相关论文: Hints of R-parity violation in B decays into $\tau…

We provide a general analysis of time reversal violation arising from misalignment between quark and squark mass eigenstates. In particular, we focus on the possibility of large enhancement effects due to the top quark mass. For…

The MSSM with right-handed neutrino supermultiplets, gauged B-L symmetry and a non-vanishing sneutrino expectation value is the minimal theory that spontaneously breaks R-parity and is consistent with the bounds on proton stability and…

We confront the indications of lepton flavor universality (LFU) violation observed in semi-tauonic $B$ meson decays with new physics (NP) searches using high $p_T$ tau leptons at the LHC. Using effective field theory arguments we correlate…

It has been shown that the anomalies observed in $\bar B\to D^{(\ast)}\tau\bar\nu_\tau$ and $\bar B\to \bar K\ell^+\ell^-$ decays can be resolved by adding a single scalar or vector leptoquark to the Standard Model, while constraints from…

We derive the upper bounds on certain products of R-parity- and lepton-flavor-violating couplings from $B \ra X_s {l_i}^+ {l_j}^-$ decays. These modes of B-meson decays can constrain the product combinations of the couplings with one or…

Within the assumption of Left-Handed (LH) New Physics (NP), we review the relations between $\mathcal{B}(B\to K^{(\ast)} \tau^+\tau^-)$ and $\mathcal{B}(B\to K^{(\ast)} \nu\bar \nu)$ for several Beyond the Standard Model (BSM) scenarios,…

In the context of lepton flavor universality violation (LFUV) studies, we fully derive a general tensor formalism to investigate the role that left- and right-handed neutrino new-physics (NP) terms may have in $b\to c \tau\bar\nu_\tau$…

We scrutinize the impact of various relevant scalar leptoquarks on the physical observables associated with the rare semileptonic decay processes of $B_s$ meson involving $b \to (u, c) l\bar \nu_l$ quark level transitions. We constrain the…

We study the decays $B\to K^{(*)}\ell^+\ell^-$ and $B_s\to \ell^+\ell^- (\ell=e,\mu)$ in the minimal supersymmetric standard model with R-parity violation (RPV). From the recent measurements of their branching ratios, we have derived new…

Recently the $B$ factories BaBar and Belle as well as the LHCb experiment have reported several anomalies in the semileptonic $B$ meson decays such as $R_{K}$ and $R_{D^{(*)}}$ etc. We investigate these deviations by considering the vector…

During the past few years, hints of Lepton Flavour Universality (LFU) violation have been observed in $b \to c \tau \bar\nu$ and $b \to s \ell^+ \ell^-$ transitions. Recently, the $D^*$ and $\tau$ polarization fractions $P_L^{D^*}$ and…

The recent measurements of lepton flavor university (LFU) violating observables in semileptonic $b \to c \ell \bar{\nu} $ and $b\to s\ell^+ \ell^-$ transitions by various experiments exhibit $(2-3)\sigma$ deviations from their corresponding…

We review the current status and implications of the anomalies (i.e. deviations from the Standard Model predictions) in semi-leptonic $B$ meson decays, both in the charged and in the neutral current. In $b\to s\ell^+\ell^-$ transitions…

Semileptonic and leptonic B decays are analyzed in the framework of the relativistic quark model. Special attention is payed to the decays involving $\tau$ lepton. It is found that the calculated particular decay branching fractions are…

We study the exclusive $b \to u \ell^- \bar{\nu}_{\ell} (\ell=\tau,\mu,e)$ decays in the MSSM with and without R-parity violation. From the experimental measurements of branching ratios $\mathcal{B}(B^-_u \to \tau^- \bar{\nu}_{\tau})$,…

In recent years, several deviations from the Standard Model predictions in semileptonic decays of $B$-meson might suggest the existence of new physics which would break the lepton-flavour universality. In this work, we have explored the…

We determine the rates of the $B$ meson decays into a $K^{(*)}$ and an $\ell^+ \ell^-$ bound state, the leptonium, where $\ell = e,\mu,\tau$. The two spin states of the leptonium, the spin singlet and the spin triplet, couple to the axial…

LHCb found hints for physics beyond the standard model in $B\to K^*\mu^+\mu^-$, $B\to K^*\mu^+\mu^-/B\to K^*e^+e^-$ and $B_s\to\phi\mu^+\mu^-$. In addition, the BABAR results for $B\to D^{(*)}\tau\nu$ and the CMS excess in…

We critically examine the potential to disentangle Standard Model (SM) and New Physics (NP) in $B \to K^* \mu^+\mu^-$ and $B\to K^* e^+ e^-$ decays, focusing on $(i)$ the LHCb anomaly, $(ii)$ the search for right-handed currents, and…

The most recent measurements of the observables $R_{D^{(*)}}$ are in tension with the Standard Model offering hints of New Physics in $b\rightarrow c \ell \bar{\nu}_{\ell}$ transitions. Motivated by these results, in this work we present an…