Issue
EPL
Volume 84, Number 5, December 2008
Article Number 56003
Number of page(s) 6
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/84/56003
Published online 16 December 2008
EPL, 84 (2008) 56003
DOI: 10.1209/0295-5075/84/56003

Abstract composition rule for relativistic kinetic energy in the thermodynamical limit

T. S. Bíró

KFKI Research Institute for Particle and Nuclear Physics - P.O. Box 49, H-1525 Budapest, Hungary, EU

tsbiro@mail.kfki.hu

received 26 September 2008; accepted in final form 28 October 2008; published December 2008
published online 16 December 2008

Abstract
We demonstrate by simple mathematical considerations that a power-law$\hbox{--} $tailed distribution in the kinetic energy of relativistic particles can be a limiting distribution seen in relativistic heavy-ion experiments. We prove that the infinite repetition of an arbitrary composition rule on an infinitesimal amount leads to a rule with a formal logarithm. As a consequence the stationary distribution of energy in the thermodynamical limit follows the composed function of the Boltzmann-Gibbs exponential with this formal logarithm. In particular, interactions described as solely functions of the relative four-momentum squared lead to kinetic energy distributions of the Tsallis-Pareto (cut power law) form in the high-energy limit.

PACS
65.40.gd - Entropy.
25.75.Ag - Global features in relativistic heavy ion collisions.

© EPLA 2008