Vector mesons on the wall

Abstract

Abstract A domain-wall configuration of the η′ meson bounded by a string (called a pancake or a Hall droplet) is recently proposed to describe the baryons with spin N c /2. In order to understand its baryon number as well as the flavor quantum number, we argue that the vector mesons (the ρ and ω mesons) should play an essential role for the consistency of the whole picture. We determine the effective theory of large-N c QCD with N f massless fermions by taking into account a mixed anomaly involving the θ-periodicity and the global symmetry. The anomaly matching requires the presence of a dynamical domain wall on which a U N f − N c $$ \mathrm{U}{\left({N}_f\right)}_{-{N}_c} $$ Chern-Simons theory is supported. We consider the boundary conditions that should be imposed on the edge of the domain wall, and conclude that there should be a boundary term that couples the U N f − N c $$ \mathrm{U}{\left({N}_f\right)}_{-{N}_c} $$ gauge field to the vector mesons. We discuss the impact on physics of the chiral phase transition and the relation to the “duality” of QCD.

Keywords

• 1/N Expansion
• Anomalies in Field and String Theories
• Chiral Lagrangians
• Duality in Gauge Field Theories