Neutron beta decay and the right-handed currenr problem

Abstract

The renormalization of the axial-vector coupling constant λ = g A / g V , extracted from the neutron lifetime ( λ τ ) and from the neutron beta decay asymmetry ( λ c ) is considered carefully In the standard model of the electroweak interaction λ τ should be equal to λ c . According to recent experimental data on neutron beta decay, λ τ and λ c seem to differ from each other. This fact is explained in the framework of the manifestly left-right symmetric model SU(2) L × SU(2) R × U(1). The possibility of the existence of the right-handed current in the neutron beta decay is pointed out. A joint analysis of neutron beta decay and muon decay is performed, the right-handed current parameters are estimated. The axial-vector constant renormalization ( λ N ) by right-handed currents is evaluated.