# metadata.dc.description.abstract[].value
Using p p collision data corresponding to 1.0     fb − 1 integrated luminosity collected by the LHCb detector, two narrow states are observed in the Λ 0 b π + π − spectrum with masses 5911.97 ± 0.12 ( stat ) ± 0.02 ( syst ) ± 0.66 ( Λ 0 b     mass )     MeV / c 2 and 5919.77 ± 0.08 ( stat ) ± 0.02 ( syst ) ± 0.66 ( Λ 0 b     mass )     MeV / c 2 . The significances of the observations are 5.2 and 10.2 standard deviations, respectively. These states are interpreted as the orbitally excited Λ 0 b baryons, Λ * 0 b ( 5912 ) and Λ * 0 b ( 5920 ) .

# metadata.dc.rights[].value
cc by (c) CERN; LHCb Collaboration, 2012

# metadata.dc.source[].value
Articles publicats en revistes (Física Quàntica i Astrofísica)