Abstract
The observation of a new b baryon via its strong decay into Ξ−bπ+ (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at √s=7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb−1. The known Ξ−b baryon is reconstructed via the decay chain Ξ−b→J/ψΞ−→μ+μ−Λ0π−, with Λ0→pπ−. A peak is observed in the distribution of the difference between the mass of the Ξ−bπ+ system and the sum of the masses of the Ξ−b and π+, with a significance exceeding 5 standard deviations. The mass difference of the peak is 14.84±0.74(stat)±0.28(syst) MeV. The new state most likely corresponds to the JP=3/2+ companion of the Ξb. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000051288Publication status
publishedExternal links
Journal / series
Physical Review LettersVolume
Pages / Article No.
Publisher
American Physical SocietyOrganisational unit
03381 - Pauss, Felicitas (emeritus)
03593 - Dissertori, Günther / Dissertori, Günther
03904 - Wallny, Rainer / Wallny, Rainer
08803 - Grab, Christoph (Tit.Prof.)
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