On radiative corrections to inverse beta decay at low energies

TL;DR

This paper calculates precise electromagnetic radiative corrections to inverse beta decay at low energies using heavy baryon chiral perturbation theory, enhancing the accuracy of cross-section predictions for reactor antineutrino experiments.

Contribution

It provides the first comprehensive inclusion of QED, QCD, and electroweak effects in inverse beta decay radiative corrections with permille-level precision.

Findings

Most accurate cross-section predictions for inverse beta decay.

Complete error budget for radiative corrections.

Positron energy spectrum including radiative effects.

Abstract

We compute electromagnetic radiative corrections in the inverse beta decay, $\bar{\nu}_e + p \rightarrow e^+ + n$, at reactor antineutrino energies within the heavy baryon chiral perturbation theory, provide the most accurate cross-section predictions for this process, and present a complete error budget. For the first time, we consistently include quantum electrodynamics, chromodynamics, and electroweak contributions and present the positron energy spectrum accounting for radiative corrections. Our calculation also improves on previous evaluations by incorporating permille-level contributions. The results can be readily applied to normalize the reactor antineutrino flux, make precise measurements of neutrino oscillation parameters, and search for new physics at nuclear power plants.