Measurement of the {eta}{sub b}(1S) mass and the branching fraction for {Upsilon}(3S){yields}{gamma}{eta}{sub b}(1S)

Journal Article · Mon Feb 01 04:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.031104· OSTI ID:21409138

Bonvicini, G; Cinabro, D; Lincoln, A; Smith, M J; Zhou, P; Zhu, J ^[1]; Naik, P; Rademacker, J ^[2]; Asner, D M; Edwards, K W; Reed, J; Robichaud, A N; Tatishvili, G; White, E J ^[3]; Briere, R A; Vogel, H ^[4]; Onyisi, P U. E.; Rosner, J L ^[5]; Alexander, J P; Cassel, D G ^[6]

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1. Wayne State University, Detroit, Michigan 48202 (United States)
2. University of Bristol, Bristol BS8 1TL (United Kingdom)
3. Carleton University, Ottawa, Ontario, Canada K1S 5B6 (Canada)
4. Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
5. University of Chicago, Chicago, Illinois 60637 (United States)
6. Cornell University, Ithaca, New York 14853 (United States)

We report evidence for the ground state of bottomonium, {eta}{sub b}(1S), in the radiative decay {Upsilon}(3S){yields}{gamma}{eta}{sub b} in e{sup +}e{sup -} annihilation data taken with the CLEO III detector. Using 6x10{sup 6} {Upsilon}(3S) decays, and assuming {Gamma}({eta}{sub b})=10{+-}5 MeV/c{sup 2}, we obtain B({Upsilon}(3S){yields}{gamma}{eta}{sub b})=(7.1{+-}1.8{+-}1.3)x10{sup -4}, where the first error is statistical and the second is systematic. The statistical significance is {approx}4{sigma}. The mass is determined to be M({eta}{sub b})=9391.8{+-}6.6{+-}2.0 MeV/c{sup 2}, which corresponds to the hyperfine splitting {Delta}M{sub hf}(1S){sub b}=68.5{+-}6.6{+-}2.0 MeV/c{sup 2}. Using 9x10{sup 6} {Upsilon}(2S) decays, we place an upper limit on the corresponding {Upsilon}(2S) decay, B({Upsilon}(2S){yields}{gamma}{eta}{sub b})<8.4x10{sup -4} at 90% confidence level.

• OSTI ID: 21409138
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 3 Vol. 81; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BOSONS
BOTTOMONIUM
BRANCHING RATIO
CESR STORAGE RING
DECAY
DIMENSIONLESS NUMBERS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
GROUND STATES
HADRONS
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
MASS
MEASURING INSTRUMENTS
MESONS
MEV RANGE
MULTIPARTICLE SPECTROMETERS
PARTICLE DECAY
PARTICLE IDENTIFICATION
PARTICLE INTERACTIONS
QUARKONIUM
RADIATIVE DECAY
SPECTROMETERS
STORAGE RINGS