TY - JOUR
T1 - First observation of excited Ω−b states
AU - LHCb Collaboration
AU - Aaij, R.
AU - Abellán Beteta, C.
AU - Ackernley, T.
AU - Adeva, B.
AU - Adinolfi, M.
AU - Afsharnia, H.
AU - Aidala, C. A.
AU - Aiola, S.
AU - Ajaltouni, Z.
AU - Akar, S.
AU - Albicocco, P.
AU - Albrecht, J.
AU - Alessio, F.
AU - Alexander, M.
AU - Alfonso Albero, A.
AU - Alkhazov, G.
AU - Alvarez Cartelle, P.
AU - Alves, A. A.
AU - Amato, S.
AU - Amhis, Y.
AU - An, L.
AU - Anderlini, L.
AU - Andreassi, G.
AU - Andreotti, M.
AU - Archilli, F.
AU - Arnau Romeu, J.
AU - Artamonov, A.
AU - Artuso, M.
AU - Arzymatov, K.
AU - Aslanides, E.
AU - Atzeni, M.
AU - Audurier, B.
AU - Bachmann, S.
AU - Back, J. J.
AU - Baker, S.
AU - Bifani, S.
AU - Calladine, R.
AU - Chatzikonstantinidis, G.
AU - Cooke, N.
AU - Farley, N.
AU - Griffith, P.
AU - Ilten, P.
AU - Lazzeroni, C.
AU - Pescatore, L.
AU - Plews, J.
AU - Popov, D.
AU - Sergi, A.
AU - Slater, M. W.
AU - Watson, N. K.
AU - Zarebski, K. A.
PY - 2020/2/25
Y1 - 2020/2/25
N2 - We report four narrow peaks in the Ξb0K- 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[ωb(6316)-]=6315.64±0.31±0.07±0.50 MeV, m[ωb(6330)-]=6330.30±0.28±0.07±0.50 MeV, m[ωb(6340)-]=6339.71±0.26±0.05±0.50 MeV, m[ωb(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 Ξb0 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[ωb(6316)-]<2.8 MeV, Γ[ωb(6330)-]<3.1 MeV and Γ[ωb(6340)-]<1.5 MeV. The natural width of the ωb(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 ωb(6316)- and ωb(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 ωb- resonances.
AB - We report four narrow peaks in the Ξb0K- 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[ωb(6316)-]=6315.64±0.31±0.07±0.50 MeV, m[ωb(6330)-]=6330.30±0.28±0.07±0.50 MeV, m[ωb(6340)-]=6339.71±0.26±0.05±0.50 MeV, m[ωb(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 Ξb0 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[ωb(6316)-]<2.8 MeV, Γ[ωb(6330)-]<3.1 MeV and Γ[ωb(6340)-]<1.5 MeV. The natural width of the ωb(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 ωb(6316)- and ωb(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 ωb- resonances.
UR - http://www.scopus.com/inward/record.url?scp=85080878467&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.124.082002
DO - 10.1103/PhysRevLett.124.082002
M3 - Article
C2 - 32167334
AN - SCOPUS:85080878467
SN - 0031-9007
VL - 124
JO - Physical Review Letters
JF - Physical Review Letters
IS - 8
M1 - 082002
ER -