Eta absorption by mesons

Abstract

Using the $[SU(3)_{\mathrm{L}} \times SU(3)_{\mathrm{R}}]_{\mathrm{global}% }\times [SU(3)_V]_{\mathrm{local}}$ chiral Lagrangian with hidden local symmetry, we evaluate the cross sections for the absorption of eta meson ($% η$) by pion ($π$), rho ($ρ$), omega ($ω$), kaon ($K$), and kaon star ($K^*$) in the tree-level approximation. With empirical masses and coupling constants as well as reasonable values for the cutoff parameter in the form factors at interaction vertices, we find that most cross sections are less than 1 mb, except the reactions $ρη\to K\bar K^*(\bar KK^*)$, $ωη\to K\bar K^*(\bar KK^*)$, $K^*η\toρK$, and $K^*η\toωK$, which are a few mb, and the reactions $πη\to K\bar K$ and $Kη\toπK$, which are more than 10 mb. Including these reactions in a kinetic model based on a schematic hydrodynamic description of relativistic heavy ion collisions, we find that the abundance of eta mesons likely reaches chemical equilibrium with other hadrons in nuclear collisions at the Relativistic Heavy Ion Collider.