Related papers: New Physics couplings from angular coefficient fun…
Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…
In this paper we study the bounds that can be inferred on New Physics couplings to heavy sterile neutrinos $N$ from the recent measurements performed by the Belle collaboration of the angular analysis of $B\to D^*\ell\bar\nu_\ell$ decays,…
We derive the expressions for the full angular distributions of $\bar B\to D\ell\bar \nu_\ell$ and $\bar B\to D^{\ast }\ell\bar \nu_\ell$ decays and discuss the spectra on each angle separately. The coefficient functions, depending on…
The increasing number of flavour anomalies calls for the investigation of new processes where tensions similar to the observed ones could emerge. Observables sensitive to physics beyond the Standard Model need to be identified. We discuss…
We study potential New Physics effects in the $\bar B \to D^{(*)} \tau \bar\nu$ decays. As a particular example of New Physics models we consider the class of leptoquark models and put the constraints on the leptoquark couplings using the…
It is well known that New Physics can contribute to weak decays of heavy mesons via virtual processes during its decays. The discovery of New Physics, using such decays is made difficult due to intractable strong interaction effects needed…
The decays $\bar{B} \rightarrow D^{(*)} \tau^- \bar{\nu}_\tau$ are good probes to new physics beyond the Standard Model. The ratios of branching fractions $R(D^{(*)}) \equiv \mathit{BF}(\bar{B} \rightarrow D^{(*)} \tau^- \bar{\nu}_\tau) /…
Reconstruction of the $B^0 \to D^{*-} \tau^+ \nu_{\tau}$ angular distribution is complicated by the strongly-biasing effect of losing the neutrino information from both the $B$ and $\tau$ decays. In this work, a novel method for making…
One of the most pragmatic ways to look for the effects of New Physics at low energy scales is to study a detailed angular distribution of various decay modes, and in particular those based on $b\to c\ell\bar \nu_\ell$. In this paper we…
The recent measurements on $R_D$, $R_{D^*}$ and $R_{J/\psi}$ by three pioneering experiments, BaBar, Belle and LHCb, indicate that the notion of lepton flavour universality is violated in the weak charged-current processes, mediated through…
The discovery of New Physics, using weak decays of mesons is difficult due to intractable strong interaction effects needed to describe it. We show how the multitude of "related observables" obtained from B\to K^* \ell^+\ell^-, can provide…
The recent anomalies in $b\to s\ell^+\ell^-$ transitions could originate from some New Physics beyond the Standard Model. Either to confirm or to rule out this assumption, more tests of $b\to s\ell^+\ell^-$ transition are needed. Polarized…
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…
We study the $\bar{B}\to D(D^*) \ell^-\bar{\nu}_{\ell}$ decays based on the up-to-date available inputs from experiments and the lattice. First, we review the standard model (SM) predictions of the different observables associated with…
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…
Recent experimental results on angular observables in the rare decay $B\to K^*\mu^+\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining…
Disentangling New Physics effects from the Standard Model requires a good understanding of all pieces that stem from the latter, especially the uncertainties that might plague the theoretical estimations within the Standard Model. In the…
The angular analysis of exclusive rare B-meson decays via intermediate vector mesons V into 4-body final states of two pseudo-scalars P_1, P_2 and a pair of light leptons l = e, mu offers a large set of observables. They can be used to test…
The significant divergence between the SM predictions and experimental measurements for the ratios, $R_{D^{(*)}}\equiv \mathcal{B}(\bar{B}\to D^{(*)}\tau^- \bar{\nu}_\tau)/ \mathcal{B}(\bar{B}\to D^{(*)} \ell^{\prime-}…
The measurements of several lepton flavor universality (LFU) violating observables in the decays induced by the quark level transition $b \to c \tau \bar{\nu}$ provide an inkling of plausible physics beyond the standard model of electroweak…