Phenomenology of light- and strange-quark simultaneous production at high energies

Abstract

This letter presents an extension of EPL116(2017)62001 to light- and strange-quark nonequilibrium chemical phase-space occupancy factors ($γ_{q,s}$). The resulting damped trigonometric functionalities relating $γ_{q,s}$ to the nucleon-nucleon center-of-mass energies $(\sqrt{s_{NN}})$ looks very similar except different coefficients. The phenomenology of the resulting $γ_{q,s}(\sqrt{s_{NN}})$ describes a rapid decrease at $\sqrt{s_{NN}}\lesssim7~$GeV followed by a faster increase up to $\sim20~$GeV. Then, both $γ_{q,s}$ become nonsensitive to $\sqrt{s_{NN}}$. Although these differ from $γ_{s}(\sqrt{s_{NN}})$ obtained at $γ_q(\sqrt{s_{NN}})=1$, various particle ratios including $\mathrm{K}^+/π^+$, $\mathrm{K}^-/π^-$, $\mathrmΛ/π^-$, $\bar{\mathrmΛ}/π^-$, $\mathrmΞ^+/π^+$, and $\mathrmΩ/π^-$, can well be reproduced, as well. We conclude that $γ_{q,s}(\sqrt{s_{NN}})$ should be instead determined from fits of various particle yields and ratios but not merely from fits to the particle ratio $\mathrm{K}^+/π^+$.