Observation of Excited Λb0 Baryons

Abstract

Using pp collision data corresponding to 1.0fb -1 integrated luminosity collected by the LHCb detector, two narrow states are observed in the Λb0π +π - spectrum with masses 5911.97±0.12(stat)±0.02(syst)±0.66(Λb0mass)MeV/c2 and 5919.77±0.08(stat)±0.02(syst)±0.66(Λb0mass)MeV/ c2. The significances of the observations are 5.2 and 10.2 standard deviations, respectively. These states are interpreted as the orbitally excited Λb0 baryons, Λb*0(5912) and Λb*0(5920). © 2012 CERN. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License.