Numerical study of the gluon propagator and confinement scenario in the minimal Coulomb gauge

Abstract
We present numerical results in SU(2) lattice gauge theory for the space-space and time-time components of the gluon propagator at equal time in the minimal Coulomb gauge. It is found that the equal-time would-be physical 3-dimensionally transverse gluon propagator Dtr(k) vanishes at k=0 when extrapolated to infinite lattice volume, whereas the instantaneous color-Coulomb potential D44(k) is strongly enhanced at k=0. This has a natural interpretation in a confinement scenario in which the would-be physical gluons leave the physical spectrum while the long-range Coulomb force confines color. Gribov’s formula Dtr(k)=(|k|/2)[(k2)2+M4]1/2 provides an excellent fit to our data for the 3-dimensionally transverse equal-time gluon propagator Dtr(k) for relevant values of k.