Charm meson production from meson-nucleon scattering.pdf

a r X i v : n u c l - t h / 0 2 0 1 0 7 4 v 2 1 F e b 2 0 0 2 Charm meson production from meson-nucleon scattering W. Liu and C. M. Ko Cyclotron Institute and Physics Department, Texas AM University, College Station, Texas 77843-3366 Abstract Using an effective hadronic Lagrangian with physical hadron masses and coupling constants determined either empirically or from SU(4) flavor sym- metry, we study the production cross sections of charm mesons from pion and rho meson interactions with nucleons. With a cutoff parameter of 1 GeV at interaction vertices as usually used in studying the cross sections for J/ψ absorption and charm meson scattering by hadrons, we find that the cross sections for charm meson production have values of a few tenth of mb and are dominated by the s channel nucleon pole diagram. Relevance of these reactions to charm meson production in relativistic heavy ion collisions is discussed. PACS numbers: 25.75.-q, 13.75.Lb, 14.40.Gx, 14.40.Lb I. INTRODUCTION Because of their large masses, open charm mesons are expected to be mostly produced in the initial preequilibrium stage of relativistic heavy ion collisions. They have thus been suggested as possible probes of the initial dynamics in these collisions. Previous studies have been concentrated on the production of charm quarks from the preequilibrium partonic matter [1,2]. In these studies, it has been found that charm quark production is sensitive to not only the rapidity and space correlations of initial minijet partons but also their energy loss in the dense partonic matter. For charm meson production from nonpartonic matter, the only study is the one [3] based on the Hadron-String Dynamics (HSD) [4] using hadronic cross sections obtained from the Quark-Gluon String Model (QGSM) [5]. Allowing scatterings between the leading quark and diquark in a baryonic string with the quark and antiquark in a mesonic string and taking their cross sections to be the same as in meson-baryon scatterings, thi