Specific Features of Heavy Quark Production. LPHD approach to heavy particle spectra

Abstract

Perturbative QCD formula for inclusive energy spectra of heavy quarks from heavy quark initiated jets which takes into account collinear and/or soft logarithms in all orders, the exact first order result and two-loop effects is applied to distributions of heavy flavoured hadrons in the framework of the LPHD concept. Fits to experimentally measured charm and bottom mean energy losses result in $\alpha_{\MSbar}(M_Z)=0.125\pm 0.003\pm 0.004$ and $(2\GeV)^{-1}\int_0^{2\GeV} dk \alpha_s^{eff}(k)= 0.18\pm 0.01\pm 0.02$ with $\alpha_s^{eff}$ an infrared finite effective QCD coupling.