Search for nucleon resonances of mass up to 8.5 GeV

Abstract Missing mass spectra were obtained by measuring recoil protons from the reaction p+p→p+X in the Jacobian peak region. Data were taken during the acceleration ramp of the Fermilab machine using an internal hydrogen gas jet target. We observe the well known N ∗ (1688) and N ∗ (2190) resonances but no significant structures at higher mass.