Abstract
We report on the measurement of the cross section from down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section has an exponential slope of at 10.7 GeV average energy. The LHCb pentaquark candidates can be produced in the channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions and cross sections .
- Received 28 May 2019
- Revised 5 July 2019
DOI:https://doi.org/10.1103/PhysRevLett.123.072001
© 2019 American Physical Society