Related papers: Flavour physics parameters from data and unitarity
This paper is a review of recent lattice QCD results for $D$ and $D_s$ meson leptonic and semileptonic decays. The theory inputs needed for the determination of $V_{cd}$ and $V_{cs}$ from experimental results are the meson decay constants…
Recently H. Georgi has introduced an unparticle $\unpart$ in order to describe the low energy physics of a nontrivial scale invariant sector of an effective theory. In this work we have explored the phenomenology of an unparticle using the…
The exclusive decay mode B ->K*ll has become one of the key players in the search for New Physics in flavor. An increasing number of observables are being studied experimentally, and with increasing precision. Its theoretical description is…
We use QCD sum rules to calculate the hadronic matrix elements governing the rare decays $B \to K \ell^+ \ell^-$ and $B \to K^* \ell^+ \ell^-$ induced by the flavour changing neutral current $b \to s$ transition. We also study relations…
We propose a new parametrization of the $B\to\pi$ vector form factor, $f_+(q^2)$, as an expansion in powers of a conformal mapping variable, which satisfies unitarity, analyticity and perturbative QCD scaling. The unitarity constraint is…
We study the decays $B\to D^{(\ast)}\tau\nu_{\tau}$ in light of the available data from BABAR, Belle and LHCb. We divide our analysis into two parts: in one part we fit the form-factors in these decays directly from the data without adding…
The nuclear matrix elements $M^{0\nu}$ of the neutrinoless double beta decay ($0\nu\beta\beta$) of most nuclei with known $2\nu\beta\beta$-decay rates are systematically evaluated using the Quasiparticle Random Phase Approximation (QRPA)…
We report a study of the semileptonic decay $D^0 \rightarrow \bar{K}^0\pi^-\mu^+\nu_{\mu}$ based on a sample of $7.9~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy of 3.773~GeV with the BESIII detector…
We discuss various tests of the factorization hypothesis making use of the close relationship between semi-leptonic and factorized nonleptonic decay amplitudes. It is pointed out that factorization leads to truely model-independent…
We investigate lepton flavour violation in a class of minimal left-right symmetric models where the left-right symmetry is broken by triplet scalars. In this context we present a method to consistently calculate the triplet-Yukawa couplings…
In this article, the electroweak transition form factors of $\Sigma_b\to\Sigma_c$, $\Xi'_b\to\Xi'_c$ and $\Omega_b\to\Omega_c$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings…
A complete and critical survey is presented of all half-life, decay-energy and branching-ratio measurements related to 20 superallowed decays; no measurements are ignored, though some are rejected for cause and others updated. A new…
The form factors of the semileptonic $B$, $B_s$ and $B_c$ meson decays are calculated in the framework of the relativistic quark model based on the quasipotential approach in QCD. They are expressed through the overlap integrals of the…
Motivated by the recent experimental results of branching fractions for D_((s))^+ arrows {\eta}^((')) l^+ {\nu}_l decays, which deviate from their SM predictions, we have investigated these decays in W' model and scalar leptoquark model to…
The extension of Majorana neutrino mass mechanism of the neutrinoless double-beta decay ($0\nu\beta\beta$) with the inclusion of right-handed leptonic and hadronic currents is revisited. While only the exchange of light neutrinos is…
We calculate $D_s^+\to \phi$ transition form factors $V$, $A_0$, $A_1$ and $A_2$, and study semileptonic decay of $D_s^+\to \phi \bar{\ell}\nu$ based on QCD sum rule method. We compare our results of the ratios of $V(0)/A_1(0)$,…
Starting from the new sources of $LL$- and $LR$- scalar (slepton) mixings due to R-parity violation, we discuss the structure of lepton-flavor violation focusing on the radiative decay of muon into electron. Using an optimal…
We review the physics of purely leptonic decays of $\pi^\pm$, $K^\pm$, $D^{\pm}$, $D_s^\pm$, and $B^\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of…
Measurements of the branching fractions of the semileptonic decays $B\to D^{(*)}\tau\bar\nu_\tau$ and $B_c\to J/\psi\tau\bar\nu_\tau$ systematically exceed the Standard Model (SM) predictions, pointing to possible signals of new physics…
We discuss some recent lattice results on a few selected hadronic quantities relevant for heavy flavour phenomenology and present some recent theoretical developments. We put the emphasis on the challenges, which have to be faced, on the…