Investigations on the tensor analyzing power t_(20) in the reaction d + p → ~3He + η

摘要

The reaction dp → ~3He η has been investigated at the COSY-ANKE experiment with both an unpolarised and a vector/tensor polarised deuteron beam in an excess energy range of Q = 0 MeV up to Q = 10 MeV. The determination of the tensor analysing power ~t20 along with the unpolarised cross section allows for the investigation of the s-wave production amplitudes near threshold. The weak energy dependence of t_(20) supports a strong final state interaction of the η~3 He system which might lead to a quasi-bound η-mesic state. Furthermore, the angular dependence of the t_(20) might reveal further insight into the production amplitude.