Towards a determination of the nucleon EDM from the quark chromo-EDM operator with the gradient flow

Abstract

In this proceedings, we lay the foundation for computing the contribution of quark chromo-electric dipole moment (qCEDM) operator to the nucleon electric dipole moment. By applying the gradient flow technique, we can parameterize the renormalization and operator mixing issues associated with the qCEDM operator on the lattice. As the nucleon mixing angle ${\alpha }_N$ is a key component for determining the neutron and proton electric dipole moments induced by the qCEDM operator, we present the formalism and preliminary results for ${\alpha }_N$ with respect to the gradient flow time $t_f$. The results are computed on $N_f=2+1$ Wilson-clover lattices provided by PACS-CS. The 3 ensembles have lattice spacing values of $a=\{0.1095,0.0936,0.0684\}$fm, whilst keeping a similar $m_{\pi }\approx 701$MeV, and a fixed box size of $L\approx 1.9$fm.

Comments: 7 pages, 9 figures, presented at the 36th International Symposium on Lattice Field Theory (Lattice 2018)