Chemical evolution of mesons in hadronic matter

We derive a set of rate equations describing the chemical equilibration of pions, rho mesons, kaons, and vector kaons, and discuss their consequences for meson equilibration in heavy ion collisions. The evolution of hadronic matter is then described by a kinetic model that takes into account mesons absorption and regeneration. The fugacity of pion decreases while the fugacity of rho, kaon, and vector kaon increase with increasing time. The quark-interchange process plays an very important role in the evolvement of hadronic matter.