[PWGLF] Add occupancy axis to the matching studies (#9433)

Author: mpuccio

PWGLF/TableProducer/Nuspex/nucleiSpectra.cxx

@@ -458,9 +458,11 @@ struct nucleiSpectra {
     }
 
     if (doprocessMatching) {
+      std::vector<double> occBins{-0.5, 499.5, 999.5, 1999.5, 2999.5, 3999.5, 4999.5, 10000., 50000.};
+      AxisSpec occAxis{occBins, "Occupancy"};
       for (int iC{0}; iC < 2; ++iC) {
         nuclei::hMatchingStudy[iC] = spectra.add<THnSparse>(fmt::format("hMatchingStudy{}", nuclei::matter[iC]).data(), ";#it{p}_{T};#phi;#eta;n#sigma_{ITS};n#sigma{TPC};n#sigma_{TOF};Centrality", HistType::kTHnSparseF, {{20, 1., 9.}, {10, 0., o2::constants::math::TwoPI}, {10, -1., 1.}, {50, -5., 5.}, {50, -5., 5.}, {50, 0., 1.}, {8, 0., 80.}});
-        nuclei::hMatchingStudyHadrons[iC] = spectra.add<THn>(fmt::format("hMatchingStudyHadrons{}", nuclei::matter[iC]).data(), ";#it{p}_{T};#phi;#eta;Centrality;Track type", HistType::kTHnF, {{23, 0.4, 5.}, {20, 0., o2::constants::math::TwoPI}, {10, -1., 1.}, {8, 0., 80.}, {2, -0.5, 1.5}});
+        nuclei::hMatchingStudyHadrons[iC] = spectra.add<THn>(fmt::format("hMatchingStudyHadrons{}", nuclei::matter[iC]).data(), ";#it{p}_{T};#phi;#eta;Centrality;Track type; Occupancy", HistType::kTHnF, {{23, 0.4, 5.}, {20, 0., o2::constants::math::TwoPI}, {10, -1., 1.}, {8, 0., 80.}, {2, -0.5, 1.5}, occAxis});
       }
     }
 
@@ -918,7 +920,7 @@ struct nucleiSpectra {
       int iC = track.signed1Pt() > 0;
       const float pt = track.pt();
       const float phi = 2.f * RecoDecay::constrainAngle(track.phi() - collision.psiFT0C(), 0.f, 2);
-      nuclei::hMatchingStudyHadrons[iC]->Fill(pt, phi, track.eta(), centrality, track.hasTPC());
+      nuclei::hMatchingStudyHadrons[iC]->Fill(pt, phi, track.eta(), centrality, track.hasTPC(), collision.trackOccupancyInTimeRange());
       if (itsResponse.nSigmaITS<o2::track::PID::Helium3>(track) > -1.) {
         nuclei::hMatchingStudy[iC]->Fill(pt * 2, phi, track.eta(), itsResponse.nSigmaITS<o2::track::PID::Helium3>(track), nSigmaTPC, o2::pid::tof::Beta::GetBeta(track), centrality);
       }