Most general neutron decay correlations: Standard Model recoil and radiative corrections

TL;DR

This paper provides a comprehensive Standard Model prediction for polarized free neutron decay, including recoil and radiative corrections, with practical tools for experimental analysis.

Contribution

It derives the full decay rate with all massive particles, incorporating recoil and radiative corrections, and introduces a new formalism compatible with realistic experiments.

Findings

Complete decay rate formula with recoil and radiative corrections.

Mathematica notebooks for evaluating corrections.

Enhanced compatibility with experimental setups.

Abstract

To continue from our previous work Phys.Rev.D 109(2024),073007, we derive the full Standard Model prediction of the most general free neutron differential decay rate with all massive particles (neutron, proton and electron) polarized, including the $\mathcal{O}(1/m_N)$ recoil corrections and $\mathcal{O}(\alpha/\pi)$ radiative corrections. For the latter we adopt the newly-developed pseudo-neutrino formalism which is compatible to realistic experimental setups, in which neutrinos and photons are not detected. We also provide readily-executable Mathematica notebooks to evaluate these corrections.