The Standard Model theory of neutron beta decay

TL;DR

This paper reviews the Standard Model theoretical framework for neutron beta decay, emphasizing recent electroweak radiative corrections, discrepancies among approaches, and the potential for high-precision tests of new physics.

Contribution

It provides a comprehensive review of radiative corrections in neutron beta decay, compares different methods, and offers recommended values for improved theoretical accuracy.

Findings

High-precision calculations at the level of 10^{-4}

Identification of discrepancies in radiative correction approaches

Neutron beta decay as a tool for new physics searches

Abstract

We review the status of the Standard Model theory of neutron beta decay. Particular emphasis is put on the recent developments in the electroweak radiative corrections. Given that some existing approaches give slightly different results, we thoroughly review the origin of discrepancies, and provide our recommended value for the radiative correction to the neutron and nuclear decay rates. The use of dispersion relation, lattice Quantum Chromodynamics and effective field theory framework allows for high-precision theory calculations at the level of $10^{-4}$, turning neutron beta decay into a powerful tool to search for new physics, complementary to high-energy collider experiments. We offer an outlook to the future improvements.