Hadronic loop effects to excited scalar charmed mesons revisited

Abstract We re-examine the hadronic loop effects on the masses of D 0 * and D s 0 * calculated in quark models in the framework of heavy meson chiral perturbation theory (HMCHPT). Unlike previous approaches, ours reproduces the observed scalar charm states reported by the Particle Data Group (PDG). We show why previous approaches of using HMCHPT in studying mass shift effects due to chiral loops gave unsatisfactory results.