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.

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

we measure:

m
= 4143.4 ^{+ 2.9} _{- 3.0} (stat.) ±
0.6(syst.) MeV/c^{2
}

&Gamma
= 15.3 ^{+ 10.4} _{- 6.1} (stat.) ±
2.5(syst.) MeV/c^{2
}

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

We also find evidence for another structure with:

m
= 4274.4 ^{+ 8.4} _{- 6.7} (stat.)

&Gamma
= 32.3 ^{+ 21.9} _{- 15.3} (stat.)

The statistical significance of the second structure is 3.1 &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

- 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