The Tsallis distribution at large transverse momenta

J Cleymans,M D Azmi

doi:10.1140/epjc/s10052-015-3629-9

Abstract

Fits to the transverse momentum distributions of charged particles produced in p - p collisions at LHC energies based on the Tsallis distribution have been shown to work over 14 orders of magnitude. Two versions of the Tsallis distribution are compared and discussed, the thermodynamically consistent version leads to a temperature of T = 74 +/- 13 MeV at the highest beam energy, a result which is in agreement with previous analyses done with lower transverse momentum data.

Highlights

It is well known that the Tsallis distribution gives excellent fits to the transverse momentum distributions observed at the Relativistic Heavy Ion Collider (RHIC) [1–3] and at the Large Hadron Collider (LHC) [4–8] with only three parameters, q, T, and d N /dy
A power law based on the Tsallis distribution [13] is used to fit the pT spectra of charged particles measured by the ATLAS and CMS collaborations
The charged particle transverse momentum spectra measured by the ATLAS and CMS detectors in proton–proton collisions at LHC energies are fitted using Eq (9)

Summary

Introduction

It is well known that the Tsallis distribution gives excellent fits to the transverse momentum distributions observed at the Relativistic Heavy Ion Collider (RHIC) [1–3] and at the Large Hadron Collider (LHC) [4–8] with only three parameters, q, T , and d N /dy (or, alternatively, a volume V [9–11]). A power law based on the Tsallis distribution [13] is used to fit the pT spectra of charged particles measured by the ATLAS and CMS collaborations. The ATLAS collaboration has reported the transverse momentum in an inclusive phase space region taking into account at least two charged particles in the kinematic range |η| < 2.5 and pT > 100 MeV [7]. The CMS collaboration has presented the differential transverse momentum distribution covering a pT range up to 200 GeV/c, the largest range ever measured in a colliding beam experiment [14]. The results are compared with those obtained in [15–17,19,20] where very good fits to transverse momentum distributions were presented. We confirm the quality of the fits but obtain different values of the parameters albeit using a different version of the Tsallis model

Tsallis distribution

Fit details

Results and discussions

Conclusions