P- versus S-wave overlinepp- annihilation at rest in LH 2
Abstract
The annihilation overlinepp→π 0π 0 was measured for antiprotons stopped in liquid hydrogen (LH 2). This reaction is only allowed from odd angular momentum states of the overlinepp- atom. The resulting branching ratio BR( overlinepp→π 0π 0) LH2=(6.93±0.22 stat±0.37 syst)×10 -4, combined with a previous measurement of the branching ratio BR( overlinepp→π +π -) 2 P in gas from the 2P-state of overlinepp suggests a fraction of P-wave annihilation in LH 2 of (28.8±3.5)%, much larger than the values obtained from other annihilation channels. A method of reconciling the contradictory results is discussed.
- Publication:
-
Physics Letters B
- Pub Date:
- December 1992
- DOI:
- 10.1016/0370-2693(92)91095-Q
- Bibcode:
- 1992PhLB..297..214A