Deuteron Magnetic Quadrupole Moment From Chiral Effective Field Theory

TL;DR

This paper calculates the deuteron magnetic quadrupole moment using chiral effective field theory, linking it to fundamental CP-violating sources and highlighting its potential for probing new physics beyond the Standard Model.

Contribution

It provides a systematic leading-order calculation of the deuteron MQM within chiral EFT, connecting it to underlying CP-violating operators and low-energy constants.

Findings

Deuteron MQM expressed in terms of five low-energy constants.

MQM shows enhanced sensitivity to the QCD vacuum angle.

Measurement of MQM offers complementary insights to light-nuclear EDMs.

Abstract

We calculate the magnetic quadrupole moment (MQM) of the deuteron at leading order in the systematic expansion provided by chiral effective field theory. We take into account parity and time-reversal violation which, at the quark-gluon level, results from the QCD vacuum angle and dimension-six operators that originate from physics beyond the Standard Model. We show that the deuteron MQM can be expressed in terms of five low-energy constants that appear in the parity- and time-reversal-violating nuclear potential and electromagnetic current, four of which also contribute to the electric dipole moments of light nuclei. We conclude that the deuteron MQM has an enhanced sensitivity to the QCD vacuum angle and that its measurement would be complementary to the proposed measurements of light-nuclear EDMs.