Linear Sigma EFT for Nearly Conformal Gauge Theories

Understand

We construct a generalized linear sigma model as an effective field theory (EFT) to describe nearly conformal gauge theories at low energies.

• The work is motivated by recent lattice studies of gauge theories near the conformal window, which have shown that the lightest flavor-singlet scalar state in the spectrum ($\sigma$) can be much lighter than the vector state ($\rho$) and nearly degenerate with the PNGBs ($\pi$) over a large range of quark masses.
• The EFT incorporates this feature.
• We highlight the crucial role played by the terms in the potential that explicitly break chiral symmetry.