Evaluation of beta-decay Part V. The Z-independent outer radiative corrections for allowed decay

Abstract

Before interpreting nuclear beta-decay in terms of nucleonic wave functions and weak coupling constants allowance must be made for the influence of virtual photon exchange and real photon emission together with Z-boson exchange—the radiative corrections. This paper discusses in detail the lowest order ‘outer’ radiative correction of Sirlin, energy-dependent but weak-interaction-mechanism-independent, and presents graphical and other material to enable its accurate evaluation for allowed decay for all beta-decay transition energies up to 20 MeV and for 0 ≤ | Z| ≤ 100. The need to use electron spectra due to a nuclear charge distribution of finite spatial extension with appropriate convolution of the leptonic and nucleonic wave functions throughout the nuclear volume is emphasized; the variation of these effects between the neutron and proton drip lines is explored. Exponentiation and higher-order Z-independent effects are also considered.