Neutron spin rotation in \vec{n}-d scattering

TL;DR

This paper investigates neutron spin rotation caused by parity-violating interactions in neutron-deuteron scattering at zero energy, highlighting the dominance of pion exchange contributions and its potential to constrain weak interaction models.

Contribution

It provides the first detailed calculation of neutron spin rotation in n-d scattering incorporating modern strong and weak interaction potentials.

Findings

Long-range pion exchange dominates the PV contribution.

Measurement of this observable can constrain hadronic weak interaction models.

Results are consistent across different potential models.

Abstract

The neutron spin rotation induced by parity-violating (PV) components in the nucleon-nucleon potential is studied in \vec{n}-d scattering at zero energy. Results are obtained corresponding to the Argonne v_{18} two-nucleon and Urbana-IX three-nucleon strong-interaction potentials in combination with either the DDH or pionless EFT model for the weak-interaction potential. We find that this observable is dominated by the contribution of the long-range part of the PV potential associated with pion exchange. Thus its measurement could provide a further constraint, complementary to that coming from measurements of the photon asymmetry in \vec{n}-p radiative capture, on the strength of this component of the hadronic weak interaction.