln

    2015-04-30T23:59:59.000Z

    The Standard Model (SM), the current theory of elementary particles and interactions, has been extremely successful in predicting and describing experimental results. The prediction of the electron's anomalous magnetic moment served as an early triumph of quantum electrodynamics, and one success after another has followed, including the discovery of the weak interaction gauge bosons $W^\\pm$ and $Z^0$, and more recently the discovery of the Higgs boson at CERN's Large Hadron Collider (LHC) in 2012. In spite of the success of the theory, though, there are phenomena which it does not explain, such as the dark matter and dark energy making up most of the universe. Extensions of the SM aiming to address its shortcomings typically predict observable deviations from the theory. Although theories predicting significant deviations from the SM in the energy regime so far explored can be immediately excluded, theories that predict deviations at higher, unexplored energies are still viable. Therefore, exploring physics...

  18. Further search for supersymmetry at ?s=7??TeV in final states with jets, missing transverse momentum, and isolated leptons with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    This work presents a new inclusive search for supersymmetry (SUSY) by the ATLAS experiment at the LHC in proton-proton collisions at a center-of-mass energy ?s=7 ??TeV in final states with jets, missing transverse momentum ...

  19. Search for Supersymmetry Using Final States with One Lepton, Jets, and Missing Transverse Momentum with the ATLAS Detector in ?s=7 TeV pp Collisions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    none,

    2011-03-01T23:59:59.000Z

    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 TeV proton-proton collisions at the LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of 35 pb?¹. No excess above the standard model background expectation is observed. Limits are set on the parameters of the minimal supergravity framework, extending previous limits. Within this framework, for A0=0 GeV, tan??=3, and ?>0 and for equal squark and gluino masses, gluino masses below 700 GeV are excluded at 95% confidence level.

  20. Stability and symmetry breaking in a three Higgs-boson doublet model with lepton family symmetry O(2)xZ2

    E-Print Network [OSTI]

    Maniatis, M; Reyes, Carlos M

    2015-01-01T23:59:59.000Z

    With a view on explaining the current neutrino data, an extension of the Standard Model with three Higgs-boson doublets has been proposed. Imposing an O(2) x Z2 family symmetry, a neutrino mixing matrix with theta23 = pi/4 and theta13 = 0 appears in a natural way. Even though these values for the mixing matrix do not follow the recent experimental constraints, they are nevertheless a good approximation. We study the Higgs potential of this model in detail. We apply recent methods which allow for the study of any three-Higgs-boson doublet model. It turns out that for a variety of parameters the potential is stable, has the correct electroweak symmetry-breaking, and has vacuum-expectation values corresponding to the electroweak precision data.

  1. Introduction New currents in DIS

    E-Print Network [OSTI]

    for precision measurement of the scattered lepton ZEUS Depleted Uranium Calorimeter Optimised for precision

  2. Introduction Model Dependent

    E-Print Network [OSTI]

    lepton ZEUS Depleted Uranium Calorimeter Optimised for precision measurement of the hadronic final state

  3. Introduction 1 INTRODUCTION

    E-Print Network [OSTI]

    organize the particles into six categories: Gauge and Higgs bosons Leptons Quarks Mesons Baryons Searches

  4. arc-continent collision origin: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Piero Olla 2008-01-23 51 Lepton-pair production in nuclear collisions - past, present, future Nuclear Experiment (arXiv) Summary: The key results on lepton-pair production...

  5. Transverse Spin Polarization of $\\tau^-$ in ${\\bar{B}}^0\\rightarrow D^{+} \\tau^- {\\bar{\

    E-Print Network [OSTI]

    Hwang, Dae Sung

    2015-01-01T23:59:59.000Z

    The spin of the $\\tau$ lepton in the semiletonic process ${\\bar{B}}^0\\rightarrow D^{+} \\tau^- {\\bar{\

  6. Polarized and Unpolarized Lepton Pair Forward-backward Asymmetries in $\\overline{B}\\rightarrow \\overline{K}_{0}^{*}(1430) \\ell^+\\ell^-$ and $\\overline{B}\\rightarrow \\overline{K} \\ell^+\\ell^-$ Decays in Two Higgs Doublet Model

    E-Print Network [OSTI]

    Falahati, F

    2015-01-01T23:59:59.000Z

    In this paper we shall focus on the effects of concrete models such as SM and Model III of 2HDM on the polarized and unpolarized forward-backward asymmetries of $\\overline{B}\\rightarrow \\overline{K}_0^{*}(1430) \\ell^+\\ell^-$ and $\\overline{B}\\rightarrow \\overline{K} \\ell^+\\ell^-$ decays. The obtained results of these decay modes are compared to each other. Also, we obtain the minimum required number of events for detecting each asymmetry and compare them with the number of produced $B\\bar{B}$ pairs at the LHC or supposed to be produced at the Super-LHC. At the end, we conclude that the study of these asymmetries for $\\overline{B}\\rightarrow \\overline{K}_0^*(1430) \\ell^+\\ell^-$ and $\\overline{B}\\rightarrow \\overline{K} \\ell^+\\ell^-$ processes are very effective tools for establishing new physics in the future B-physics experiments.

  7. 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]

    Gomez-Ceballos, Guillelmo

    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, ...

  8. Search for the Standard Model Higgs Boson Decaying to W[superscript +]W[superscript -] in the Fully Leptonic Final State in pp Collisions at ?s = 7 TeV

    E-Print Network [OSTI]

    Alver, B.

