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

Study of color suppressed modes B0→Dˉ(∗)0η(′)B^0 \to \bar D^{(*)0} \eta^{(\prime)}

The color suppressed modes $B^0 \to \bar D^{(*)0} \eta^{(\prime)}$ are analyzed in perturbative QCD approach. We find that the dominant contribution is from the non-factorizable diagrams. The branching ratios calculated in our approach for $B^0 \to \bar D^{(*)0} \eta$ agree with current experiments. By neglecting the gluonic contribution, we predict the branching ratios of $B^0 \to \bar D^{(*)0} \eta'$ are at the comparable size of $B^0 \to \bar D^{(*)0} \pi^0$, but smaller than that of $B^0 \to \bar D^{(*)0} \eta$.Comment: revtex, 5 pages, axodraw.st

B -> J/psi K^* Decays in QCD Factorization

The hadronic decay B -> J K^* is analyzed within the framework of QCD factorization. The spin amplitudes A_0, A_\parallel and A_\perp in the transversity basis and their relative phases are studied using various different form-factor models for B-K^* transition. The effective parameters a_2^h for helicity h=0,+,- states receive different nonfactorizable contributions and hence they are helicity dependent, contrary to naive factorization where a_2^h are universal and polarization independent. QCD factorization breaks down even at the twist-2 level for transverse hard spectator interactions. Although a nontrivial strong phase for the A_\parallel amplitude can be achieved by adjusting the phase of an infrared divergent contribution, the present QCD factorization calculation cannot say anything definite about the phase phi_\parallel. Unlike B -> J/psi K decays, the longitudinal parameter a_2^0 for B -> J/psi K^* does not receive twist-3 corrections and is not large enough to account for the observed branching ratio and the fraction of longitudinal polarization. Possible enhancement mechanisms for a_2^0 are discussed.Comment: 21 pages, 1 figure, a table and a reference added, some typos correcte

Testing QCD factorisation and charming penguins in charmless B→PV{\boldsymbol{B\to PV}}

We try a global fit of the experimental branching ratios and CP-asymmetries of the charmless $B\to PV$ decays according to QCD factorisation. We find it impossible to reach a satisfactory agreement, the confidence level (CL) of the best fit is smaller than .1 %. The main reason for this failure is the difficulty to accomodate several large experimental branching ratios of the strange channels. Furthermore, experiment was not able to exclude a large direct CP asymmetry in $\bar {B^0}\to\rho^+ \pi^-$, which is predicted very small by QCD factorisation. Trying a fit with QCD factorisation complemented by a charming-penguin inspired model we reach a best fit which is not excluded by experiment (CL of about 8 %) but is not fully convincing. These negative results must be tempered by the remark that some of the experimental data used are recent and might still evolve significantly.Comment: 21 pages, 4 figures; several typos corrected, added one footnote and two references, comments added about PQCD. To appear in Phys.Rev.

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

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.

Newly observed two-body decays of B mesons in a hybrid perspective

In consistency with the b --> c type of (quasi) two body decays, recently observed two body decays of B mesons are studied in a hybrid perspective in which their amplitude is given by a sum of factorizable and non-factorizable ones, and a role of the latter in these decays are discussed.Comment: 7 page

Charmless two-body B decays: A global analysis with QCD factorization

In this paper, we perform a global analysis of $B \to PP$ and $PV$ decays with the QCD factorization approach. It is encouraging to observe that the predictions of QCD factorization are in good agreement with experiment. The best fit $\gamma$ is around $79^\circ$. The penguin-to-tree ratio $|P_{\pi \pi}/T_{\pi \pi}|$ of $\pi^+ \pi^-$ decays is preferred to be larger than 0.3. We also show the confidence levels for some interesting channels: $B^0 \to \pi^0 \pi^0$, $K^+ K^-$ and $B^+ \to \omega \pi^+$, $\omega K^+$. For $B \to \pi K^\ast$ decays, they are expected to have smaller branching ratios with more precise measurements.Comment: 20 pages, 4 figures, version to appear in Phys. Rev.

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.

Branching ratio and CP asymmetry of Bs→π+π−B_s \to \pi^+ \pi^- decays in the perturbative QCD approach

In this paper, we calculate the decay rate and CP asymmetry of the $B_s \to \pi^+\pi^-$ decay in perturbative QCD approach with Sudakov resummation. Since none of the quarks in final states is the same as those of the initial $B_s$ meson, this decay can occur only via annihilation diagrams in the standard model. Besides the current-current operators, the contributions from the QCD and electroweak penguin operators are also taken into account. We find that (a) the branching ratio is about $4 \times 10^{-7}$; (b) the penguin diagrams dominate the total contribution; and (c) the direct CP asymmetry is small in size: no more than $3$; but the mixing-induced CP asymmetry can be as large as ten percent testable in the near future LHC-b experiments.Comment: 12 pages, 4 figures included, RevTe