The Influence of High Multiplicities at RHIC on the Gamov Factor

Abstract

The corrections for two-pion correlations due to electromagnetic final-state interactions at high secondary multiplicities are investigated. The analysis is performed by solving the Schrödinger equation with a potential which is dictated by the multi-particle environment. Two different post-freeze-out scenarios are examined. First, for a uniformly spread environment of secondary particles, a screened Coulomb potential is exploited. It is shown that the presence of a static and uniform post-freeze-out medium results in a noticeable deviation from the standard Gamov factor. However, after going to a more realistic model of an expanding pion system, this conclusion changes drastically. We argue that the density of the secondary pions n_π(t,R), where R is a distance from the fireball, is bounded from above by n_π(t,R)\le const/R^2 for all times t. Then, a two-particle scalar potential which is found as a solution of the Maxwell equation for non-uniform medium replaces the screened one. Even this upper limit does not result in an essential deviation from the Gamov correction.