Nucleon electromagnetic form factors using Nf=2+1+1 twisted mass fermion ensembles at the physical mass point

Abstract

We present results for the nucleon electromagnetic form factors using Nf=2+1+1 twisted mass lattice QCD with clover improvement and with quarks with masses tuned to their physical values. Our preliminary analysis includes three ensembles at similar physical volume and varying lattice spacing allowing us to take the continuum limit at the physical point. Both connected and disconnected contributions are evaluated, allowing us to take the isovector and isoscalar contributions as well as the individual proton and neutron form factors in the flavour isospin limit. For each ensemble we assess excited state effects using several sink-source time separations in the range 0.8 fm - 1.6 fm, exponentially increasing statistics with the separation.