Rho and omega production in pi+p interactions at 15.7 GeV/c.

Abstract

We report the results of a study of \ensuremath{\rho} and \ensuremath{\omega} production in ${\ensuremath{\pi}}^{+}$p interactions at 15.7 GeV/c. The SLAC hybrid bubble-chamber facility was used to study reactions in which neutral particles are produced. Three tantalum plates inside the 40-in. bubble chamber and a large array of lead glass downstream of the chamber provided photon detection over a large solid angle. Final states with two neutral particles have been isolated with kinematic fits in which neutral pions were reconstructed in the plates and lead glass. Data from an earlier untriggered ${\ensuremath{\pi}}^{+}$p bubble-chamber experiment at 15 GeV/c were used to obtain samples of events in channels which did not trigger the hybrid system. Cross sections for \ensuremath{\rho} and \ensuremath{\omega} production are given for several exclusive final states. Relative \ensuremath{\rho} and \ensuremath{\omega} production rates are studied. The ratio of nondiffractive \ensuremath{\omega} to ${\ensuremath{\rho}}^{0}$ production is measured to be \ensuremath{\omega}/${\ensuremath{\rho}}^{0}$=0.44\ifmmode\pm\else\textpm\fi{}0.07. We estimate the inclusive \ensuremath{\omega} cross section to be 1.9\ifmmode\pm\else\textpm\fi{}0.3 mb. The results are compared to the Lund model of low-${p}_{T}$ hadronic reactions.