相关论文: Threshold Resummation in Semi-Inclusive B decays
We develop threshold resummation for single-particle inclusive cross sections in hadron-hadron collisions to the level of next-to-next-to-leading logarithm, up to full matching with two-loop hard functions. We define and calculate all…
Semileptonic and nonleptonic decays of the B_c meson to charmonium and D mesons are studied in the framework of the relativistic quark model. The decay form factors are explicitly expressed through the overlap integrals of the meson wave…
Exclusive semileptonic B decays into excited charmed mesons are investigated at order $\Lambda_{QCD}/m_Q$ in the heavy quark effective theory. Differential decay rates for each helicity state of the four lightest excited $D$ mesons ($D_1$,…
Two body non-leptonic decays:Lambda_b-->Lambda_c P(V) are investigated. Baryon form factors of the heavy quark effective theory are employed. Form factors for renormalization in full QCD are also considered. We find that contributions of…
We discuss the simultaneous resummation of threshold and recoil enhancements to partonic cross sections due to soft radiation. Our method is based on a refactorization of the parton cross section near its partonic threshold. It avoids…
The semileptonic B_c-meson decays into the heavy quarkonia J/\psi (\eta_c) and a pair of leptons are investigated in the framework of three-point sum rules of QCD and NRQCD. Calculations of analytical expressions for the spectral densities…
The semileptonic decay form factors of the double heavy $B_{c}$ meson provide a unique opportunity to study the strong interactions between two heavy quarks. A fully relativistic model, with effective non-local quark-meson interactions, is…
In this paper we investigate the effect of the resummation of threshold logs on the rate for B -> X_s gamma. We calculate the differential rate dGamma/dE_gamma including the infinite set of terms of the form alpha_s^n log^{n+1}(1-x) and…
We resum to next-to-leading order the distribution in the ratio of the invariant hadron mass mX to the total hadron energy EX and the distribution in mX in the semileptonic decays B -> Xu l nu. By expanding our formulas, we obtain the…
The form factors of the semileptonic $B_c\to S(AV)\ell\nu$ $(\ell=\tau, \mu, e)$ transitions, where S and AV denote the scalar $X_{c0}$ and axial vector $(X_{c1}, h_{c})$ mesons, are calculated within the framework of the three-point QCD…
In this work we summarize the current status of measured exclusive semileptonic branching fractions containing charm mesons. We use the available experimental data to evaluate the difference between the sum of exclusive measurements and the…
We calculate the next-to-next-to-leading order QCD corrections to the leptonic invariant mass ($q^2$) spectrum of semileptonic $b \to c$ inclusive decays, taking into account the mass of the charm quark and the charged lepton in the final…
A relativistic quark model is applied to the description of semileptonic and non-leptonic charmed decays of the B-meson. The exclusive semileptonic modes B -> D l \nu and B -> D* l \nu are described through the universal Isgur-Wise form…
I discuss the motivation for resummation of the effects of initial-state soft gluon radiation, to all orders in the strong coupling strength, for processes in which the near-threshold region in the partonic subenergy is important. I…
The QCD factorization approach provides the theoretical basis for a systematic analysis of nonleptonic decay amplitudes of B mesons in the heavy-quark limit. After recalling the basic ideas underlying this formalism, several tests of QCD…
In this paper, we review recent progress in the field of semileptonic decays of charm mesons, including topics on the relative branching ratio and the form factors. The comparison between the experimental form factor measurements and the…
We present the results of a calculation of semileptonic form factors of D and B mesons. The calculation uses nonperturbatively order a improved quenched lattice QCD and two values of the coupling. Results for charm mesons show reasonable…
We present new results on the summation of nonpower-series expansions in QCD Analytic Perturbation Theory (APT) in the one-loop approximation. We show how to generalize the approach suggested by one of us earlier to the cases of APT and…
We discuss one-particle inclusive B decays in the limit of heavy b and c quarks. Using the large-N_C limit we factorize the non-leptonic matrix elements, and we employ a short distance expansion. Modeling the remaining nonperturbative…
We compute next-to-next-to-leading order corrections to the semileptonic decay rate of $B$ mesons for arbitrary values of the final-state quark mass. For the contribution with one massive quark in the final state, we extend the literature…