Contributions of s and p Waves in pparrow pnπ^+ near Threshold
Abstract
Analyzing powers for pparrow pnπ^+ were measured for the first time at η = 0.22, 0.42, and 0.50, enabling a decomposition of the first four contributing partial waves. Cross sections were measured at seven different beam energies; those that overlap a previous experiment(W. W. Daehnick phet al.), Phys. Rev. Lett. 74, 2913 (1995). Hardie phet al., Preprint submitted to Phys. Rev. C, (1996). agree with the earlier measurements. The preliminary analyzing powers are A_NO = -0.13± .02, -0.28± .02, and -0.29± .03 at the three respective energies. These A_NO's are significantly smaller than the equivalent values measured for pparrow dπ^+.(E. Korkmaz phet al.), Nucl. Phys. A535, 636 (1991). Pion s-wave channels dominate the reaction; the non-resonant p-wave channel contributes less than 1% of the cross section at these energies. The p-wave channel containing the Δ resonance contributes a fraction, 0.08± .01, of the cross section at η = 0.22, 0.25± .04 at η = 0.42, and 0.27± .04 at η = 0.50.
- Publication:
-
APS April Meeting Abstracts
- Pub Date:
- April 1997
- Bibcode:
- 1997APS..APR..B905F