Off-diagonal gluon mass generation and infrared Abelian dominance in the maximally Abelian gauge in lattice QCD

We study effective mass generation of off-diagonal gluons and infrared Abelian dominance in the maximally Abelian (MA) gauge. Using SU(2) lattice QCD, we investigate the propagator and the effective mass of the gluon field in the MA gauge with U(1)(3) Landau gauge fixing. The Monte Carlo simulation is performed on the 12(3) X 24 lattice with 2.2 less than or equal to beta less than or equal to 2.4, and also on the 16(4) and 20(4) lattices with 2.3 less than or equal to beta less than or equal to 2.4. In the MA gauge, the diagonal gluon component A(u)(3) shows long-range propagation, and infrared Abelian dominance is found for the gluon propagator. In the MA gauge, the off-diagonal gluon component A(mu)(+/-) behaves as a massive vector boson with the effective mass M-off similar or equal to 1.2 GeV in the region of r greater than or similar to 0.2 fm, and its propagation is limited within a short range. We conjecture that infrared Abelian dominance can be interpreted as infrared inactivity of the off-diagonal gluon due to its large mass generation induced by the MA gauge fixing. [S0556-2821(99)05223-6].