Add generator for V0s in jets with injection (#2459)

Author: alcaliva

MC/config/PWGLF/ini/GeneratorLFV0sInJets_pp536TeV.ini

@@ -0,0 +1,15 @@
+### V0s in jets - pp collisions at 5.36 TeV
+
+[GeneratorExternal]
+# Generate jet-biased Pythia8 events and require the presence of one V0 particle
+fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGLF/pythia8/generator_pythia8_LF.C
+funcName=generateLFTriggered("${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGLF/pythia8/generator/v0particlelist.gun", 2)
+
+[GeneratorPythia8]
+# Underlying pp event: HardQCD production with jet-pT bias and rope hadronization
+config=${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGLF/pythia8/generator/pythia8_jet_ropes_536tev.cfg
+includePartonEvent=false
+
+[DecayerPythia8]
+# Standard Pythia8 decay configuration
+config[0]=${O2DPG_MC_CONFIG_ROOT}/MC/config/common/pythia8/decayer/base.cfg

MC/config/PWGLF/ini/tests/GeneratorLFV0sInJets_pp536TeV.C

@@ -0,0 +1,57 @@
+int External()
+{
+  std::string path{"o2sim_Kine.root"};
+  int numberOfInjectedSignalsPerEvent{1};
+  std::vector<int> injectedPDGs = {
+    310,    // K0S
+    3122,   // Lambda
+    -3122   // Anti-Lambda
+  };
+  auto nInjection = injectedPDGs.size();
+
+  TFile file(path.c_str(), "READ");
+  if (file.IsZombie()) {
+    std::cerr << "Cannot open ROOT file " << path << "\n";
+    return 1;
+  }
+
+  auto tree = (TTree*)file.Get("o2sim");
+  if (!tree) {
+    std::cerr << "Cannot find tree o2sim in file " << path << "\n";
+    return 1;
+  }
+  std::vector<o2::MCTrack>* tracks{};
+  tree->SetBranchAddress("MCTrack", &tracks);
+
+  std::vector<int> nSignal;
+  for (int i = 0; i < nInjection; i++) {
+    nSignal.push_back(0);
+  }
+
+  auto nEvents = tree->GetEntries();
+  for (int i = 0; i < nEvents; i++) {
+    auto check = tree->GetEntry(i);
+    for (int idxMCTrack = 0; idxMCTrack < tracks->size(); ++idxMCTrack) {
+      auto track = tracks->at(idxMCTrack);
+      auto pdg = track.GetPdgCode();
+      auto it = std::find(injectedPDGs.begin(), injectedPDGs.end(), pdg);
+      int index = std::distance(injectedPDGs.begin(), it); // index of injected PDG
+      if (it != injectedPDGs.end())                        // found
+      {
+        // count signal PDG
+        nSignal[index]++;
+      }
+    }
+  }
+  std::cout << "--------------------------------\n";
+  std::cout << "# Events: " << nEvents << "\n";
+  for (int i = 0; i < nInjection; i++) {
+    std::cout << "# Injected nuclei \n";
+    std::cout << injectedPDGs[i] << ": " << nSignal[i] << "\n";
+    if (nSignal[i] == 0) {
+      std::cerr << "No generated: " << injectedPDGs[i] << "\n";
+      return 1; // At least one of the injected particles should be generated
+    }
+  }
+  return 0;
+}

MC/config/PWGLF/pythia8/generator/v0particlelist.gun

@@ -0,0 +1,4 @@
+# PDG           N      ptMin   ptMax  etaMin  etaMax  genDecayed
+310             1      0.2     10     -1.2    1.2
+3122            1      0.2     10     -1.2    1.2
+-3122           1      0.2     10     -1.2    1.2