Study of pure annihilation type decays B→Ds∗KB \to D_s^{*} K

In this work, we calculate the rare decays $B^0 \to D_s^{*-} K^+$ and $B^+ \to D_s^{*+} \bar{K}^0$ in perturbative QCD approach with Sudakov resummation. We give the branching ratio of $10^{-5}$ for $B^0 \to D_s^{*-}K^+$, which will be tested soon in $B$ factories. The decay $B^+ \to D_s^{*+} \bar{K}^0$ has a very small branching ratio at ${\cal O}(10^{-8})$, due to the suppression from CKM matrix elements $|V_{ub}^* V_{cd}|$. It may be sensitive to new physics contributions.Comment: 14 pages, 1 figur

Molecular mechanisms underlying anti-tumor promoting activities of heat-processed Panax ginseng C.A. Meyer.

Recently, there have been considerable efforts to search for naturally occurring substances that can inhibit, reverse, or retard the multi-stage carcinogenesis. A wide array of phenolic substances derived from edible and medicinal plants have been reported to possess anticarcinogenic and antimutagenic activities and in many cases, the chemopreventive activities of phytochemicals are associated with their anti-inflammatory and/or antioxidative properties. Panax ginseng C.A. Meyer cultivated in Korea has been widely used in traditional herbal medicine for the treatment of various diseases. Certain fractions or purified ingredients of ginseng have been shown to exert anticarcinogenic and antimutagenic activities. Our previous studies have revealed that the methanol extract of heat-processed Panax ginseng C.A. Meyer attenuates the lipid peroxidation in rat brain homogenates and is also capable of scavenging superoxide generated by xanthine- xanthine oxidase or by 12-O-tetradecanoylphorbol-13-acetate (TPA) in differentiated human promyelocytic leukemia (HL-60) cells. Topical application of the same extract onto shaven backs of female ICR mice also suppressed TPA-induced skin tumor promotion. Likewise, topical application of ginsenoside Rg3, one of the constituents of heat-treated ginseng, significantly inhibited TPA-induced mouse epidermal ornithine decarboxylase activity and skin tumor promotion. Expression of cyclooxygenase-2 (COX-2) in TPA-stimulated mouse skin was markedly suppressed by Rg3 pretreatment. In addition, Rg3 inhibited TPA-stimulated activation of NF-kappaB and extracellular-regulated protein kinase (ERK), one of the mitogen-activated protein (MAP) kinase in mouse skin and also in cultured human breast epithelial cells (MCF-10A)

A Detailed Analysis of One-loop Neutrino Masses from the Generic Supersymmetric Standard Model

In the generic supersymmetric standard model which had no global symmetry enforced by hand, lepton number violation is a natural consequence. Supersymmetry, hence, can be considered the source of experimentally demanded beyond standard model properties for the neutrinos. With an efficient formulation of the model, we perform a comprehensive detailed analysis of all one-loop contributions to neutrino masses.Comment: 27 pages Revtex, no figur

Branching ratios of B+→D(∗)+K(∗)0B^+ \to D^{(*)+}K^{(*)0} decays in perturbative QCD approach

We study the rare decays $B^+ \to D^{(*)+}K^{(*)0}$, which can occur only via annihilation type diagrams in the standard model. We calculate all of the four modes, $B \to PP, VP, PV, VV$, in the framework of perturbative QCD approach and give the branching ratios of the order about $10^{-6}$.Comment: 18 pages, 1 figure, Revte

Possible Large Direct CP Violations in Charmless B-Decays

We discuss the perturbative QCD approach for the exclusive two body B-meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on factorization approach. We show numerical results which are compatible with present experimantal data for the charmless B-meson decays. Specailly we predict the possibility of large direct CP violation effects in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm7$ and $B^0\to K^{+}\pi^{-}$ $(-17\pm5$. In the last section we investigate two methods to determine the weak phases $\phi_2$ and $\phi_3$ from $B \to \pi\pi,K\pi$ processes. We obtain bounds on $\phi_2$ and $\phi_3$ from present experimental measurements.Comment: 18 pages, latex, 8 figures and 8 tables, typos corrected and added more tables and references. Presented at the 3rd workshop on Higher Luminosity B Factory, 6-7 August 2002, Kanagawa, Japan; Submitted to Phys. Rev.

QCD factorization for B -> PP

In this work, we give a detailed discussion for QCD factorization involved the complete chirally enhanced power corrections for B decays to two light pseudoscalar mesons, and present some detailed calculations of radiative corrections at the order of alpha_s. We point out that the infrared finiteness of the vertex corrections in the chirally enhanced power corrections requires twist-3 light-cone distribution amplitudes (LCDAs) of the light pseudoscalar symmetric. However, even in the symmetric condition, there is also logarithmic divergence from the endpoints of the twist-3 LCDAs in the hard spectator scattering. We point out that the decay amplitudes of B --> PP predicted by QCD factorization are really free of the renormalization scale dependence, at least at the order of alpha_s. At last, we briefly compare the QCD factorization with the generalized factorization and PQCD method.Comment: 31 pages, 3 eps figure

One-loop Neutron Electric Dipole Moment from Supersymmetry without R-parity

We present a detailed analysis together with exact numerical calculations on one-loop contributions to neutron electric dipole moment from supersymmetry without R-parity, focusing on the gluino, chargino, and neutralino contributions. Apart from the neglected family mixing among quarks, complete formulae are given for the various contributions, through the quark dipole operators, to which the present study is restricted. We discuss the structure and main features of the R-parity violating contributions and the interplay between the R-parity conserving and violating parameters. In particular, the parameter combination $\mu_i^*\lambda^{\prime}_{i11}$, under the optimal parametrization adopted, is shown to be solely responsible for the R-parity violating contributions in the supersymmetric loop diagrams. While $\mu_i^*\lambda^{\prime}_{i11}$ could bear a complex phase, the latter is not necessary to have a R-parity violating contribution.Comment: 43 pages Revtex with 15 eps- and 4 ps- figure files incoporated; proofread version to be published in Phys. Rev.