Improved measurements of two-photon widths of the states and helicity analysis for
Based on 448.1 x 106 ψ(3686) events collected with the BESIII detector, the decays ψ(3686) → γχcJ,χcJ → γγ(J = 0,1,2) are studied in this paper. The decay branching fractions of χc0,2 → γγ are measured to be β(χc0 → γγ) = (1.93 ± 0.08 ± 0.05 ± 0.05) x 10-4 and β(χc2 → γγ) = (3.10 ± 0.09 ± 0.07 ± 0.11) x 10-4, which correspond to two-photon decay widths of Γγγ(χc0) = 2.03 ± 0.08 ± 0.06 ± 0.13 keV and Γγγ(χc2) = 0.60 ± 0.02 ± 0.01 ± 0.04 keV with a ratio of R = Γγγ(χc2)/Γγγ(χc0) = 0.295 ± 0.014 ± 0.007 ± 0.027, where the uncertainties are statistical, systematic and associated with the uncertainties of β(ψ(3686) → γχc0,2) and the total widths Γ(χc0,2), respectively. For the forbidden decay of χc1 → γγ, no signal is observed, and an upper limit on the two-photon width is obtained to be Γγγ(χc1) < 5.3 eV at the 90% confidence level. Finally, the ratio of the two-photon widths between helicity-zero and helicity-two components in the decay χc2 → γγ is also measured to be f0/2 = Γλ=0γγ(χc2)/Γλ=2γγ(χc2) = (0.0 ± 0.6 ± 1.2) x 10-2, where the uncertainties are statistical and systematic, respectively.
- Research Organization:
- George Washington Univ., Washington, DC (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- Contributing Organization:
- BESIII Collaboration
- Grant/Contract Number:
- SC0016583; FG02-05ER41374; SC-0010118; SC-0010504; SC-0012069
- OSTI ID:
- 1440860
- Alternate ID(s):
- OSTI ID: 1489057
- Journal Information:
- Physical Review D, Vol. 96, Issue 9; ISSN 2470-0010
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Observation of the decays
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journal | January 2020 |
Decay and detection of a light scalar boson mixing with the Higgs boson
|
journal | January 2019 |
Decay and Detection of a Light Scalar Boson Mixing with the Higgs | text | January 2018 |
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