# Experimental constraint on quark electric dipole moments

## TL;DR

This paper uses current and future measurements of nucleon EDMs and tensor charges to set and improve constraints on quark EDMs, providing insights into potential new sources of CP violation beyond the standard model.

## Contribution

It combines experimental data and theoretical analysis to establish current limits on quark EDMs and projects future improvements with upcoming experiments.

## Key findings

- Current limits on quark EDMs are approximately 1.2 x 10^{-24} e·cm.
- Future experiments could improve constraints by about three orders of magnitude.
- Enhanced sensitivity will better probe new physics models involving CP violation.

## Abstract

The electric dipole moments (EDMs) of nucleons are sensitive probes of additional $\cal CP$ violation sources beyond the standard model to account for the baryon number asymmetry of the universe. As a fundamental quantity of the nucleon structure, tensor charge is also a bridge that relates nucleon EDMs to quark EDMs. With a combination of nucleon EDM measurements and tensor charge extractions, we investigate the experimental constraint on quark EDMs, and its sensitivity to $\cal CP$ violation sources from new physics beyond the electroweak scale. We obtain the current limits on quark EDMs as $1.27\times10^{-24}\,e\cdot{\rm cm}$ for the up quark and $1.17\times10^{-24}\,e\cdot{\rm cm}$ for the down quark at the scale of $4\,\rm GeV^2$. We also study the impact of future nucleon EDM and tensor charge measurements, and show that upcoming new experiments will improve the constraint on quark EDMs by about three orders of magnitude leading to a much more sensitive probe of new physics models.