Measurement of vector-tensor spin-transfer observables for the reaction H(p,d)π+ between 580 and 1300 MeV Original Research Article

The three polarization tensor components of the deuteron produced in the View the MathML source reaction have been measured for the first time. The experiment was performed using a vertically polarized proton beam produced by the SATURNE accelerator. The deuteron polarization was measured with the POLDER polarimeter. The three polarizing powers t2000, t2100 and t2200 and the three spin-transfer observables t2011, t2211 and t2211 have been extracted at a proton kinetic energy of 580 MeV over a wide angular range and at two fixed center-of-mass angles, 132° and 151°, between 800 and 1300 MeV. The six observables, calculated in the C.M. helicity frame, have been compared with predictions of the most refined partial-wave analyses and also with the predictions of a theoretical coupled-channel model which includes the NN-NΔ transition. The comparison between the data and the theory/partial-wave analyses shows some discrepancies which get worse with increasing proton energy. Adding these data to the world database should improve significantly future partial-wave analyses. The Ay0 analyzing power has also been measured over the same kinematical range. The partial-wave analysis predictions are in good agreement with this observable.