Abstract
This chapter describes the event and data quality selections needed for analysis, as well as the corrections to MC and its systematic uncertainties.
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Notes
- 1.
For \(m\!_{jj}\) distributions, this cut is at 0.6. In addition there is no cut on \(y_{B}\).
- 2.
For mass distributions, the corresponding cut is at \(m\!_{jj}= 1100\) GeV.
- 3.
In practice this means that the actual leading jet \(p_{\mathrm T}\) cut was slightly higher.
- 4.
If there were only one trigger, the event weight would be \(\langle p_i\rangle \).
- 5.
The ROOT method TH1::Smooth() is used, which employs the 353QH smoothing algorithm, using the repeated median of intervals (3, 5, 3 bins wide) and also includes the smoothed residuals [6].
- 6.
Like for cleaning, this is based on the finding that below this fraction, the maximum energy smearing in a masked module would not introduce changes in the ordering of jets.
- 7.
cf. the \(|\eta |\) coverage of the Tile calorimeter, Chapter 5.
- 8.
Although most of the shift is removed in the normalisation, and only the shape change remains, the rate decrease reduces the statistical power of the data.
- 9.
The best estimate: the value maximising the likelihood.
- 10.
The exact binning can be seen in for instance Fig. 10.4, showing the EW corrections.
- 11.
Details in Appendix A.
- 12.
Signal injection: adding the signal prediction to the SM prediction.
- 13.
Remember: the \(m\!_{jj}\) binning is 300 GeV wide.
- 14.
The p-value relates to this \(\sigma \) via the standard deviations of a Gaussian distribution: the p value is the probability to obtain a value \(q \ge q_0\) where \(q_0\) is the observed value, when sampling a Gaussian distribution \(G(\mu , \sigma )\). The location of \(q_0\) in G is indicated by the number of \(\sigma \).
- 15.
In practice, this is not the wording that would be used, but something more model-agnostic.
- 16.
Closure in a MC- derived correction means independence of the used variables by construction.
- 17.
The calibrations and corresponding uncertainties are worked out in Combined Performance groups.
- 18.
The systematic variations are a what-if-scenario, implying that they need to be treated in the same manner as the nominal prediction.
- 19.
The details of the PDF uncertainty calculation are given in Appendix A.
- 20.
Shape effects are, as we have seen, a sign of both angular shifts and \(m\!_{jj}\) migrations.
- 21.
The generator and shower uncertainties are one-sided.
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Bryngemark, L.K. (2017). Analysis of Angular Distributions at \(\sqrt{s}= 8 \) and 13 TeV. In: Search for New Phenomena in Dijet Angular Distributions at √s = 8 and 13 TeV. Springer Theses. Springer, Cham. https://doi.org/10.1007/978-3-319-67346-2_10
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