BTagging workflow

The BTagging workflow is a slightly changed base workflow. The main difference is that the BTagging workflow includes derivation of BTagging efficiencies for a given analysis as recommended by [BTV](https://btv-wiki.docs.cern.ch/PerformanceCalibration/fixedWPSFRecommendations/#b-tagging-efficiencies-in-simulation). The processor that implements the main operations performed can be found at higgs_dna/workflows/btagging:BTaggingProcessor.

To use b-jet related variables and weights, one has to adhere to the following procedures:

  • Variables * Execute first pull_files.py –target bTag * Choose an appropriate btagging MVA: deepJet (all NanoAOD versions >= v11), particleNet (NanoAOD >= v12) and robustParticleTransformer (NanoAOD >= v12)

    • Set it in the processor variable self.bjet_mva

    • Choose the Working Point: L (Loose), M (Medium), T (Tight), XT (extra Tight) or XXT (extra extra Tight) * Set it in the processor variable self.bjet_wp

  • Weights * Execute first pull_files.py –target bTag * Since the btagging efficiency weights have to be computed per analysis, we have to produce them first with the BTagging processor

    • Example Btagging processor found in ./higgs_dna/workflows

      • Important: You have to apply your selections before the indicated MANDATORY PART. The latter must not be changed.

    • Select in your runner.json for the workflow BTagging and run the processor with no systematics (they are not necessary for the BTagging processor) over all your samples of your analysis

    • Pickle .pkl files are produced that contain the btagging efficiencies binned as per recommendation by [BTV](https://btv-wiki.docs.cern.ch/PerformanceCalibration/fixedWPSFRecommendations/) * pT in [20, 30, 50, 70, 100, 140, 200, 300, 600, 1000] * abs(eta): No Binning * hadronFlavour: [0, 4, 5]

    • Once .pkl files are produced, generate the correctionlib file by calling btagging_eff.py –input path/to/BTagging/output –output-name analysis-name , where analysis-name is the name the correctionlib will be saved as (per default in ./higgs_dna/systematics/JSONs/bTagEff/year/analysis-name.json.gz )

    • When the correctionlib is produced and stored in ./higgs_dna/systematics/JSONs/bTagEff/year , we have to add an additional string to the dictionary in runner.json:     “bTagEffFileName”: “analysis-name.json.gz” (Important: Only state the name of the file. Do not add the path, as HiggsDNA looks for it in ./higgs_dna/systematics/JSONs/bTagEff/ by itself!)

    • Now, you can add the desired corrections and systematics to your runner.json and launch the production of your samples * Currently only bTagFixedWP_PNetTight (MVA: ParticleNet, Tight WP) is implemented. But feel free to add more with the new function for fixed btagging working points bTagFixedWP found in higgs_dna/systematics/event_weight_systematics.py

    • If a systematic or correction from bTagFixedWP is used, the weights weight and weight_central are not containing the weight of the btagging scale factors. Instead it is added separately as weight_bTagFixedWP to be used later.

An example JSON for the BTaggingProcessor could look like this:

Then after the production of the .pkl files, the final runner.json for your analyis involving the Particle Net MVA with a tight working point could look like this:

Right now, the following btagging corrections and systematics are implemented:

  • Particle Net

    • bTagFixedWP_PNetLoose (Loose WP)

    • bTagFixedWP_PNetMedium (Medium WP)

    • bTagFixedWP_PNetTight (Tight WP)

    • bTagFixedWP_PNetExtraTight (Extra Tight WP)

    • bTagFixedWP_PNetExtraExtraTight (Extra Extra Tight WP)

  • Deep Jet

    • bTagFixedWP_deepJetLoose (Loose WP)

    • bTagFixedWP_deepJetMedium (Medium WP)

    • bTagFixedWP_deepJetTight (Tight WP)

    • bTagFixedWP_deepJetExtraTight (Extra Tight WP)

    • bTagFixedWP_deepJetExtraExtraTight (Extra Extra Tight WP)

  • Robust Particle Transformer

    • bTagFixedWP_robustParticleTransformerLoose (Loose WP)

    • bTagFixedWP_robustParticleTransformerMedium (Medium WP)

    • bTagFixedWP_robustParticleTransformerTight (Tight WP)

    • bTagFixedWP_robustParticleTransformerExtraTight (Extra Tight WP)

    • bTagFixedWP_robustParticleTransformerExtraExtraTight (Extra Extra Tight WP)

IMPORTANT: When the systematics are applied, the weights weight and weight_central are not containing the weight of the btagging scale factors. Instead it is added separately as weight_bTagFixedWP to be used later.