Vertex operators for production of baryon resonances in nucleon-gamma collisions with preserving gauge invariance and analyticity

TL;DR

This paper constructs gauge-invariant and analytic vertex operators for baryon resonance production in nucleon-gamma collisions, accommodating arbitrary spin-parity states, and ensuring consistency with fundamental physical principles.

Contribution

It introduces a novel method to build vertex operators that satisfy gauge invariance and analyticity for any baryon spin-parity in photo- and electro-production processes.

Findings

Vertex operators obey gauge invariance and analyticity.

The approach applies to arbitrary baryon spin-parity states.

Ensures consistency with the generalized Siegert theorem.

Abstract

Vertex operators for photo- and electro-production of baryon states with arbitrary spin-parity, $ \gamma + N\to B(J^P)$, are constructed. The operators obey gauge invariance and analyticity constraints. Analyticity is realized as a requirement of the generalized Siegert theorem for vertex form factors.