Imaging the Space-Time Evolution of High Energy Nucleus-Nucleus Collisions with Bremsstrahlung

TL;DR

This paper explores how bremsstrahlung photons emitted during high-energy nucleus collisions can reveal the space-time evolution of electric charge, comparing different theoretical models to interpret experimental data.

Contribution

It introduces a method to use bremsstrahlung photon measurements to distinguish between different models of nuclear collision dynamics.

Findings

Bremsstrahlung photons below 200 MeV can reveal charge evolution.

Different models produce similar final charge distributions but differ in photon emission.

Separation of bremsstrahlung photons from other sources is crucial for analysis.

Abstract

The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Bremsstrahlung photons with energies below 100 to 200 MeV are sufficient to discern the gross features of the space-time evolution of electric charge, if they can be separated from other sources of photons experimentally. This is illustrated explicitly by considering two very different models, one Bjorken-like, the other Landau-like, both of which are constructed to give the same final charge rapidity distribution.