Corrections to νe− νμ universality in neutral current interactions

Abstract

We examine the effects of higher-order corrections on the universality between ν μ and ν e in the Weinberg-Salam model. The leading correction to neutral current amplitudes is an apparent difference in the values of sin 2θ as measured by ν μ and ν e beams. The difference is 〈 sin 2θ〉 ν μ − 〈 sin 2θ〉 ν e = ( α 6π ) ln( m 2 μ m 2 e ) .