    A search for the standard model Higgs boson decaying to W[superscript +]W[superscript ?] in pp collisions at ?s = 7 TeV is reported. The data are collected at the LHC with the CMS detector, and correspond to an integrated ...

  9. 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]

    The CDF Collaboration

    2012-08-09T23:59:59.000Z

    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.

  10. Measurement of the Top-antitop Production Cross Section in pp Collisions at sqrt(s)=7 TeV using the Kinematic Properties of Events with Leptons and Jets

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2011-09-01T23:59:59.000Z

    A measurement of the top-antitop production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 inverse picobarns and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are used to separate the top-antitop signal from W+jets and QCD multijet background events. The measured cross section is 173 + 39 - 32 (stat. + syst.) pb, consistent with standard model expectations.

  11. 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]

    Bauer, Gerry P.

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

  12. Measurement of WZ production and searches for anomalous top quark decays and Higgs boson production using tri-lepton final states in ppbar collisions at ?s = 1.96 TeV

    E-Print Network [OSTI]

    McGivern, Carrie Lynne

    2012-05-31T23:59:59.000Z

    . . . . . 21 2-4 The new RunII central tracking system. . . . . . . . . . . . . . . . . . . 22 2-5 Silicon microstrip tracker. . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2-6 (a) The uranium/liquid-argon electromagnetic, fine hadronic, and coarse.... . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2-7 Uranium/liquid-argon plates configuration. . . . . . . . . . . . . . . . . 25 2-8 Expanded view of (a) the muon wire drift chambers and (b) the muon scintillation detectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2...

  13. Search for $W' \\to t\\bar{b}$ in the lepton plus jets final state in proton-proton collisions at a centre-of-mass energy of $\\sqrt{s}$ = 8 TeV with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-03-06T23:59:59.000Z

    A search for new charged massive gauge bosons, called $W'$, is performed with the ATLAS detector at the LHC, in proton-proton collisions at a centre-of-mass energy of $\\sqrt{s}$ = 8 TeV, using a dataset corresponding to an integrated luminosity of 20.3 fb$^{-1}$. This analysis searches for $W'$ bosons in the $W' \\to t\\bar{b}$ decay channel in final states with electrons or muons, using a multivariate method based on boosted decision trees. The search covers masses between 0.5 and 3.0 TeV, for right-handed or left-handed $W'$ bosons. No significant deviation from the Standard Model expectation is observed and limits are set on the $W' \\to t\\bar{b}$ cross-section times branching ratio and on the $W'$-boson effective couplings as a function of the $W'$-boson mass using the CL$_s$ procedure. For a left-handed (right-handed) $W'$ boson, masses below 1.70 (1.92) TeV are excluded at 95% confidence level.

  14. Measurements of Higgs boson production and couplings in the four-lepton channel in pp collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    The final ATLAS Run 1 measurements of Higgs boson production and couplings in the decay channel H?ZZ*??[superscript +]?[superscript?]?' [superscript +], ?' [superscript ?], where ?, ??=e or ?, are presented. These measurements ...

  15. Neutrino masses, dominant neutrinoless double beta decay, and observable lepton flavor violation in left-right models and SO(10) grand unification with low mass $\\bf W_R, Z_R$ bosons

    E-Print Network [OSTI]

    Ram Lal Awasthi; M. K. Parida; Sudhanwa Patra

    2013-08-07T23:59:59.000Z

    While the detection of $W_R$-boson at the Large Hadron Collider is likely to resolve the mystery of parity violation in weak interaction, observation of neutrinoless double beta decay ($0\

  16. 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]

    Taylor, Frank E.

    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 proton–proton (pp) collision data collected ...

  17. Search for light top squark pair production in final states with leptons and b-jets with the ATLAS detector in ?s = 7 TeV proton–proton collisions

    E-Print Network [OSTI]

    Taylor, Frank E.

    The results of a search for pair production of light top squarks are presented, using 4.7 fb[superscript ?1] ?s = 7 TeV proton–proton collisions collected with the ATLAS detector at the Large Hadron Collider. This search ...

  18. Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in ?s = 7 TeV pp collisions with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb[superscript -1] of ?s = 7 TeV ...

  19. Search for Direct Top Squark Pair Production in Final States with One Isolated Lepton, Jets, and Missing Transverse Momentum in ?s=7??TeV pp Collisions Using 4.7??fb[superscript -1] of ATLAS Data

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search is presented for direct top squark pair production in final states with one isolated electron or muon, jets, and missing transverse momentum in proton-proton collisions at ?s=7??TeV. The measurement is based on ...

  20. Measurement of the tt-bar production cross section in pp-bar collisions at s?=1.96??TeV using kinematic characteristics of lepton+jets events

    E-Print Network [OSTI]

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

    2007-11-27T23:59:59.000Z

    of an electromagnetic section with depleted Uranium absorber plates, a fine hadronic section with Uranium-Niobium absorbers, and a coarse hadronic sec- tion with Copper (stainless steel) absorbers in the CC (EC). The calorimeter is compact and highly segmented...

  1. Fiducial and differential cross sections of Higgs boson production measured in the four-lepton decay channel in pp collisions at ?s = 8 TeV with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    Measurements of fiducial and differential cross sections of Higgs boson production in the H?ZZ*?4? decay channel are presented. The cross sections are determined within a fiducial phase space and corrected for detection ...

