A study of the J/ψ-meson photoproduction at large transverse momentum at HERA energies via the charm quark excitation in the photon is presented. Based on perturbative QCD, nonrelativistic quark model and photon structure function formalism, our calculation demonstrates that the charm content of the photon may be very important for the J/ψ photoproduction at the large transverse momentum. It is...

We calculate the contribution to inclusive high tranverse momentum (pT ) charm production at HERA from the excitation of charm in the photon. At large values of pT the results of such a calculation, in the structure function language, will be more reliable as it sums the large logs, log(pT /m 2 c), as opposed to calculating the contribution of the 2 → 3 subprocess in fixed order of perturbation...

We present here recent results on the investigations of the mass spectrum ( S-states and P-states), decay constants, decay widths and life time of the D, Ds,and Bcmesons within the framework of phenomenological potential models.We also present the binding energy and the masses of the di-meson molecular systems with one or more charm meson combinations. Many of the newly found experimental open ...

I discuss the physics reach of a fixed-target charm experiment which can reconstruct >10 charm decays, three orders of magnitude beyond the largest extant sample. Such an experiment may run at Fermilab shortly after the Year 2000. In addition to “programmatic” charm physics such as spectroscopy, lifetimes, and tests of QCD, this “Charm2000” experiment will have significant sensitivity to new ph...

We compute the mass of the charm quark using both quenched and dynamical lattice QCD calculations. We examine the effects of mass dependent lattice artifacts by comparing two different formalisms for the heavy quarks. We take the continuum limit of the charm mass in quenched QCD by extrapolating from three different lattice spacings. At a fixed lattice spacing, the mass of the charm quark is co...

We address Standard Model predictions for flavor-changing radiative transitions of the pseudoscalar charm mesons. Short-distance contributions in D radiative transitions are contrasted with those in B decays. A full analysis is presented of the c → u+ γ electromagnetic penguin amplitude with QCD radiative corrections included. Given the importance of long-range effects for the charm sector, spe...

Motivated by recent experimental results we reconsider semileptonic D → P ℓν ℓ decays within a model which combines heavy quark symmetry and properties of the chiral Lagrangian. We include excited charm meson states, some of them recently observed, in our Lagrangian and determine their impact on the charm meson semileptonic form factors. We find that the inclusion of excited charm meson states ...