Influence of the nuclear autocorrelation function on the positron production in heavy-ion collisions

Abstract

The influence of a nuclear reaction on atomic positron production in heavy-ion collisions is investigated. Using statistical concepts, we describe the nuclear $S$ matrix for a heavy-ion induced reaction as a statistically fluctuating function of energy. The positron production rate is then dependent on the autocorrelation function of this $S$ matrix, and on the ratio of the "direct" versus the "fluctuating" part of the nuclear cross section. Numerical calculations show that in this way, current experimental results on positron production in heavy-ion collisions can be reproduced in a semiquantitative fashion.