  2. Searches for D0 - Anti-D0 Mixing, Rare Charm And Tau Decays

    SciTech Connect (OSTI)

    Swain, Sanjay K.; /SLAC

    2007-01-25T23:59:59.000Z

    I discuss the results on D{sup 0}-{bar D}{sup 0} mixing through hadronic as well as semi-leptonic charm decays, rare flavor-changing neutral currents in the charm sector and the lepton flavor violating {tau} decaying to charged lighter leptons. The results from both BABAR and Belle are presented in this review.

  3. Current Status of Nucleon Decay Searches with Super-Kamiokande

    E-Print Network [OSTI]

    Brett Viren

    1999-03-16T23:59:59.000Z

    Evidence for Nucleon Decay has yet to be observed. Current results from the observation of a 45 kton-year exposure of Super-Kamiokande and lifetime limits for nucleons to decay via lepton + pion, lepton + eta and lepton + kaon modes are presented.

  4. Are the B decay anomalies related to neutrino oscillations?

    E-Print Network [OSTI]

    Boucenna, Sofiane M; Vicente, Avelino

    2015-01-01T23:59:59.000Z

    Neutrino oscillations are solidly established, with a hint of CP violation just emerging. Similarly, there are hints of lepton universality violation in $b \\to s$ transitions at the level of $2.6 \\sigma$. By assuming that the unitary transformation between weak and mass charged leptons equals the leptonic mixing matrix measured in neutrino oscillation experiments, we predict several lepton flavor violating (LFV) B meson decays. We are led to the tantalizing possibility that some LFV branching ratios for B decays correlate with the leptonic CP phase $\\delta$ characterizing neutrino oscillations. Moreover, we also consider implications for $\\ell_i \\to \\ell_j \\ell_k \\ell_k$ decays.

  5. Importance of neutrinoless double beta decay

    E-Print Network [OSTI]

    Utpal Sarkar

    2007-12-17T23:59:59.000Z

    A natural explanation for the smallness of the neutrino mass requires them to be Majorana particles violating lepton number by two units. Since lepton number violation can have several interesting consequences in particle physics and cosmology, it is of utmost importance to find out if there is lepton number violation in nature and what is its magnitude. The neutrinoless double beta decay experiment can answer these questions: if there is lepton number violation and if neutrinos are Majorana particles. In addition, the magnitude of neutrinoless double beta decay will constrain any other lepton number violating processes. This lepton number violation may also be relatd to the matter-antimatter asymmetry of the universe, dark matter and cosmological constant.

  6. O?[]O? nuclear ?-decay of ?²Ga 

    E-Print Network [OSTI]

    Hyman, Bruce Carl

    1999-01-01T23:59:59.000Z

    and quarks with interactions taking place through the exchange of particles known as bosons [22]. There are six quarks grouped together in pairs or "generations", and three lepton generations as well. The Standard Model is able to predict weak interactions... very well. According to the Standard Model weak interactions are mediated by W and Z bosons [22]. In weak interactions between leptons, couplings to the W take place within a particular lepton generation [22]. This is so assuming that neutrinos...

  7. Left-Right Symmetry: from LHC to Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Vladimir Tello; Miha Nemevsek; Fabrizio Nesti; Goran Senjanovi?; Francesco Vissani

    2011-03-29T23:59:59.000Z

    The Large Hadron Collider has a potential to probe the scale of left-right symmetry restoration and the associated lepton number violation. Moreover, it offers hope of measuring the right-handed leptonic mixing matrix. We show how this, together with constraints from lepton flavor violating processes, can be used to make predictions for neutrinoless double beta decay. We illustrate this deep connection in the case of the type-II seesaw.

  8. Left-Right Symmetry: From the LHC to Neutrinoless Double Beta Decay

    SciTech Connect (OSTI)

    Tello, Vladimir [SISSA, Trieste (Italy); Nemevsek, Miha [ICTP, Trieste (Italy); Jozef Stefan Institute, Ljubljana (Slovenia); Nesti, Fabrizio [Universita di Ferrara, Ferrara (Italy); Senjanovic, Goran [ICTP, Trieste (Italy); Vissani, Francesco [LNGS, INFN, Assergi (Italy)

    2011-04-15T23:59:59.000Z

    The Large Hadron Collider has the potential to probe the scale of left-right symmetry restoration and the associated lepton number violation. Moreover, it offers the hope of measuring the right-handed leptonic mixing matrix. We show how this, together with constraints from lepton flavor violating processes, can be used to make predictions for neutrinoless double beta decay. We illustrate this connection in the case of the type-II seesaw.

  9. Acceptance and resolution simulation studies for the dielectron spectrometer HADES at GSI

    E-Print Network [OSTI]

    R. Schicker; A. Brenschede; K. Garrow; H. Schoen; A. Balanda; H. Bokemeyer; J. Friese; W. Karig; P. Kienle; W. Koenig; W. Kuehn; F. Lefevre; V. Metag; G. Roche; P. Salabura; A. Schroeter; J. Stroth; H. Tsertos

    1996-05-21T23:59:59.000Z

    Design studies for a second generation Dilepton Spectrometer to be built at the SIS accelerator of GSI are presented. The basic design parameters of this system are specified and the different detector components for charged particle tracking and for lepton identification are described. The geometrical acceptance for lepton pairs is given. Results on single track momentum resolution and on lepton pair mass resolution are reported.

