相关论文: Semileptonic $B-\to p\bar{p} \ell-\bar{\nu}_\ell$ …

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.…

Based on 88 million Y(4S)->BB decays collected by the BaBar experiment at the PEP-II asymmetric-energy B factory at SLAC, we report preliminary results of four analyses which study in semileptonic charmless B decays, B->Xulnu and measure…

We search for the rare leptonic decay B+ --> tau+ nu_tau in a sample of 232x10^6 BBbar pairs collected with the BABAR detector at the SLAC PEP-II B-Factory. Signal events are selected by examining the properties of the B meson recoiling…

We report results of a search for the charmless two-body baryonic decays B^0 \to p \bar{p}, B^0 \to \Lambda \bar{\Lambda}, and B^+\to p \bar{\Lambda} based on the analysis of a 140 fb^{-1} data sample. We set 90% confidence level upper…

The tree-level $b\rightarrow c{\ell}\bar\nu_{\ell}$ based hadronic transitions have been on the focus of much attention since recording significant deviations of the experimental data, on the ratios of the branching fractions in $ \tau $…

We review the two and three-body baryonic $B$ decays with the dibaryon (${\bf B\bar B'}$) as the final states. Accordingly, we summarize the experimental data of the branching fractions, angular asymmetries, and $CP$ asymmetries. Using the…

The $B$ meson semileptonic modes to $\rho(770)$ and $a_1 (1260)$ are useful to pin down possible non Standard Model effects. The 4d differential $\bar B \to \rho(\pi \pi) \ell^- \bar \nu_\ell$ and $ \bar B \to a_1 (\rho \pi) \ell^- \bar…

A search is presented for the four-body decay $B^0\rightarrow p p \bar{p} \bar{p}$ in a sample of $471$ million $B\bar{B}$ pairs collected with the BaBar detector, operated at the SLAC PEP-II asymmetric-energy $e^+e^-$ collider. The…

In this paper, we compare the branching ratio and rate difference of electron channel to muon channel of $B \rar K_0^\ast (1430) \ell^+ \ell^-$ and $B \rar K^\ast \ell^+ \ell^-$decays, where $K_0^\ast (1430)$ is the p--wave scalar meson, in…

We present a systematic analysis for the rare baryonic exclusive decays of $\Lambda_b\to\Lambda l^+ l^- (l=e,\mu,\tau)$. We study the differential decay rates and the di-lepton forward-backward, lepton polarization and various CP…

Recently hints of lepton flavor non-universality emerged when the BaBar Collaboration observed deviations from the standard model predictions in $R(D^{(*)}) \equiv {\cal B}({\bar B} \to D^{(*)+} \tau^- {\bar\nu}_\tau) / {\cal B}({\bar B}…

I report results in semileptonic decays of B mesons from the CLEO collaboration, with a focus on recent results. Results for exclusive reconstruction of B -> D* l nu, B -> D l nu and B -> rho l nu are given including the q^2 dependence of…

We study the exclusive $b \to u \ell^- \bar{\nu}_{\ell} (\ell=\tau,\mu,e)$ decays in the MSSM with and without R-parity violation. From the experimental measurements of branching ratios $\mathcal{B}(B^-_u \to \tau^- \bar{\nu}_{\tau})$,…

We present the first evidence for B semileptonic decays into the charmed baryon Lambda_c+ based on 420 fb-1 of data collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are tagged by fully…

We study the semileptonic decay $\bar{B}_s \to K^{*+} \ell^-\bar\nu_\ell$, which is induced by $b\to u \ell^- \bar\nu_\ell$ transitions at the quark level. We take into account the standard model (SM) operator from $W$-boson exchange as…

Inclusive semileptonic B_s^0 -> X^+ l^- \nu decays are studied for the first time using a 23.6 fb^{-1} data sample collected on the Y(5S) resonance with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. These decays are…

We study the exclusive leptonic and semileptonic $B$ decays $B \to \ell^- \bar\nu$ and $B \to D^{(\ast)} \ell^-\bar\nu$ in the framework of the covariant quark model with built-in infrared confinement. We compute the relevant form factors…

We present precise theoretical predictions for the absolute branching fractions of $\Lambda_c^+ \to \Lambda \ell^+ \nu_\ell\,(\ell=e,\mu)$ decays in the covariant confined quark model. This study is motivated by two recent and accurate…

Leptonic rare decays of $B^0_{s,d}$ mesons offer a powerful tool to search for physics beyond the Standard Model. The $B^0_{s}\to\mu^+\mu^-$ decay has been observed at the Large Hadron Collider and the first measurement of the effective…

In this paper we study the semileptonic decays of $B^\ast$, $B_s^\ast$, and $B_c^\ast$ by using the Bethe-Salpeter method with instantaneous approximation. Both the $V\to Pl^-\bar\nu_l$ and $V\to Vl^-\bar\nu_l$ cases are considered. The…