Related papers: Hints of R-parity violation in B decays into $\tau…
We investigate the possibility of explaining the enhancement in semileptonic decays of $\bar B \to D^{(*)} \tau \bar \nu$, the anomalies induced by $b\to s\mu^+\mu^-$ in $\bar B\to (K, K^*, \phi)\mu^+\mu^-$ and violation of lepton…
We study leptonic decays D_s\to \tau \nu and B^+ \to \tau \nu in R-parity violating (RPV) supersymmetric standard model. The interference between the s-channel slepton exchange and the t-channel squark exchange diagrams could be destructive…
We investigate leptonic decays $D_s \to \tau \nu_\tau$ and $B^+ \to \tau \nu_\tau$ in R-parity violating (RPV) supersymmetric standard model. Taking account of interference between the s-channel slepton exchange and the $t$-channel squark…
Recent experimental results from the LHCb, BaBar and Belle collaborations on the semitauonic decays of $B$ meson, $\bar{B}\rightarrow D^{(\ast)}\tau \bar{\nu}$, showing a significant deviation from the Standard Model (SM), hint towards a…
In the past few years, several hints of lepton flavour universality (LFU) violation have emerged in the $b \to c \tau \bar\nu$ and $b \to s \ell^+ \ell^-$ data. Quite recently, the Belle Collaboration has reported the first measurement of…
The existence of R-parity in supersymmetric models can be naturally explained as being a discrete subgroup of gauged baryon minus lepton number (B-L). The most minimal supersymmetric B-L model triggers spontaneous R-parity violation, while…
Recent measurements of semileptonic $B$-meson decays into $\tau$-leptons are somewhat higher than expected in the standard model. Although the deviations are less than 3$\sigma$, they suggest the possibility of new physics affecting…
We study the decays Bu -> l nu and Bc -> l nu in the context of the Minimal Supersymmetric Standard Model (MSSM) with explicit R parity violation. We analyse the correlation between the two decays and show that branching ratios (BRs) for Bc…
In recent years, intriguing hints for the violation of Lepton Flavour Universality (LFU) have been accumulated in semileptonic $B$ decays, both in the neutral-current transitions $b\to s\ell^+\ell^-$ (i.e., $R_K$ and $R_{K^*}$) and the…
We present a complete study of R-parity violating supersymmetric effects in thirteen exclusive and inclusive semi-leptonic $b \to (s,d) \nu \bar{\nu}$ decays, including $B^+_u\to K^{(*)+}\nu\bar{\nu}$, $B^0_d\to K^{(*)0}\nu\bar{\nu}$,…
The purely leptonic decays D -> e nu and Ds -> e nu, for which no experimental limits exist, are highly suppressed in the Standard Model. Mere observation of these decays at the B factories BELLE/BaBar or forthcoming CLEO-c would be a clear…
We present a comprehensive update of the bounds on R-Parity violating supersymmetric couplings from lepton-flavour- and lepton-number-violating decay processes. We consider tau and mu decays as well as leptonic and semi-leptonic decays of…
The $R(D^{(*)})$ puzzle stands for a $\sim3\sigma$ violation of lepton flavor universality between the decay rates of $B\to D^{(*)}\tau\nu$ and $B\to D^{(*)}\ell\nu$, where $\ell=e,\mu$. If it is accounted for by new physics, there is no…
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…
We investigate the effects of R-parity violation on the semileptonic decays of B-meson in the minimal supersymmetric standard model with explicit R-parity violation and discuss its physical implications. We find that the semileptonic decays…
The rare decays B_s -> \mu^+\mu^- and B -> K^{(*)}\mu^+\mu^- are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on B(B_s -> \mu^+\mu^-) has been improved…
Semileptonic decays provide an excellent environment for testing the Standard Model (SM). Violation of lepton universality would be a smoking gun for physics beyond the SM. Using semi-tauonic $B$ decays, LHCb finds a value of…
We re-visit the problem of New Physics (NP) contribution to the branching ratio of the $B_s \to \mu^+ \mu^-$ decay in light of the recent observation of this decay by LHCb. We consider R-parity violating (RPV) supersymmetric models as a…
We put constraints on several products of R-parity violating lambda lambda' and lambda' lambda' type couplings from leptonic and semileptonic tau, B_d and B_s decays. Most of them are one to two orders of magnitude better than the existing…
Being strictly forbidden in the standard model, experimental detection of the lepton flavor violating decays $B(\bar B)\to\tau^+\mu^-$ and $b(\bar b)\to X\tau^+\mu^-$ would constitute an unmistakable indication of new physics. We study…