Study of the D 0 p amplitude in Λ b 0 → D 0 pπ − decays
R. Aaij (European Organization for Nuclear Research (CERN), Geneva, Switzerland); B. Adeva (Universidad de Santiago de Compostela, Santiago de Compostela, Spain); M. Adinolfi (H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom); Z. Ajaltouni (Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France); S. Akar (University of Cincinnati, Cincinnati, OH, United States); et al - Show all 768 authors
An amplitude analysis of the decay Λ b 0 → D 0 pπ − is performed in the part of the phase space containing resonances in the D 0 p channel. The study is based on a data sample corresponding to an integrated luminosity of 3.0 fb −1 of pp collisions recorded by the LHCb experiment. The spectrum of excited Λ c + states that decay into D 0 p is studied. The masses, widths and quantum numbers of the Λ c (2880) + and Λ c (2940) + resonances are measured. The constraints on the spin and parity for the Λ c (2940) + state are obtained for the first time. A near-threshold enhancement in the D 0 p amplitude is investigated and found to be consistent with a new resonance, denoted the Λ c (2860) + , of spin 3 / 2 and positive parity.
