Observation of a new excited beauty strange baryon decaying to Xi_b^- pi+ pi-статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 15 июля 2021 г.
Аннотация: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/ψ Ξ− and J/ψ Ξ− Λ K−. 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. 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−.