  10. Herwig++ Physics and Manual.

    E-Print Network [OSTI]

    Bahr, M; Gieseke, Stefan; Giggs, M; Grellscheid, D; Hamilton, K; Latunde-Dada, Oluseyi; Platzer, S; Richardson, P; Seymour, Michael H; Sherstnev, A; Webber, Bryan R

    . . . . . . . . . . . . . . . . . . . . . . . . . 68 7.2 Cluster fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 7.3 Cluster decays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 7.3.1 Mixing weights... . . . . . . . . . . . . . . . . . . . . . . 135 C Contrib 136 D Tuning 137 3 1 Introduction Herwig++ is a general-purpose event generator for the simulation of high-energy lepton-lepton, lepton-hadron and hadron-hadron collisions with special emphasis on the accurate simulation of QCD radiation...

  11. adults identifying future: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    shower, while those which involve multi-body kinematics may still have discrimination power. For leptonic boosted tops, we consider variables which characterize the separation...

  12. Electric dipole moments, from e to tau

    E-Print Network [OSTI]

    A. G. Grozin; I. B. Khriplovich; A. S. Rudenko

    2008-12-12T23:59:59.000Z

    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.

  13. Electric dipole moments, from e to tau

    E-Print Network [OSTI]

    Grozin, A G; Rudenko, A S

    2008-01-01T23:59:59.000Z

    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.

  14. Electric dipole moments, from e to {tau}

    SciTech Connect (OSTI)

    Grozin, A. G., E-mail: A.G.Grozin@inp.nsk.su; Khriplovich, I. B., E-mail: khriplovich@inp.nsk.su; Rudenko, A. S., E-mail: saber_@inbox.r [Budker Institute of Nuclear Physics (Russian Federation)

    2009-07-15T23:59:59.000Z

    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.

  15. Muon-Induced Backgrounds in the Double Chooz Neutrino Oscillation Experiment

    E-Print Network [OSTI]

    for neutrinoless double-beta decay, a lepton-number violating nuclear process. The observation of a non-zero rate

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

    E-Print Network [OSTI]

    M. Deniz er al.; TEXONO Collaboration

    2010-08-09T23:59:59.000Z

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

  17. Flavor $\\S_{4}$ [circle times operator] $\\Z_{2}$ symmetry and neutrino mixing

    E-Print Network [OSTI]

    Zhang, H

    2007-01-01T23:59:59.000Z

    We present a model of the lepton masses and flavor mixing based on the discrete group $S^{}_4\\otimes Z^{}_2$. In this model, all the charged leptons and neutrinos are assigned to the ${\\bf \\underline{3}}_\\alpha$ representation of $S^{}_4$ in the Yamanouchi bases. The charged lepton and neutrino masses are mainly determined by the vacuum expectation value structures of the Higgs fields. Our model predicts a nearly tri-bimaximal lepton flavor mixing pattern, which is fully in agreement with the current experimental results. The neutrino mass spectrum takes the nearly degenerate pattern, which may be well tested in the future precise experiments.

  18. active npc inverters: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    radiative lepton decays in supersymmetric models is described. Links to neutrinoless double beta decay are also briefly discussed. The analysis leads to two distinct matrix...

  19. asymmetric reproductive interference: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    inversely related to Gouldian finch reproduc- tive 4 Lepton-Flavored Asymmetric Dark Matter and Interference in Direct Detection HEP - Phenomenology (arXiv) Summary: In flavored...

  20. EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN-EP/2003-013

    E-Print Network [OSTI]

    Boyer, Edmond

    EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN-EP/2003-013 March 26, 2003 Search for Excited Leptons at LEP The L3 Collaboration Abstract A search for charged and neutral excited leptons is performed [5­7]. Searches for excited electrons and neutrinos were also performed at the HERA [8] ep collider

  1. Study of Very High Energy Gamma-ray Emission from the Pulsar Wind Nebula in

    E-Print Network [OSTI]

    Enomoto, Ryoji

    telescopes have achieved remarkably high sensitivity in the very high energy gamma-ray band. This is well-wavelength spectra were per- formed, based on both leptonic and hadronic models. In the leptonic model, gamma raysStudy of Very High Energy Gamma-ray Emission from the Pulsar Wind Nebula in MSH 15-52 with CANGAROO

  2. Searching for New Physics at SuperB - The Super Flavor Factory

    ScienceCinema (OSTI)

    David Hitlin

    2010-01-08T23:59:59.000Z

    SuperB ? a Super Flavor Factory, an electron-positron collider with a luminosity of 1036 cm-2 s-1, can conduct conduct unique sensitive searches for New Physics effects such as lepton flavor violation and new sources of CP violation in the quark and lepton sectors.

  3. SCIPP 07/12 CDF/PUB/EXOTIC/PUBLIC/8837

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    , the final search results are kinematically limited by the center-of-mass energy [2]. The Tevatron boson couplings to b quarks and leptons. Efficient lepton identification and b-jet tagging for each Higgs boson mass hypothesis. The comparison of expected background and observed data (Figure 1

  4. CDF/ANAL/TOP/PUB/7680 Measurement of the Top Quark Mass using the Template Method

    E-Print Network [OSTI]

    Quigg, Chris

    CDF/ANAL/TOP/PUB/7680 Measurement of the Top Quark Mass using the Template Method in the Lepton, 2005) We report a measurement of the top quark mass in the lepton plus jets channel of t¯t events from, which brings 138 t¯t candidates separated into four subsamples. A top quark mass is reconstructed

  5. Search for neutrinoless tau decays involving pi(0) or eta mesons

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1997-08-01T23:59:59.000Z

    We have searched for lepton flavor violating decays of the tau lepton using final states with an electron Or a muon and one or two pi(0) or eta mesons but no neutrinos. The data used in the search were collected with the CLEO II detector...

