Electric Dipole Moment Results from lattice QCD

Abstract

We utilize the gradient flow to define and calculate electric dipole moments induced by the strong QCD $\theta$-term and the dimension-6 Weinberg operator. The gradient flow is a promising tool to simplify the renormalization pattern of local operators. The results of the nucleon electric dipole moments are calculated on PACS-CS gauge fields (available from the ILDG) using $N_f=2+1$, of discrete size $32^3\times 64$ and spacing $a\simeq 0.09$ fm. These gauge fields use a renormalization-group improved gauge action and a non-perturbatively $O(a)$ improved clover quark action at $\beta =1.90$, with $c_{SW}=1.715$. The calculation is performed at pion masses of $m_{\pi }\simeq 411,701$ MeV.

Comments: 8 pages, 13 figures, presented at the 35th International Symposium on Lattice Field Theory (Lattice 2017)