Understanding the $K^{\ast }/K$ ratio in heavy ion collisions

Abstract

We study the $K^{\ast }$ meson dissociation in heavy ion collisions during the hadron gas phase. We use the production and absorption cross sections of the $K^{\ast }$ and $K$ mesons in a hadron gas, which were calculated in a previous work. We compute the time evolution of the $K^{\ast }$ abundance and the $K^{\ast }/K$ ratio during the hadron gas phase. Assuming a Bjorken type cooling and using an empirical relation between the freeze-out temperature and the central multiplicity density, we are able to write $K^{\ast }/K$ as a function of ($dN/d\eta (\eta =0)$). The obtained function is in very good agreement with recent experimental data.

9 pages, 5 figures