The scalar spectrum of many-flavour QCD

TL;DR

This paper investigates the scalar spectrum of many-flavour SU(3) gauge theories using lattice simulations, focusing on scalar glueballs and flavour-singlet mesons to understand their role in walking technicolor models.

Contribution

It introduces spectroscopic methods for scalar states and reports on the current status of the scalar spectrum in N_f=12 QCD from the LatKMI collaboration.

Findings

Development of methods to study scalar glueballs and singlet mesons.

Progress in understanding the scalar spectrum in N_f=12 QCD.

Insights into the role of scalar states in walking technicolor scenarios.

Abstract

The LatKMI collaboration is studying systematically the dynamical properties of N_f = 4,8,12,16 SU(3) gauge theories using lattice simulations with (HISQ) staggered fermions. Exploring the spectrum of many-flavour QCD, and its scaling near the chiral limit, is mandatory in order to establish if one of these models realises the Walking Technicolor scenario. Although lattice technologies to study the mesonic spectrum are well developed, scalar flavour-singlet states still require extra effort to be determined. In addition, gluonic observables usually require large-statistic simulations and powerful noise-reduction techniques. In the following, we present useful spectroscopic methods to investigate scalar glueballs and scalar flavour-singlet mesons, together with the current status of the scalar spectrum in N_f = 12 QCD from the LatKMI collaboration.