20,588 research outputs found

    CP violation in supersymmetric theories

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    We review the present status of CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the supersymmetric CP phases and show that only the scenarios with flavour-off- diagonal CP violation remain attractive. These scenarios require hermitian Yukawa matrices which naturally arise in models with left-right symmetry or a SU(3) flavour symmetry. In this case, epsilon_K and epsilon'/epsilon can be saturated by a small non-universality of the soft scalar masses through the gluino and chargino contributions respectively. The model also predicts a strong correlation between A_{CP}(b-> s gamma) and the neutron electric dipole moment. In this framework, the standard model gives a the leading contribution to the CP asymmetry in B ->psi K_S decay, while the dominant chargino contribution to this asymmetry is < 0.2. Thus, no constraint is set on the non-universality of this model by the recent BaBar and Belle measureets.Comment: 34 pages, 10 figures. Invited review article for International Journal of Modern Physics

    Upper bounds on SUSY contributions to b to s transitions from B_s - B_sbar mixing

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    We study the constraints on supersymmetric contributions to b to s transitions from the recent allowed range and measurement of Bs-Bsbar mixing obtained by the D0 and CDF collaborations at the Tevatron. We compute the upper bounds on the relevant off-diagonal squark mass terms and compare them with the bounds coming from Delta F=1 decays. We find that the constraints on chirality-flipping mass insertions are unaffected. Conversely, the measurement of Bs-Bsbar mixing is effective in constraining chirality-conserving mass insertions, and it has striking effects in the case in which left- and right-handed insertions have similar size. Finally, we discuss the phase of the Bs-Bsbar mixing amplitude in the presence of SUSY contributions.Comment: 4 pages, 4 figures; v2: CDF measurement include

    Dark Left-Right Model: CDMS, LHC, etc

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    The Standard Model of particle interactions is extended to include fermion doublets (n,e)_R transforming under the gauge group SU(2)_R such that n is a Dirac scotino (dark-matter fermion), with odd R parity. Based on recent CDMS data, it is shown how this new dark left-right model (DLRM2) favors a Z' gauge boson at around 1 or 2 TeV and be observable at the LHC. The new W_R gauge bosons may also contribute significantly to lepton-flavor-changing processes such as mu to e gamma and mu-e conversion in a nucleus or muonic atom.Comment: 7 pages, 4 figures, typo corrected, talk at Dark Side of Universe 2010, Leon, Mexic

    On the Parity-Flavor-Breaking Phase in QCD With Two Flavors of Wilson Fermions

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    We present further data in search of a parity-flavor-breaking phase in simulations of dynamical QCD with two flavors of light Wilson fermions in the strong coupling region. This is done on lattice sizes of 4^4 an up to 10^4 for a variety of values of beta and kappa as well as the coefficient, h, of an explicit breaking term included in the action. We confirm the existence of a region in the beta-kappa plane where such a phase exists at beta=6/g^2 smaller than 5.0 and above kappa_c.Comment: 3 pages latex209 with 3 postscript figures included by epsf, contribution to LAT'9

    Phenomenological Aspects of TeV Scale Alternative Left-Right Model

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    We revisit the alternative left-right symmetric model, motivated by superstring-inspired E6E_6 model. We systematically analyze the constraints imposed by theoretical and experimental bounds on the parameter space of this class of models. We perform a comprehensive analysis of the Higgs sector and show that three neutral CP-even and two CP-odd Higgs bosons in addition to two charged Higgs bosons can be light, of O(100){\cal O}(100) GeV. We emphasise that our model has a potential to account for the recent Large Hadron Collider results for signal strength of Higgs decays. We also explore discovery signatures of the exotic down-type quark, which is one of the salient predictions of this model.Comment: 21 pages, 8 figure

    Path Integrals and Voronin's Theorem on the Universality of the Riemann Zeta Function

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    We explore a new approach to the path integral for a latticized quantum theory. This talk is based on work with N. Khuri and H. Ren
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