Differential cross sections and analyzing powers for the $\overrightarrow{p}p\to d{\pi }^{+}$ reaction have been measured to within $T_{\pi }^{\mathrm{cm}}=85\mathrm{}\mathrm{keV}$ of threshold. The $S$-wave strength is extracted and found to be $\sim 13\%$ larger than that determined from recent measurements of $\mathrm{np}\to d{\pi }^0$. Both the analyzing power and the anisotropy in the angular distribution show the expected energy dependence and these data are used to obtain values for the two contributing $P$-wave amplitudes.

• Received 9 February 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.1012