Abstract
The study of photoproduction at low energies has consequences for the understanding of multiple aspects of nonperturbative QCD, ranging from mechanical properties of the proton to the binding inside nuclei and the existence of hidden-charm pentaquarks. Factorization of the photon- and nucleon dynamics or vector meson dominance are often invoked to justify these studies. Alternatively, open-charm intermediate states have been proposed as the dominant mechanism underlying photoproduction. As the latter violates this factorization, it is important to estimate the relevance of such contributions. We analyze the latest differential and integrated photoproduction cross sections from the GlueX and experiments. We show that the data can be adequately described by a small number of partial waves, which we parametrize with generic models enforcing low-energy unitarity. The results suggest a non-negligible contribution from open-charm intermediate states. Furthermore, most of the models present an elastic scattering length incompatible with previous extractions based on vector meson dominance and thus call into question its applicability to heavy mesons. Our results indicate a wide array of physics possibilities that are compatible with present data and need to be disentangled.
- Received 10 May 2023
- Accepted 14 August 2023
DOI:https://doi.org/10.1103/PhysRevD.108.054018
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society
