Limiting properties in inclusive π+p reactions at 8 and 16 GeV/c with exotic and non-exotic particle combinations

Abstract The distributions in the Feynman variable x for the pions produced in the inclusive reactions (1) π + p → π − + anything and (2) π + p → π + + anything are compared at 8 and 16 GeV/c. The distributions are similar in first approximation, but second order differences are observed. In particular, at x ≈ 0 the distributionsfor π + overlap at the two energies for π − they are different, and at x ≈ −2 they are similar for π − but not for π + . Comparison of the lonigtudinal momentum spectra in the lab. (target) system gives results consistent with limiting fragmentation for reaction (1), but not for reaction (2). Since the combination (abc) is (π + pπ + ), exotic, for reaction (1) and (π + pπ − ), non exotic, for reaction (2), these results are consistent with the suggestion of Chan et al. that when (ab c ) is exotic, limiting fragmentation may set in already at moderate (accelerator) energies.