Research Papers in Physics and Astronomy


Date of this Version



Published by American Physical Society. Phys. Rev. Lett. 84, 2094 (2000). Copyright © 2000 American Physical Society. Permission to use.


We have reconstructed the radiative decays χ b(1P) → Υ (1S) γ and χb(2P) → Υ (1S) γ in pp̅ collisions at √s = 1.8 TeV, and measured the fraction of Υ(1S) mesons that originate from these decays. For Υ(1S) mesons with pTY > 8.0 GeV/c, the fractions that come from χ b(1P) and χb(2P) decays are [27.1 ± 6.9(stat) ± 4.4(syst)]% and [10.5 ± 4.4(stat) ± 1.4(syst)]%, respectively. We have derived the fraction of directly produced Υ(1S) mesons to be [50.9 ± 8.2(stat) ± 9.0(syst)]%.

Included in

Physics Commons