Determination of the CP violating weak phase γ\gamma from the Decays B→DπB \to D \pi

We propose a new method to extract the CP violating weak phase $\gamma$ (the phase of $V_{ub}^*$) in the CKM paradigm of the Standard Model, using $B^- \rightarrow D^0 \pi^- \rightarrow f \pi^-$ and $B^- \rightarrow \bar D^0 \pi^- \rightarrow f \pi^-$ decays, where $f$ are final states such as $K^+ \pi^-$, $K^+ \rho^-$, $K \pi\pi$, {\it etc.} We also study the experimental feasibility of our new method. With possibility of new phases in the CKM matrix, we re-examine some of the previously proposed methods to determine $\gamma$, and find that it would be in principle possible to identify $\gamma$ and a new phase angle $\theta$ separately.Comment: 12 pages, 1 figure, LaTex; the version to be published in European Physical Journal

Determination of the CP Phase γ\gamma with Possibility of New Physics

We propose a new method to extract the CP violating weak phase $\gamma$ in the CKM paradigm of the Standard Model, using $B^- \to D^0 \pi^- \to f \pi^-$ and $B^- \to \bar D^0 \pi^- \to f \pi^-$ decays, where $f$ are final states such as $K^+ \pi^-$, $K^+ \rho^-$, $K \pi\pi$, {\it etc.} We also study the experimental feasibility of our new method. With possibility of new phases in the CKM matrix, we re-examine some of the previously proposed methods to determine $\gamma$, and find that it would be in principle possible to identify $\gamma$ and a new phase angle $\theta$ separately.Comment: 4 pages, LaTeX; Using two-column style file (ltwol.sty); To be published in the Proceedings of the Fourth International Workshop on B Physics and CP Violation, Ise-Shima, Japan, February 18 - 23, 200

Charmless Non-Leptonic B Decays and R-parity Violating Supersymmetry

We examine the charmless hadronic B decay modes in the context of R-parity violating (\rpv) supersymmetry. We try to explain the large branching ratio (compared to the Standard Model (SM) prediction) of the decay $B^{\pm}\to \eta' K^{\pm}$. There exist data for other observed $\eta^{(\prime)}$ modes and among these modes, the decay $B^{0}\to \eta K^{*0}$ is also found to be large compared to the SM prediction. We investigate all these modes and find that only two pairs of \rpv coupling can satisfy the requirements without affecting the other B\ra PP and B\ra VP decay modes barring the decay B\ra\phi K. From this analysis, we determine the preferred values of the \rpv couplings and the effective number of color $N_c$. We also calculate the CP asymmetry for the observed decay modes affected by these new couplings.Comment: 14 pages, 7 figures; revtex; version published in Phys. Lett.

Hadronic B Decays to Charmless VT Final States

Charmless hadronic decays of B mesons to a vector meson (V) and a tensor meson (T) are analyzed in the frameworks of both flavor SU(3) symmetry and generalized factorization. We also make comments on B decays to two tensor mesons in the final states. Certain ways to test validity of the generalized factorization are proposed, using $B \to VT$ decays. We calculate the branching ratios and CP asymmetries using the full effective Hamiltonian including all the penguin operators and the form factors obtained in the non-relativistic quark model of Isgur, Scora, Grinstein and Wise.Comment: 27 pages, no figures, LaTe

Probing sterile neutrino in BB (DD) meson decays at Belle II (BESIII)

We present, how a systematic study of $B \to D\ell N$ ($D \to K \ell N$) decays with $\ell=\mu,\tau$, at Belle II (BESIII) can provide unambiguous signature of a heavy neutrino $N$ and/or constrain its mixing with active neutrinos $\nu_\ell$, which is parameterized by $|U_{\ell N}|^2$. Our constraint on $|U_{\mu N}|^2$ that can be achieved from the full Belle II data is comparable with what can be obtained from the much larger data set of the upgraded LHCb. Additionally, our method offers better constraint on $|U_{\mu N}|^2$ for mass of sterile neutrino $m_N < 2$ GeV. We can also probe the Dirac and Majorana nature of $N$ by observing the sequential decay of $N$, including suppression from observation of a displaced vertex as well as helicity flip, for Majorana $N$.Comment: 9 pages, 6 figures. This is a pre-print of an article published in European Physical Journal C. The final authenticated version is available online at https://doi.org/10.1140/epjc/s10052-020-8310-

Hadronic decays of B involving a tensor meson through a b→cb \to c transition

We re-analyze hadronic decays of B mesons to a pseudoscalar (P) and a tensor meson (T), or a vector meson (V) and a tensor meson, through a $b \to c$ transition. We discuss possible large uncertainties to branching ratios (BR's) of the relevant modes, mainly arising from uncertainties to the hadronic form factors for the $B \to T$ transition. The BR's and CP asymmetries for $B \to PT$ and VT decays are then calculated by using the form factors given in the ISGW2 model (the improved version of the original Isgur-Scora-Grinstein-Wise (ISGW) model). We find that the estimated BR's of many modes are increased by an order of magnitude, compared to the previous results calculated within the ISGW model.Comment: 22 pages, LaTex; minor clarifications included; to appear in Phys. Rev.