Speaker:

Andreas Athenodorou

Speaker affiliation:

University of Cyprus

Date:

Friday, March 18, 2016 - 13:00

Room:

Seminar Room

Title:

The Neutron Electric Dipole Moment on the Lattice

Abstract:

We evaluate the neutron electric dipole moment (nEDM) on the Lattice using configurations produced with $N_f=2+1+1$ twisted mass fermions at lattice spacing of a=0.082fm and a light quark mass that corresponds to $M_{\pi}=370 MeV$. We do so by extracting the CP-odd form factor $F_3$ at the limit of zero momentum transfer. This limit is taken using a parametrization of the momentum dependence by a dipole fit as well as using the position space methods of “Application of the derivative to the ratio technique” and “elimination of the momentum in the plateau region technique”. The evaluation of F_3 requires the calculation of the topological charge. We measure the topological charge via cooling and the gradient flow using the Wilson, Symanzik tree-level improved and Iwasaki actions for smoothing. We obtain consistent results for all choices of smoothing actions, smoothing procedures and momentum dependence treating techniques. We report an nEDM in units of the $\theta$ vacuum angle of |d_n|/ \theta = −0.045(6)(1) e·fm.