Multi-particle quantum-statistical correlation functions in a Hubble-expanding hadron gas

TL;DR

This paper investigates how interactions with an expanding hadron gas can modify quantum-statistical correlation functions in high-energy physics, potentially affecting interpretations of space-time structures in heavy-ion collisions.

Contribution

It introduces an analytical and numerical study of how the hadron gas environment influences multi-particle Bose-Einstein correlations, highlighting a novel Aharonov-Bohm-like effect.

Findings

The effect becomes significant at high source densities.

Modifications can alter the interpretation of femtoscopic measurements.

The study provides a framework for including medium interactions in correlation analyses.

Abstract

Quantum-statistical correlation measurements in high-energy physics represent an important tool to obtain information about the space-time structure of the particle-emitting source. There are several final state effects which may modify the measured femtoscopic correlation functions. One of these may be the interaction of the investigated particles with the expanding hadron gas, consisting of the other final state particles. This may cause the trajectories - and hence the phases - of the quantum-correlated pairs to be modified compared to free streaming. The resulting effect and could be interpreted as an Aharonov-Bohm-like phenomenon, in the sense that the possible paths of a quantum-correlated pair represent a closed loop, with an internally present field caused by the hadron gas. In this paper, the possible role of the effect in heavy-ion experiments is presented with analytical calculations and a simple numerical model. The modification of the strength of multi-particle Bose-Einstein correlation functions is investigated, and the is found that in case of sufficiently large source density, this effect may play a non-negligible role.