Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction $\gamma p\to p\pi^0$ for photon energies between 0.85 and 2.50 GeV. The $\pi^0$ mesons are observed in their dominant neutral decay mode: $\pi^0\to\gamma\gamma$. For the first time, the differential cross sections cover the very forward region, $\theta_{ \rm c.m.}<60^\circ$. A partial-wave analysis of these data within the Bonn-Gatchina framework observes the high-mass resonances $G_{ 17}$(2190), $D_{ 13}$(2080), and $D_{ 15}$(2070).
Categories: nucl-ex hep-ex hep-ph