Role of quark-interchange processes in evolution of mesonic matter

TL;DR

This paper investigates the role of quark-interchange processes in meson-meson reactions, establishing rate equations to model how these processes influence the evolution of mesonic matter in high-energy environments.

Contribution

It introduces a detailed model incorporating quark-interchange, annihilation, and resonant processes into master rate equations for meson evolution, highlighting the significance of quark-interchange in inelastic scattering.

Findings

Quark-interchange processes significantly affect meson density evolution.

The model shows opposite effects on pion/rho and kaon/vector kaon densities.

Quark-interchange contributions are crucial for understanding mesonic matter dynamics.

Abstract

We divide the cross section for a meson-meson reaction into three parts. The first part is for the quark-interchange process, the second for quark-antiquark annihilation processes and the third for resonant processes. Master rate equations are established to yield time dependence of fugacities of pions, rhos, kaons and vetor kaons. The equations include cross sections for inelastic scattering of pions, rhos, kaons and vector kaons. Cross sections for quark-interchange-induced reactions, that were obtained in a potential model, are parametrized for convenient use. The number densities of pion and rho (kaon and vector kaon) are altered by quark-interchange processes in equal magnitudes but opposite signs. The master rate equations combined with the hydrodynamic equations for longitudinal and transverse expansion are solved with many sets of initial meson fugacities. Quark-interchange processes are shown to be important in the contribution of the inelastic meson-meson scattering to evolution of mesonic matter.