Composite (Goldstone) Higgs Dynamics on the Lattice: Spectrum of SU(2) Gauge Theory with two Fundamental Fermions

TL;DR

This study investigates the meson spectrum of an SU(2) gauge theory with two fundamental fermions, providing insights relevant for composite Higgs models and predicting scalar states including a potential 125 GeV Higgs.

Contribution

First lattice calculation of meson spectrum in SU(2) gauge theory with two fundamental fermions, relevant for composite Higgs and Technicolor models.

Findings

Determined masses of lightest vector and axial vector mesons.

Obtained preliminary scalar meson mass results.

Set lower limits for vector meson masses for collider experiments.

Abstract

We study the meson spectrum of the SU(2) gauge theory with two Wilson fermions in the fundamental representation. The theory unifies both Technicolor and composite Goldstone Boson Higgs models of electroweak symmetry breaking. We have calculated the masses of the lightest spin one vector and axial vector mesons. In addition, we have also obtained preliminary results for the mass of the lightest scalar (singlet) meson state. The simulations have been done with multiple masses and two different lattice spacings for chiral and continuum extrapolations. The spin one meson masses set lower limits for accelerator experiments, whereas the scalar meson will mix with a pGB of the theory and produce two scalar states. The lighter of the states is the 125 GeV Higgs boson, and the heavier would be a new yet unobserved scalar state.