Evidence for a N * (1450) in pp collisions at 10 GeV/c

Recently, pion-nucleon phase-shift analyses (x,2) have demonstrated the complexity of the scheme of nucleon isobars for masses between 1400 and 1700MeV/c 2. Moreover, invariant-mass distributions from counter and bubble chamber experiments have shown significant peaks in this mass region (3) (see ref. (4-il) for observation of a peak in the (1400.'---1500) MeV/c 2 mass region), and thus shown the need for more detailed inves-