The reaction π + p → ϱ 0 Δ ++ (1236) at 16 GeV/ c has been studied. Cross section, differential cross section, single and joint spin-density matrix elements are given. Correlations between the ϱ 0 and Δ ++ (1236) decay distributions are observed. Unnatural spin-parity exchanges, mainly observed at small t ' values, dominate the ϱ 0 Δ ++ (1236) production. The natural exchange contributions are only (7 ± 2)% and become as important as the unnatural exchanges beyond t ' = 0.3 GeV 2 . Contributions to Δ ++ (1236) helicity 3 2 states do not exceed 20% of the total ϱ 0 Δ ++ (1236) cross section and are mainly due to unnatural exchanges.
'SLICE METHOD' USED TO HANDLE RESONANCE TAILS AND BACKGROUND.
FROM EVENTS WITHIN MASS-CUTS FOR RESONANCES AND NORMALIZED TO TOTAL CROSS SECTION.
'B'.
Cross sections, differential cross sections, density matrix elements and statistical tensors are given for the reactions π + p → ( ϱ 0 , ω ) Δ ++ at 13.2 GeV/ c . A discussion of the results in terms of particle exchanges, quark model or dipole coupling constraints, and the equal phase hypothesis is presented in some detail for the high statistics ϱ 0 Δ ++ channel.
BREIT-WIGNER FITS WHICH CORRECT FOR RESONANCE TAILS AND BACKGROUNDS.
No description provided.
JACKSON FRAME DENSITY MATRIX ELEMENTS.
Forum