The Ξb-π+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 Ξb- is reconstructed via its decays to J/ψΞ- and J/ψΛK-. A narrow resonance, labeled Ξb(6100)-, is observed at a Ξb-π+π- invariant mass of 6100.3±0.2(stat)±0.1(syst)±0.6(Ξb-) MeV, where the last uncertainty reflects the precision of the Ξb- 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 Ξb- baryon, with spin and parity quantum numbers JP=3/2-.

Sirunyan A.M., Tumasyan A., Adam W., Andrejkovic J.W., Bergauer T., Chatterjee S., et al. (2021). Observation of a New Excited Beauty Strange Baryon Decaying to Ξb- π+π-. PHYSICAL REVIEW LETTERS, 126(25), 1-19 [10.1103/PhysRevLett.126.252003].

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

Battilana C.;Bonacorsi D.;Borgonovi L.;Braibant-Giacomelli S.;Castro A.;Cuffiani M.;Diotalevi T.;Fanfani A.;Giommi L.;Guiducci L.;Lunerti L.;Primavera F.;Rovelli T.;Siroli G. P.;
2021

Abstract

The Ξb-π+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 Ξb- is reconstructed via its decays to J/ψΞ- and J/ψΛK-. A narrow resonance, labeled Ξb(6100)-, is observed at a Ξb-π+π- invariant mass of 6100.3±0.2(stat)±0.1(syst)±0.6(Ξb-) MeV, where the last uncertainty reflects the precision of the Ξb- 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 Ξb- baryon, with spin and parity quantum numbers JP=3/2-.
2021
Sirunyan A.M., Tumasyan A., Adam W., Andrejkovic J.W., Bergauer T., Chatterjee S., et al. (2021). Observation of a New Excited Beauty Strange Baryon Decaying to Ξb- π+π-. PHYSICAL REVIEW LETTERS, 126(25), 1-19 [10.1103/PhysRevLett.126.252003].
Sirunyan A.M.; Tumasyan A.; Adam W.; Andrejkovic J.W.; Bergauer T.; Chatterjee S.; Dragicevic M.; Escalante Del Valle A.; Fruhwirth R.; Jeitler M.; Kr...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/859925
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