Progress on $Sp(4)$ lattice theories with Grid: Möbius domain wall fermions and continuum extrapolations

Abstract

We present preliminary results obtained in the first extensive study of the Möbius domain wall fermion (MDWF) lattice formulation of the four-dimensional Sp(4) gauge theory coupled to two dynamical fermions transforming in the fundamental representation. This theory is important for extensions of the Standard Model, as it provides the microscopic origin for both composite Higgs and dark matter models based on the SU(4)/Sp(4) coset. We scan the space of bare lattice parameters, including those entering the MDWF, and monitor spurious effects, such as the residual mass. We identify optimised regions of parameter space in which lattice artefacts affecting the global symmetries of the theory are suppressed. We then perform preliminary measurements of the lightest pseudoscalar and vector meson masses, together with the pseudoscalar decay constant. We demonstrate the potential of the MDWF formulation to enable continuum-limit extrapolations with reduced lattice discretisation effects.