Time and space dependence of the electromagnetic field in relativistic heavy-ion collisions

Exact analytical solution for the space-time evolution of electromagnetic field in electrically conducting nuclear matter produced in heavy-ion collisions is discussed. It is argued that the parameter that controls the strength of the matter effect on the field evolution is sigma gamma b, where sigma is electrical conductivity, gamma is the Lorentz boost-factor, and b is the characteristic transverse size of the matter. When this parameter is of the order 1 or larger, which is the case at the Relativistic Heavy Ion Collider and the Large Hadron Collider, the space-time dependence of the electromagnetic field completely differs from that in vacuum.