Relativistic Hard-Scattering and Tsallis Fits to pT Spectra in pp Collisions at the LHC

Abstract

Motivated by the good Tsallis fits to the high-pT spectra in pp collisions at the LHC, we study the relativistic hard-scattering model and obtain an approximate analytical expression for the differential hard-scattering cross section at \eta ~ 0. The power-law behaviour of the transverse spectra, in the form of d\sigma/dpT^2 \propto 1/pT^n, gives a power index n in the range of 4.5-5.5 for jet production as predicted by pQCD, after the dependencies of the structure functions and the running coupling constant are properly taken into account. The power indices for hadron production n are slightly greater than those for jet production.

Comments: 10 pages, 2 figures, presented at the Low-x Workshop, May 30 - June 4, 2013, Rehovot and Eilat, Israel