Speaker
Description
We present an extensive study of Möbius domain wall fermions (MDWF) in four-dimensional $Sp(4)$ gauge theory with two dynamical fermions transforming in the fundamental representation. This is, to our knowledge, the first comprehensive application of MDWF to $Sp(4)$ lattice gauge theories, which are relevant to composite Higgs and dark matter models based on the $SU(4)/Sp(4)$ coset. The MDWF algorithm improves the realisation of the enhanced global symmetry at finite fifth-dimensional extent by applying a Möbius transformation to the Wilson kernel, reducing residual global symmetry breaking at fixed computational cost after suitable tuning. As preparation for large-scale spectroscopy, we scan the residual mass over the bare gauge coupling and the unphysical Möbius-kernel parameters. This identifies regions where the Hermitian Wilson-kernel spectrum lies safely above the mobility edge, limiting the impact of non-localised near-zero modes. Guided by this tuning strategy, future MDWF spectroscopy studies can improve on previous Wilson-fermion measurements and enable continuum-limit extrapolations with reduced lattice discretisation effects.