Study of ππ correlations at RHIC and LHC energies in pp collisions within the Quark-Gluon String Model

Abstract

The Quark Gluon String Model (QGSM) reproduces well the global characteristics of the pp collisions at RHIC and LHC, e.g., the pseudorapidity and transverse momenta distributions at different centralities. The main goal of this work is to employ the Monte Carlo QGSM for description of femtoscopic characteristics in pp collisions at RHIC and LHC. The study is concentrated on the low multiplicity and multiplicity averaged events, where no collective effects are expected. The different procedures for fitting the one-dimensional correlation functions of pions are studied and compared with the space-time distributions extracted directly from the model. Particularly, it is shown that the double Gaussian fit reveals the contributions coming separately from resonances and from directly produced particles. The comparison of model results with the experimental data favors decrease of particle formation time with rising collision energy.

Femtoscopic and Nonfemtoscopic Two-Particle Correlations inA+Aandp+pCollisions at RHIC and LHC Energies

“…This section of the review is based on the results of [40]. The attempt of the systematic theoretical analysis of the pion femtoscopy of + collisions at the top RHIC and √ = 0.9 TeV LHC energies was made in [75] within Quark-Gluon String Model (QGSM). It was found that for a satisfactory description of the interferometry radii one needs to reduce significantly the formation time by increasing the string tension value relative to the one fixed by the QGSM description of the spectra and multiplicity.…”