相关论文: New physics solutions for $R_D$ and $R_{D^*}$
The measurement of lepton universality parameters $R_{K^{(*)}}$ was updated by LHCb in December 2022, which indicated that the well-known anomalies in flavor-changing neutral current (FCNC) processes of B meson decays have faded away.…
Several experimental measurements of $B$ meson decays, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits to the Wilson…
Tests of lepton-universality as rate ratios in $b\to s \ell\ell$ transitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of the…
It has been shown recently that the anomalies observed in $\bar B\to D^{(\ast)}\tau\bar\nu_\tau$ and $\bar B\to \bar K\ell^+\ell^-$ decays could be resolved with just one scalar leptoquark. Fitting to the current data on $R(D^{(\ast)})$…
We provide a comprehensive, up-to-date analysis of possible New Physics contributions to the mass difference $\Delta M_D$ in $D^0$-${\bar D}^0$ mixing. We consider the most general low energy effective Hamiltonian and include leading order…
The experimental measurements on flavour physics, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits on the Wilson…
The recent measurement of $R_{K^*}$ is yet another hint of new physics (NP), and supports the idea that it is present in $b\to s\mu^+\mu^-$ decays. We perform a combined model-independent and model-dependent analysis in order to deduce…
Recently, several indications of lepton non-universality observables have been perceived in semileptonic $B$ meson decay processes, both in the neutral-current ($b \to s ll $) and charged-current ($b \to c l \bar \nu_l$) transitions.…
The experimental studies of the observables associated with the $b \rightarrow c$ transitions in the semileptonic $B-$ meson decays at BaBar, Belle and LHCb have shown some deviations from the Standard Model (SM) predictions, consequently,…
The rare decays {$B^- \to \tau \bar\nu$}, \mbox{$B \to \tau^+ \tau^-$}, {$b \to X \nu \bar\nu$} and \mbox{$b \to X \tau^+ \tau^-$} all contain third generation leptons in the final state, and hence are sensitive to new physics that couples…
Motivated by the anomalies present in $b \to s\,l^+\,l^-$ neutral current decays, we study the corresponding $B_c \to (D_s,\,D^{\ast}_s)\mu^+\mu^-$ decays within the standard model and beyond. We use a model independent effective theory…
The measured $\bar{B}\to D^{(*)} l \bar\nu$ decay rates for light leptons ($l=e,\mu$) constrain all $\bar{B}\to D^{(*)}$ semileptonic form factors, by including both the leading and ${\cal O}(\Lambda_{\text{QCD}}/m_{c,b})$ subleading…
A comprehensive study of the impact of new-physics on different observables for $B_{s}\to \phi \ell^{+}\ell^{-}$ has been done. We examine the new physics models such as $Z^{\prime}$ and UED models, where the effects of new physics coming…
The Wilson coefficient C7 governing the radiative electromagnetic decays of B meson has been calculated to a very high accuracy in the Standard Model, but experimental bounds on either the magnitude or the sign of C7 are often…
Very compelling deviations in the recently observed lepton nonuniversality observables $\big (R_{D^{(*)}}, R_{K^{(*)}}, R_{J/\psi} \big )$ of semileptonic $B$ meson decays from their Standard Model predictions hint towards the presence of…
The LHCb experiment has made several measurements in $b \to s$ transitions which indicate tensions with the Standard Model predictions. Assuming the source of these tensions to be new physics, we present new global fits to all Wilson…
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…
Extensions of the Standard Model which involve a new scale, $\Lambda$, may, for energies sufficiently small compared to this new scale, be expressed in terms of operators with energy dimension greater than four. The coefficients of just…
In this article, we investigate the potential of the angular distribution of the $B \rightarrow D^* \ell {\nu}_{\ell}$ process to search for new physics signals. The Belle collaboration has analysed it to constraint $V_{cb}$ and the $B\to…
We derive compact expressions for the helicity amplitudes of the many-body $B \to D^{(*)}(\to DY)\tau(\to X\nu)\nu$ decays, specifically for $X = \ell \nu$ or $\pi$ and $Y = \pi$ or $\gamma$. We include contributions from all ten possible…