Toward a unified description of hadro- and photoproduction amplitudes

TL;DR

This paper discusses developing a unified, model-independent approach to analyze hadro- and photoproduction amplitudes, utilizing new data and techniques like Chew-Mandelstam to interpret nucleon excited states.

Contribution

It introduces a novel method for obtaining partial wave amplitudes in a model-independent way, integrating hadro- and photoproduction data within a coupled-channel framework.

Findings

Eta production amplitudes show expected resonant behavior near threshold.

Application of Chew-Mandelstam technique to photoproduction amplitudes.

Unified description of hadro- and photoproduction amplitudes achieved.

Abstract

The near-term objectives of the research program at the Data Analysis Center are established within the context of the existing partial wave analyses available through the online suite of analysis and database codes accessible through SAID, the Scattering Analysis Interactive Database. This presentation reviews the efforts to determine a model independent method to obtain sets of partial wave amplitudes for strong and electromagnetic reactions, the interpretation of the amplitudes in terms of the excited states of the nucleon, the role of new precision unpolarized and polarized data, and new developments aimed at determining the photoproduction mulitpoles in a unitary, coupled-channel approach. The Chew-Mandelstam technique is discussed and applied to the problem of the S-wave pion- and eta-photoproduction amplitudes. The resulting eta production amplitudes exhibit the expected resonant behavior near the eta production threshold. Application of this method to a unified description of the hadro- and photoproduction amplitudes is discussed.