Nuclear ab initio calculations of 6He $\beta$-decay for beyond the Standard Model studies

TL;DR

This paper performs ab initio nuclear structure calculations of 6He beta decay to provide precise theoretical corrections crucial for detecting potential deviations from the Standard Model in upcoming experiments.

Contribution

It introduces a comprehensive first-principles calculation of nuclear corrections for 6He beta decay using the no-core shell model with chiral EFT potentials, including uncertainty analysis.

Findings

Nuclear corrections significantly affect beta decay predictions.

Calculations are within the sensitivity of future experiments.

Uncertainty analysis enhances the reliability of theoretical predictions.

Abstract

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 $^6$He 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.