相关论文: Lattice QCD calculation of form factors for $\Lamb…

We present the results of a lattice computation of the form factors for B^0 ->pi^- l^+nu_l decays near zero-recoil. These results will allow a determination of the CKM matrix element |Vub| when measurements of the differential decay rate…

We develop perturbative QCD factorization theorems for the exclusive semileptonic heavy baryon decay $\Lambda_b \to pl{\bar\nu}$, in which the relevant hadronic form factor is expressed as the convolution of a hard subamplitude with the…

The leading electromagnetic (e.m.) and strong isospin-breaking corrections to the $\pi^+ \to \mu^+ \nu[\gamma]$ and $K^+ \to \mu^+ \nu[\gamma]$ leptonic decay rates are evaluated for the first time on the lattice. The results are obtained…

We present the first unquenched lattice-QCD calculation of the form factors for the decay $B\rightarrow D^\ast\ell\nu$ at nonzero recoil. Our analysis includes 15 MILC ensembles with $N_f=2+1$ flavors of asqtad sea quarks, with a strange…

We present a lattice-QCD determination of the vector and axial-vector form factors that describe the charm-baryon semileptonic decays $\Xi_c\to \Xi \ell^+ \nu_\ell$. The calculation uses a domain-wall action for the up, down, and strange…

We present a preliminary study toward a lattice determination of the vector and scalar form factors of the $B \to \pi \ell \nu$ semileptonic decays. We compute the form factors relative to the transition between heavy-light pseudoscalar…

The rare hyperon decay $\Sigma^+ \to p \ell^+ \ell^-$ is a flavour-changing neutral current process mediated by an $s \to d$ transition that occurs only at loop level within the Standard Model. Consequently, this decay is highly suppressed,…

Using a fully relativistic lattice fermion action, we compute the form factors of the semileptonic decay $B\to\pi\ell\nu$, which is required for the determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{ub}|$. We employ the…

The form factors of the $\Lambda_{b} \to N^\ast \ell^+ \ell^-$ decay are calculated in the framework of the light cone QCD sum rules. In the calculations the contribution of the negative parity $\Lambda_b^\ast$ baryon is eliminated by…

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…

We present the results of a high statistics lattice calculation of hadronic form factors relevant for $D-$ and $B-$meson semi-leptonic decays into light pseudoscalar and vector mesons. The results have been obtained by averaging over 170…

Hadronic form factors for semileptonic decay of the $\Lambda_c$ are calculated in a nonrelativistic quark model. The full quark model wave functions are employed to numerically calculate the form factors to all relevant orders in ($1/m_c$,…

We have computed the form factors for B --> pi and D --> K(pi) semileptonic decays on the lattice by using full non-perturbative O(a) improvement, in the quenched approximation. Our results are expressed in terms of few parameters which…

We present a lattice QCD calculation of the $B \rightarrow D l \nu$ semileptonic decay form factors $f_+(q^2)$ and $f_0(q^2)$ for the entire physical $q^2$ range. Non-relativistic QCD (NRQCD) bottom quarks and Highly Improved Staggered…

We present the first perturbative QCD calculations of the $\Xi_b \to (\Lambda, \Sigma)$ transition form factors at leading order in $\alpha_s$, which govern the Cabibbo-suppressed semileptonic decays $\Xi_b \to (\Lambda, \Sigma)\ell…

Semileptonic $B_{(s)}$ decays are of great phenomenological interest because they allow to determine e.g. CKM matrix elements or test lepton flavor universality. Taking advantage of already existing lattice data, we demonstrate the analysis…

The $\Lambda_b \rightarrow \Lambda_c \ell^- \bar{\nu}_\ell$ process has been discussed in the literatures as a probe for new physics. This process receives contributions in new physics models from scalar, vector, and tensor hadronic…

We calculate the $\Lambda_b \to \Lambda_c^*(2595) l \nu$ and $\Lambda_b \to \Lambda_c^*(2625) l \nu$ form factors and decay rates for all possible $b \to c l \bar\nu$ four-Fermi interactions in and beyond the Standard Model (SM), including…

We present a light-cone QCD sum rule analysis of the semileptonic decays of $\Xi_c$ baryons, focusing on the channels $\Xi_c^0 \to \Xi^- \ell^+ \nu_\ell$, and $\Xi_c^+ \to \Xi^0 \ell^+ \nu_\ell$. The transition form factors are calculated…

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…