[PWGHF,Trigger] Beauty 2nd Vertex in triggers #8895
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apalasciano
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Hi @apalasciano, Thanks a lot for the very important implementation! All looks good to me! let's see if fabrizio has comments or suggestions on this. |
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Ciao @apalasciano many thanks!
The main features are there, but I would suggest a few changes (see comments below)
EventFiltering/PWGHF/HFFilter.cxx
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| if (activateSecVtx) { | ||
| helper.setVtxConfiguration(df2, propagateToPCA, useAbsDCA, useWeightedFinalPCA, maxR, maxDZIni, minParamChange, minRelChi2Change); | ||
| helper.setVtxConfiguration(dfB, propagateToPCA, useAbsDCA, useWeightedFinalPCA, maxR, maxDZIni, minParamChange, minRelChi2Change); |
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In the B vertex we should use useAbsDCA==True always to avoid errors due to the vertex between a pseudotrack (the D) and a track. In general, I would consider to put all the configurations hard-coded (it is very unlikely that we will change them).
| helper.setVtxConfiguration(dfB, propagateToPCA, useAbsDCA, useWeightedFinalPCA, maxR, maxDZIni, minParamChange, minRelChi2Change); | |
| helper.setVtxConfiguration(dfB, propagateToPCA, true, useWeightedFinalPCA, maxR, maxDZIni, minParamChange, minRelChi2Change); |
EventFiltering/PWGHF/HFFilter.cxx
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| @@ -231,6 +260,20 @@ struct HfFilter { // Main struct for HF triggers | |||
| for (int iBeautyPart{0}; iBeautyPart < kNBeautyParticles; ++iBeautyPart) { | |||
| hMassVsPtB[iBeautyPart] = registry.add<TH2>(Form("fMassVsPt%s", beautyParticleNames[iBeautyPart].data()), Form("#it{M} vs. #it{p}_{T} distribution of triggered %s candidates;#it{p}_{T} (GeV/#it{c});#it{M} (GeV/#it{c}^{2});counts", beautyParticleNames[iBeautyPart].data()), HistType::kTH2F, {ptAxis, massAxisB[iBeautyPart]}); | |||
| } | |||
| constexpr int kNBinsHfVtxStages = kNHfVtxStage; | |||
| std::string labels[kNBinsHfVtxStages]; | |||
| labels[HfVtxStage::Skimmed] = "Skimm CharmHad"; | |||
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| labels[HfVtxStage::Skimmed] = "Skimm CharmHad"; | |
| labels[HfVtxStage::Skimmed] = "Skimm CharmHad-Pi pairs"; |
EventFiltering/PWGHF/HFFilter.cxx
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| std::shared_ptr<TH2> hCpaVsPtB; | ||
| std::shared_ptr<TH2> hDecayLengthVsPtB; | ||
| std::shared_ptr<TH2> hImpactParamProductVsPtB; |
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I would define these as arrays, as hMassVsPtB to easy the extension to the 3 prongs
EventFiltering/PWGHF/HFFilter.cxx
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| hCpaVsPtB = registry.add<TH2>(Form("fCpaVsPt%s", beautyParticleNames[0].data()), Form("#it{M} vs. #it{p}_{T} distribution of triggered %s candidates;#it{p}_{T} (GeV/#it{c});#it{M} (GeV/#it{c}^{2});counts", beautyParticleNames[0].data()), HistType::kTH2F, {ptAxis, {100, -1, 1}}); | ||
| hDecayLengthVsPtB = registry.add<TH2>(Form("fDecayLengthVsPt%s", beautyParticleNames[0].data()), Form("#it{M} vs. #it{p}_{T} distribution of triggered %s candidates;#it{p}_{T} (GeV/#it{c});#it{M} (GeV/#it{c}^{2});counts", beautyParticleNames[0].data()), HistType::kTH2F, {ptAxis, {100, 0, 20}}); | ||
| hImpactParamProductVsPtB = registry.add<TH2>(Form("fImpactParamProductVsPt%s", beautyParticleNames[0].data()), Form("#it{M} vs. #it{p}_{T} distribution of triggered %s candidates;#it{p}_{T} (GeV/#it{c});#it{M} (GeV/#it{c}^{2});counts", beautyParticleNames[0].data()), HistType::kTH2F, {ptAxis, {100, -2.5, +2.5}}); |
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It is convenient to have them as arrays to simplify the extension to charm 3 prongs (see above)
EventFiltering/PWGHF/HFFilter.cxx
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| Configurable<bool> propagateToPCA{"propagateToPCA", true, "create tracks version propagated to PCA"}; | ||
| Configurable<bool> useAbsDCA{"useAbsDCA", true, "Minimise abs. distance rather than chi2"}; | ||
| Configurable<bool> useWeightedFinalPCA{"useWeightedFinalPCA", false, "Recalculate vertex position using track covariances, effective only if useAbsDCA is true"}; | ||
| Configurable<double> maxR{"maxR", 200., "reject PCA's above this radius"}; | ||
| Configurable<double> maxDZIni{"maxDZIni", 4., "reject (if>0) PCA candidate if tracks DZ exceeds threshold"}; | ||
| Configurable<double> minParamChange{"minParamChange", 1.e-3, "stop iterations if largest change of any B+ is smaller than this"}; | ||
| Configurable<double> minRelChi2Change{"minRelChi2Change", 0.9, "stop iterations is chi2/chi2old > this"}; |
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I would consider to have these hard-coded (unlikely that we will change them)
EventFiltering/PWGHF/HFFilter.cxx
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| @@ -76,6 +94,7 @@ struct HfFilter { // Main struct for HF triggers | |||
| Configurable<LabeledArray<double>> cutsTrackBeauty4Prong{"cutsTrackBeauty4Prong", {hf_cuts_single_track::cutsTrack[0], hf_cuts_single_track::nBinsPtTrack, hf_cuts_single_track::nCutVarsTrack, hf_cuts_single_track::labelsPtTrack, hf_cuts_single_track::labelsCutVarTrack}, "Single-track selections per pT bin for 4-prong beauty candidates"}; | |||
| Configurable<std::string> paramCharmMassShape{"paramCharmMassShape", "2023_pass3", "Parametrisation of charm-hadron mass shape (options: 2023_pass3)"}; | |||
| Configurable<float> numSigmaDeltaMassCharmHad{"numSigmaDeltaMassCharmHad", 2.5, "Number of sigma for charm-hadron delta mass cut in B and D resonance triggers"}; | |||
| Configurable<LabeledArray<float>> topolCutsBeautyHadron{"topolCutsBeautyHadron", {cutsTopolBeautyHadron[0], 3, kNBeautyParticles, labelsRowsTopolBeauty, labelsColumnsDeltaMassB}, "Cuts on CosPa, DecayLength and ImpactParameterProduct for beauty species"}; | |||
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I would make them pT dependent, with very few bins, e.g. 2-3 should be enough (I know that it adds the complication of an extra dimension that we have to handle). A possibility is to add one LabeledArray per variable (2 dimensions, pT and species) or one LabeledArray per species (2 dimensions, pT and variables).
I would then also add the invariant-mass window here (instead of having a pT independent value as it is now, to have the flexibility to enlarge it at high pT)
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I implemented something similar to what is done in the standard selectors (your second option).
For every beauty species (for the moment only the B+), a set of cuts will be needed
Hi @fgrosa , @zhangbiao-phy ,
This is the first draft for reconstructing secondary vertices in triggers.
This PR is for testing the B+(->D0).
Selections (CPA, DecLength, ImpactParameterProduct) are implemented for beauty candidates.