Dynamical fluctuations in baryon-meson ratios

Abstract

The event-by-event dynamical fluctuations in kaon-proton and proton-pion ratios have been studied as a function of the center-of-mass energies of nucleon-nucleon collisions root s. Based on the changing phase space volume which apparently is the consequence of the phase transition(s) from hadrons to a quark-gluon plasma at large root s, the single-particle distribution function f is assumed to be modified. Varying f and the phase space volume are implemented in the grand-canonical ensemble, especially at root s > 17 GeV, so that the hadron resonance gas model, when taking into account the experimental acceptance A and the quark phase space occupation factor gamma, turns out to be able to reproduce the dynamical fluctuations in (K+ + K-)/(p + (p) over bar) and (p + (p) over bar)/(pi(+) + pi(-)) ratios over the entire range of root s. It seems that the applied thermodynamic statistics could come up with a new modification to the Tsallis statistics. Both non-extensivity and changing the phase space are suggested and utilized in the present work.