Related papers: Looking for the effects of New Physics in the $\La…

In a recent paper we studied the effect of new-physics operators with different Lorentz structures on the semileptonic $\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau}$ decay. This decay is of interest in light of the $R({D^{(*)}})$ puzzle in…

We adopt an effective-lagrangian approach to compute the new-physics contributions to T-violating triple-product correlations in charmless Lambda_b decays. We use factorization and work to leading order in the heavy-quark expansion. We find…

Motivated by the recent measurement of the dimuon asymmetry by the D{\O} collaboration, which could be interpreted as an enhanced decay rate difference in the neutral $B_d$-meson system, we investigate the possible size of new-physics…

Recent anomalies in decays induced by $b\to c \ell^- \bar\nu_\ell$ transitions raise the question about such phenomena in the $D$ decays induced by $c\to (s,d)\ell^+\nu_\ell$ transitions. In the experimental side, current measurements on…

We provide a determination of the complete angular distribution for the four body rare decay $\Lambda_b \to \Lambda(\to N \pi) \ell^+\ell^-$, with unpolarized $\Lambda_b$ baryons and massive leptons, in the operator basis approach which…

The $R(D^{(\ast)})$ anomalies observed in $B\to D^{(\ast)}\tau\nu$ decays have attracted much attention in recent years. In this paper, we study the $B\to D^{(\ast)}\tau\nu$, $\Lambda_b\to\Lambda_c\tau\nu$, $B_c\to…

We study possible new physics contributions in $B\to\pi\tau\bar\nu $ and $B\to\tau\bar\nu$ employing the model-independent effective Lagrangian that describes the quark-level transition $b \to u \tau\nu$ at low energies. The decay rate of…

Rare decays of the kind $B\to K^*\mu^+\mu^-$ and $B_s\to \phi\mu^+\mu^-$ are key players for testing the Standard Model. The current experimental data for their decay rates and angular observables show tensions with the theoretical…

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 BaBar Collaboration has recently reported the measurement of the ratio of the branching fractions of $\bar{B} \to D(D^{*}) \tau^{-} \bar{\nu_\tau}$ to $\bar{B} \to D(D^{*}) \ell^{-} \bar{\nu_\ell}$ which deviates from the Standard Model…

I review the current status of measurements involving semi-tauonic $B$ meson decay at the $B$-factories. I briefly discuss the experimental methods and highlight the importance of background contributions especially from poorly understood…

We study possible New Physics (NP) effects in the exclusive decays $\bar{B}^0 \to D^{(\ast)} \tau^- \bar{\nu}_{\tau}$. We extend the Standard Model (SM) by taking into account right-handed vector (axial), left- and right-handed…

In $\Lambda_b^0 \to \Lambda_c^+ (\to \Lambda^0 \pi^+) \tau^- \bar{\nu}_\tau $ decay, the solid angle of the final-state particle $\tau^-$ cannot be determined precisely since the decay products of the $\tau^-$ include an undetected…

Heavy quark decays provide a very advantageous investigation to test the Standard Model (SM). Recently, promising experiments with \textit{b} quark, as well as the analysis of the huge data sets produced at the B factories, have led to an…

We derive the four-fold angular distribution for the semileptonic decay $\bar{B}\to D_2^*(\to D \pi)\,\ell \bar{\nu}$ where $D_2^*$(2460) is a tensor meson. We start with the most general beyond the Standard Model (SM) dimension-six…

Hints of lepton flavor universality violation observed in various flavor ratios such as $R_D$, $R_{D^*}$, $R_{J/\psi}$, $P_\tau^{D^*}$ and $F_L^{D^*}$ in $B\to D^{(*)}\,\ell \, \nu$ and $B_c\to J/\psi \, \ell\, \nu$ charge current decays…

Recent experimental results for the ratios of the branching fractions of the decays $\bar{B} \to D^{(*)} \tau \bar\nu$ and $\bar{B} \to D^{(*)} \mu \bar\nu$ came as a surprise and lead to a discussion of possibility of testing New Physics…

We present a complete method to construct QCD-protected observables based on the exclusive 4-body $B$-meson decay $\bar{B} \to \bar{K}^{*0}\ell^+\ell^-$ in the low dilepton mass region. The core of the method is the requirement that the…

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 present allowed regions in the space of observables of certain non-leptonic B-meson decays that characterize these modes within the Standard Model. A future measurement of observables lying significantly outside of these regions would…