Two narrow resonant states are observed in the Λb0K-π+ mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6 fb-1. The minimal quark content of the Λb0K-π+ system indicates that these are excited Ξb0 baryons. The masses of the Ξb(6327)0 and Ξb(6333)0 states are m[Ξb(6327)0]=6327.28-0.21+0.23±0.12±0.24 and m[Ξb(6333)0]=6332.69-0.18+0.17±0.03±0.22 MeV, respectively, with a mass splitting of Δm=5.41-0.27+0.26±0.12 MeV, where the uncertainties are statistical, systematic, and due to the Λb0 mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξb(6327)0]<2.20(2.56) and Γ[Ξb(6333)0]<1.60(1.92) MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξb0 resonances.

Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., et al. (2022). Observation of Two New Excited Ξb0 States Decaying to Λb0 K-π+. PHYSICAL REVIEW LETTERS, 128(16) [10.1103/PhysRevLett.128.162001].

Observation of Two New Excited Ξb0 States Decaying to Λb0 K-π+

Borsato M.;Calvi M.;Capelli S.;Cardini A.;Carniti P.;Fazzini D.;Garcia Pardinas J.;Gotti C.;Grillo L.;Khanji B.;Kucharczyk M.;Martinazzoli L.;Martinelli M.;Meloni S.;Minotti A.;Petruzzo M.;Pizzichemi M.;Salomoni M.;Shields E. B.;
2022

Abstract

Two narrow resonant states are observed in the Λb0K-π+ mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6 fb-1. The minimal quark content of the Λb0K-π+ system indicates that these are excited Ξb0 baryons. The masses of the Ξb(6327)0 and Ξb(6333)0 states are m[Ξb(6327)0]=6327.28-0.21+0.23±0.12±0.24 and m[Ξb(6333)0]=6332.69-0.18+0.17±0.03±0.22 MeV, respectively, with a mass splitting of Δm=5.41-0.27+0.26±0.12 MeV, where the uncertainties are statistical, systematic, and due to the Λb0 mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξb(6327)0]<2.20(2.56) and Γ[Ξb(6333)0]<1.60(1.92) MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξb0 resonances.
Articolo in rivista - Articolo scientifico
Flavor Physics; Spectroscopy; Bottom Baryons; Strong Interaction; Quantum Chromodynamics; Quark Model; Hadron Colliders;
English
21-apr-2022
2022
128
16
162001
open
Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., et al. (2022). Observation of Two New Excited Ξb0 States Decaying to Λb0 K-π+. PHYSICAL REVIEW LETTERS, 128(16) [10.1103/PhysRevLett.128.162001].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/377018
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