Nuclear ab initio calculations of 6He β-decay for beyond the Standard Model studies

Precision measurements of beta-decay observables offer the possibility to search for deviations from the Standard Model. A possible discovery of such deviations requires accompanying first-principles calculations. Here we compute the nuclear structure corrections for the beta-decay of He-6 which is of central interest in several experimental efforts. We employ the impulse approximation together with wave functions calculated using the ab initio no-core shell model with potentials based on chiral effective field theory. We use these state-of-the-art calculations to give a novel and comprehensive analysis of theoretical uncertainties. We find that nuclear corrections, which we compute within the sensitivity of future experiments, create significant deviation from the naive Gamow-Teller predictions, making their accurate assessment essential in searches for physics beyond the Standard Model. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

Precision measurements of beta-decay observables provide a way to search for deviations from the Standard Model, which requires accompanying first-principles calculations. In this study, nuclear structure corrections for the beta-decay of He-6 are computed using the impulse approximation and wave functions calculated with the ab initio no-core shell model. The results present a novel and comprehensive analysis of theoretical uncertainties, showing that the computed nuclear corrections significantly deviate from the naive Gamow-Teller predictions within the sensitivity of future experiments, emphasizing the importance of accurate assessment in the search for physics beyond the Standard Model.