Photoproduction of straight phi(1020) mesons on the proton at large momentum transfer

Phys Rev Lett. 2000 Nov 27;85(22):4682-6. doi: 10.1103/PhysRevLett.85.4682.

Abstract

The cross section for straight phi meson photoproduction on the proton has been measured for the first time up to a four-momentum transfer -t = 4 GeV2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. At low four-momentum transfer, the differential cross section is well described by Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV2, the data support a model where the Pomeron is resolved into its simplest component, two gluons, which may couple to any quark in the proton and in the straight phi.