Coulomb and strong interactions in the final state of HBT correlations for L\'evy type source functions

TL;DR

This paper models two-pion correlations in high energy heavy ion collisions, incorporating Coulomb and strong interactions with Le9vy source functions, highlighting the importance of strong interactions for accurate experimental parameter extraction.

Contribution

It introduces a detailed calculation framework for two-pion HBT correlations with Le9vy sources, including Coulomb and strong final state interactions, extending beyond Gaussian assumptions.

Findings

Strong interactions significantly influence correlation shapes.

Le9vy source functions better fit experimental data.

Including strong interactions is crucial for accurate source parameter extraction.

Abstract

We present detailed calculations about the expected shape of two-pion Bose-Einstein (or HBT) correlations in high energy heavy ion collisions that include a realistic treatment of final state Coulomb interaction as well as strong interactions (dominated by s-wave scattering). We assume L\'evy type source functions, a generalization that goes beyond the Gaussian approximation. Various recent experimental results found the use of such source types necessary to properly describe the shape of the measured correlation functions. We find that strong final state interactions may play an important role in the shape of the two-pion correlation functions, especially if one considers source parameters beyond the Gaussian HBT radii. Precise experimental determination of these source parameters (such as L\'evy stability exponent, correlation strength, etc.) seems to require the inclusion of the treatment of strong interaction not just for heavier particles (e.g. protons, lambdas) but also in case of two-pion measurements.