Abstract

We report a measurement of the differential cross section for the ?n?p-p process from the CLAS detector at Jefferson Laboratory in Hall B for photon energies between 1.0 and 3.5GeV and pion center-of-mass (c.m.) angles (?c.m.) between 50°and 115°. We confirm a previous indication of a broad enhancement around a c.m. energy (s) of 2.1GeV at ?c.m.=90°in the scaled differential cross section s7dsdt and a rapid falloff in a center-of-mass energy region of about 400MeV following the enhancement. Our data show an angular dependence of this enhancement as the suggested scaling region is approached for ?c.m. from 70°to 105°. © 2009 The American Physical Society.