Isospin correlations in high-energy heavy-ion collisions

TL;DR

This paper investigates the potential for large isospin fluctuations in high-energy heavy-ion collisions, emphasizing the role of direct pion production without isovector pairs in generating such fluctuations.

Contribution

It introduces a semiclassical model for pion production and analyzes isospin fluctuations, highlighting the significance of direct pion production over paired production.

Findings

Large isospin fluctuations occur only with direct pion production.

The model quantifies pion correlations and their dependence on production mechanisms.

Direct production without isovector pairs enhances isospin fluctuation effects.

Abstract

We study the posibility of large isospin fluctuations in high-energy heavy-ion collisions by assuming that pions are produced semiclassically both directly and in pairs through the isovector channel. The leading-particle effect and the factorization property of the scattering amplitude in the impact parameter space are used to define the classical pion field. In terms of the joint probability function $P_{II_{3}}(n_{0},n_{\_})$ for producing $n_{0}$ neutral and $n_{\_}$ negative pions from a definite isospin state $II_{3}$ of the incoming leading-particle system we calculate the two pion correlation parameters $f_{2,n_{\_}}^{0}$ and the average number of neutral pions $(< n_{0} >_{n_{\_}})$ as a function of negative pions $(n_{\_})$ produced. We show that only direct production of pions without isovector pairs leads to large isospin fluctuations.