Title

Measurement of the eta_b(1S) mass and the Branching Fraction for Upsilon(3S) --> gamma eta_b(1S)

Author(s)/Creator(s)

Raymond Mountain, Syracuse UniversityFollow
Marina Artuso, Syracuse UniversityFollow
S. Blusk, Syracuse UniversityFollow
Sadia Khalil, Syracuse University

Document Type

Article

Date

6-28-2011

Language

English

Disciplines

Physics

Description/Abstract

We report evidence for the ground state of bottomonium, eta_b(1S), in the radiative decay Upsilon(3S) --> gamma eta_b in e^+e^- annihilation data taken with the CLEO III detector. Using 6 million Upsilon(3S) decays, and assuming Gamma(eta_b) = 10 MeV/c^2, we obtain B(Upsilon(3S) --> gamma eta_b) = (7.1 +- 1.8 +- 1.1) X 10^{-4}, where the first error is statistical and the second is systematic. The statistical significance is about 4 sigma. The mass is determined to be M(eta_b) = 9391.8 +- 6.6 +- 2.0 MeV/c^2, which corresponds to the hyperfine splitting Delta M_{hf}(1S)_b = 68.5 +- 6.6 +- 2.0 MeV/c^2. Using 9 million Upsilon(2S) decays, we place an upper limit on the corresponding Y(2S) decay, B(Y(2S) --> gamma eta_b) < 8.4 X 10^{-4} at 90 % confidence level.

Additional Information

10 pages, 3 figures, accepted by Phyical Review D Rapid Communications More information at http://arxiv.org/abs/0909.5474

Listed authors are from Syracuse University; 89 additional authors not listed.

Recommended Citation

Mountain, Raymond; Artuso, Marina; Blusk, S.; and Khalil, Sadia, "Measurement of the eta_b(1S) mass and the Branching Fraction for Upsilon(3S) --> gamma eta_b(1S)" (2011). Physics - All Scholarship. 393.
https://surface.syr.edu/phy/393

Source

Harvested from Arxiv.org

Creative Commons License

This work is licensed under a Creative Commons Attribution 3.0 License.