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., Tumasyan, A., Adam, W., Andrejkovic, J., 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) [10.1103/PhysRevLett.126.252003].

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

Benaglia A.;Brivio F.;Cetorelli F.;Ciriolo V.;De Guio F.;Dinardo M. E.;Ghezzi A.;Govoni P.;Guzzi L.;Malberti M.;Massironi A.;Monti F.;Moroni L.;Paganoni M.;Ragazzi S.;Tabarelli De Fatis T.;Valsecchi D.;Zuolo D.;Ortona G.;Fiorendi S.;Gerosa R.;Lucchini M. T.;
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-.
Articolo in rivista - Articolo scientifico
Ground state; Hadrons; Mass spectrometry
English
2021
126
25
252003
none
Sirunyan, A., Tumasyan, A., Adam, W., Andrejkovic, J., 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) [10.1103/PhysRevLett.126.252003].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/475840
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