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
B. Aubert et al. (BABAR Collaboration)
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].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/389521
Citazioni
  • Scopus 219
  • ???jsp.display-item.citation.isi??? 157
Social impact