59,933 research outputs found

    The Thermodynamic Potentials of Kerr-AdS Black Holes and their CFT Duals

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    String or M-theory in the background of Kerr-AdS black holes is thought to be dual to the large n limit of certain conformal field theories on a rotating sphere at finite temperature. The five dimensional black hole is associated to N=4 supersymmetric Yang-Mills theory on a rotating three-sphere and the four dimensional one to the superconformal field theory of coinciding M2 branes on a rotating two-sphere. The thermodynamic potentials can be expanded in inverse powers of the radius of the sphere. We compute the leading and subleading terms of this expansion in the field theory at one loop and compare them to the corresponding supergravity expressions. The ratios between these terms at weak and strong coupling turns out not to depend on the rotation parameters in the case of N=4 SYM. For the field theory living on one M2 brane we find a subleading logarithmic term. No such term arises from the supergravity calculation.Comment: 14 pages (harvmac b-mode), signs corrected, minor changes otherwis

    On the graphical extraction of multipole mixing ratios of nuclear transitions

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    We propose a novel graphical method for determining the mixing ratios {\delta} and their associated uncertainties for mixed nuclear transitions. It incorporates the uncertainties both on both the measured and the theoretical conversion coefficients. The accuracy of the method has been studied by deriving the corresponding probability density function. The domains of applicability of the method are carefully defined

    Search for pair production of first or second generation leptoquarks in proton-proton collisions at √s = 7 TeV using the ATLAS detector at the LHC

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    This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35  pb^(-1) of proton-proton collision data recorded by the ATLAS detector at √s=7  TeV. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95% CL for masses M_(LQ)<376 (319) GeV and M_(LQ)<422 (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark to a charged lepton is equal to 1.0 (0.5)

    Limits on the production of the standard model Higgs boson in pp collisions at √s = 7 TeV with the ATLAS detector

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    A search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV is reported, based on a total integrated luminosity of up to 40 pb^(−1) collected by the ATLAS detector in 2010. Several Higgs boson decay channels: H→γγ, H→ZZ^((∗))→ℓℓℓℓ, H→ZZ→ℓℓΜΜ, H→ZZ→ℓℓqq, H→WW^((∗))→ℓΜℓΜ and H→WW→ℓΜqq (ℓ is e, ÎŒ) are combined in a mass range from 110 GeV to 600 GeV. The highest sensitivity is achieved in the mass range between 160 GeV and 170 GeV, where the expected 95% CL exclusion sensitivity is at Higgs boson production cross sections 2.3 times the Standard Model prediction. Upper limits on the cross section for its production are determined. Models with a fourth generation of heavy leptons and quarks with Standard Model-like couplings to the Higgs boson are also investigated and are excluded at 95% CL for a Higgs boson mass in the range from 140 GeV to 185 GeV

    Measurement of the ΄ (1S) production cross-section in pp collisions at √s = 7 TeV in ATLAS

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    A measurement of the cross-section for ΄ (1S)→Ό^+ÎŒ^− production in proton–proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the ΄ (1S) transverse momentum in two bins of rapidity, |y^(΄(1S))| 4 GeV and pseudorapidity |η^ÎŒ| < 2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb^(−1), collected with the ATLAS detector at the Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees to within a factor of two with a prediction based on the NRQCD model including colour-singlet and colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with the next-to-leading order prediction based on the colour-singlet model

    Expanding Our Reach: Cross-Institutional Collaborations and Teacher Preparation in Hispanic Serving Institutions

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    This paper addresses the role of cross-institutional collaborations among Hispanic Serving Institutions (HSI). Specifically, we focus on the Enseñamos en el Valle Central Initiative—a five-year, Title V, Developing Hispanic Serving Institutions (DHSI) grant for recruiting and preparing bilingual, Latinx teachers with a strong sense of self and service to their communities. While California four-year state institutions have historically been at the helm of preparing bilingual Kindergarten through 12th grade (K-12) teachers, this has not been the case for community colleges, which continue to be the first entry point into higher education for many Latinx communities. We discuss how the process of a two-week summer institute among two- and four-year faculty at two community colleges and one university expands conventional notions of teacher preparation, and how these non-normative approaches can lend to stronger pathways into the profession. Moreover, we share how our faculty development approaches disrupt the status quo in teacher preparation and how non-tenured Faculty of Color navigate the politics of disruption and how these race-gendered experiences hold relevance for how we understand teacher preparation and expanding access to underrepresented Teachers of Color into the teaching profession

    Flipped Angles and Phases: A Systematic Study

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    We discuss systematically the fermion mass and mixing matrices in a generic \linebreak field-theoretical flipped SU(5)SU(5) model, with particular applications to neutrino and baryon number-changing physics. We demonstrate that the different quark flavour branching ratios in proton decay are related to the Cabibbo-Kobayashi-Maskawa angles, whereas the lepton flavour branching ratios are undetermined. The light neutrino mixing angles observable via oscillation effects are related to the heavy conjugate (right-handed) neutrino mass matrix, which also plays a key role in cosmological baryogenesis. The ratios of neutrino and charged lepton decay modes in baryon decay may also be related to neutrino oscillation parameters. Plausible Ans\"atze for the generation structure of coupling matrices motivate additional relations between physical observables, and yield a satisfactory baryon asymmetry.Comment: 13 pages, no figures, latex (twice), CERN-TH.6842/93, UMN-TH-1130/93, CTP-TAMU-11/9
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