The expressions for dynamical masses of quarks in the chiral limit in QCD in a strong magnetic field are obtained. A low energy effective action for the corresponding Nambu-Goldstone bosons is derived and the values of their decay constants as well as the velocities are calculated. The existence of a threshold value of the ' number of colors Ncthr, dividing the theories with essentially different dynamics, is established. For the number of colors Nc≪Ncthr, an anisotropic dynamics of confinement with the confinement scale much less than AΛQCD and a rich spectrum of light glueballs is realized. For Nc of order Ncthr or larger, a conventional confinement dynamics takes place. It is found that the threshold value Ncthr grows rapidly with the magnetic field [Ncthr≳ 100 for |eB|≳(1 Gev)2]. In contrast with QCD with a nonzero baryon density, there are no principal obstacles for examining these results and predictions in lattice computer simulations.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)