Meson spectrum of Sp(4) lattice gauge theory with two fundamental Dirac fermions

TL;DR

This study computes the meson spectrum of the Sp(4) lattice gauge theory with two fundamental Dirac fermions, providing insights into its potential as a UV completion for composite Higgs models and analyzing its strongly coupled dynamics.

Contribution

It presents the first detailed calculation of the meson spectrum for Sp(4) gauge theory with two fundamental flavors, including continuum extrapolations and effective field theory fits.

Findings

Meson masses and decay constants obtained across multiple lattice couplings.

Continuum extrapolated results consistent with low-energy effective theories.

Comparison with related lattice theories highlights unique features of Sp(4) dynamics.

Abstract

We calculate the meson spectrum of the Sp(4) lattice gauge theory coupled to two fundamental flavours of dynamical Dirac fermions. We focus on some of the lightest (flavoured) spin-0 and spin-1 states. This theory provides an ultraviolet completion for composite Higgs models based upon the SU(4)/Sp(4) coset. We analyse the strongly coupled dynamics in isolation, without explicit coupling to the standard model. We carry out continuum extrapolations using dynamical ensembles generated at five different values of bare lattice coupling, and for several values of the bare fermion mass. We fit the resulting meson masses and decay constants to a low-energy effective field theory built along the ideas of hidden local symmetry. We also compare our results to those of other closely related lattice gauge theories, which have matter content consisting of two fundamental Dirac flavours.