Geometry and space-time extent of pion emission region at FCC energies

TL;DR

This paper investigates how the space-time characteristics of pion emission regions depend on energy in high-energy collisions, providing estimations for FCC energies and exploring potential lasing behavior of secondary pions.

Contribution

It introduces smooth approximation functions for energy dependence of emission parameters and applies them to FCC energy estimations, including space-time quantities and particle densities.

Findings

Reasonable agreement of approximations with experimental data above 5 GeV

Estimations of space-time quantities at FCC energies

Potential for lasing behavior of secondary pions at FCC energies

Abstract

The energy dependence is investigated for a wide set of space-time characteristics derived from Bose - Einstein correlations of secondary pion pairs produced in proton-proton and nucleus-nucleus interactions. Analytic functions suggested for smooth approximations of the energy dependence of emission region parameters demonstrate reasonable agreement with all available experimental results for proton-proton collisions while the approximations correspond to most of experimental data for nucleus-nucleus collisions at energies above 5 GeV. Estimations for a wide set of space-time quantities are obtained for energies for the Future Circular Collider (FCC) project based on the smooth approximations. The space particle densities at freeze-out are derived also from estimations for the volume of the emission region and for total multiplicity at FCC energies. Estimations for charged particle density and its critical value allow the possibility of lasing behavior for secondary pions in nucleus-nucleus collisions at FCC energy. The mathematical formalism is presented for study of the peak shape of correlation function for general case of central-symmetrical Levy - Feldheim distribution.