  6. WUE-ITP-2004-029 hep-ph/0408140

    E-Print Network [OSTI]

    corrections to the slepton mass matrices which enhance the rates of charged lepton avor violating processes, with a Majorana mass term and Yukawa cou- plings Y #23; to the left-handed lepton doublets 1;2 . At energies much below the Majorana mass scale MR , electroweak symmetry breaking leads to the neutrino mass matrix M #23

  7. NSAC Subcommittee Double Beta Decay

    E-Print Network [OSTI]

    and Lawrence Berkeley National Laboratory #12;2 Decay #12;2 0 0 Decay If 0 occurs then the neutrino is a Majorana particle and the neutrino and antiparticle are not distinct. Lepton number is not conserved! #12 30 ) Experimental Resolution #12;Higgs Boson, Majorana Mass and Lepton Number Conservation #12;LVD

  8. A select overview of neutrino experiments

    SciTech Connect (OSTI)

    Stefanski, Raymond J.

    2004-11-01T23:59:59.000Z

    The relationship between the lepton sector and the quark sector is an interesting source of discourse in the current theoretical climate. Models that might someday supersede the Standard Model typically require quark structure, with implications for the lepton sector. This talk will explore some of the consequences of newer models, in the context of certain neutrino experiments.

  9. Tau identification at the Tevatron

    SciTech Connect (OSTI)

    Levy, Stephen; /Chicago U., EFI

    2005-07-01T23:59:59.000Z

    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.

  10. Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-01-01T23:59:59.000Z

    A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb$^{-1}$ of proton-proton collision data recorded by the ATLAS experiment at $\\sqrt{s}=8$ TeV at the Large Hadron Collider. Five final states, targeting the decays $H\\to WW^*$, $\\tau\\tau$, and $ZZ^*$, are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons ($e$ or $\\mu$) without a hadronically decaying $\\tau$ lepton; three light leptons; two same-charge light leptons with a hadronically decaying $\\tau$ lepton; four light leptons; and one light lepton and two hadronically decaying $\\tau$ leptons. No significant excess of events is observed above the background expectation. The best fit for the $t\\bar t H$ production cross section, assuming a Higgs boson mass of 125 GeV, is $2.1 ^{+1.4}_{-1.2}$ times the SM expectation, and the observed (expected) upper limit at the 95% confidence level is 4.7 (2.4) times the SM rate. The $p$-value f...

  11. The "Goldstone Exception" II: Absence of a Higgs Fine-Tuning Problem in the Spontaneously Broken Limit of the Gell Mann Levy Linear Sigma Model: O(4) with PCAC and SU(2)_L with PCAC and Standard Model Quarks and Leptons

    E-Print Network [OSTI]

    Bryan W. Lynn; Glenn D. Starkman; Katherine Freese; Dmitry I. Podolsky

    2013-01-23T23:59:59.000Z

    More than four decades ago, Lee and Symanzik proved that, in the Gell Mann-Levy (GML) model with partially conserved axial-vector currents (PCAC), tadpole renormalization (a Higgs Vacuum Stability Condition) forces all S-matrix ultra-violet quadratic divergences (UVQD) to be absorbed into the physical renormalized pseudo-scalar pion (pole) mass squared. We show that this includes "new" UVQD (widely unfamiliar to modern audiences). We also show that tadpole renormalization is an automatic consequence of Ward-Takahashi identities. We prove that all UVQD therefore vanish identically in the Goldstone-mode limit, where pions are Nambu-Goldstone Bosons (NGB), and where Lee and Symanzik's Goldstone Symmetry Restoration Condition (a renormalization prescription) enforces spontaneous symmetry breaking and the massless-ness of NGB. Axial-vector current conservation is restored as is SU(2)(L-R) chiral symmetry: the vanishing of UVQD is therefore achieved in the Goldstone-mode by restoration of an exact symmetry, and therefore (by definition) without fine-tuning! A weak-scale Higgs mass is therefore not UVQD fine-tuned in the spontaneously broken GML LSM. That is simply another (albeit unfamiliar) consequence of the Goldstone Theorem. Hence Goldstone-mode O(4) LSM symmetries are sufficient to ensure that the theory does not suffer from the Higgs Fine Tuning Problem. This is contrary to the widely accepted belief that UVQD in the Higgs mass lead to such problems in the O(4) LSM, which are then presumed to be inherited by the Standard Model (SM). The key observation is to regard the spontaneously broken O(4) LSM as the Goldstone-mode limit of the GML LSM. We prove this first at 1-loop then at all loop orders for the pure scalar GML model. We then break the O(4) symmetry to SU(2)L with SM Yukawa couplings, and show that the above remains true.

  12. Search for Pair Production of Heavy Top-Like Quarks Decaying to a High-p[subscript T]W Boson and a b Quark in the Lepton Plus Jets Final State at ?s = 7 TeV with the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search is presented for production of a heavy up-type quark (t[superscript ?]) together with its antiparticle, assuming a significant branching ratio for subsequent decay into a W boson and a b quark. The search is ...

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

    SciTech Connect (OSTI)

    Attal, Alon J.; /UCLA

    2006-11-01T23:59:59.000Z

    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.

