Photoproduction of the $\omega$ meson on the proton at large momentum transfer

TL;DR

This paper measures the differential cross section for omega meson photoproduction on protons at high momentum transfer, revealing a flat behavior at large -t that suggests quark interchange processes alongside gluon exchange.

Contribution

It provides new experimental data at high momentum transfer and introduces a model combining quark interchange with gluon exchange to explain the observed flat cross section.

Findings

Low -t region shows diffractive pattern from Pomeron and Reggeon exchange.

At large -t, the cross section becomes flat, indicating additional processes.

Quark interchange processes are needed to explain the data.

Abstract

The differential cross section, $d\sigma/dt$ for $\omega$ meson exclusive photoproduction on the proton above the resonance region ($2.6<W<2.9$ GeV) was measured up to a momentum transfer $-t = 5$ GeV$^2$ using the CLAS detector at Jefferson Laboratory. The $\omega$ channel was identified by detecting a proton and $\pi^+$ in the final state and using the missing mass technique. While the low momentum transfer region shows the typical diffractive pattern expected from Pomeron and Reggeon exchange, at large $-t$ the differential cross section has a flat behavior. This feature can be explained by introducing quark interchange processes in addition to the QCD-inspired two-gluon exchange.