The quark mass gap in a magnetic field

A magnetic field and the resulting Landau degeneracy enhance the infrared contributions to the quark mass gap. The gap does not grow arbitrarily, however, for models of asymptotic free interactions. For B -> infinity, the magnetic field decouples from the dimensionally reduced self-consistent equations, so that the gap behaves as similar to Lambda(QCD) (or less), instead of similar to root vertical bar eB vertical bar. On the other hand, the number of participants to the chiral condensate keeps increasing as similar to vertical bar eB vertical bar so that vertical bar <(psi) over bar psi >vertical bar similar to vertical bar eB vertical bar Lambda(QCD). After the mass gap stops developing, nothing tempers the growth of screening effects as B -> infinity. These features are utilized to interpret the reduction of critical temperatures for the chiral and deconfinement phase transitions at finite B, recently found on the lattice. The structures of mesons are analyzed and light mesons are identified. Applications for cold, dense quark matter are also briefly discussed. (C) 2013 Elsevier B.V. All rights reserved.