Lattice studies of chimera baryons in Sp(4) gauge theory

TL;DR

This paper investigates the spectrum of chimera baryons in an Sp(4) gauge theory using lattice calculations, providing insights relevant for composite Higgs models and top quark mass generation.

Contribution

It presents the first non-perturbative lattice study of chimera baryons in Sp(4) gauge theory, including quenched and dynamical fermion results.

Findings

Numerical spectrum results in the continuum and massless limits.

Spectral density analysis for dynamical fermions.

Implications for composite Higgs models and top quark partners.

Abstract

We study chimera baryons, fermion bound states composed of two (hyper)quarks transforming in the fundamental and one in the antisymmetric representation of a non-Abelian gauge group. While in QCD they coincide with ordinary baryons, in composite Higgs models (CHMs) with top partial compositeness, spin-1/2 chimera baryons serve as partners of the top quark and are responsible for its large mass. We perform non-perturbative lattice calculations of the low-lying spectrum of the chimera baryons, in a specific realization of CHMs based on a Sp(4) gauge theory. In the quenched approximation, we present the numerical results in the continuum and massless limits. Then, for dynamical fermions, we measure the spectrum and matrix elements by employing a newly developed spectral density analysis for several choices of the lattice parameters.