UC Irvine

Using a sample of 3.8 M ψ(2S) events accumulated with the BES detector, the process ψ(2S) →π+π-J/ψ is studied. The angular distributions are compared with the general decay amplitude analysis of Cahn. We find that the dipion system requires some D wave amplitude, as well as S wave. On the other hand, the J/ψ-(π+π-) relative angular momentum is consistent with being pure S wave. The decay distributions have been fit to heavy quarkonium models, including the Novikov-Shifman model. This model, which is written in terms of the parameter κ, predicts that D wave pions should be present. We determine κ=0.183 ±0.002±0.003 based on the joint mππ-cos θπ* distribution. The fraction of D wave amplitude as a function of mππ is found to decrease with increasing mππ, in agreement with the model. We have also fit the Mannel-Yan model, which is another model that allows D wave pions. ©2000 The American Physical Society.