  14. Baryogenesis via neutrino oscillations

    E-Print Network [OSTI]

    E. Kh. Akhmedov; V. A. Rubakov; A. Yu. Smirnov

    1998-07-29T23:59:59.000Z

    We propose a new mechanism of leptogenesis in which the asymmetries in lepton numbers are produced through the CP-violating oscillations of ``sterile'' (electroweak singlet) neutrinos. The asymmetry is communicated from singlet neutrinos to ordinary leptons through their Yukawa couplings. The lepton asymmetry is then reprocessed into baryon asymmetry by electroweak sphalerons. We show that the observed value of baryon asymmetry can be generated in this way, and the masses of ordinary neutrinos induced by the seesaw mechanism are in the astrophysically and cosmologically interesting range. Except for singlet neutrinos, no physics beyond the Standard Model is required.

  15. Top quark mass measurements at the LHC

    E-Print Network [OSTI]

    Fuster, Juan; The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    The latest measurements of the top quark mass using the ATLAS and CMS experiments at the LHC are presented. The discussion includes the results obtained using the conventional methods (Template/Ideogram) and those derived from the so called alternative methods. Results from the conventional methods using the various top final states (lepton+jets, di-lepton and full hadronic) are reviewed. Determinations using the inclusive ttbar production, the ttbar production with an additional jet and the lepton-b-jet invariant mass distribution are also discussed.

  16. Top polarization as a probe of new physics

    E-Print Network [OSTI]

    Rohini M Godbole; Saurabh D Rindani; Kumar Rao; Ritesh K Singh

    2010-04-16T23:59:59.000Z

    We investigate the effects of new physics scenarios containing a high mass vector resonance on top pair production at the LHC, using the polarization of the produced top. In particular we use kinematic distributions of the secondary lepton coming from top decay, which depends on top polarization, as it has been shown that the angular distribution of the decay lepton is insensitive to the anomalous tbW vertex and hence is a pure probe of new physics in top quark production. Spin sensitive variables involving the decay lepton are used to probe top polarization. Some sensitivity is found for the new couplings of the top.

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

    SciTech Connect (OSTI)

    Forrest, Robert David; /California U., Davis

    2011-09-01T23:59:59.000Z

    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.

  18. Preon Trinity

    E-Print Network [OSTI]

    J. -J. Dugne; S. Fredriksson; J. Hansson; E. Predazzi

    1998-02-17T23:59:59.000Z

    We present a new minimal model for the substructure of all known quarks, leptons and weak gauge bosons, based on only three fundamental and stable spin-1/2 preons. As a consequence, we predict three new quarks, three new leptons, and six new vector bosons. One of the new quarks has charge $-4e/3$. The model explains the apparent conservation of three lepton numbers, as well as the so-called Cabibbo-mixing of the $d$ and $s$ quarks, and predicts electromagnetic decays or oscillations between the neutrinos $\\bar{\

  19. androgen excess produces: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    mixture of leptons-antileptons and b-bbar or into b-bbar only. Focusing on the prompt gamma-ray emission, previous works found that the best fit to the data corresponds to...

  20. A research Program in Elementary Particle Physics

    SciTech Connect (OSTI)

    Sobel, Henry; Molzon, William; Lankford, Andrew; Taffard, Anyes; Whiteson, Daniel; Kirkby, David

    2013-07-25T23:59:59.000Z

    Work is reported in: Neutrino Physics, Cosmic Rays and Elementary Particles; Particle Physics and Charged Lepton Flavor Violation; Research in Collider Physics; Dark Energy Studies with BOSS and LSST.

  1. Form factors for $\\mathrm B_\\mathrm s \\to \\mathrm K \\ell ?$ decays in Lattice QCD

    E-Print Network [OSTI]

    Felix Bahr; Fabio Bernardoni; John Bulava; Anosh Joseph; Alberto Ramos; Hubert Simma; Rainer Sommer

    2014-11-14T23:59:59.000Z

    We present the current status of the computation of the form factor $f_+ (q^2)$ for the semi-leptonic decay $\\mathrm B_\\mathrm s \\to \\mathrm K \\ell \

  2. Reconciling leptogenesis with observable mu --> e gamma rates

    E-Print Network [OSTI]

    Steve Blanchet; Thomas Hambye; Francois-Xavier Josse-Michaux

    2010-02-15T23:59:59.000Z

    We perform a detailed analysis of thermal leptogenesis in the framework of seesaw models which approximately conserve lepton number. These models are known to allow for large Yukawa couplings and a low seesaw scale in agreement with neutrino mass constraints, and hence to lead to large lepton flavour violating rates that can be probed experimentally. Although large Yukawa couplings lead to (inverse) decay rates much larger than the Hubble expansion rate, we show that the leptogenesis washout induced is generically small if the mass splitting between the right-handed neutrinos is small enough. As a result, large lepton flavour violating rates are compatible with successful leptogenesis. We emphasize that this scenario does not require any particular flavour structure. A small splitting is natural and radiatively stable in this context because it is protected by the lepton number symmetry.

  3. Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production in polarized proton collisions at [the square root of sigma] = 200 GeV.

    E-Print Network [OSTI]

    Hoffman, Alan Michael

    2009-01-01T23:59:59.000Z

    Twenty years of polarized lepton-nucleon scattering experiments have found that the contribution from quark spins (1/2[delta] [sigma]) to the spin of the proton is only ~ 35%. This has lead researchers to look elsewhere, ...

