Flavor changing neutrino interactions and CP violation in neutrino oscillations

We investigate the interference effects of non-standard neutrino-matter interactions (NSNI) with the mass-induced neutrino oscillations. The NSNI is composed of flavor-changing neutrino interactions (FCNI) and flavor-diagonal neutrino interactions (FDNI). Both of the interactions are introduced in the \nu_\mu -\nu_\tau sector and the \nu_e -\nu_\mu sector in order to study their effects in \nu_\mu\to\nu_\tau and \nu_\mu\to\nu_e oscillations, respectively. The FCNI effect proves to possibly dominate the CP violating effect and significantly survive as a fake CP violating effct in the neutrino energy region where the pure CP violating effect, ordinary matter effect and FDNI effect fall, for example, above 4 GeV at the baseline of L=730 km in the \nu_\mu\to\nu_\tau oscillation for the maximum parameter values of FCNI and FDNI allowed by the atmospheric neutrino oscillation data. The FCNI and FDNI effects on CP violation in the $\nu_\mu\to\nu_e$ oscillation are negligibly small due to the stringent constraints on FCNI from the bounds on lepton flavor violating processes and on FDNI from the limits on lepton universality violation.Comment: 18 pages in LaTeX2e, 12 ps figures. The discussion of detectability of the CP violation is delete

Are the New Physics Contributions from the Left-Right Symmetric Model Important for the Indirect CP Violation in the Neutral B Mesons?

Several works analyzing the new physics contributions from the Left-Right Symmetric Model to the CP violation phenomena in the neutral B mesons can be found in the literature. These works exhibit interesting and experimentally sensible deviations from the Standard Model predictions but at the expense of considering a low right scale \upsilon_R around 1 TeV. However, when we stick to the more conservative estimates for \upsilon_R which say that it must be at least 10^7 GeV, no experimentally sensible deviations from the Standard Model appear for indirect CP violation. This estimate for \upsilon_R arises when the generation of neutrino masses is considered. In spite of the fact that this scenario is much less interesting and says nothing new about both the CP violation phenomenon and the structure of the Left-Right Symmetric Model, this possibility must be taken into account for the sake of completeness and when considering the see-saw mechanism that provides masses to the neutrino sector.Comment: LaTex file. 19 pages, 4 figures. Change in the way the paper address the problem. As a result, change in title, abstract, and some sections. Conclusions unchanged. Version to appear in Foundations of Physics Letter

On Testing V-A in Lambda_b Decays

We comment on a recent suggestion by Amundson, Rosner, Worah and Wise to test the chirality of the $b$-quark decay coupling via polarized $\Lambda_b$ baryons produced in $e^+e^-\rightarrow Z\rightarrow \Lambda_b +X$. We study the effect of contributions from an amplitude in which a right-handed $b$ to $c$ current couples to a V-A lepton current.Comment: (6 pages, PHYZZX, 1 figure, available upon request), SLAC-PUB-589

Effects of the K+→π+ννˉK^+\to\pi^+\nu\bar{\nu} and of other processes on the mixing hierarchies in the four-generation model

We analyze in the four-generation model the first measurement of the branching ratio of rare kaon decay $K^+\to\pi^+\nu\bar{nu}$, along with the other processes of $K_L-K_S$ mass difference $\Delta m_K$, CP-violating parameter $\epsilon_K, B_d-\bar{B_d}$ mixing, $B_s-\bar{B_s}$ mixing, $B(K_L\to\mu\bar{\mu})$, and the upper bound values of $D^0-\bar{D^0}$ mixing and $B(K_L\to\pi^0\nu\bar{\nu})$, and try to search for mixing of the fourth generation in the hierarchical mixing scheme of the Wolfenstein parametrization. Using the results for the mixing of the fourth generation, we discuss predictions of the $D^0-\bar{D^0}$ mixing ($\Delta m_D$) and the branching ratio of directly CP-violating decay process $K_L\to\pi^0\nu\bar{\nu}$, and the effects on the CP asymmetry in neutral B meson decays and the unitarity triangle.Comment: 29 pages written in LaTex. 6 figures(drawn on LaTeX). Revised from "$K^+\to\pi^+\nu\bar{\nu}$ in the four-generation model" of the same Authors(TOKUSHIMA 99-1, January 1999). A minor chang

CP violation effect in long-baseline neutrino oscillation in the four-neutrino model

We investigate CP-violation effect in the long-baseline neutrino oscillation in the four-neutrino model with mass scheme of the two nearly degenerate pairs separated with the order of 1 eV, by using the data from the solar neutrino deficit, the atmospheric neutrino anomaly and the LSND experiments along with the other accelerator and reactor experiments. By use of the most general parametrization of the mixing matrix with six angles and six phases, we show that the genuine CP-violation effect could attain as large as 0.3 for $\Delta P(\nu_\mu\to\nu_\tau) \equiv P(\nu_\mu\to\nu_\tau) - P(\bar{\nu_\mu}\to\bar{\nu_\tau})$ and that the matter effect is negligibly small such as at most 0.01 for $\Delta P(\nu_\mu\to\nu_\tau)$ for $\Delta m^2 = (1-5)\times 10^{-3} {\rm eV}^2$, which is the mass-squared difference relevant to the long-baseline oscillation.Comment: 21 pages in LaTeX, 9 ps figures. Some changes in the Introduction and Reference

New Physics in CP Asymmetries and Rare B Decays

We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics will therefore also contribute to rare, flavor-changing B decays. Through a study of such decays, we show that it is possible to partially distinguish the different models of new physics.Comment: 42 pages, plain TeX (macros included), 1 figure (included). A few sentences added, references updated. Present manuscript is now identical to the version accepted for publication in Phys. Rev.