Magnetic Monopoles, Chiral Symmetries, and the NuTeV Anomaly

Abstract

The long-sought "magnetic monopole" appears to be -- not a fermion distinct from the electrons and quarks -- but a charge carried by the known electrons and the quarks themselves. Similarly to the "Z" charge of electroweak theory, however, this magnetic monopole charge only manifests its interactions at sufficiently-high energy, and its interactions may not respect chiral symmetry. Calculated cross-section enhancements from magnetic monopole interactions at s=M_z^2 reduce the observed weak mixing angle for e e-bar --> mu mu-bar decays by about delta sin^2 theta_W = -.0030 relative to v v-bar --> mu mu-bar decays, and so may help account for the NuTeV anomaly. Similar, though less-pronounced reductions are calculated for e e-bar --> q q-bar.