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

    E-Print Network [OSTI]

    Taylor, Frank E.

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

  5. Searching the inclusive l gamma EslashT+b-quark signature for radiative top quark decay and non-standard-model processes

    E-Print Network [OSTI]

    Xie, Si

    We compare the inclusive production of events containing a lepton (?), a photon (?), significant transverse momentum imbalance (E?[subscript T]), and a jet identified as containing a b-quark, to SM predictions. The search ...

  6. Search for the Decays B(s)-->e+mu- and B(s)-->e+e- in CDF Run II

    E-Print Network [OSTI]

    Xie, Si

    We report results from a search for the lepton flavor violating decays B[subscript s][superscript 0]?e[superscript +]?[superscript -] and B[superscript 0]?e[superscript +]?[superscript -], and the flavor-changing neutral-current ...

  7. Search for WH production with a light Higgs boson decaying to prompt electron-jets in proton–proton collisions at root s= 7 TeV with the ATLAS detector

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    of the Standard Model (SM) Higgs boson [3–5] at this mass.Zupan J 2010 Discovering Higgs boson decays to lepton jetslepton jets from light Higgs boson decay in proton- proton

  8. Search for pair production of third-generation scalar leptoquarks and top squarks in proton–proton collisions at ?s = 8 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a ...

  9. atf2 high availability: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 41 high...

  10. Physics Letters B 557 (2003) 167175 www.elsevier.com/locate/npe

    E-Print Network [OSTI]

    2003-01-01T23:59:59.000Z

    .L. on the lifetime for neutrinoless double beta decay of 130Te. In terms of effective neutrino mass this leads lepton violating decays of 130Te and on the neutrinoless double beta decay of 128Te to the ground state

  11. Indirect measurement of sin[superscript 2]?[subscript W] (or M[subscript W) using ?[superscript +]?[superscript ?] pairs from ?*/Z bosons produced in p[bar over p] collisions at a center-of-momentum energy of 1.96 TeV

    E-Print Network [OSTI]

    Goncharov, Maxim

    Drell-Yan lepton pairs are produced in the process p[bar over p] ? ?[superscript +]?[superscript ?] + X through an intermediate ?[superscript ?]/Zboson. The forward-backward asymmetry in the polar-angle distribution of the ...

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

    E-Print Network [OSTI]

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

    2008-08-28T23:59:59.000Z

    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.

  13. E-Print Network 3.0 - acoplanar jet topology Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Physics, High Energy Physics Group Collection: Physics 2 Search for invisible Higgs boson decays at centre-of-mass energies up to 184 GeV Summary: and acoplanar lepton...

  14. Further evidence for narrow exotic low mass baryons

    E-Print Network [OSTI]

    B. Tatischeff

    2004-04-29T23:59:59.000Z

    Although narrow low mass baryonic structures, observed mainly in SPES3 (Saturne) data, were not confirmed in recent experiments using lepton probes, their existence is confirmed in other data, where hadronic probes were used.

  15. RARE KAON DECAYS.

    SciTech Connect (OSTI)

    LITTENBERG, L.

    2005-07-19T23:59:59.000Z

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.

  16. Search for supersymmetry in events with opposite-sign dileptons and missing transverse energy using an artificial neural network

    E-Print Network [OSTI]

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

    2013-04-02T23:59:59.000Z

    In this paper, a search for supersymmetry (SUSY) is presented in events with two opposite-sign isolated leptons in the final state, accompanied by hadronic jets and missing transverse energy. An artificial neural network ...

  17. WW Production at the LHC in NLO Simulations

    SciTech Connect (OSTI)

    Vranjes, N.; Simic, Lj.; Reljic, D.; Vudragovic, D.; Popovic, D. S. [Institute of Physics, Belgrade (Serbia and Montenegro)

    2007-04-23T23:59:59.000Z

    The WW production via leptonic decay is studied using next-to-leading order generators. The output from the Baur, Han and Ohnemus (BHO) NLO code is compared with MC-NLO generator.

  18. Leptin acts centrally to induce the prepubertal secretion of luteinizing hormone in the female rat: a potential early role in the pubertal process

    E-Print Network [OSTI]

    Dearth, Robert Keith

    1999-01-01T23:59:59.000Z

    in controlling LH secretion during late juvenile and peripubertal development, hence contributing to hypothalamic-pituitary function during sexual maturation. Therefore, this study was conducted to determine if lepton is capable of stimulating LH release during...

  19. Limits on flavor changing neutral currents in D-0 meson Decays

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1996-04-01T23:59:59.000Z

    Using the CLEO II detector at the Cornell Electron Storage Ring, we have searched for flavor changing neutral currents and lepton family number violations in D-0 meson decays. The upper limits on the branching fractions ...

  20. DESY 09143 arXiv:0909.3587v1

    E-Print Network [OSTI]

    . Keywords: Lepton-Nucleon Scattering. #12; The HERMES Collaboration A. Airapetian 12;15 , N. Akopov 26 , Z. Akopov 5 , E.C. Aschenauer 6;a , W. Augustyniak 25 , R. Avakian 26 , A. Avetissian 26 , E. Avetisyan 5

  1. Measurement of the tt? production cross section in pp collisions at ?s=7??TeV in dilepton final states containing a ?

    E-Print Network [OSTI]

    Bauer, Gerry P.

