Study of $\pi\pi$ correlations at LHC and RHIC energies in $pp$ collisions within the quark-gluon string model

TL;DR

This study uses the Quark Gluon String Model to analyze pion correlations in proton-proton collisions at RHIC and LHC, revealing insights into particle formation times and the contributions of resonances versus direct production.

Contribution

It applies the QGSM to femtoscopic pion correlation analysis at high energies, comparing fitting procedures and extracting space-time emission characteristics.

Findings

Double Gaussian fits distinguish resonance and direct particle contributions.

Model results suggest decreasing particle formation time with higher collision energy.

QGSM reproduces global collision characteristics and provides femtoscopic insights.

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.