Non-extensive statistical effects in high-energy collisions

Abstract

Abstract. Following the basic prescriptions of the relativistic Tsallis' non-extensive thermostatistics, we investigate from a phenomenological point of view the relevance of non-extensive statistical effects on relativistic heavy-ion collisions observable, such as rapidity spectra of net proton production, transverse momentum distributions and transverse momentum fluctuations. Moreover, we study the nuclear and the subnuclear equation of state, investigating the critical densities of a phase transition to a hadron-quarkgluon mixed phase by requiring the Gibbs conditions on the global conservation of the electric and the baryon charges. The relevance of small deviations from the standard extensive statistics is studied in the context of intermediate and high energy heavy-ion collisions.PACS. 25.75.-q Relativistic heavy-ion collisions -25.75.Nq Quark deconfinement, quark-gluon plasma production, and phase transitions -05.90.+m Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems

Nonextensive effects in the Nambu–Jona-Lasinio model of QCD

“…In fact, we have used the same nonextensive version of the standard FD distributions (discussed in [18]), but this time applied to quarks and antiquarks and for both q > 1 and q < 1 cases. On the other hand, when calculating energies, quark condensates and densities we followed prescription advocated in [9,5].…”

“…On the other hand, again following [9,5], densities which are given by the the q-version of Eq. (9) are calculated with n q 's (not with n q q , as in (23) and in (24)).…”

“…This was confirmed in [7] when investigating transverse momenta distributions in heavy ion collisions, namely the gradual accounting for the intrinsic dynamical fluctuations in the hadronizing system by switching from pure statistical approach to the modified Hagedorn formula including temperature fluctuations [7], resulted in sizeable decreasing ‡ Applications of the nonextensive approach are numerous and cover all branches of physics [3]. For those in high energy multiparticle production processes see [4,6,7] whereas [5,8,9] deal with different aspects of nuclear and quark matter. The nonextensive framework can also be derived from a special treatment of kinetic theory investigating complex systems in their nonequilibrium stationary states [8,10,11].…”

“…[2,3,4,5] and references therein). The new phenomenological nonextensivity parameter q occurring here accounts for all possible dynamical factors violating assumptions of the usual BG statistics which is recovered in the limit of q → 1.…”

Nonextensive statistical effects in the quark-gluon plasma formation at relativistic heavy-ion collisions energies

“…From a phenomenological point of view, the non-extensive index is considered here as a free parameter, even if it is actually not because it should depend, in principle, on the physical conditions generated in the reaction and on the fluctuation of the temperature, and also be related to microscopic quantities (such as the mean inter-particle interaction length, the screening length and the collision frequency into the parton plasma). In the present investigation we are going to study small deviations from the standard statistics and values of > 1 only, because these values were obtained in several phenomenological studies of high energy heavy ion collisions (see, for example, Ref.s [22,23,27,28,33,34,44,45]). …”