The Ξ−bπ+π− invariant mass spectrum is investigated with an event sample of proton-proton collisions at √s=13  TeV, collected by the CMS experiment at the LHC in 2016–2018 and corresponding to an integrated luminosity of 140  fb−1. The ground state Ξ−b is reconstructed via its decays to J/ψΞ− and J/ψΛK−. A narrow resonance, labeled Ξb(6100)−, is observed at a Ξ−bπ+π− invariant mass of 6100.3±0.2(stat)±0.1(syst)±0.6(Ξ−b)  MeV, where the last uncertainty reflects the precision of the Ξ−b baryon mass. The upper limit on the Ξb(6100)− natural width is determined to be 1.9  MeV at 95% confidence level. The low Ξb(6100)− signal yield observed in data does not allow a measurement of the quantum numbers of the new state. However, following analogies with the established excited Ξc baryon states, the new Ξb(6100)− resonance and its decay sequence are consistent with the orbitally excited Ξ−b baryon, with spin and parity quantum numbers JP=3/2−.

(2021). Observation of a New Excited Beauty Strange Baryon Decaying to Ξb−π+π− [journal article - articolo]. In PHYSICAL REVIEW LETTERS. Retrieved from http://hdl.handle.net/10446/186584

Observation of a New Excited Beauty Strange Baryon Decaying to Ξb−π+π−

Re, V.;Vai, I.;
2021-01-01

Abstract

The Ξ−bπ+π− invariant mass spectrum is investigated with an event sample of proton-proton collisions at √s=13  TeV, collected by the CMS experiment at the LHC in 2016–2018 and corresponding to an integrated luminosity of 140  fb−1. The ground state Ξ−b is reconstructed via its decays to J/ψΞ− and J/ψΛK−. A narrow resonance, labeled Ξb(6100)−, is observed at a Ξ−bπ+π− invariant mass of 6100.3±0.2(stat)±0.1(syst)±0.6(Ξ−b)  MeV, where the last uncertainty reflects the precision of the Ξ−b baryon mass. The upper limit on the Ξb(6100)− natural width is determined to be 1.9  MeV at 95% confidence level. The low Ξb(6100)− signal yield observed in data does not allow a measurement of the quantum numbers of the new state. However, following analogies with the established excited Ξc baryon states, the new Ξb(6100)− resonance and its decay sequence are consistent with the orbitally excited Ξ−b baryon, with spin and parity quantum numbers JP=3/2−.
articolo
2021
Sirunyan, A.  M.; Tumasyan, A.; Adam, W.; Andrejkovic, J.  W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Escalante Del Valle, A.; Frühwirth, R.; J...espandi
(2021). Observation of a New Excited Beauty Strange Baryon Decaying to Ξb−π+π− [journal article - articolo]. In PHYSICAL REVIEW LETTERS. Retrieved from http://hdl.handle.net/10446/186584
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10446/186584
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