Bremsstrahlung from relativistic heavy ions in a fixed target experiment at the LHC

摘要

We calculate the emission of bremsstrahlung from lead and argon ions in AFixed Target ExpeRiment (AFTER) that uses the LHC beams. With nuclear chargesof $Ze$ equal $208$ and $18$ respectively, these ions are accelerated toenergies of $7$ TeV$\times Z $. The bremsstrahlung peaks around $\approx 100$GeV and the spectrum exposes the nuclear structure of the incoming ion. Thepeak structure is significantly different from the flat power spectrumpertaining to a point charge. Photons are predominantly emitted within an angleof $1/\gamma$ to the direction of ion propagation. Our calculations are basedon the Weizs\"{a}cker-Williams method of virtual quanta with application ofexisting experimental data on photonuclear interactions.