Supersymmetric Models and CP violation in B decays

In this talk CP violation in the supersymmetric models, and especially in B-decays is discussed. We review our analysis of the supersymmetric contributions to the mixing CP asymmetries of $B\to \phi K_S$ and $B\to \eta^{\prime} K_S$ processes. Both gluino and chargino exchanges are considered in a model independent way by using the mass insertion approximation method. The QCD factorization method is used, and parametrization of this method in terms of Wilson coefficients is presented in both decay modes. Correlations between the CP asymmetries of these processes and the direct CP asymmetry in $b\to s \gamma$ decay are shown.Comment: 16 pages, 7 figures. Prepared for the proceedings of the 1st GUC workshop on High Energy Physics, Cairo, Jan 9-13, 200

Penanganan Pascapanen dan Kualitas Jagung sebagai Bahan Pakan di Kabupaten Pasaman Barat

A rapid survey was carried out to study the quality of corn produced by farmers in relation to post harvest practices in West Pasaman district. Twenty-six corn farmers, which were located in two sub districts of Kinali and Luhak Nan Duo, were selected and interviewed. Data and information collected including: farm size, farming and post harvest practices, quality of product and marketing. During the survey, samples of corn were collected and then analyzed for moisture, protein and crude fiber content, the rate of corn contaminated by fungi and contaminants. The corn contained crude protein and fiber in normal level of 11.8 % and 2,5 %, respectively. The moisture content was however found relatively high of 21.3 % in average and about 34 % of corn contaminated by fungi. Mainly insufficient handling and drying after harvesting caused the poor quality

Chargino contributions to the CP asymmetry in B -> Phi K(S) decay

We perform a model independent analysis of the chargino contributions to the CP asymmetry in B -> Phi K(S) process. We use the mass insertion approximation method generalized by including the possibility of a light right-stop. We find that the dominant effect is given by the contributions of the mass insertions deltaU_LL(32) and deltaU_RL(32) to the Wilson coefficient of the chromomagnetic operator. By considering both these contributions simultaneously, the CP asymmetry in B -> Phi K(S) process is significantly reduced and negative values, which are within the 1-sigma experimental range and satisfy the b -> s gamma constraints, can be obtained.Comment: 14 pages, LaTeX, 3.eps Figure

SUSY R parity violation and CP asymmetry in semi-leptonic tau-decays

We analyze the CP violation in the semileptonic | \Delta S|=1 tau-decays in supersymmetric extensions of the standard model (SM) with R parity violating term. We show that the CP asymmetry of tau-decay is enhanced significantly and the current experimental limits obtained by CLEO collaborations can be easily accommodated. We argue that observing CP violation in semi leptonic tau-decay would be a clear evidence for R-parity violating SUSY extension of the SM.Comment: 5 pages, 2 figure

Sterile neutrino dark matter in B−LB-L extension of the standard model and galactic 511 keV line

Sterile right-handed neutrinos can be naturally embedded in a low scale gauged $U(1)_{B-L}$ extension of the standard model. We show that, within a low reheating scenario, such a neutrino is an interesting candidate for dark matter. We emphasize that if the neutrino mass is of order of MeV, then it accounts for the measured dark matter relic density and also accommodates the observed flux of 511 keV photons from the galactic bulge.Comment: 10 pages, 1 figure, references added, final version appeared in JCA

Radion Flavor Violation in Warped Extra Dimension

We analyze the flavor violation in warped extra dimension due to radion mediation. We show that \Delta S=2 and \Delta B=2 flavor violating processes impose stringent constraints on radion mass, m_\phi and the scale \Lambda_\phi. In particular, for \Lambda_\phi ~ O(1) TeV, B_d^0-\bar{B}^0_d implies that m_\phi ~ 65 GeV. We also study radion contributions to lepton flavor violating processes: \tau -> (e,\mu) \phi, \tau -> e\mu^+\mu^- and B -> l_i l_j. We show that BR(B_s -> \mu^+ \mu^-) can be of order 10^{-8}, which is reachable at the LHCb. The radion search at LHC, through the flavor violation decays into \tau \mu or top-charm quarks, is also considered.Comment: 23 pages, 9 figure

Constraining supersymmetric models from B_d - B-bar_d mixing and the B_d --> J/psi K_S asymmetry

We analyze the chargino contributions to B_d - B-bar_d mixing and CP asymmetry of the B_d --> J/psi K_S decay, in the framework of the mass insertion approximation. We derive model independent bounds on the relevant mass insertions. Moreover, we study these contributions in supersymmetric models with minimal flavor violation, Hermitian flavor structure, and small CP violating phases and universal strength Yukawa couplings. We show that in supersymmetric models with large flavor mixing, the observed values of sin(2 beta) may be entirely due to the chargino-up-squark loops.Comment: 22 pages, 1 figure, minor corrections, version to appear in Phys. Rev.