Abstract
We have measured the ratios of normalized yields for the elastic scattering of charged pions from in the backward hemisphere. At we have completed the angular distribution measured earlier, adding six new data points in the angular range from to in the -nucleus center of mass. We also measured an excitation function with data points at 180, 220, and 256 MeV at the largest angle achievable with our detector—between and in the -nucleus center of mass. The data, taken as a whole, show an apparent role reversal of the two charge-symmetric ratios and in the backward hemisphere. For data we observe a strong dependence of the ratios on independent of or The superratio R data match very well with calculations based on the forward-hemisphere data that predict the value of the difference between the even-nucleon radii of Comparisons are also made with recent calculations incorporating different wave functions and double-scattering models.
- Received 22 April 2002
DOI:https://doi.org/10.1103/PhysRevC.66.054006
©2002 American Physical Society