Measurement of the decay ϒ‧→ ϒπ+π-
Abstract
We report the first observation of the decay ϒ‧→ϒπ +π -→ l+l-π +π -. The 7 events seen yield a branching ratio B( ϒ‧→ ϒπ+π-)=(19±8)%. A consistent value of B=(26±13)% is obtained from the charged multiplicities of the ϒ‧ and ϒ decays. Using these values we deduce Γtot( ϒ‧)=(31 +10-8) keV and Bee( ϒ‧)=(1.8±0.5)%. Furthermore we estimate Γ( ϒ‧→gg ϒ)=(10±5) keV in agreement with QCD predictions using vector gluons while one would expect 100 keV with scalar gluons.
- Publication:
-
Physics Letters B
- Pub Date:
- March 1981
- DOI:
- 10.1016/0370-2693(81)90295-1
- Bibcode:
- 1981PhLB..100...95N