2026-04-17T01:16:26Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1750322025-11-21T05:48:54Zcom_2072_1057col_2072_478823col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Alfonso Albero, Alejandro author Calvo Gómez, Míriam author Camboni, Alessandro author Coquereau, Samuel author Garrido Beltrán, Lluís author Gascón Fora, David author Gironella Gironell, Pere author Graciani Díaz, Ricardo author Graugés Pous, Eugeni author Manera Escalero, R. author Vilasis-Cardona, Xavier author LHCb Collaboration author 2021-03-12T13:07:11Z 2021-03-12T13:07:11Z 2020-02-25 2021-03-12T13:07:11Z We report four narrow peaks in the Ξ0bK− 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 Ξ0b 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+1.0−0.8±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 Ω−b resonances. Gran Col·lisionador d'Hadrons Quarks Large Hadron Collider (France and Switzerland) Quarks First Observation of Excited Omega(-)(b) States