Energy dependence of the tensor polarisation t₂₀in π⁺-d elastic scattering

The tensor polarisation t20 of the recoil deuterons from pi + -d elastic scattering has been measured between Tpi =110 and 150 MeV. An excitation curve of t20 shows a clear peak near the mass 2.14 GeV with a structure 20 MeV wide. The angular distributions at 117, 134 and 151 MeV confirm the rapidly changing behaviour with energy. A phase-shift analysis of all pi + -d scattering data in this energy range has been performed. The strong energy and angular dependence are believed to manifest evidence for non-conventional dynamics.