  At low temperature and for finite spin scattering in a weakly disordered
metal, for a certain value, predicted from our theory, of the
material-dependent paramagnon interaction, the total conductivity becomes
highly sensitive to the orbital effects of a finite magnetic field. As a
consequence, positive giant magnetoresistance and giant corrections to the Hall
coefficient arise. We obtain very good agreement between this theory and recent
positive giant magnetoresistance experiments, while making specific
material-dependent predictions.
