Collisional energy loss and the chiral magnetic effect

Collisional energy loss of a fast particle in a medium is mostly due to the medium polarization by the electromagnetic fields of the particle. A small fraction of energy is carried away by the Cherenkov radiation. In chiral medium there is an additional contribution to the energy loss due to induction of the anomalous current proportional to the magnetic field. It causes the particle to lose energy mostly in the form of the chiral Cherenkov radiation. We employ classical electrodynamics, adequate in a wide range of particle energies, to compute the collisional energy loss by a fast particle in a homogenous chiral plasma and apply the results to quark-gluon plasma and a Weyl semimetal. In the latter case photon spectrum is strongly enhanced in the ultraviolet and x-ray regions which makes it amenable to experimental investigation. Our main observation is that while the collisional energy loss in a nonchiral medium is a slow, at most logarithmic, function of energy epsilon, the chiral Cherenkov radiation is proportional to epsilon(2) when the recoil is neglected and to e when it is taken into account.

Automated summary

The study investigates the collisional energy loss of fast particles in chiral medium, revealing that the energy loss of chiral Cherenkov radiation is proportional to the square of the particle energy, and the impact of recoil on the particle is dependent on the energy.