First Observation of Excited Ω[superscript -][subscript b] States
We report four narrow peaks in the Ξ_{b}^{0}K^{-} mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb^{-1} recorded by the LHCb experiment. Referring to these states by their mass, the mass values are m[Ω_...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society (APS)
2020
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| Online Access: | https://hdl.handle.net/1721.1/125876 |
| _version_ | 1826218115011182592 |
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| author | Boettcher, Thomas Julian Craik, Daniel C Weisser, Constantin Williams, Michael |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Boettcher, Thomas Julian Craik, Daniel C Weisser, Constantin Williams, Michael |
| author_sort | Boettcher, Thomas Julian |
| collection | MIT |
| description | We report four narrow peaks in the Ξ_{b}^{0}K^{-} mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb^{-1} recorded by the LHCb experiment. Referring to these states by their mass, the mass values are m[Ω_{b}(6316)^{-}]=6315.64±0.31±0.07±0.50 MeV, m[Ω_{b}(6330)^{-}]=6330.30±0.28±0.07±0.50 MeV, m[Ω_{b} 6340)^{-}]=6339.71±0.26±0.05±0.50 MeV, m[Ω_{b}(6350)^{-}]=6349.88±0.35±0.05±0.50 MeV, where the uncertainties are statistical, systematic, and the last is due to the knowledge of the Ξ_{b}^{0} mass. The natural widths of the three lower mass states are consistent with zero, and the 90% confidence-level upper limits are determined to be Γ[Ω_{b}(6316)^{-}]<2.8 MeV, Γ[Ω_{b}(6330)^{-}]<3.1 MeV and Γ[Ω_{b}(6340)^{-}]<1.5 MeV. The natural width of the Ω_{b}(6350)^{-} peak is 1.4_{-0.8}^{+1.0}±0.1 MeV, which is 2.5σ from zero and corresponds to an upper limit of 2.8 MeV. The peaks have local significances ranging from 3.6σ to 7.2σ. After accounting for the look-elsewhere effect, the significances of the Ω_{b}(6316)^{-} and Ω_{b}(6330)^{-} peaks are reduced to 2.1σ and 2.6σ, respectively, while the two higher mass peaks exceed 5σ. The observed peaks are consistent with expectations for excited Ω_{b}^{-} resonances. Keywords: Hadronic decays, Quark model, Exotic baryons |
| first_indexed | 2024-09-23T17:14:24Z |
| format | Article |
| id | mit-1721.1/125876 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T17:14:24Z |
| publishDate | 2020 |
| publisher | American Physical Society (APS) |
| record_format | dspace |
| spelling | mit-1721.1/1258762022-10-03T11:19:34Z First Observation of Excited Ω[superscript -][subscript b] States First Observation of Excited Ωb- States Boettcher, Thomas Julian Craik, Daniel C Weisser, Constantin Williams, Michael Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Laboratory for Nuclear Science We report four narrow peaks in the Ξ_{b}^{0}K^{-} mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb^{-1} recorded by the LHCb experiment. Referring to these states by their mass, the mass values are m[Ω_{b}(6316)^{-}]=6315.64±0.31±0.07±0.50 MeV, m[Ω_{b}(6330)^{-}]=6330.30±0.28±0.07±0.50 MeV, m[Ω_{b} 6340)^{-}]=6339.71±0.26±0.05±0.50 MeV, m[Ω_{b}(6350)^{-}]=6349.88±0.35±0.05±0.50 MeV, where the uncertainties are statistical, systematic, and the last is due to the knowledge of the Ξ_{b}^{0} mass. The natural widths of the three lower mass states are consistent with zero, and the 90% confidence-level upper limits are determined to be Γ[Ω_{b}(6316)^{-}]<2.8 MeV, Γ[Ω_{b}(6330)^{-}]<3.1 MeV and Γ[Ω_{b}(6340)^{-}]<1.5 MeV. The natural width of the Ω_{b}(6350)^{-} peak is 1.4_{-0.8}^{+1.0}±0.1 MeV, which is 2.5σ from zero and corresponds to an upper limit of 2.8 MeV. The peaks have local significances ranging from 3.6σ to 7.2σ. After accounting for the look-elsewhere effect, the significances of the Ω_{b}(6316)^{-} and Ω_{b}(6330)^{-} peaks are reduced to 2.1σ and 2.6σ, respectively, while the two higher mass peaks exceed 5σ. The observed peaks are consistent with expectations for excited Ω_{b}^{-} resonances. Keywords: Hadronic decays, Quark model, Exotic baryons 2020-06-19T13:24:59Z 2020-06-19T13:24:59Z 2020-02 2020-01 2020-02-25T15:07:27Z Article http://purl.org/eprint/type/JournalArticle 0031-9007 1079-7114 https://hdl.handle.net/1721.1/125876 Aaij, R. et al (LHCb Collaboration). "First Observation of Excited Ω−b States." Physical Review of Letters, 124, 8 (February 2020): 082002. © 2020 CERN, for the LHCb Collaboration en http://dx.doi.org/10.1103/PhysRevLett.124.082002 Physical Review of Letters Creative Commons Attribution 3.0 unported license http://creativecommons.org/licenses/by/3.0 CERN application/pdf American Physical Society (APS) American Physical Society |
| spellingShingle | Boettcher, Thomas Julian Craik, Daniel C Weisser, Constantin Williams, Michael First Observation of Excited Ω[superscript -][subscript b] States |
| title | First Observation of Excited Ω[superscript -][subscript b] States |
| title_full | First Observation of Excited Ω[superscript -][subscript b] States |
| title_fullStr | First Observation of Excited Ω[superscript -][subscript b] States |
| title_full_unstemmed | First Observation of Excited Ω[superscript -][subscript b] States |
| title_short | First Observation of Excited Ω[superscript -][subscript b] States |
| title_sort | first observation of excited ω superscript subscript b states |
| url | https://hdl.handle.net/1721.1/125876 |
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