Related papers: Constraining new physics in $b\to c\ell\nu$ transi…
The transitions $B_{s,d}\rightarrow \ell^+\ell^-$ (for $\ell=e, \mu, \tau$), although extremely suppressed within the SM, are exceptionally clean channels particularly sensitive to New Physics contributions. So far only the branching ratio…
We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated…
The rare decays $B\to K^{(*)}\ell^+\ell^-$, $B\to K^{(*)}\nu\bar\nu$ and $B_s\to\mu^+\mu^-$ are analyzed in a generic scenario where New Physics effects enter predominantly via $Z$ penguin contributions. We show that this possibility is…
The ability of present and future experiments to test the Standard Model in the $B$ meson sector is described. We examine the loop effects of new interactions in flavor changing neutral current $B$ decays and in $Z\to b\bar b$,…
The LHCb experiment, bolstered up by the 10^12 b-hadrons to be produced yearly in its interaction region, is an excellent place to study rare B decays. Flavor-changing neutral currents are forbidden at tree level in the Standard Model. They…
Rare decays mediated by $b \to s \nu \bar \nu$ transitions have been reported by the Belle II experiment. The branching ratio of the decay $B^+ \to K^+ \nu \bar \nu$ is found to be enhanced with respect to the standard model value. If taken…
Flavour changing neutral currents are suppressed in the Standard Model, making them a prime avenue to search for new physics. Although several measurements of the decay $B^{0}\to{}K^{\ast{}0}\mu^{+}\mu^{-}$ have shown deviations from the…
Semileptonic $B_s \to K \ell \nu$ decays provide an alternative $b$-decay channel to determine the CKM matrix element $|V_{ub}|$, and to obtain a $R$-ratio to investigate lepton-flavor-universality violations. Results for the CKM matrix…
The rare decay B to K* (to K pi) mu+ mu- is regarded as one of the crucial channels for B physics since its angular distribution gives access to many observables that offer new important tests of the Standard Model and its extensions. We…
We study the exclusive decays of $B\to K^{(*)}\ell^+ \ell^-$ by the results in the perturbative QCD with the heavy quark effective theory and lattice calculations. We obtain the form factors for the $B\to K^{(*)}$ transitions in the whole…
The data on high-precision flavour observables reveal certain puzzles when compared to Standard Model expectations based on a global fit of the CKM unitarity triangle and general theoretical estimates. The discussion of these tensions in…
Rare flavour-changing neutral-current transitions of the type $s \to d \ell^+\ell^-(\nu\bar\nu)$ and $b \to s \ell^+\ell^-(\nu\bar\nu)$ are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is…
We perform an analysis of the consequences of various new physics operators on the lepton flavor violating (LFV) decay modes mediated through $b \to s \ell _1 \ell _2$ transitions. We scrutinize the imprints of the (pseudo)scalar and…
We investigate the crossing-symmetry relation between $b\to c\tau^-\bar\nu$ decay and $b\bar c\to \tau^-\bar\nu$ scattering to derive direct correlations of New Physics in semi-tauonic $B$-meson decays and the mono-tau signature at the LHC…
Motivated by the experimental accessibility of rare $B$ decays in the ongoing and planned experiments, we propose to undertake a model-independent analysis of the inclusive decay rates and distributions in the processes \bgamaxs~ and \Bsell…
The study of flavour-changing neutral currents (FCNC) gives access to important tests of the Standard Model (SM) and allows to search for hints of beyond the SM phenomena. We present here the study of the very rare decays $B^0\rightarrow…
Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the…
Studies of rare decays play an important role in the search of physics beyond the standard model. New particles may participate in the loop processes and can be probed by seeing any deviations from the standard model predictions. The very…
We investigate a new constraint on new-physics interpretations of the anomalies observed in $B\to D^{(*)}\tau\nu$ decays making use of the lifetime of the $B_c^-$ meson. A constraint is obtained by demanding that the rate for…
Recent measurements of exclusive $B^{-} \to \tau^{-}\,\nu$ and $B^0 \to \pi^{+}\,l^{-}\,\bar{\nu}_l$ decays via the $b \to u\,l\,\nu$ transition process differ from the standard model expectation and, if they persist in future $B$…