Topological quantization of vector meson anomalous couplings

TL;DR

This paper uncovers a topological structure in the hidden-local-symmetry formulation of vector mesons, which could explain anomalous couplings and support their gauge nature, with experimental tests proposed.

Contribution

It identifies a Wess--Zumino--Witten structure in HLS vector mesons leading to topological quantization of anomalous couplings, a novel insight.

Findings

Topological quantization of vector-meson anomalous couplings.

Explanation of vector-meson dominance via topological-action saturation.

Potential experimental tests at BESIII and Super τ-Charm Facility.

Abstract

We identify an overlooked Wess--Zumino--Witten structure in the hidden-local-symmetry~(HLS) formulation of vector mesons. The newly identified term generically leads to the topological quantization of the vector-meson anomalous couplings. If confirmed experimentally, this structure would expose the gauge nature of vector mesons in the anomalous sector and single out HLS over matter-field descriptions. The observed success of vector-meson dominance in anomalous interactions can then be explained by topological-action saturation of the odd-intrinsic-parity processes. Precision measurements of $\eta^{(\prime)}\to\pi^+\pi^-\gamma^*$ form factors at BESIII and the Super $\tau$-Charm Facility can directly test this saturation picture.