Cross sections for meson-meson nonresonant reactions

Meson-meson nonresonant reactions governed by the quark-interchange mechanism are studied in a potential that is derived from QCD. S-wave elastic phase shifts for I = 2 ππ and I = 3/2 Kπ scattering are obtained with wave functions determined by the central spin-independent term of the potential. The reactions include inelastic scatterings of two mesons in the ground-state pseudoscalar octet and the ground-state vector nonet. Cross sections for reactions involving π, ρ, K and K∗ indicate that mesonic interactions in matter consisting of only K and K∗ can be stronger than mesonic interactions in matter consisting of only π and ρ and the reaction of I = 3/2 πK∗ → ρK is most important among the endothermic nonresonant reactions. By the quark-interchange mechanism we can offer √ s-dependences of φ absorption cross sections in collisions with π and ρ and relevant average cross sections what are very small for the reaction of I = 1 πφ → K∗K∗ and remarkably large for the reaction of I = 1 ρφ → K∗K∗. It is found from the √s-dependences of cross sections that ρ and K∗ creation cross sections can be larger than their absorption cross sections, respectively. PACS: 25.75.-q; 13.75.Lb; 12.38.Mh