Glueball spectra in the presence of a magnetic field

Abstract

One of the interesting properties of QCD is the fact that the carriers of the strong force, gluons, are able to interact with themselves. This allows for the gluons to form bound states in the form of glueballs. To find out more about the properties of these glueballs, we study how their mass spectrum reacts to an external magnetic field in the case of strong interactions. For this, we use improved holographic QCD to construct a gravitational dual to pure Yang-Mills theory which is coupled to a constant external magnetic field. Surprisingly, we find that for increasing values of the magnetic field strength, the masses decrease. This is the opposite of effects known from Landau quantization, where a stronger external magnetic field heightens the mass spectra.