Abstract
The reactions have been studied at , and the invariant mass distributions measured down to the threshold. The yield near threshold is close to zero for and increases dramatically with increasing A (from 12 to 40 to 208). A phase analysis indicates that the pairs in this range of have . In the case of there is some strength near threshold regardless of A, and the pairs have . The experimental results indicate that nuclear matter strongly modifies the ππ interaction in the channel.
- Received 14 February 1996
DOI:https://doi.org/10.1103/PhysRevLett.77.603
©1996 American Physical Society