Initial and final state temperatures of antiproton emission sources in high energy collisions

TL;DR

This paper analyzes antiproton spectra in various high-energy collisions to extract initial and final state temperatures, revealing that these temperatures and flow velocities increase with energy and collision centrality, indicating greater excitation and expansion.

Contribution

It introduces a comprehensive analysis of antiproton spectra across multiple collision systems and energies using several models to extract temperature and flow parameters, highlighting their dependence on energy and centrality.

Findings

Temperatures and flow velocities increase with collision energy.

Higher excitation and expansion in central, high-energy collisions.

Consistent trends across different collision systems.

Abstract

The momentum or transverse momentum spectra of antiprotons produced at mid-rapidity in proton-helium ($p$+He), gold-gold (Au+Au), deuton-gold ($d$+Au), and lead-lead (Pb+Pb) collisions over an energy range from a few GeV to a few TeV are analyzed by the Erlang distribution, the inverse power-law (the Hagedorn function), and the blast-wave fit, or the superposition of two-component step function. The excitation functions of parameters such as the mean transverse momentum, initial state temperature, kinetic freeze-out temperature, and transverse flow velocity increase (slightly) from a few GeV to a few TeV and from peripheral to central collisions. At high energy and in central collisions, large collision energy is deposited in the system, which results in high degrees of excitation and expansion.