Neutral-pion photoproduction off protons in the energy range 0.3 GeV<E(gamma)<3 GeV

Phys Rev Lett. 2005 Jan 14;94(1):012003. doi: 10.1103/PhysRevLett.94.012003. Epub 2005 Jan 14.

Abstract

Single pi(0) photoproduction has been studied with the CB-ELSA experiment at Bonn using tagged photon energies between 0.3 and 3.0 GeV. The experimental setup covers a very large solid angle of approximately 98% of 4pi. Differential cross sections dsigma/dOmega have been measured. Complicated structures in the angular distributions indicate a variety of different resonances being produced in the s channel intermediate state gammap-->N(*)(Delta(*))-->ppi(0). A combined analysis including the data presented in this letter along with other data sets reveals contributions from known resonances and evidence for a new resonance N(2070)D15.