Parity violation in atoms: neutrino-mediated long range forces and finite nuclear size

TL;DR

This paper analyzes neutrino-mediated parity-violating interactions in atoms, accounting for nuclear size effects, and finds that these interactions have negligible impact on atomic parity violation measurements.

Contribution

It derives an effective neutrino-mediated potential considering nuclear form factors, clarifying its limited range and negligible effect on atomic parity violation.

Findings

The potential range matches the nuclear radius.

The correction to nuclear weak charge is tiny.

The potential changes sign within the atom.

Abstract

We consider neutral-current parity-violating interactions in an atom mediated by the exchange of a neutrino-antineutrino pair. We explicitly account for the nuclear finite size encoded in the nuclear form factor. Based on its general properties, we derive an effective neutrino-mediated potential and determine its properties at short and long distances. We demonstrate that, once the form factor properties are correctly accounted for, the range of such an effective potential corresponds to the nuclear radius, removing any sensitivity to shorter-distance contributions. This potential changes sign over the atom's volume, so that the correction to the effective nuclear weak charge induced by this interaction is tiny and does not alter the interpretation of atomic parity violation experiments.