G. Carlino et al., QUARK NUMBER FRACTIONALIZATION IN N=2 SUPERSYMMETRIC SU(2)XU(1)(NF) GAUGE-THEORIES, JOURNAL OF HIGH ENERGY PHYSICS, (4), 1998, pp. 62-74
Physical quark-number charges of dyons are determined, via a formula w
hich generalizes that of Witten for the electric charge, in N = 2 supe
rsymmetric theories with SU(2) x U(1)(Nf) gauge group. The quark numbe
rs of the massless monopole at a nondegenerate singularity of the spac
e of vacua turn out to vanish in all cases. A puzzle related to CP inv
ariant cases is solved. Generalization of our results to SU(N-c) x U(1
)(Nf) gauge theories is straightforward.