On Distributions of Emission Sources and Speed of Sound in Proton-proton (Proton-antiproton) Collisions

TL;DR

This paper applies a three-source Landau hydrodynamic model to analyze rapidity distributions in high-energy proton-proton and proton-antiproton collisions, extracting the speed of sound from experimental data across a wide energy range.

Contribution

It introduces a revised three-source hydrodynamic model with Monte Carlo fitting to experimental data, providing new insights into particle emission sources and sound speed in high-energy collisions.

Findings

The model fits experimental data from 0.2 to 13 TeV.

The squared speed-of-sound parameter varies with collision energy.

The central source's Gaussian distribution covers a wide rapidity range.

Abstract

The revised (three-source) Landau hydrodynamic model is used in this paper to study the (pseudo)rapidity distributions of charged particles produced in proton-proton and proton-antiproton collisions at high energies. The central source is assumed to contribute with a Gaussian function which covers the rapidity distribution region as wide as possible. The target and projectile sources are assumed to emit isotropically particles in their respective rest frames. The model calculations obtained with a Monte Carlo method are fitted to the experimental data over an energy range from 0.2 to 13 TeV. The values of the squared speed-of-sound parameter in different collisions are then extracted from the width of the rapidity distributions.