# Different Non-extensive Models for heavy-ion collisions

## TL;DR

This paper compares various non-extensive statistical models for describing transverse momentum spectra in heavy-ion collisions, exploring their relations and revisiting the Soft+Hard model with new assumptions.

## Contribution

It introduces two different linear relations between temperature and Tsallis parameter based on different assumptions and revisits the Soft+Hard model with a T-independent average p_T^2.

## Key findings

- Qualitative agreement with Wilk's results
- Derivation of two linear T-q relations under different assumptions
- Comparison with Kaniadakis' κ distribution

## Abstract

The transverse momentum ($p_T$) spectra from heavy-ion collisions at intermediate momenta are described by non-extensive statistical models. Assuming a fixed relative variance of the temperature fluctuating event by event or alternatively a fixed mean multiplicity in a negative binomial distribution (NBD), two different linear relations emerge between the temperature, $T$, and the Tsallis parameter $q-1$. Our results qualitatively agree with that of G.~Wilk. Furthermore we revisit the "Soft+Hard" model, proposed recently by G.~G.~Barnaf\"oldi \textit{et.al.}, by a $T$-independent average $p_T^2$ assumption. Finally we compare results with those predicted by another deformed distribution, using Kaniadakis' $\kappa$ parametrization.