Differential cross sections for photoproduction from protons have been measured at in the backward direction. A bump structure has been observed above GeV in the total energy. No such bump is observed in , and photoproductions. It is inferred that this unique structure in photoproduction is due to a baryon resonance with a large component that is strongly coupled to the channel.
DOI:https://doi.org/10.1103/PhysRevC.80.052201
©2009 American Physical Society
Spectrum of missing mass square for at and to , where is the scattering angle of mesons. The peaks are attributable to , , , , and meson photoproductions. The red curve is the fitting results. The pink, blue, green, and light-blue curves are for , , , and photoproductions determined by a fit to the data, respectively. The dashed curve is the distribution of the sum of them. The hatched histogram is for the meson.
Reuse & PermissionsDifferential cross sections for photoproduction plotted as a function of the total energy . The angular range is indicated. The solid circles are the present results. Statistical error is plotted as error bars, and the blue boxes show systematic uncertainties. The open triangles and open squares are the experimental data from CLAS [5] and CB-ELSA [6], respectively. The solid and dashed curves are the results of SAID [12] and ETA-MAID [13], respectively.
Reuse & PermissionsDifferential cross sections for , and photoproductions plotted as a function of the total energy at .
Reuse & Permissions
