Production of the Nucleon Isobars 1236, 1410, 1518, and 1688 MeV in Proton-Proton Collisions at 2.85, 4.55, 6.06, and 7.88 GeV/c

Momentum spectra of protons scattered inelastically in proton-proton collisions were obtained in an external beam at Nimrod using incident proton momenta of 2.85, 4.55, 6.06, and 7.88 GeV/c and various scattering angles in the range 22 to 144 mrad. There is evidence for the production of the 1410 MeV isobar at small angles. The well-known isobars of mass values 1236, 1518, and 1688 MeV are also seen. The differential cross sections are presented for the production of these isobars. They are analyzed in terms of the usual variables $s$ and $t$. Fits to the observed momentum spectra indicate for the $N^{*}\mathrm{}\left(1410\right)\mathrm{}$ a mass of 1410 ± 15 MeV and a width of 125 ± 20 MeV.