Analysis of the reaction γ+n→p+π− in the first and second resonance regions

Helicity amplitudes for photoexcitation of nucleon resonances off neutrons

“…In bubble chambers all outgoing charged particles are detected [43,44] and the events are kinematically fully reconstructed. No correction for Fermi motion is hence required.…”

“…[45], red open squares are from [46], green open triangles are from [47], blue filled circles are from [48], pink filled squares are from [49], black filled triangles are from [50], red filled stars are from [51], green open stars are from [52], blue open diamonds are from [53]. [60], red open squares are from [61], green open triangles are from [62], blue filled circles are from [63], pink filled squares are from [64], black filled triangles are from [65], red filled stars are from [43], green open stars are from [44], blue open diamonds are from [66].…”

“…The data on γd → pπ − (p) are fitted simultaneously with data on the inverse reaction π − p → nγ [60,61,62,63,64,65,66,67,68] (and data from bubble chambers [43,44]) which are free from Fermi corrections. The total cross sections for these two reactions -linked by time reversal invariance -are shown in Fig.…”

Measurement of inverse pion photoproduction at energies spanning theN(1440)resonance

“…For details, see Section V. Figure 6 also displays our comparison of the predictions from the SAID PWA [8] and the MAID [13] analyses of existing data. In both analyses, large disagreements with some older bremsstrahlung measurements [28,29] are obvious, particularly at lower energies. Also plotted is the best-fit (SH04), based on a SAID analysis incorporating the current set of measurements.…”

“…The MAID solutions [13] are plotted with dashed lines. Previous measurements [28,29,30] are shown as open circles. neutron and proton target data.…”