``GLUELUMP'' SPECTRUM AND ADJOINT SOURCE POTENTIAL IN LATTICE QCD$_3$

Abstract

We calculate the potential between ``quarks'' which are in the adjoint representation of SU(2) color in the three-dimensional lattice theory. We work in the scaling region of the theory and at large quark separations $R$. We also calculate the masses $M_{Qg}$ of color-singlet bound states formed by coupling an adjoint quark to adjoint glue (``gluelumps''). Good scaling behavior is found for the masses of both magnetic (angular momentum $J=0$) and electric ($J=1$) gluelumps, and the magnetic gluelump is found to be the lowest-lying state. It is naively expected that the potential for adjoint quarks should saturate above a separation $R_{\rm scr}$ where it becomes energetically favorable to produce a pair of gluelumps. We obtain a good estimate of the naive screening distance $R_{\rm scr}$. However we find little evidence of saturation in the potential out to separations $R$ of about twice $R_{\rm scr}$.