Chi/sub b/ states in exclusive radiative decay of the UPSILON(2S)

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.34.2611· OSTI ID:6983099

Walk, W; Zschorsch, P; Antreasyan, D; Aschman, D; Besset, D; Bienlein, J K; Bloom, E D; Brock, I; Cabenda, R; Cartacci, A

The Crystal Ball detector at the DESY storage ring DORIS II has been used to study radiative decays of the UPSILON(2S) resonance. We report on the analysis of the exclusive channel UPSILON(2S)..--> gamma..chi/sub b/, chi/sub b/..--> gamma..UPSILON(1S)..-->..e/sup +/e/sup -/ or ..mu../sup +/..mu../sup -/. We detect two chi/sub b/ states by observing two monochromatic photon lines at energies (107.0 +- 1.1 +- 1.3) MeV and (131.7 +- 0.9 +- 1.3) MeV, respectively. The product branching ratios B(UPSILON(2S)..--> gamma..chi/sub b/) x B(chi/sub b/..--> gamma..UPSILON(1S) ) are (1.6 +- 0.3 +- 0.2)% for the first state and (2.1 +- 0.3 +- 0.3)% for the second. For the product branching ratio of the third chi/sub b/ state, which has been observed in inclusive measurements, we find an upper limit of 0.2% (90% C.L.). Combining our results with inclusive measurements, branching ratios for chi/sub b/..--> gamma..UPSILON(1S) are derived. Using theoretical estimates for the radiative widths of the chi/sub b/ states, we determine their hadronic widths; the results are compared with QCD predictions.

• Research Organization: California Institute of Technology, Pasadena, California 91125
• OSTI ID: 6983099
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 34:9; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Electromagnetic Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BRANCHING RATIO
DORIS STORAGE RING
ELECTRONS
ELEMENTARY PARTICLES
EXCLUSIVE INTERACTIONS
FERMIONS
FIELD THEORIES
INTERACTIONS
LEPTONS
MASS DIFFERENCE
MASSLESS PARTICLES
MUONS
PAIR PRODUCTION
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PHOTONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKONIUM
RADIATIVE DECAY
STORAGE RINGS
UPSILON-10000 RESONANCES
UPSILON-9500 RESONANCES