75 research outputs found

    B_{s,d} -> l^+ l^- and K_L -> l^+ l^- in SUSY models with non-minimal sources of flavour mixing

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    We present a general analysis of B_{s,d}-> l^+ l^- and K_L -> l^+ l^- decays in supersymmetric models with non-minimal sources of flavour mixing. In spite of the existing constraints on off-diagonal squark mass terms, these modes could still receive sizeable corrections, mainly because of Higgs-mediated FCNCs arising at large tan(beta). The severe limits on scenarios with large tan(beta) and non-negligible {tilde d}^i_{R(L)}-{d-tilde}^j_{R(L)} mixing imposed by the present experimental bounds on these modes and Delta B=2 observables are discussed in detail. In particular, we show that scalar-current contributions to K_L -> l^+ l^- and B-{bar B} mixing set non-trivial constraints on the possibility that B_s -> l^+ l^- and B_d -> l^+ l^- receive large corrections.Comment: 18 pages, 4 figures (v2: minor changes, published version

    Beneficial immunostimulatory effect of short-term Chlorella supplementation: enhancement of natural Killer cell activity and early inflammatory response (Randomized, double-blinded, placebo-controlled trial)

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    Background - In vitro and animal studies have demonstrated that Chlorella is a potent biological response modifier on immunity. However, there were no direct evidences for the effect of Chlorella supplementation on immune/inflammation response in healthy humans. Methods - This study was designed for an 8-week randomized, double-blinded, placebo-controlled trial: 5g of Chlorella (n=23) or Placebo (n=28) as form of tablets. Mainly, cytotoxic activities of Natural killer (NK) cells and serum concentrations of interferon-¿, interleukin-1ß and interleukin-12 were measured. Results - After the 8-week, serum concentrations of interferon-¿ (

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

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    Realistic predictions are made for the rates of lepton flavour violating Higgs boson decays, tau --> mu gamma, mu --> e gamma, Bs --> mu+mu-, Bs --> tau mu and tau --> 3mu, via a top-down analysis of the Minimal Supersymmetric Standard Model(MSSM) constrained by SU(5) unification with right-handed Neutrinos and large tan beta. The third family neutrino Yukawa coupling is chosen to be of order 1, in this way our model bares a significant resemblance to supersymmetric SO(10). In this framework the large PMNS mixings result in potentially large lepton flavour violation. Our analysis predicts tau --> mu gamma and mu --> e gamma rates in the region (10^{-8}-10^{-6}) and (10^{-15}-10^{-14}) respectively. We also show that the rates for lepton flavour violating Higgs decays can be as large as 10^{-7}. The non-decoupling nature of H --> tau mu is observed which leads to its decay rate becoming comparable to that for tau --> mu gamma for large values of m_0 and M_1/2. We also find that the present bound on Bs --> mu+mu- is an important constraint on the rate of lepton flavour violating Higgs decays. The recently measured Bs-Bsbar mixing parameter Delta Ms is also investigated.Comment: 27 pages, 15 postscript figures, 1 table. Small changes made to the text and title. Updated references. Bs-Bsbar analysis also include

    Lepton polarization correlations in BKττ+B \to K^* \tau^- \tau^+

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    In this work we will study the polarizations of both leptons (τ\tau) in the decay channel BKττ+B\to K^* \tau^- \tau^+. In the case of the dileptonic inclusive decay BK+B\to K^* \ell^- \ell^+, where apart from the polarization asymmetries of single lepton \ell, one can also observe the polarization asymmetries of both leptons simultaneously. If this sort of measurement is possible then we can have, apart from decay rate, FB asymmetry and the six single lepton polarization asymmetries (three each for \ell^- and +\ell^+), nine more double polarization asymmetries. This will give us a very useful tool in more strict testing of SM and the physics beyond. We discuss the double polarization asymmetries of τ\tau leptons in the decay mode BKττ+B\to K^* \tau^- \tau^+ within the SM and the Minimal Supersymmetric extensions of it.Comment: 21 pages, 21 figures; version to match paper to appear in PR

