par Chatrchyan, Serguei;Clerbaux, Barbara 
;De Lentdecker, Gilles ;Gay, Arnaud ;Hreus, Tomas ;Leonard, Alexandre ;Marage, Pierre ;Reis, Thomas ;Thomas, Laurent ;Vander Velde, Catherine ;Vanlaer, Pascal ;Wang, Jian ;Charaf, Othman ;Dero, Vincent ; [et al.]
Référence Physical review letters, 108, 25, 252002
Publication Publié, 2012
;De Lentdecker, Gilles ;Gay, Arnaud ;Hreus, Tomas ;Leonard, Alexandre ;Marage, Pierre ;Reis, Thomas ;Thomas, Laurent ;Vander Velde, Catherine ;Vanlaer, Pascal ;Wang, Jian ;Charaf, Othman ;Dero, Vincent ; [et al.]Référence Physical review letters, 108, 25, 252002
Publication Publié, 2012
Article révisé par les pairs
| Résumé : | The observation of a new b baryon via its strong decay into Ξb-π + (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at √s=7TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3fb -1. The known Ξb- baryon is reconstructed via the decay chain Ξb-→J/ψΞ -→μ +μ -Λ0π -, with Λ0→pπ -. A peak is observed in the distribution of the difference between the mass of the Ξb-π + system and the sum of the masses of the Ξb- 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 Ξ b. |
