Electric dipole moments of three-nucleon systems in the pionless effective field theory

TL;DR

This paper calculates the electric dipole moments of three-nucleon systems using pionless effective field theory, considering both one-body and two-body CP-odd contributions, and explores their form factors and symmetries.

Contribution

It provides leading-order calculations of EDMs for triton and helium-3 in pionless EFT, including the Wigner-SU(4) symmetric limit and form factor analysis.

Findings

EDMs of triton and helium-3 calculated at leading order

Electric dipole form factor shares momentum dependence with charge form factor in Wigner limit

Results highlight the role of CP-odd interactions in three-nucleon systems

Abstract

We calculate the electric dipole moments (EDMs) of three-nucleon systems at leading order in pionless effective field theory. The one-body contributions that arise from permanent proton and neutron EDMs and the two-body contributions that arise from CP-odd nucleon-nucleon interactions are taken into account. Neglecting the Coulomb interaction, we consider the triton and ${}^3$He, and also investigate them in the Wigner-SU(4) symmetric limit. We also calculate the electric dipole form factor and find numerically that the momentum dependence of the electric dipole form factor in the Wigner limit is, up to an overall constant (and numerical accuracy), the same as the momentum dependence of the charge form factor.