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 2.7 fb^{-1} of integrated luminosity.

B^{+} → Y(4140)K^{+};
Y(4140) →J/ψ φ ;
J/Ψ → μ^{+}μ^{-};
φ → K^{+} K^{-}

we measure:

m
= 4143.0 ± 2.9 (stat.) ±
1.2(syst.) MeV/c^{2
}

&Gamma
= 11.7 ^{+ 8.3} _{- 5.0} (stat.) ±
3.7(syst.) MeV/c^{2
}

The statistical significance of the Y(4140) signal is over 3.8 &sigma

### Major points of the analysis

- Use L
_{xy} to separate B vertex from primary vertex
- Use kaon particle identification to reduce combinatorial background

### Plots

- B sideband subtracted invariant mass of KK GIF, EPS
- Dalitz plot GIF, EPS
- B mass before applying L
_{xy} and kaon PID GIF, EPS
- B mass before applying kaon PID but after L
_{xy} GIF, EPS
- Control signal B
^{+} → J/ψ K^{+} GIF, EPS
- Control signal B
_{s} → J/ψ φ GIF, EPS
- Dalitz plot from phase space Monte Carlo GIF, EPS
- Mass difference from phase space Monte Carlo GIF, EPS
- Dalitz plot from Bs contamination channel (Monte Carlo) GIF, EPS
- Mass difference for Lxy >100 um GIF, EPS
- Mass difference for vertex probability>0.00001 and # of SVT hits>=3 GIF, EPS

### Documentation