相关论文: Parton Hadron Duality in nonleptonic B hadron deca…
A way of circumventing the gauge and infrared problems with effective Wilson coefficients is shown. Implications of experimentally measured charmless $B$ decays are discussed.
A preliminary measurement of the second moments of the hadron mass in B --> X l nu decays by the BABAR Collaboration is reported. These measurements are performed as a function of the lepton momentum above a given threshold.
Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the…
We study two and three meson decays of the tau lepton within the framework of the Resonance Chiral Theory, that is based on the following properties of QCD: its chiral symmetry in the massless case, its large-N_C limit, and the asymptotic…
Several high energy experiments have been actively pursuing the analyses of semileptonic decays of charm mesons, resulting in numerous new results and publications. In this report, we summarize the recent efforts on the topics of…
The semileptonic decay of a b-quark, b--> c l nu, is considered in the relativistic limit where the decay products are approximately collinear. Analytic results for the double differential lepton energy distributions are given for finite…
A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find…
We present new results on charm hadron decays from the CLEO II experiment. The D*+ width is measured for the first time, Gamma(D*+) = 96 +- 4 +- 22 keV. The semileptonic decay branching fractions are determined to be B(D+ --> Kbar*0 e+…
Consequences of the interference between spectator amplitudes for the lifetimes and semileptonic decay fractions of B^0 and B^+ mesons are discussed. Assuming duality and constructive interference between spectator amplitudes we are able to…
The evaluation, systematic analysis and numerical study of the semileptonic $\tau$-lepton decays with two mesons in the final state has been made in the frame of the standard model extended by right handed neutrinos. In the analysis,…
We investigate rare semileptonic \bar B -> \bar K^* l^+ l^- decays, providing a comprehensive treatment of theoretical uncertainties in the low-q^2 region as needed for interpreting current and future LHCb and B-factory data in terms of the…
There are two apparent puzzles connected with the two-body and three-body doubly charmed baryonic B decays. First, earlier calculations based on QCD sum rules or the diquark model predict $Br(\bar B^0\to\Xi_c^+\bar\Lambda_c^-)\approx…
Implications of recent measurements of hadronic charmless B decays are discussed.
By introducing Q^2-dependence in resonance-reggeon "soft" dual models with nonlinear trajectories, they are extended to "hard" processes, sharing the property of parton-hadron duality. The resulting object is a two-component complex…
A global previous analysis of two-body nonleptonic decays of $D$ mesons has been extended to the decays involving light scalar mesons. The allowance for final state interaction also in nonresonant channels provides a fit of much improved…
Data in $B$-meson decays indicate violations of lepton flavour universality, thereby raising the question about such phenomena in the charm sector. We perform a model-independent analysis of NP contributions in (semi)-leptonic decays of…
Exclusive hadronic decays of the tau lepton provide an excellent framework to study the hadronization of QCD currents in a non-perturbative energy region populated by many resonances. I give a short review both on the main theoretical tools…
Meson mixing is considered to be an ideal candidate for new physics searches. Current experimental precision has greatly increased over the recent years, excelling in several cases the theoretical precision. A possible limit in the…
We review the current status of experimental measurements of the branching fractions for exclusive semileptonic decays of B mesons to charmless hadrons and the determination of the Standard Model CKM parameter |Vub| from these measurements.
A summary of WG II of the CKM 2018 conference on semileptonic and leptonic $b$-hadron decays is presented. This includes discussions on the CKM matrix element magitudes $|V_{ub}|$ and $|V_{cb}|$, lepton universality tests such as $R(D^{*})$…