Dilepton production in nucleon-nucleon collisions reexamined

TL;DR

This paper develops a relativistic, gauge-invariant model for dilepton production in nucleon-nucleon collisions, comparing it with existing covariant and semiclassical models to understand differences in predicted cross sections.

Contribution

It introduces a fully relativistic, gauge-invariant framework based on meson-exchange for calculating dilepton production cross sections in nucleon-nucleon collisions.

Findings

Quantum and semiclassical models yield noticeably different cross sections.

The new model provides a consistent relativistic approach.

Comparisons highlight discrepancies among different modeling approaches.

Abstract

We present a fully relativistic and gauge invariant framework for calculating the cross sections of dilepton production in nucleon-nucleon ($NN$) collisions which is based on the meson-exchange approximation for the $NN$ scattering amplitudes. Predictions of our model are compared with those of other covariant models that have been used earlier to describe this reaction. Our results are also compared with those of the semiclassical models which are employed to get the input elementary cross sections in the transport model calculations of the dilepton production in nucleus-nucleus collisions. It is found that cross sections obtained within the semiclassical and quantum mechanical models differ noticeably from each other.