On Continuum-State and Bound-State Beta Decay Rates of the Neutron

TL;DR

This paper analyzes neutron beta decay rates, incorporating recent axial coupling data, radiative corrections, and weak couplings, to predict decay behaviors and guide experimental measurements of bound-state decays into hyperfine states.

Contribution

It provides a detailed theoretical analysis of continuum and bound-state neutron beta decay rates considering new axial coupling values and weak interactions, aiding experimental investigations.

Findings

Neutron predominantly decays into hydrogen with F=0 hyperfine state.

Calculated decay rates depend on axial, scalar, and tensor weak couplings.

Predicted angular distributions can assist experimental measurements.

Abstract

We analyse the continuum-state and bound-state beta^-decay rates of the neutron. For the calculation of theoretical values of the decay rates we use the new value for the axial coupling constant g_A = 1.2750(9), obtained recently by H. Abele (Progr. Part. Nucl. Phys., 60, 1 (2008)) from the fit of the experimental data on the neutron spin-electron correlation coefficient of the electron energy spectrum of the continuum-state beta^- decay of the neutron. We take into account the contribution of radiative corrections and the scalar and tensor weak couplings. We define correlation coefficients of the electron energy spectrum in terms of axial, scalar and tensor coupling constants. Using recent precise experimental data for the lifetime of the neutron and correlation coefficients we estimate the scalar and tensor weak coupling constants. The bound-state beta^- decay rates of the neutron we calculate as functions of axial, scalar and tensor weak coupling constants. We show that dominantly the neutron decays into hydrogen in the hyperfine states with total angular momentum F = 0. The calculated angular distributions of the probabilities of the bound-state beta^- decays of the polarised neutron can be used for the experimental measurements of the bound-state beta^- decays into the hyperfine states with a total angular momentum F = 1.