TENSOR ANALYZING POWER T-20 FOR CUMULATIVE PION-PRODUCTION FROM DEUTERONS IN THE GEV ENERGY REGION

The tensor analyzing power T-20 for the reaction d up arrow + C-12 --> pi(+/-)(0 degrees) + X has been measured with a polarized deuteron be am from 6.2 to 9.0 GeV/c at a pion momentum of 3.0 GeV/c. This experim ent is focused on ''cumulatively produced pions'', which are produced beyond the kinematically allowed limit for free nucleon-nucleon collis ions. The measured values of T-20 rum out to be close to zero. They ar e in disagreement with the results of our impulse approximation calcul ation which is based on a single NN --> pi NN interaction and takes in to account the internal motion of nucleons in the deuteron, Possible e xplanations of the result are discussed. (C) 1997 Elsevier Science B.V .