Observation of a new Xi(b) baryon


Date

2012-06-22

Publication Type

Journal Article

ETH Bibliography

yes

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Data

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.

Publication status

published

Editor

Book title

Volume

108 (25)

Pages / Article No.

252002

Publisher

American Physical Society

Event

Edition / version

Methods

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Geographic location

Date collected

Date created

Subject

Organisational unit

03381 - Pauss, Felicitas (emeritus) check_circle
03593 - Dissertori, Günther / Dissertori, Günther check_circle
03904 - Wallny, Rainer / Wallny, Rainer check_circle
08803 - Grab, Christoph (Tit.Prof.) check_circle

Notes

Funding

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