Study ofΔ++(1236)+ Boson Production inπ+pInteractions at 18.5 GeV/c

The production of the ${\rho }^0$, $f^0$, $g^0$, ${\eta }^0$, and ${\omega }^0$ bosons in the pseudo-two-body final state with the ${\Delta }^{++}\mathrm{}\left(1236\right)\mathrm{}$ baryon is studied. The cross sections and their $t$ dependence are discussed. The $s$ dependence of ${\Delta }^{++}{\rho }^0$ and ${\Delta }^{++}{\omega }^0$ final states is fitted with the expression $\sigma =k{\left(\frac{p}{p_0}\right)}^{-n}$ and yields values of $n$ in the range 1.5-2.5. Using $\mathrm{SU}\left(3\right)\mathrm{}$ invariance, we determine the phase angle between ${\rho }^0$ and ${\omega }^0$ production as a function of incident momentum. The $t$ dependence for ${\rho }^0{\Delta }^{++}$ production shows that the Regge model of the conspiring pion is not correct. Correlations between the ${\Delta }^{++}$ and the ${\rho }^0$ decays are observed and are consistent with quarkmodel predictions.