Search for the X(5568)

Primary author: Pat Lukens

CDF searches for the production of the X(5568) through the decay chain
X(5568) → Bs0 π±, Bs0 → J/ψ φ, J/ψ → μ+μ-, φ → K+K-.
This resonance was observed by D0 (PRL 117, 022003 (2016)).
The data was collected in 9.6 fb-1 of collisions.
The analysis was approved for public distribution on 21 Dec. 2017, and a description of the analysis and its results are available here
The seminar given on 23 Feb 2018 at FNAL is available as Powerpoint or PDF

Blessed plots, both "png" and "eps" formats are available

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J/ψ K*0 and J/ψ φ mass distributions showing the B0 and Bs0 signals and sidebands used in the analysis.
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Simulated X(5568) for three representative pT ranges Simulated X(5568) signal shape obtained for pT(Bs0) > 10 GeV/c Acceptance and efficiency as a function of lower pT(Bs0) cut.
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J/ψ φ mass distribution showing the B0 and Bs0 signals and sidebands used in the analysis. Bs0 π mass distribution with candidates omitted that are within ±Γ of the X(5568). Curves are the background models obtained with the D0 signal amplitude, ±σ. J/ψ φ mass distribution showing the fit with a floating signal component (red) and the null hypothesis (green).
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Bs0 π mass distribution with candidates omitted that are within ±Γ of the X(5568). Red curve is the fit obtained with the D0 signal amplitude. Pink curves indicate ±σ statistical uncertainty on the fit. Bs0 π mass distribution made with B0 π+ candidates. Red curve is the fit to the data. Pink curves indicate ±σ statistical uncertainty on the fit. Bs0 π mass distribution made with B0 π- candidates. Red curve is the fit to the data. Pink curves indicate ±σ statistical uncertainty on the fit.
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Bs0 π mass distribution made with B0 π+ candidates. Bs0 π mass distribution made with B0 π- candidates.
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Fit of the Bs0 π mass distribution made with B0 π+ background model. Fit of the Bs0 π mass distribution made with B0 π- background model.
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ΔR plotted against Bs0 π mass to show the correlation. The affect of ΔR requirements on the Bs0 π mass distribution. The affect of pT(π) requirements on the Bs0 π mass distribution after a tight ΔR requirement.
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ΔR plotted against Bs0 π mass to show the correlation. This sample is created from the B0 candidates. The affect of ΔR requirements on the Bs0 π mass distribution. This sample is created from the B0 candidates. The affect of pT(π) requirements on the Bs0 π mass distribution after a tight ΔR requirement. This sample is created from the B0 candidates.