Baryon masses from full QCD+QED${}_{\text{C}}$ simulations

Abstract

In these proceedings we present preliminary results for the masses of the proton, neutron and ${\Omega }^{-}$ baryons obtained from QCD+QED lattice simulations performed with four dynamical quarks using C${}^{\ast }$ boundary conditions. These results are part of the ongoing effort of the RC${}^{\ast }$ collaboration discussed in the companion proceedings, and have been obtained on a single ensemble in which the renormalised electromagnetic coupling is ${\alpha }_{\text{em}}\sim 0.04$, the physical volume is $L\sim 1.7$ fm and the masses of the four dynamical quarks have been tuned at the $U$--spin symmetric point $m_d=m_s$. We demonstrate on this unphysical ensemble that baryon masses can be calculated with satisfactory precision when including QED without the need for gauge--fixing and perturbation theory. This makes us confident in the effectiveness of the strategy presented here also in the case of simulations closer to the physical point.

Comments: 8 pages, 5 figures; for the 38th International Symposium on Lattice Field Theory (LATTICE2021), 26th-30th July 2021, Zoom/Gather@Massachusetts Institute of Technology