Production ofN*(1236)andY1*(1382)in Nucleon-Antinucleon Collisions

Abstract

The absorption model has been applied to the production of $N^{*}\mathrm{}\left(1238\right)\mathrm{}$ and ${Y_1}^{*}\mathrm{}\left(1382\right)\mathrm{}$, both singly and in pairs, in $\overline{p}N$ collisions. The shapes of the differential cross sections and the decay distributions are in agreement with exchange of a pseudoscalar meson, but the predicted magnitudes of the differential cross sections are generally too large. This discrepancy decreases with increasing energy. A combination of vector and pseudoscalar exchange improves the prediction for the magnitude of $\frac{d\sigma }{\mathrm{dt}}$ (over a restricted range in momentum transfer) but is unable to fit the observed decay distributions, and therefore seems to be excluded. Analysis of the reactions involving strange particles is hampered by insufficient data, but a comparison of the predicted and observed $\frac{\overline{\Sigma }{Y_1}^{*}}{\overline{\Lambda }{Y_1}^{*}}$ ratio again indicates pseudoscalar exchange with $D+\frac{2}{3}F$ coupling. Some suggestions are made to explain the improved agreement between theory and experiment at the higher energies.