Precise Discussion of Time-Reversal Asymmetries in B-meson decays

BaBar collaboration announced that they observed time reversal (T) asymmetry through $B$ meson system. In the experiment, time dependencies of two distinctive processes, $B_- \rightarrow \bar{B^0}$ and $\bar{B^0}\rightarrow B_-$($-$ expresses CP value) are compared with each other. In our study, we examine event number difference of these two processes. In contrast to the BaBar asymmetry, the asymmetry of events number includes the overall normalization difference for rates. Time dependence of the asymmetry is more general and it includes terms absent in one used by BaBar collaboration. Both of the BaBar asymmetry and ours are naively thought to be T-odd since two processes compared are related with flipping time direction. We investigate the time reversal transformation property of our asymmetry. Using our notation, one can see that the asymmetry is not precisely a T-odd quantity, taking into account indirect CP and CPT violation of K meson systems. The effect of $\epsilon_K$ is extracted and gives rise to $\mathcal{O}(10^{-3})$ contribution. The introduced parameters are invariant under rephasing of quarks so that the coefficients of our asymmetry are expressed as phase convention independent quantities. Some combinations of the asymmetry enable us to extract parameters for wrong sign decays of $B_d$ meson, CPT violation, etc. We also study the reason why the T-even terms are allowed to contribute to the asymmetry, and find that several conditions are needed for the asymmetry to be a T-odd quantity.Comment: 29pages, 5 figures. In version3, the title is changed. The difference between the event number asymmetry and the asymmetry measured by BaBar experiment is clarifie

CP violation of Extended Higgs sector and Its impact on D^0 -> mu^+ mu^- decay

We study the impact of the CP violation of the extra Higgs sector on $D^0$ decay. The CP even and CP odd neutral Higgs mixing of the two Higgs doublet model is studied and we show how the CP violating effect of the mixing may lead to the longitudinal muon polarization asymmetry of $D^0 \to \mu^+ \mu^-$. The asymmetry of the short-distance contribution is sensitive to the CP violating phase of the extended Higgs sector.Comment: 7 pages, 2 figures, presented as a poster in GUT2012 (YITP,Kyoto,15-17 March2012

Effects of Large Threshold Corrections in Supersymmetric Type-I Seesaw Model

We investigate lepton flavor violating (LFV) radiative processes and the relic abundance of neutralino dark matter in supersymmetric type-I seesaw model. We carefully derive threshold corrections to the flavor off-diagonal elements of slepton mass matrix and up-type Higgs mass squared and find that they can be large in the case of large $B_N^0$. We examine how the branching ratios of LFV radiative decays and the relic abundance of neutralino dark matter can be significantly affected by the large threshold corrections. Soft scalar mass squared parameter of up-type Higgs scalar is also affected by the threshold corrections. Since the higgsino mass depends on the mass parameter for up-type Higgs, the LFV processes and the relic abundance of the neutralino dark matter are correlated with each other. We show that there are parameter regions where the predictions of the relic abundance of neutralino dark matter are consistent with WMAP observation and the branching ratios of LFV radiative decays are predicted to be testable in future experiments. We find that the masses of scalar supersymmetric particles are not necessarily small so that the branching ratios of LFV decays can be testable in future experiment, which is distinctive feature of this scenario.Comment: 32 pages, 6 figures, references are added, the version to appear in JHE