We report the results of a search for the bottomonium ground state ηb(1S) in the photon energy spectrum with a sample of (109±1) million of Υ(3S) recorded at the Υ(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at Eγ=921.2-2.8+2.1(stat)±2.4(syst)MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition Υ(3S) →γηb(1S). This photon energy corresponds to an ηb(1S) mass of 9388.9-2.3+3.1(stat)±2.7(syst)MeV/c2. The hyperfine Υ(1S)- ηb(1S) mass splitting is 71.4-3.1+2.3(stat)±2.7(syst)MeV/c2. The branching fraction for this radiative Υ(3S) decay is estimated to be [4.8±0.5(stat)±1.2(syst)]×10-4.

Aubert, B., Bona, M., Karyotakis, Y., Lees, J., Poireau, V., Prencipe, E., et al. (2008). Observation of the bottomonium ground state in the decay Υ(3S)→γηb. PHYSICAL REVIEW LETTERS, 101(7) [10.1103/PhysRevLett.101.071801].

Observation of the bottomonium ground state in the decay Υ(3S)→γηb

Carpinelli M;
2008

Abstract

We report the results of a search for the bottomonium ground state ηb(1S) in the photon energy spectrum with a sample of (109±1) million of Υ(3S) recorded at the Υ(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at Eγ=921.2-2.8+2.1(stat)±2.4(syst)MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition Υ(3S) →γηb(1S). This photon energy corresponds to an ηb(1S) mass of 9388.9-2.3+3.1(stat)±2.7(syst)MeV/c2. The hyperfine Υ(1S)- ηb(1S) mass splitting is 71.4-3.1+2.3(stat)±2.7(syst)MeV/c2. The branching fraction for this radiative Υ(3S) decay is estimated to be [4.8±0.5(stat)±1.2(syst)]×10-4.
Articolo in rivista - Articolo scientifico
BABAR detector
English
2008
101
7
071801
none
Aubert, B., Bona, M., Karyotakis, Y., Lees, J., Poireau, V., Prencipe, E., et al. (2008). Observation of the bottomonium ground state in the decay Υ(3S)→γηb. PHYSICAL REVIEW LETTERS, 101(7) [10.1103/PhysRevLett.101.071801].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/389521
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