Υ dipion transitions at energies near the Υ(4S)
Abstract
Using a 4.19 fb-1 data sample collected with the CLEO II detector at the Cornell Electron Storage Ring, we have searched for dipion transitions between pairs of Υ resonances at center of mass energies Ec.m.=10.58 GeV and Ec.m.=10.52GeV. We obtain the 90% confidence level upper limits B(Υ(4S)-->Υ(2S)π+π-)<3.9×10-4 and B(Υ(4S)-->Υ(1S)π+π-)<1.2×10-4. We also observe the transitions Υ(3S)-->Υ(1S)π+π-, Υ(3S)-->Υ(2S)π+π-, and Υ(2S)-->Υ(1S)π+π-, from which we measure the cross sections for the radiative processes e+e--->Υ(3S)γ and e+e--->Υ(2S)γ. We obtain σee-->Υ(3S)γ=(17.8+/-3.0+/-1.7) pb and σee-->Υ(2S)γ=(15.5+/-1.3+/-1.4) pb at Ec.m.=10.58 GeV, and σee-->Υ(3S)γ=(27.3+/-5.0+/-2.6) pb and σee-->Υ(2S)γ=(16.3+/-1.8+/-1.5) pb at Ec.m.=10.52 GeV, which we compare with theoretical predictions.
- Publication:
-
Physical Review D
- Pub Date:
- March 1999
- DOI:
- 10.1103/PhysRevD.59.052003
- arXiv:
- arXiv:hep-ex/9808008
- Bibcode:
- 1999PhRvD..59e2003G
- Keywords:
-
- 13.25.Gv;
- 13.65.+i;
- Decays of J/psi Upsilon and other quarkonia;
- High Energy Physics - Experiment
- E-Print:
- 17 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLNS