Bremsstrahlung photons from stopping in heavy-ion collisions

Understand

We examine the spectrum of bremsstrahlung photons that results from the stopping of the initial net charge distributions in ultrarelativistic nucleus-nucleus collisions at the CERN Large Hadron Collier (LHC).

• This effect has escaped detection so far since it becomes sizable only at very low transverse momentum and at sufficiently forward rapidity.
• We argue that it may be within reach of the next-generation LHC heavy-ion detector ALICE-3 that is currently under study, and we comment on the physics motivation for measuring it.