pp → dπ+ precise angular distributions close to threshold from 0.3 to 5 MeV

For the first time the reaction pp→ dπ+ was measured close to threshold. A magnetic spectrometer (3Q2DQ) which allows ray tracing was applied to detect the recoiling deuterons and reconstruct their momenta. The measured anisotropies are between 0.008 and 0.29, indicating the importance of p-wave amplitudes even close to threshold. The presented data support the validity of isospin and time reversal symmetries.