Chiral disorder and QCD at finite chemical potential

We investigate the effects of a finite chemical potential FL in QCD viewed as a disordered medium. In the quenched approximation, A(4) = i mu induces a complex electric Aharonov-Bohm effect that causes the diagonal contribution to the quark return probability to vanish at mu = m(pi)/2 (half the pion mass). In two-color QCD, the weak-localization contribution to the quark return probability remains unaffected causing a mutation in the spectral statistics. In full QCD, the complex electric flux is screened and the light quarks are shown to diffuse asymmetrically with a substantial decrease in the conductivity along the 'spatial' directions. Mean-field arguments suggest that a d = 1 percolation transition may take place in the range 1.5 rho(o) < rho < 3 rho(o), where rho(o) is nuclear matter density. (C) 1998 Elsevier Science B.V. All rights reserved.