Observation of Y(4140) in the J/&psi &phi Mass Spectrum in B+ → J/ψ φ K+

CDF public note

This web page summarizes the results of the search for exotics in the J/&psi &phi Mass Spectrum in B+ → J/ψ φ K+ decays. The search is based on data comprising 6.0 fb-1 of integrated luminosity. Using the fully reconstructed decay

B+ → Y(4140)K+;     Y(4140) →J/ψ φ ;     J/Ψ → μ+μ-;     φ → K+ K-    
 
we measure:

The statistical significance of the Y(4140) signal is over 5.0 &sigma


We also find evidence for another structure with:

The statistical significance of the second structure is 3.1 &sigma



GIF EPS



GIF EPS



GIF EPS

Major points of the analysis

  • Use Lxy to separate B vertex from primary vertex
  • Use kaon particle identification to reduce combinatorial background

Plots

  • Dalitz plot GIF, EPS
  • Mass difference in B mass window and B sideband GIF, EPS
  • Mass difference in B mass window for 2.7 ifb and 6.0ifb GIF, EPS
  • Toy MC for Y(4140) GIF, EPS
  • Toy MC for Y(4140) with fit to chisq PDF GIF, EPS
  • Fit to the second peak GIF, EPS
  • Toy MC for the second peak GIF, EPS


Documentation