Mapping the Electromagnetic Fields of Heavy-Ion Collisions with the Breit-Wheeler Process

Understand

Ultra-relativistic heavy-ion collisions are expected to produce the strongest electromagnetic fields in the known Universe.

• These highly-Lorentz contracted fields can manifest themselves as linearly polarized quasi-real photons that can interact via the Breit-Wheeler process to produce lepton anti-lepton pairs.
• The energy and momentum distribution of the produced dileptons carry information about the strength and spatial distribution of the colliding fields.
• Recently it has been demonstrated that photons from these fields can interact even in heavy-ion collisions with hadronic overlap, providing a purely electromagnetic probe of the produced medium.