Abstract
Differential cross sections and photon-beam asymmetries have been measured for the and reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of at . The cross section ratio of , expected to be 2 on the basis of the isospin exchange, is found to be close to 1. For the reaction, large positive asymmetries are observed, indicating the dominance of exchange. The large difference between the asymmetries for the and reactions cannot be explained by simple theoretical considerations based on Regge model calculations.
- Received 6 February 2006
DOI:https://doi.org/10.1103/PhysRevLett.97.082003
©2006 American Physical Society