Workshop on Electromagnetic Effects in Strongly Interacting Matter

Electromagnetic probes, such as photon and dilepton emission, are invaluable tools for characterizing the properties of quark-gluon plasma produced in heavy-ion collisions. Not only can they tell the temperature of the plasma but also its magnetic field. I will review recent results for the photon and dilepton emission from a strongly magnetized quark-gluon plasma. In the leading order, the corresponding rates are determined by the absorptive part of the photon polarization tensor. I will discuss the energy and angular dependence of the corresponding differential rates. The theoretical predictions reveal that the photon and dilepton emissions can be highly anisotropic. The rates also depend nontrivially on the transverse momentum and the invariant mass. I will argue that the observed large ellipticity of the direct photon emission may indicate the presence of a strong magnetic field in heavy-ion collisions. I will also claim that the future measurements of the dilepton rate in the region of small invariant masses can reconfirm this claim and constrain the value of the magnetic field in the plasma.