Examination of the species and beam energy dependence of particle spectra using Tsallis statistics

Abstract

Tsallis statistics was used to investigate the non-Boltzmann distribution of particle spectra and their dependence on particle species and beam energy in the relativistic heavy-ion collisions at SPS and RHIC. Produced particles are assumed to acquire radial flow and be of non-extensive statistics at freeze-out. J/ψ, and the particles containing strangeness were examined separately to study their radial flow and freeze-out. We found that the strange hadrons approach equilibrium quickly from peripheral to central A+A collisions and they tend to decouple earlier from the system than the light hadrons but with the same final radial flow. These results provide an alternative picture of freeze-outs: a thermalized system is produced at the partonic phase; the hadronic scattering at a later stage is not enough to maintain the system in equilibrium and does not increase the radial flow of the copiously produced light hadrons. The J/ψ in Pb+Pb collisions at SPS is consistent with early decoupling and obtains little radial flow. The J/ψ spectra at RHIC are also inconsistent with the bulk flow profile.

Consequences of temperature fluctuations in observables measured in high-energy collisions

“…[20,31] and presented in [17]. The most recent applications of this approach come from the STAR and PHENIX Collaborations at RHIC [32,33] and from the CMS [34,35], ALICE [36,37] and ATLAS [38] Collaborations at LHC (see also a recent compilation [39,40]) 4 . In sect.…”

The imprints of superstatistics in multiparticle production processes

“…1 obtained from ( ). Namely, as observed in [13,24], it turns out that in the fitting procedure parameters T and are strongly correlated. This is why values evaluated in different analysis of rapidity distributions [18,32] …”

“…Accounting for it thus explains automatically the observed -dependence of the multiplicity fluctuations measured in nuclear collisions on the centrality of collision [12] (cf. also [13]). …”

“…Since the review [2], Tsallis distributions have been used more widely, for example, they were successfully applied to the analysis of the recent PHENIX [15] and LHC CMS [16,17] data (cf. also the compilation [13]). In what follows we present our recent results in this field in more detail: a derivation of -sum rules unifying different fluctuations -in Section 2, a generalization of thermodynamic uncertainty relations and their applications -in Section 3.…”

Nonextensive statistical mechanics: Applications to high energy physics

“…It is important to address here the fact that the distribution of transverse momenta in high-energy collisions of proton-proton, and heavy nuclei (e.g., Pb-Pb and Au-Au) have received and are receiving great attention [62][63][64][65][66][67][68] [69]: see Fig. 16.…”