Ab initio calculation of the β -decay spectrum of He6

Abstract

Searches for new physics can be conducted by brute force or, like the perihelion shift of Mercury, looking for subtle but persistent discrepancies. This detailed paper carries out high-precision calculations of the $\ensuremath{\beta}$-decay spectrum of ${}^{6}$He, and estimates the experimental precision needed to reveal hints of charged-current interactions beyond the Standard Model and/or sterile neutrinos.