Electric dipole moment of light nuclei in chiral effective field theory

Alex Gnech,Sachin Shain,Michele Viviani,Jordy De Vries

doi:10.1051/epjconf/202225806007

Abstract

CP-violating interactions at quark level generate CP-violating nuclear interactions and currents, which could be revealed by looking at the presence of a permanent nuclear electric dipole moment. Within the framework of chiral effective field theory, we discuss the derivation of the CP-violating nuclear potential up to next-to-next-to leading order (N2LO) and the preliminary results for the charge operator up to next-to leading order (NLO). Moreover, we introduce some renormalization argument which indicates that we need to promote the short-distance operator to the leading order (LO) in order to reabsorb the divergences generated by the one pion exchange. Finally, we present some selected numerical results for the electric dipole moments of 2H, 3He and 3H discussing the systematic errors introduced by the truncation of the chiral expansion.

Highlights

The measurement of electric dipole moments (EDMs) of particles is the most promising observable for studying new sources of charge (C) and parity (P) violation [1, 2]
The ap detailed tables with all the coefficients for all the di↵erent cuto↵s can be found in Ref. [16]. In this proceeding we presented the calculation of the EDMs of nuclei within χEFT
We discussed the derivation of the CP-violating nuclear interaction with particular attention on the necessity of overcoming the Weinberg’s power counting by adding the CP-violating counterterm at leading order (LO) in order to reabsorb the divergences generated by the one-pion exchange (OPE) in the Schrödinger equation

Summary

Introduction

The measurement of electric dipole moments (EDMs) of particles is the most promising observable for studying new sources of charge (C) and parity (P) violation [1, 2]. From the χEFT Lagrangian is possible to derive the CP-violating nuclear interactions and currents, which, in combination with modern few-body ab-initio techniques, can be used to compute the EDM of light nuclei. It is important to note that the LECs have di↵erent chiral order based on the source of CP-violation [11, 12] In this sense only several independent measurements of di↵erent nuclear EDMs can permit to fix all the LECs and to distinguish between the various possible sources of CP-violation. We need to reconsider the chiral order at which some of the interactions appear

Basics on nuclear EDMs

CP-violating interaction and charge operator

Selected numerical results

Conclusions