# The Contribution of Novel CP Violating Operators to the nEDM using Lattice QCD

## TL;DR

This paper discusses calculating matrix elements of novel CP-violating operators using lattice QCD to better constrain physics beyond the Standard Model through neutron EDM measurements.

## Contribution

It introduces a lattice QCD strategy, including the Schr"odinger source method, to compute matrix elements of quark EDM and chromo EDM operators relevant for neutron EDM constraints.

## Key findings

- Initial lattice results show promising signal quality for connected contributions.
- The Schr"odinger source method effectively reduces computational complexity.
- Ongoing work aims to improve signal and renormalization understanding.

## Abstract

In this talk, we motivate the calculation of the matrix elements of novel CP violating operators, the quark EDM and the quark chromo EDM operators, within the nucleon state using lattice QCD. These matrix elements, combined with the bound on the neutron EDM, would provide stringent constraints on beyond the standard model physics, especially as the next generation of neutron EDM experiments reduce the current bound. We then present our lattice strategy for the calculation of these matrix elements, in particular we describe the use of the Schr\"odinger source method to reduce the calculation of the 4-point to 3-point functions needed to evaluate the quark chromo EDM contribution. We end with a status report on the quality of the signal obtained in the lattice calculations of the connected contributions to the quark chromo EDM operator and the pseudoscalar operator it mixes with under renormalization.