    CP violation in Bd,sl+lB_{d,s} \to l^+l^- in the model III 2HDM

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    We have calculated the Wilson coefficients C10,CQiC_{10}, C_{Q_i} (i=1,2) in the MSˉ\bar{MS} renormalization scheme in the model III 2HDM. Using the obtained Wilson coefficients, we have analyzed the CP violation in decays Bq0l+lB^0_q\to l^+l^- (q=d,s) in the model. The CP asymmetry, ACPA_{CP}, depends on the parameters of models and ACPA_{CP} in Bdl+lB_d\to l^+l^- can be as large as 40% and 35% for l=τl=\tau and l=μl=\mu respectively. It can reach 4% for Bs0B^0_s decays. Because in SM CP violation is smaller than or equal to O(10310^{-3}) which is unobservably small, an observation of CP asymmetry in the decays Bq0l+l(q=d,s)B^0_q \to l^+l^- (q=d,s) would unambiguously signal the existence of new physics.Comment: revtex4, 16 pages, 7 figure

    Lepton Flavor Violating Process in Bi-maximal texture of Neutrino Mixings

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    We investigate the lepton flavor violation in the framework of the MSSM with right-handed neutrinos taking the large mixing angle MSW solution in the quasi-degenerate and the inverse-hierarchical neutrino masses. We predict the branching ratio of μe+γ\mu \to e+\gamma and τμ+γ\tau \to \mu+\gamma processes assuming the degenerate right-handed Majorana neutrino masses. We find that the branching ratio in the quasi-degenerate neutrino mass spectrum is 100 times smaller than the ones in the inverse-hierarchical and the hierarchical neutrino spectra. We emphasize that the magnitude of Ue3U_{e3} is one of important ingredients to predict BR(μe+γ\mu \to e +\gamma ). The effect of the deviation from the complete-degenerate right-handed Majorana neutrino masses are also estimated. Furtheremore, we examine the S_{3\sL}\times S_{3\sR} model, which gives the quasi-degenerate neutrino masses, and the Shafi-Tavartkiladze model, which gives the inverse-hierarchical neutrino masses. Both predicted branching ratios of μe+γ\mu\to e+\gamma are smaller than the experimantal bound.Comment: Latex file, 38 pages, 10 figures, revised versio

    Supersymmetric effects on Forward Backward asymmetries of BK+B \to K \ell^+ \ell^-

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    Leptonic and semi-leptonic rare decays of B-mesons are very clean (both theoretically and experimentally) signatures of any new physics beyond the Standard Model (SM). More specifically the decay \btokll has been theoretically observed to be very sensitive to new physics as the Forward Backward (FB) asymmetry in this decay mode vanishes in the SM. Supersymmetry, however, predicts a non-vanishing value of this asymmetry. In this work we will study the polarized lepton pair FB asymmetry, i.e. the FB asymmetry of the lepton when one (or both) final state lepton(s) are polarized. We will study these asymmetries both within the SM and for Supersymmetric corrections to the SM.Comment: 18 pages, RevTeX file including 21 eps figures; version accepted for publication in Phys. Rev. D. Some references adde

    Supersymmetry beyond minimal flavour violation

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    We review the sources and phenomenology of non-minimal flavour violation in the MSSM. We discuss in some detail the most important theoretical and experimental constraints, as well as promising observables to look for supersymmetric effects at the LHC and in the future. We emphasize the sensitivity of flavour physics to the mechanism of supersymmetry breaking and to new degrees of freedom present at fundamental scales, such as the grand unification scale. We include a discussion of present data that may hint at departures from the Standard Model.Comment: 23pp. Version to appear in the EPJC special volume "Supersymmetry on the Eve of the LHC", dedicated to the memory of Julius Wess. References and brief discussion on collider signatures adde

    Neodymium-doped cladding pumped aluminosilicate fiber laser tunable in the 0.9 micron wavelength range

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    A tunable high-power cladding-pumped neodymium-doped aluminosilicate fiber laser is demonstrated. The maximum power reached was 2.4 W with a slope efficiency of 41% and a threshold pump power of 1.68 W, both with respect to launched pump power, when cladding pumped by two 808 nm diode pump sources at both fiber ends. The dependence of the tuning range on the fiber length is investigated. The tuning range changed from 922 to 942 nm for a 25 m-long fiber to 908-938 nm with a 14 m-long fiber, because of reabsorption effects. The output linewidth was 0.26 nm in a diffraction-limited beam. Operation on the challenging 0.9 µm three-level transition in neodymium-doped double-clad fiber laser was facilitated by a W-type core refractive index profile. This filtered out the unwanted and competing strong transition at 1.06 µm while guidance of 0.9 µm remained intact
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