Rotor Spectra and Berry Phases in the Chiral Limit of QCD on a Torus

Abstract

We consider the finite-volume spectra of QCD in the chiral limit of massless up and down quarks and massive strange quarks in the baryon number sectors $B=0$ and $B=1$ for different values of the isospin. Spontaneous symmetry breaking gives rise to rotor spectra, as the chiral order parameter precesses through the vacuum manifold. Baryons of different isospin influence the motion of the order parameter through non-trivial Berry phases and associated abstract monopole fields. Our investigation provides detailed insights into the dynamics of spontaneous chiral symmetry breaking in QCD on a torus. It also sheds new light on Berry phases in the context of quantum field theory. Interestingly, the Berry gauge field resulting from QCD solves a Yang-Mills-Chern-Simons equation of motion on the vacuum manifold $SU(2)=S^3$.

21 pages, 3 figures. Revised version: Slightly expanded introduction and conclusion, a few references added

References in corpus (6)

• Pion in a Box
• Non-Abelian Berry Phases and BPS Monopoles
• Rotor Spectra, Berry Phases, and Monopole Fields: from Antiferromagnets to QCD
• Low-Energy QCD in the Delta Regime
• The QCD rotator with a light quark mass
• Casimir squared correction to the standard rotator Hamiltonian for the O($n$) sigma-model in the delta-regime

Cited by in corpus (1)

• Broken Symmetry and Fractionalized Flux Strings in a Staggered U(1) Pure Gauge Theory