Experimental Test of Charge Independence inn+p→d+π0

The differential and total cross sections for the reaction $n+p\to d+{\pi }^0$ were measured for neutron kinetic energies between threshold (275 MeV) and 700 MeV. Results are presented based on 90 000 events. A comparison is made with existing data for $p+p\to d+{\pi }^{+}$ to test the prediction of charge independence, $d\sigma (np\to d{\pi }^0)=\frac{1}{2}d\sigma (pp\to d{\pi }^{+})$, at the same c.m. energy and angle. No evidence for a violation is seen. Limits of a few percent are placed on the real part of certain amplitudes for isospin-nonconserving transitions from a study of the symmetry of the angular distributions about ${\theta }^{*}=90\mathrm{}°$.