STUDY OF THE rho$sup 0$ MESON FORMED IN $pi$$sup -$+p$Yields$ $pi$$sup - $+$pi$$sup +$ + n BETWEEN 1.38 AND 3.00 GeV/c.

The final state of ${\ensuremath{\pi}}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}+{\ensuremath{\pi}}^{+}+n$ has been studied from data at laboratory pion momenta of 1.38, 1.71, 2.75, and 3.00 GeV/c. The ${\ensuremath{\rho}}^{0}$ resonance dominates the final state throughout the region. The ${\ensuremath{\rho}}^{0}$ production and decay angular distributions are compared with Gottfried and Jackson's one-pion-exchange model including absorption effects. The data are in better agreement with the model at the higher momenta, as expected. The $\ensuremath{\pi}\ensuremath{\pi}$ effective-mass distribution with ${\ensuremath{\Delta}}^{2}\ensuremath{\le}4{\ensuremath{\mu}}^{2}$ and $|{cos\ensuremath{\theta}}_{\ensuremath{\pi}\ensuremath{\pi}}|l0.3$ for the combined data peaks near 730 MeV with 255 events in the plot. The effective-mass distribution without kinematic restrictions gives a ${\ensuremath{\rho}}^{0}$ peak at 765 MeV with 6744 events.