2023/04/19 by Tanmoy Bhattacharya, Bhattacharya, Tanmoy, Vincenzo Cirigliano +9
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2304.09929
openalex publication_date 2023/04/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present a lattice QCD study of the contribution of the isovector quark chromo-electric dipole moment (qcEDM) operator to the nucleon electric dipole moments (nEDM). The calculation was carried out on four 2+1+1-flavor of highly improved staggered quark (HISQ) ensembles using Wilson-clover quarks to construct correlation functions. This clover-on-HISQ formulation is not fully O(a) improved, and gives rise to additional systematics over and above those due to removing excited state contributions to getting ground-state matrix elements, and the final chiral and continuum extrapolations to get the physical result. We use the non-singlet axial Ward identity including corrections up to O(a) to show how to control the power-divergent mixing of the isovector qcEDM operator with the lower dimensional pseudoscalar operator. The residual corrections are observed to give rise to O(25%) violations in relations arising from the axial Ward identity. We devise three methods attempting to control the resulting uncertainty in the CP violating form factor; each of these, however, can have large O(a2) corrections. Preliminary results for the nEDM due to qcEDM are presented choosing the method giving the most uniform behavior.