Rho meson decay width in SU(2) gauge theories with 2 fundamental flavours

TL;DR

This paper presents the first calculation of the rho-meson decay width in SU(2) gauge theories with two fundamental flavors, relevant for composite electroweak models, using lattice simulations.

Contribution

It introduces a novel lattice calculation of the rho-meson decay width in an SU(2) gauge theory with two flavors, extending methods from QCD to beyond Standard Model physics.

Findings

Preliminary decay width results obtained in a moving frame.

Use of two ensembles for initial calculations.

Plans to improve accuracy with more frames and ensembles.

Abstract

SU(2) gauge theories with two quark flavours in the fundamental representation are among the most promising theories of composite dynamics describing the electroweak sector. Three out of five Goldstone bosons in these models become the longitudinal components of the W and Z bosons giving them mass. Like in QCD, we expect a spectrum of excitations which appear as resonances in vector boson scattering, in particular the vector resonance corresponding to the rho-meson in QCD. In this talk I will present the preliminary results of the first calculation of the rho-meson decay width in this theory, which is analogous to rho to two pions decay calculation in QCD. The results presented were calculated in a moving frame with total momentum (0,0,1) on two ensembles. Future plans include using 3 moving frames on a larger set of ensembles to extract the resonance parameters more reliably and also take the chiral and continuum limits.