Energy dependence of space-time extent of pion source in nuclear collisions

TL;DR

This study investigates how the space-time characteristics of pion emission in nuclear collisions vary with energy, proposing a scaled femtoscopic radius approach that aligns well with experimental data across a wide energy range.

Contribution

The paper introduces a scaled femtoscopic radius method for analyzing pion emission regions, enabling consistent comparison across different ion collision types and energies.

Findings

No sharp changes in femtoscopic parameters with increasing energy.

Analytic functions effectively approximate energy dependence of femtoscopic parameters.

Estimates provided for LHC and FCC energy regimes.

Abstract

Energy dependence of space-time parameters of pion emission region at freeze-out is studied for collisions of various ions and for all experimentally available energies. The using of femtoscopic radii scaled on the averaged radius of colliding ions is suggested. This approach allows the expansion of the set of interaction types, in particular, on collisions of non-symmetrical ion beams which can be studied within the framework of common treatment. There is no sharp changing of femtoscopic parameter values with increasing of initial energy. Analytic functions suggested for smooth approximations of energy dependence of femtoscopic parameters demonstrate reasonable agreement with most of experimental data at $\sqrt{s_{NN}} \geq 5$ GeV. Estimations of some observables are obtained for energies of the LHC and FCC project.