相关论文: Semileptonic width ratios among beauty hadrons

We study the impact of third-order QCD corrections for several kinematic moments of the inclusive semileptonic $B$ decays, to first order in the $1/m_b$ expansion. We consider the first four moments of the charged-lepton energy $E_\ell$…

The perturbative QCD approach has achieved great success in the study of hadronic B decays. Utilizing the constrained parameters in these well measured decay channels, we study most of the possible charmless $B_s \to PP$, $PV$ and $VV$…

Recent results relevant for the B-physics phenomenology, obtained from lattice QCD simulations by the APE Collaboration, are reviewed. This includes the B0-B0bar mixing amplitude, B-> pi semileptonic decay and the relative width difference…

We use the heavy quark expansion to investigate the width difference $\Delta\Gamma_{B_s}$ between the $B_s$ mass eigenstates. The corrections of ${\cal O}(\Lambda_{QCD}/m_b)$ and ${\cal O}(m_s/m_b)$ to the leading order expression in the…

We review current status of theoretical predictions of lifetimes of heavy hadrons in heavy-quark expansion. We present a calculation of subleading 1/m_b corrections to spectator effects in the ratios of beauty hadron lifetimes. We find that…

We present the results of a calculation of the perturbative QCD corrections for the semileptonic inclusive width of a heavy flavored meson. Within the Heavy Quark Expansion we analytically compute the QCD correction to the coefficient of…

The semileptonic decays of $\Omega_c$ and $\Omega_b$ are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy $\Lambda$ baryons. Analytic results for the form factors for…

We study semileptonic sum rules for $b \to c \tau \overline{\nu}$ transitions involving orbitally excited charm hadrons. Starting from the amplitude-level relation implied by the heavy quark symmetry, we construct sum rules relating these…

Exclusive semileptonic Lambda_b decays to excited charmed Lambda_c baryons are investigated at order Lambda_{QCD}/m_Q in the heavy quark effective theory. The differential decay rates are analyzed for the J^\pi=1/2^- Lambda_c(2593) and the…

We report OPE predictions for hadronic mass and q^2 moments in inclusive semileptonic B decays without charm, taking into account experimental cuts on the charged lepton energy and on the hadronic invariant mass, and address the related…

A simple model of Omega_Q and Omega_Q^(*) baryons containing one heavy quark Q is constructed. Amplitudes are represented by loop graphs with one line for the heavy quark and another for the light degrees of freedom. The latter are modelled…

Theoretical predictions for B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency of this expansion is shown both at low and high…

Large apparent $SU(3)_F$ breaking and a tension with lattice QCD have recently emerged in semileptonic decays of singly charmed baryons, hinting at either an unexpected hadronic mechanism or new physics. We formulate a framework that…

We make predictions and propose tests for the semi-leptonic decays $B\to D^{(*)} l \bar{\nu}_l$ and $\Lambda_b\to \Lambda_c l \bar{\nu}_l$, with $l$ = $e$, $\mu$ and $\tau$. Preliminarily, we study such processes according to the $\ell-s$…

We update the Standard Model (SM) predictions for $B$-meson lifetimes within the heavy quark expansion (HQE). Including for the first time the contribution of the Darwin operator, SU(3)$_F$ breaking corrections to the matrix element of…

We update the Standard Model (SM) predictions for the lifetimes of the $B^+$, $B_d$ and $B_s$ mesons within the heavy quark expansion (HQE), including the recently determined NNLO-QCD corrections to non-leptonic decays of the free…

Neutral-current semileptonic $B$ decays are plagued by hadronic resonances across the dilepton invariant-mass squared spectrum, $q^2$. For light leptons, $\ell=e,\mu$, these resonances can be avoided with suitable $q^2$ cuts. This strategy…

The constituent picture of hadrons implies certain quantum mechanical inequalities which must hold in the potential models. Basing on this qualitative consideration I argue that it is not easy to increase significantly the scale of the…

Studies of semileptonic decays of b hadrons with the LHCb experiment are reported. In particular, measurements of the b hadron production fractions at the LHC and Bs semileptonic decays in P-wave charmed mesons are presented. An outlook of…

We perform a preliminary study of the 1/2+ and 3/2+ ground-state baryons containing a heavy quark in the framework of the chiral SU(3) quark model. By using the calculus of variations, masses of Lambda_Q, Sigma_Q, Xi_Q, Omega_Q, Sigma_Q^*,…