Sp(4) gauge theory on the lattice: towards SU(4)/Sp(4) composite Higgs (and beyond)

TL;DR

This paper explores the lattice properties of Sp(4) gauge theory with two flavors, aiming to inform composite Higgs models, by presenting initial results on glueball spectra, meson decay constants, and phase transitions using various computational strategies.

Contribution

It provides the first lattice results for Sp(4) glueball spectra and explores the mesonic spectrum and phase structure of the theory with dynamical fermions.

Findings

First lattice results for Sp(4) glueball spectrum

Evidence of a bulk phase transition with Wilson fermions

Initial setup for future mesonic spectrum studies

Abstract

The Sp(4) gauge theory with two Dirac fundamental flavours provides a candidate for the microscopic origin of composite-Higgs models based on the SU(4)/Sp(4) coset. We employ a combination of two different, complementary strategies for the numerical lattice calculations, based on the Hybrid Monte Carlo and on the Heat Bath algorithms. We perform pure Yang-Mills, quenched computations and exploratory studies with dynamical Wilson fermions. We present the first results in the literature for the spectrum of glueballs of the pure Sp(4) Yang-Mills theory, an EFT framework for the interpretation of the masses and decay constants of the lightest pion, vector and axial-vector mesons, and a preliminary calculation of the latter in the quenched approximation. We show the first numerical evidence of a bulk phase transition in the lattice theory with dynamical Wilson fermions, and perform the technical steps necessary to set up future investigations of the mesonic spectrum of the full theory.