The dp → 3He π0 reaction at threshold

The reaction rate and deuteron tensor analysing power t20 for the dp → 3He π0 process at threshold are analysed within a two-body cluster model for the 3He nucleus. Providing D-state effects are included, the cross section can be well described by parameters deduced from pp → dπ+. The new polarisation data however suggest that the analogous production of spin-singlet n-p pairs is significantly smaller than the value found from quasifree pion capture experiments, in agreement with theoretical prejudices. (author)