Phase diagram of SU(2) with 2 flavors of dynamical adjoint quarks

TL;DR

This study explores the phase diagram of SU(2) gauge theory with two adjoint quark flavors, revealing a line of first order transitions and light meson masses near the phase boundary, indicating potential near-conformal behavior.

Contribution

The paper provides a detailed numerical survey of the phase structure of SU(2) with adjoint quarks, highlighting the nature of phase transitions and meson mass behavior in this model.

Findings

Identified a line of first order phase transitions from beta=0 to beta≈2.0.

Observed light, approximately degenerate pion and rho masses near the phase boundary.

Discussions on the continuum limit implications of the phase structure.

Abstract

We report on numerical simulations of SU(2) lattice gauge theory with two flavors of light dynamical quarks in the adjoint of the gauge group. The dynamics of this theory is thought to be very different from QCD -- the theory exhibiting conformal or near conformal behavior in the infrared. We make a high resolution survey of the phase diagram of this model in the plane of the bare coupling and quark mass on lattices of size 8^3 \times 16. Our simulations reveal a line of first order phase transitions extending from beta=0 to beta=beta_c \sim 2.0. For beta > beta_c the phase boundary is no longer first order but continues as the locus of minimum meson mass. For beta > 2.0 we observe the pion and rho masses along the phase boundary to be light, independent of bare coupling and approximately degenerate. We discuss possible interpretations of these observations and corresponding continuum limits.