Type: Article
Publication Date: 2004-09-10
Citations: 54
DOI: https://doi.org/10.1103/physrevlett.93.112002
An enhancement near the mp+MΛ mass threshold is observed in the combined pΛ¯ and p¯Λ invariant-mass spectrum from J/ψ→pK−Λ¯+c.c. decays. It can be fit with an S-wave Breit-Wigner resonance with a mass m=2075±12(stat)±5(syst) MeV and a width of Γ=90±35(stat)±9(syst) MeV; it can also be fit with a P-wave Breit-Wigner resonance. Evidence for a similar enhancement is also observed in ψ′→pK−Λ¯+c.c. decays. The analysis is based on samples of 5.8×107J/ψ and 1.4×107ψ′ decays accumulated in the BES II detector at the Beijing Electron-Positron Collider.Received 19 May 2004DOI:https://doi.org/10.1103/PhysRevLett.93.112002©2004 American Physical Society