Sudden to adiabatic transition in β decay

Abstract

We discuss effects in beta decays at very low beta energies, of the order of the kinetic energies of atomic electrons. As the beta energy is lowered the atomic response changes from sudden to adiabatic. As a consequence, the beta decay rate increases slightly and the ejection of atomic electrons (shake off) and subsequent production of X rays is turned off. We estimate the transition energy, and the change in decay rate. The rate increase is largest in heavy atoms, which have a small Q value in their decay. The X ray switch-off is independent of Q value. P.A.C.S.:23.40.-s, 23.90.+w

Accurate CI and Hylleraas-CI wave functions for the atomic effects in the whole-atom-nuclear β−-decay of the Li atom

“…The weight of the atomic effects in nuclear β-decay has not been sufficiently investigated yet. Theoretical results estimate that the shape of the spectra, life-times and rates of decay in atoms are small but still observable [19]. Atomic effects were studied theoretically with the pioneering work of Feinberg [20], Migdal [21,22] and Levinger [23], and experimentally [24].…”