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

We systematically study the semileptonic decays of ${\bf B_c} \to {\bf B_n}\ell^+ \nu_{\ell}$ in the light-front constituent quark model, where ${\bf B_c}$ represent the anti-triplet charmed baryons of $(\Xi_c^0,\Xi_c^+,\Lambda_c^+)$ and…

The $\bar{B}_s^0 \to D_s^{(*)+} l^- \bar{\nu}_l$ semileptonic decays were calculated in the framework of the standard model (SM) by employing the perturbative QCD (pQCD) factorization approach. We defined four ratios of the branching ratios…

We update the branching ratios for the inclusive decays $B\to X_s \ell^+ \ell^-$ and the exclusive decays $B\to (K,K^*) \ell^+ \ell^-$, with $\ell=e, \m$, in the standard model by including the explicit $O(\a_s)$ and $\Lambda_{\hbox{\tiny…

We study the charmless baryonic three-body decays of B mesons: B+ to p Lambdabar gamma, B+ to p Lambdabar pi0 and B0 to p Lambdabar pi-. The partial branching fractions as a function of the baryon-antibaryon mass and the polar angle…

The semileptonic decays $\bar{B}\to D(D^*)\pi\ell\bar{\nu}$ are analyzed by heavy quark and chiral symmetries. The branching ratio is of order of a few percent for $\dpi$, but it is much smaller for $\dstar$, of order $10^{-4}-10^{-5}$. The…

It is experimentally observed that ratios of branching fractions for semitauonic and semileptonic $B$ decays, known as the $R(D^{(*)})$, are higher than Standard Model (SM) predictions. The $B \to \bar{D}^{(*)} \tau^{+} \nu_{\tau}$ decays,…

We present Standard Model predictions for lepton flavour universality ratios of inclusive $B\to X_{(c)} \ell \bar\nu_\ell$. For the $\ell=\mu,e$, these ratios are very close to unity as expected. For the $\tau$ mode, we update the SM…

We present a search for the decay $\B^+ \to \ell^+ \nu_{\ell} (\ell = \tau, \mu, \mathrm{or} e)$ in $(458.9 \pm 5.1) \times 10^{6}$ $\Upsilon(4S)$ decays recorded with the Babar detector at the SLAC PEP-II $B$-Factory. A sample of events…

Using the full data sample of 980 $\mathrm{fb}^{-1}$ collected with the Belle detector at the KEKB asymmetric energy electron-positron collider, we report the results of the first search for the rare semileptonic decays $\Xi_c^0 \to…

Semileptonic $B$ meson decays into the four lightest excited charmed meson states ($D_0^*$, $D_1^*$, $D_1$, and $D_2^*$) and their counterparts with $s$ quarks are investigated, including the full lepton mass dependence. We derive the…

We investigate the semileptonic decays $\Lambda_{b} \to \Lambda_{c} \ell^- \bar{\nu}_\ell$ (with $\ell = e, \mu, \tau$) within the framework of perturbative QCD (pQCD). The six independent $\Lambda_b \to \Lambda_c$ transition form factors…

Semileptonic and leptonic B decays are analyzed in the framework of the relativistic quark model. Special attention is payed to the decays involving $\tau$ lepton. It is found that the calculated particular decay branching fractions are…

This proceeding summarizes the recent measurements of semileptonic $b\to u$ decays from the Belle experiment. These analyses use the full data set collected at the $\Upsilon(4S)$ resonance at KEKB accelerator complex with a center-of-mass…

Among the various "rare" semi-leptonic decays of $B$-mesons the $B \to K^* \ell^+ \ell^-$ mode is of special interest. This is because it has the highest branching ratio among all the semi-leptonic B decays within the SM. This channel also…

We report on a measurement of the charmless semileptonic B decays, B0->pi^-l^+nu and B0->rho^-l^+nu, based on 140 fb^{-1} data collected with the Belle detector at the KEKB e^+e^- asymmetric collider. In this analysis, accompanying B mesons…

Among (semi)leptonic rare $B$-decays induced by the $b \to d$ flavor changing neutral current, the decay $B^+ \to \pi^+ \mu^+ \mu^-$ is the only one observed so far experimentally. Related decays involving the $e^+e^-$ and $\tau^+ \tau^-$…

We present a lattice-QCD determination of the $\Lambda \to p$ vector and axial-vector form factors, providing theoretical input for studies of the semileptonic decay $\Lambda \to p\ell\bar{\nu}_\ell$. The calculation is carried out on a…

We examine the semileptonic $B \to D^{(*)} \ell \nu_\ell$ and $B \to \pi \ell \nu_\ell$ decays adopting the unitarity-based Dispersive Matrix (DM) method, which allows to determine the shape of the relevant hadronic form factors (FFs) in…

The rare decay $B\to\pi\ell^+\ell^-$ arises from $b\to d$ flavor-changing neutral currents and could be sensitive to physics beyond the Standard Model. Here, we present the first $ab$-$initio$ QCD calculation of the $B\to\pi$ tensor form…

The heaviness of the top quark makes its 2-body decay mode $t \to bW^+$ to be dominant, at such level that hardly any other decay mode reaches a detectable branching ratio (BR) within the SM. Here we study the decay $t \to bW^+\ell^-\ell^+$…