Study of new scaling of direct photon production in pp collisions at high energies using MC simulation

Abstract

The new scaling, z-scailing, of prompt proton production in pp collisions at high energies is studied: The scaling function H( z) is expressed via the inclusive cross section of photon production Ed 3 σ/ dq 3 and the multiplicity density of charged particles ρ( s) at pseudorapidity η = 0. Monte Carlo (MC) simulation based on the PYTHIA code is used to calculate the cross section and to study the scaling. The MC technique used to construct the scaling function is described. The H( z) dependence on the scaling variable z, the center-of-mass energy √ s at a produced angle of θ = 90 is investigated. The predictions of the Ed 3 σ/ dq 3 dependence on transverse momentum q⊥ at a colliding energy of √ s = 0.5, 5.0 and 14.0 TeV are made. The obtained results are compared with the experimental data and can be of interest for future experiments at RHIC (BNL), LHC (CERN), HERA (DESY) and Tevatron (Batavia).