The $p+p\to {\pi }^{+}+d$ reaction is studied at excess energies between 0.275 and 3.86 MeV. Differential and total cross section were measured employing a magnetic spectrometer with nearly $4\pi$ acceptance in the center of mass system. The measured anisotropies between 0.008 and 0.29 indicate that the p wave is not negligible even so close to threshold. The data are compared to other data offering no evidence for charge symmetry breaking or time reversal violation. The s-wave and p-wave contributions at threshold are deduced.

• Received 24 July 1995

DOI:https://doi.org/10.1103/PhysRevLett.77.454