Phenomenological analysis of rapidity distribution of negative pions in central 12C+12C collisions at $\sqrt{s_{nn}} = 3.14\, {\rm GeV}$

Abstract

Various aspects of the simple phenomenological model, the grand combinational model (GCM), proposed earlier for the systematic description of the center-of-mass (cm) rapidity distributions of different particles produced in high energy heavy ion collisions, were analyzed. The values of GCM parameters were extracted from fitting the cm rapidity distributions of the negative pions in 12 C +12 C collisions at [Formula: see text] both in the experiment and using Modified FRITIOF Model. The GCM parameters extracted for the central 12 C +12 C collisions were compared with those obtained in central Pb + Pb collisions at super proton synchrotron (SPS) and alternating gradient synchrotron (AGS) energies between [Formula: see text] and [Formula: see text] and in central Au + Au collisions at Relativistic heavy ion collider (RHIC) energies between [Formula: see text] and [Formula: see text]. The plausible physical interpretations for the GCM parameters were given. The initial assumption that the parameter β of GCM should be zero for symmetric systems with identical colliding nuclei was validated. The parameter γ of GCM was deduced to follow an approximate asymptotic behavior (γ → 0 as [Formula: see text] at very large cm energies, and γ ≅ 0 could possibly be related to complete dehadronization of the whole collision system, along with attaining its maximum possible energy density, in central collisions of identical nuclei. The behavior of cm energy dependence of γ suggested that it could possibly be sensitive to deconfinement phase transition.