First results on nucleon resonance photocouplings from the γp → π+π-p reaction

Abstract We report the first experimental measurements of the nine 1-fold differential cross sections for the γ p → π + π − p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV W Δ ( 1620 ) 1 / 2 − , Δ ( 1700 ) 3 / 2 − , N ( 1720 ) 3 / 2 + , and Δ ( 1905 ) 5 / 2 + resonances, which have dominant decays into the ππN final states rather than the more extensively studied single meson decay channels.