    The top quark pair production cross section is measured in dilepton events with one electron or muon, and one hadronically decaying ? lepton from the decay tt? ?(??[subscript ?])(?[subscript h]?[subscript ?])bb? , (?=e,?). ...

  2. Search for New Physics with Same-Sign Isolated Dilepton Events with Jets and Missing Transverse Energy

    E-Print Network [OSTI]

    Bauer, Gerry P.

    A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated ...

  3. Search for supersymmetry in events with opposite-sign dileptons and missing transverse energy using an artificial neural network

    E-Print Network [OSTI]

    Apyan, Aram

    In this paper, a search for supersymmetry (SUSY) is presented in events with two opposite-sign isolated leptons in the final state, accompanied by hadronic jets and missing transverse energy. An artificial neural network ...

  4. anomalous gtt couplings: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yukawa Couplings HEP - Phenomenology (arXiv) Summary: In the standard model, the Higgs boson h couples to the quarks and charged leptons according to the well-known formula...

  5. anomalous gravity effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    addition, a large A term orand a large stop mass are needed to have about a 126 GeV Higgs boson with three families of quarks and leptons. Thus, we suggest an inverted effective...

  6. atlas event production: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    collaboration 2012-01-01 13 Search for chargino and neutralino production with a Higgs boson in the decay chain in 1 or 3 leptons final state events with ATLAS CERN Preprints...

  7. arhioluhi tshto zh: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at International Linear Collider (ILC). Using e+e- -> ZH process, the mass of Higgs boson can be measured by two lepton tracks from decay of Z boson, even if the Higgs boson...

  8. atlas tau trigger: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    beyond the Standard Model, and to get precise measurements of the properties of the Higgs boson decaying to tau-leptons. We present the performance of the hadronic tau trigger...

  9. anomalous exciton-radiation coupling: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yukawa Couplings HEP - Phenomenology (arXiv) Summary: In the standard model, the Higgs boson h couples to the quarks and charged leptons according to the well-known formula...

  10. airborne particle mass: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    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...

  11. Radiative Penguin Decays at the B Factories

    SciTech Connect (OSTI)

    Cuhadar-Donszelmann, T.; /British Columbia U.

    2007-03-05T23:59:59.000Z

    Recent results from the B-Factories on radiative decays such as b {yields} s(d){gamma}, b {yields} s{ell}{ell} and leptonic decay B{sup 0} {yields} {tau}{sup +}{tau}{sup -} are reviewed.

  12. Experimental and Computational Investigations of Candidate Fuel Salt Melt Properties and Corrosion and Irradiation Damage in Nickel for a Molten Chloride Fission System

    E-Print Network [OSTI]

    Sooby, Elizabeth S

    2014-12-10T23:59:59.000Z

    , physicists have dug deeper into the structure of the atom. The trail of discoveries from protons, neutrons, electrons, quarks, leptons, to most recently the discovery of Higgs Boson spans 100 years of particle physics discoveries. Even though a vast amount...

  13. arXiv:0706.1732v2[hep-ph]11Jul2007 NUHEP-TH/07-06 GeV Seesaw, Accidentally Small Neutrino Masses, and Higgs Decays to Neutrinos

    E-Print Network [OSTI]

    mixing and will provide important input for interpretation of next-generation neutrinoless double beta decay experiments. Measurement of the mass hierarchy is important input to the search for leptonic CP

  14. PHYSICAL REVIEW C 89, 064308 (2014) Chiral two-body currents and neutrinoless double-decay in the quasiparticle

    E-Print Network [OSTI]

    Engel, Jonathan

    2014-01-01T23:59:59.000Z

    , then lepton number conservation violating processes could be observable (e.g. the neutrinoless double beta decay discussed in x 3 and the #23; ! #23; \\oscillations"). Massive Majorana neutrinos have #22; #23

  15. Supernova deleptonization asymmetry: Impact on self-induced flavor conversion

    E-Print Network [OSTI]

    Sovan Chakraborty; Georg Raffelt; Hans-Thomas Janka; Bernhard Mueller

    2014-12-01T23:59:59.000Z

    During the accretion phase of a core-collapse supernova (SN), the deleptonization flux has recently been found to develop a global dipole pattern (LESA---Lepton Emission Self-sustained Asymmetry). The $\

  16. a4-based tri-bimaximal mixing: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    W. Grimus; L. Lavoura 2009-02-24 20 Tri-bimaximal neutrino mixing and neutrinoless double beta decay HEP - Phenomenology (arXiv) Summary: We present a tri-bimaximal lepton...

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

    SciTech Connect (OSTI)

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

    1993-11-01T23:59:59.000Z

    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.

  18. Probing the Majorana nature of the neutrino with neutrinoless double beta decay

    E-Print Network [OSTI]

    S. Morisi

    2009-10-14T23:59:59.000Z

    Neutrinoless double beta decay (NDBD) is the only experiment that could probe the Majorana nature of the neutrino. Here we study the theoretical implications of NDBD for models yielding tri-bimaximal lepton mixing like A4 and S4.

  19. annihilation lifetime study: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    photons andor other similar pairs 7 Bounds on Cross-sections and Lifetimes for Dark Matter Annihilation and Decay into Charged Leptons from Gamma-ray Observations of Dwarf...

  20. Direct Measurement of the Total Decay Width of the Top Quark

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We present a measurement of the total decay width of the top quark using events with top-antitop quark pair candidates reconstructed in the final state with one charged lepton and four or more hadronic jets. We use the ...