Study of excited Λb0 states decaying to Λb0π+π− in proton-proton collisions at s=13TeV

Abstract A study of excited Λ b 0 baryons is reported, based on a data sample collected in 2016–2018 with the CMS detector at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of up to 140 fb − 1 . The existence of four excited Λ b 0 states: Λ b ( 5912 ) 0 , Λ b ( 5920 ) 0 , Λ b ( 6146 ) 0 , and Λ b ( 6152 ) 0 in the Λ b 0 π + π − mass spectrum is confirmed, and their masses are measured. The Λ b 0 π + π − mass distribution exhibits a broad excess of events in the region of 6040–6100 MeV, whose origin cannot be discerned with the present data.