Near and Far from Equilibrium Power-Law Statistics
  We analyze the connection between $p_T$ and multiplicity distributions in a statistical framework. We connect the Tsallis parameters, $T$ and $q$, to physical properties like average energy per particle and the second scaled factorial moment, $F_2=\langle n(n-1) \rangle / {\langle n \rangle}^2$, measured in multiplicity distributions. Near and far from equilibrium scenarios with master equations for the probability of having $n$ particles, $P_n$, are reviewed based on hadronization transition rates, $\mu_n$, from $n$ to $n+1$ particles. 
Tamas S Biro, Gergely G Barnafoldi, Gabor Biro, Ke Ming Shen
hep-ph