Related papers: Semileptonic B to Scalar meson Decays in the Stand…
In the Standard Model, b quarks produced in e^+e^- annihilation at the Z^0 peak have a large average longitudinal polarization of -0.94. Some fraction of this polarization is expected to be transferred to b-flavored baryons during…
A measurement of the ratio of the branching fractions of the $B^{+}\rightarrow K^{+}\mu^{+}\mu^{-}$ and $B^{+}\rightarrow K^{+}e^{+}e^{-}$ decays is presented using proton-proton collision data, corresponding to an integrated luminosity of…
We present partial branching fractions for inclusive charmless semileptonic B decays Bbar --> X_u ell nubar, and the determination of the CKM matrix element |V_{ub}|. The analysis is based on a sample of 383 million Y(4S) decays into B Bbar…
Using our relativistic constituent quark model we present results on the exclusive nonleptonic and semileptonic decays of the Bc-meson. The nonleptonic decays are studied in the framework of the factorization approximation. We calculate the…
We study the effects of a fourth generation t-prime quark in various extensions of the standard model. In the Randall-Sundrum model, the decay t-prime -> t Z has a large branching ratio that could be detected at the Large Hadron Collider…
I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…
We calculate the differential decay rate for inclusive $\bar B\to\tau\,\bar\nu\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. We show that using a systematic $1/m_b$…
In this paper, we study rare semileptonic decays of B_c meson in the context of type-I, II, and III two Higgs doublet model. We follow the relativistic quark model for parameterizing the form factors used in matrix elements of weak…
We analyze the $B\to K_2^*(\to K\pi)l^+l^-$ (with $l=e,\mu,\tau$) decay in the standard model and two new physics scenarios: vector-like quark model and family non-universal $Z'$ model. We derive its differential angular distributions,…
Analytic formulae are given for order alpha_s perturbative QCD corrections to the double differential distribution of the tau lepton energy and the invariant mass of the tau + antineutrino system in semileptonic decays of the bottom quark.…
We study $B_c \to (D,\,D^{\ast})\,l\,\nu$ semileptonic decays mediated via $b \to u\,l\,\nu$ charged current interactions using the $B_c \to (D,\,D^{\ast})$ transition form factors obtained in the covariant light front quark model. We give…
We report a first study of the semileptonic decay $D^0\rightarrow K^-\pi^0\mu^{+}\nu_{\mu}$ by analyzing an $e^+e^-$ annihilation data sample of $7.9~\mathrm{fb}^{-1}$ collected at the center-of-mass energy of 3.773 GeV with the BESIII…
Theoretical predictions for B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency of this expansion is shown both at low and high…
Leptonic and semi-leptonic rare decays of B-mesons are very clean (both theoretically and experimentally) signatures of any new physics beyond the Standard Model (SM). More specifically the decay \btokll has been theoretically observed to…
This proceeding summarizes the recent measurements of semileptonic $b\to u$ decays from the Belle experiment. These analyses use the full data set collected at the $\Upsilon(4S)$ resonance at KEKB accelerator complex with a center-of-mass…
We calculate the rates for the charged lepton flavour violating (LFV) decays l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, the six three-body leptonic decays tau^- -> l_i^- l_j^+ l_k^- and the rate for mu-e conversion…
We calculate the complete ${\cal O}(\alpha_s)$ corrections to the quark decay $b\to ccs$ taking full account of the quark masses, but neglecting penguin contributions. For a c to the b quark mass ratio $m_c/m_b= 0.3$ and a strange quark…
We study the lepton angular distributions in $B\to D^{(*)} \ell \nu_{\ell}$ decays. The lepton angular asymmetries in the decays with the general effective interactions are examined. We demonstrate that the asymmetries are sensitive to new…
We present intermediate results on our ongoing investigation concerning semileptonic decays of heavy pseudoscalar mesons into pseudoscalar and vector mesons. The corresponding formfactors are evaluated at several momenta and appropriate…
The exclusive (B -> K_2 l^+ l^-) decay is studied using the most general, model independent four-fermion interaction. The sensitivity of the ratio of the decay widths when K_2 meson is longitudinally and transversally polarized, the…