Related papers: $\Lambda_b \to (\Lambda_c,\,p)\,\tau\,\nu$ decays …

The branching fraction of the rare $B^0_s\rightarrow\phi\mu^+\mu^-$ decay is measured using data collected by the LHCb experiment at center-of-mass energies of $7$, $8$ and $13\,\rm{TeV}$, corresponding to integrated luminosities of $1$,…

We study the impact of including the baryonic decay $\Lambda_b\to \Lambda(\to p \pi^-)\mu^+\mu^-$ in a Bayesian analysis of $|\Delta B | = |\Delta S| = 1$ transitions. We perform fits of the Wilson coefficients $C_{9}$, $C_{9'}$, $C_{10}$…

We report the first observation of the semi-muonic decay $D^+\to \omega \mu^+\nu_\mu$ using an $e^+e^-$ collision data sample corresponding to an integrated luminosity of $2.93~\mathrm{fb}^{-1}$ collected with the BESIII detector at a…

We report a measurement of the ratios of branching fractions $\mathcal{R}(D) = {\cal B}(\bar{B} \to D \tau^- \bar{\nu}_{\tau})/{\cal B}(\bar{B} \to D \ell^- \bar{\nu}_{\ell})$ and $\mathcal{R}(D^{\ast}) = {\cal B}(\bar{B} \to D^* \tau^-…

Considering the recent experimental results on exclusive semileptonic $B$ meson decays showing sizable departure from their Standard Model prediction of lepton flavor universality and keeping ongoing and proposed non-standard Higgs searches…

We present a search for the decay $B^{-} \to \tau^{-} \bar{\nu}_{\tau}$ in a sample of $88.9 \times 10^{6}$ $B\bar{B}$ pairs recorded with the BaBar detector at the SLAC $B$-Factory. One of the two $B$ mesons from the $\Upsilon(4S)$ is…

One of the exciting results in flavor physics in recent times is the $R_D$/$R_{D^*}$ puzzle. The measurements of these flavor ratios performed by the B-factory experiments, BaBar and Belle, and the LHCb experiment are about $4\sigma$ away…

We present a search for the decay $B^{+} \to \tau^{+} \nu_{\tau}$ in $88.9 \times 10^{6}$ $\Upsilon(4S)$ decays recorded with the BABAR detector at the SLAC $B$-Factory. A sample of semi-exclusive, semi-leptonic B decays ($B^{-} \to D^{0}…

Evidence is presented for the baryonic $B$ meson decay $\bar{B}\rightarrow D^0 \Lambda \bar{\Lambda}$ based on a data sample of $471 \times 10^6$ $B\bar{B}$ pairs collected with the {\it BABAR} detector at the PEP2 asymmetric $e^+e^-$…

Within the left-right symmetric model (LRM) the decays $$S_1\to\mu^++\tau^-,\qquad S_1\to\mu^-+\tau^+$$ where $S_1$ is an analog of the standard model Higgs boson, are considered. The widths of this decays are found in the third order of…

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…

Using 482~pb$^{-1}$ of $e^+e^-$ collision data collected at a center-of-mass energy of $\sqrt{s} = 4.009$ GeV with the BESIII detector, we measure the branching fractions of the decays $D_s^+\to\mu^+\nu_\mu$ and $D_s^+\to\tau^+\nu_\tau$. By…

The Cabibbo-suppressed semileptonic decay $B^{+}\to p\overline{p}\mu^{+}\nu_{\mu}$ is observed for the first time using a sample of $pp$ collisions corresponding to an integrated luminosity of 1.0, 2.0 and 1.7fb$^{-1}$ at centre-of-mass…

Semileptonic $b$-hadron decays proceed via charged-current interactions and provide powerful probes for testing the Standard Model and searching for New Physics effects. The advantages of studying such decays include the large branching…

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…

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…

Utilizing $7.33~\mathrm{fb}^{-1}$ of $e^+e^-$ collision data taken at the center-of-mass energies of 4.128, 4.157, 4.178, 4.189, 4.199, 4.209, 4.219, and 4.226 GeV with the BESIII detector, the branching fraction of the leptonic decay…

The differential branching fraction of the decay $\Lambda_b^0\rightarrow\Lambda\mu^+\mu^-$ is measured as a function of the square of the dimuon invariant mass, $q^2$. A yield of $78\pm12$ $\Lambda_b^0\rightarrow\Lambda\mu^+\mu^-$ decays is…

Decays of $B$ mesons with leptons in the final state offer an interesting laboratory to search for possible effects of physics from beyond the Standard Model. In view of puzzling patterns in experimental data, the violation of lepton…

In this work we compute the branching fraction of $B \to D^{(*)} \,\tau \, \nu_{\tau}$ and $B_s \to D_s^{(*)}\, \tau\, \nu_{\tau}$ within the Relativistic Independent Quark Model, emphasizing the harmonic potential model dependent analysis…