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Boosted Object Reconstruction

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Part of the book series: Springer Theses ((Springer Theses))

Abstract

After a detailed exposition of the various reconstruction techniques in Chap. 5, further selections and quality criteria are applied to define a set of baseline and candidate reconstructed objects that will be used in the analysis and the kinematic variables to discriminate between signal and background and maximize the sensitivity for a discovery of new physics. These reconstructed objects include jets, reclustered large radius jets, b-tagged jets, leptons and missing transverse momentum. Additionally, the procedure for removing energy overlaps among the reconstructed objects will be detailed.

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Notes

  1. 1.

    The term “lepton” exclusively refers to electron or muon in this thesis.

  2. 2.

    The term “lepton” exclusively refers to electron or muon in this thesis.

  3. 3.

    Unless otherwise specified, “jets” will always refer to the candidate, overlap-removed (see Sect. 6.2.4), small-R jets.

  4. 4.

    At the 77% working point, the corresponding rejection factors against jets originating from c-quarks, τ-leptons, and light quarks & gluons are 6, 22, and 134, respectively [82].

  5. 5.

    The optimization did sometimes favor the 85% working point, but 77% was not significantly worse. On top of this, there are some benefits using a lower efficiency working point for background estimation due to the enhanced purity of the flavor composition.

  6. 6.

    The muon and electron definition choices were optimized in the previous version of the analysis [79].

  7. 7.

    If you have a very boosted top quark, you often have a real electron close to a real b-jet. This is why both the electron and b-tagged jet would be kept.

  8. 8.

    These jets usually have very few matching ID tracks.

  9. 9.

    Unless otherwise specified, “large-R” jets will always refer to the candidate, re-clustered, trimmed jets.

  10. 10.

    The JES uncertainties are used to describe the mass uncertainty on the re-clustered jets. In the signal regions, less than 2% of these re-clustered jets were formed from a single small-R jet, so the mass of the re-clustered jet originates from the \({p_{\text{T}, i}^{\text{jet}}}\) and separation between small-R jets.

  11. 11.

    Trimming for re-clustered jets means to remove subjets where \({\;pT ^{\text{subjet}}} < {f_{\text{cut}}} {p_{\text{T}, i}^{\text{jet}}} \). For this analysis, subjets with pT < 10% of the re-clustered pTjet were removed.

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Stark, G. (2020). Boosted Object Reconstruction. In: The Search for Supersymmetry in Hadronic Final States Using Boosted Object Reconstruction. Springer Theses. Springer, Cham. https://doi.org/10.1007/978-3-030-34548-8_6

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