Multi-representation dynamics of SU(4) composite Higgs models: chiral limit and spectral reconstructions

We present a lattice study of the SU(4) gauge theory with two Dirac fermions in the fundamental and two in the two-index antisymmetric representation, a model close to a theory of partial compositeness proposed by G. Ferretti. Focus of this work are the methodologies behind the computation of the spectrum and the extrapolation of the chiral point for a theory with matter in multiple representations. While being still technical, this study provides important steps towards a non-perturbative understanding of the spectrum of theories of partial compositeness, which present a richer dynamics compared to single-representation theories. The multi-representation features are studied first in perturbation theory, and then non-perturbatively by adopting a dual outlook on lattice data through a joint analysis of time-momentum correlation functions and smeared spectral densities.

Automated summary

We conducted a lattice study of the SU(4) gauge theory with two Dirac fermions in the fundamental and two in the two-index antisymmetric representation. Our work mainly focuses on the methods used to compute the spectrum and extrapolate the chiral point for theories with matter in multiple representations. This study is significant for gaining a non-perturbative understanding of the spectrum of theories of partial compositeness, which exhibit a more complex dynamics compared to single-representation theories. We analyze the multi-representation features using perturbation theory and a non-perturbative approach that involves a joint analysis of time-momentum correlation functions and smeared spectral densities.