G. Wilk

Modified Hagedorn formula including temperature fluctuation: Estimation of temperatures at RHIC experiments

We have systematically estimated the possible temperatures obtained from an analysis of recent data on pt distributions observed at RHIC experiments. Using the fact that the observed pt distributions cannot be described by the original Hagedorn formula in the whole range of transverse momenta (in particular above 6xa0GeV/c), we propose a modified Hagedorn formula including temperature fluctuation. We show that by using it we can fit pt distributions in the whole range and can estimate consistently the relevant temperatures, including their fluctuations.

Analyses of k(t) distributions at RHIC by means of some selected statistical and stochastic models

The new data on k_t distributions obtained at RHIC are analysed by means of selected models of statistical and stochastic origin in order to estimate their importance in providing new information on hadronization process, in particular on the value of the temperature at freeze-out to hadronic phase.

Rapidity spectra analysis in terms of non-extensive statistic approach

We provide the description of rapidity spectra of particles produced in pp collisions using the anomalous diffusion approach to account for their non-equilibrium character. In particular, we exhibit connections between multiproduction processes and anomalous diffusion described through the nonlinear Focker-Planck equation with a nonlinearity given by the nonextensivity parameter q describing the underlying Tsallis q-statistics. We demonstrate how this leads to the Feynman scaling violation in these collisions. The q parameter obtained in this way turns out to be closely connected to the parameter 1k converting the original poissonian multiplicity distribution to its observed Negative Binomial form. The inelasticity of the reaction has also been calculated and found to slightly decrease with increasing reaction energy.Abstract We provide the description of rapidity spectra of particles produced in pp collisions using the anomalous diffusion approach to account for their non-equilibrium character. In particular, we exhibit connections between multiproduction processes and anomalous diffusion described through the nonlinear Focker-Planck equation with a nonlinearity given by the nonextensivity parameter q describing the underlying Tsallis q-statistics. We demonstrate how this leads to the Feynman scaling violation in these collisions. The q parameter obtained in this way turns out to be closely connected to the parameter 1 k converting the original poissonian multiplicity distribution to its observed Negative Binomial form. The inelasticity of the reaction has also been calculated and found to slightly decrease with increasing reaction energy.

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

We present a nonextensive version of the QCD-based Nambu-Jona-Lasinio (NJL) model of a many-body field theory describing the behavior of strongly interacting matter. It is based on the nonextensive generalization of Boltzmann- Gibbs (BG) statistical mechanics used in the NJL model, which was taken in the form proposed by Tsallis characterized by a dimensionless nonextensivity parameter q (for q → 1 one recovers the usual BG case). This new phenomenological parameter accounts summarily for all possible effects resulting in a departure from the conditions required by the application of the BG approach, and allows for a simple phenomenological check of the sensitivity of the usual NJL model to such effects (in particular to fluctuations of temperature and correlations in a system of quarks). As an example, we discuss the sensitivity of such a q-NJL model to the departures from the NJL form, both for q > 1 and q < 1 cases, for such observables as the temperature dependences of chiral symmetry restoration, masses of π and σ mesons and characteristic features of spinodal decomposition.We present a nonextensive version of the QCD-based Nambu JonaLasinio (NJL) model of a many-body field theory describing the behavior of strongly interacting matter. It is based on the nonextensive generalization of Boltzmann-Gibbs (BG) statistical mechanics used in the NJL model, which was taken in the form proposed by Tsallis characterized by a dimensionless nonextensivity parameter q (for q → 1 one recovers the usual BG case). This new phenomenological parameter accounts summarily for all possible effects resulting in a departure from the conditions required by application of the BG approach, and allows for a simple phenomenological check of the sensitivity of the usual NJL model to such effects (in particular to fluctuations of temperature and correlations in a system of quarks). As an example, we discuss the sensitivity of such a q-NJL model to the departures from the NJL form, both for q > 1 and q < 1 cases, for such observables as the temperature dependencies of chiral symmetry restoration, masses of π and σ mesons and characteristic features of spinodal decomposition. PACS numbers: 21.65.Qr; 25.75.Gz; 05.90.+m; 11.30.Rd Nonextensive effects in the Nambu–Jona-Lasinio model of QCD 2

Strangelets in cosmic rays

Recently new data from the Cosmo-LEP project appeared, this time from the DELPHI detector. They essentially confirm the findings reported some time ago by ALEPH, namely the appearance of bundles of muons with unexpectedly high multiplicities, which so far cannot be accounted for by present day models. We argue, using arguments presented by us some time ago, that this phenomenon could be regarded as one more candidate for the presence in the flux of cosmic rays entering the Earths atmosphere from outer space nuggets of Strange Quark Matter (SQM) in form of so called strangelets .

Scaling behavior of transverse momenta distributions in hadronic and nuclear collisions

It has been recently noticed that transverse momenta (

Nonextensive/Dissipative Correspondence in Relativistic Hydrodynamics

p_T

What information can we obtain from the yield ratio {pi}{sup {minus}}/{pi}{sup +} in heavy-ion collisions?

) distributions observed in high energy production processes exhibit remarkably universal scaling behavior. This is seen when they are in some suitable variable, replacing the usual

Multiplicity fluctuations in high energy hadronic and nuclear collisions

p_T

Quasiscaling in the analysis of the yield ratio {pi}{sup {minus}}/{pi}{sup +}: Mathematical structure and estimation of source size

. On the other hand, it is also known that transverse momenta distributions in general follow a power-like Tsallis distribution, rather than an exponential Boltzmann-Gibbs, with a (generally energy dependent) nonextensivity parameter