Features of the Reactionπ+d→π+dπ+π−at 4.2 GeV/c

Prominent features of this reaction include $d^{*}$ production in the $d{\pi }^{+}$ system, ${\rho }^0$ production, and a low-mass enhancement ($A_1$) in the ${\rho }^0{\pi }^{+}$ system. A model for $\pi d$ scattering has been found to provide an adequate description of the properties of the $d^{*}$. A Reggeized pion-exchange model successfully predicts the properties of the ${\rho }^0{\pi }^{+}d$ final state, whether or not $d^{*}$ formation occurs.