Prompt charmonia in OO midrapidity with traigger gap 2 (default was 5) (#2169)

* Create Generator_InjectedPromptCharmoniaMidy_TriggerGap_2_OO5TeV.ini

* Create Create Generator_InjectedPromptCharmoniaMidy_TriggerGap_2_OO5TeV.C

* Rename Create Generator_InjectedPromptCharmoniaMidy_TriggerGap_2_OO5TeV.C to Generator_InjectedPromptCharmoniaMidy_TriggerGap_2_OO5TeV.C

Author: shreyasiacharya

MC/config/PWGDQ/ini/Generator_InjectedPromptCharmoniaMidy_TriggerGap_2_OO5TeV.ini

@@ -0,0 +1,7 @@
+### The external generator derives from GeneratorPythia8.
+[GeneratorExternal]
+fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGDQ/external/generator/generator_pythia8_withInjectedPromptSignals_gaptriggered_dq.C
+funcName=GeneratorPythia8InjectedPromptCharmoniaGapTriggered(2,12)
+
+[GeneratorPythia8]
+config=${O2DPG_MC_CONFIG_ROOT}/MC/config/common/pythia8/generator/pythia8_OO_536.cfg

MC/config/PWGDQ/ini/tests/Generator_InjectedPromptCharmoniaMidy_TriggerGap_2_OO5TeV.C

@@ -0,0 +1,84 @@
+int External()
+{
+    int checkPdgSignal[] = {443,100443};
+    int checkPdgDecay = 11;
+    std::string path{"o2sim_Kine.root"};
+    std::cout << "Check for\nsignal PDG " << checkPdgSignal << "\ndecay PDG " << checkPdgDecay << "\n";
+    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");
+    std::vector<o2::MCTrack>* tracks{};
+    tree->SetBranchAddress("MCTrack", &tracks);
+
+    int nLeptons{};
+    int nAntileptons{};
+    int nLeptonPairs{};
+    int nLeptonPairsToBeDone{};
+    int nSignalJpsi{};
+    int nSignalPsi2S{};
+    int nSignalJpsiWithinAcc{};
+    int nSignalPsi2SWithinAcc{};
+    auto nEvents = tree->GetEntries();
+    o2::steer::MCKinematicsReader mcreader("o2sim", o2::steer::MCKinematicsReader::Mode::kMCKine);
+    Bool_t isInjected = kFALSE;
+
+    for (int i = 0; i < nEvents; i++) {
+        tree->GetEntry(i);
+        for (auto& track : *tracks) {
+            auto pdg = track.GetPdgCode();
+	    auto rapidity =  track.GetRapidity();
+	    auto idMoth = track.getMotherTrackId();
+            if (pdg == checkPdgDecay) {
+                // count leptons
+                nLeptons++;
+            } else if(pdg == -checkPdgDecay) {
+                // count anti-leptons
+                nAntileptons++;
+            } else if (pdg == checkPdgSignal[0] || pdg == checkPdgSignal[1]) {
+                if(idMoth < 0){
+		// count signal PDG 
+		pdg == checkPdgSignal[0] ? nSignalJpsi++ : nSignalPsi2S++;
+                // count signal PDG within acceptance 
+		if(std::abs(rapidity) < 1.0) { pdg == checkPdgSignal[0] ? nSignalJpsiWithinAcc++ : nSignalPsi2SWithinAcc++;}
+		}
+		auto child0 = o2::mcutils::MCTrackNavigator::getDaughter0(track, *tracks);
+                auto child1 = o2::mcutils::MCTrackNavigator::getDaughter1(track, *tracks);
+                if (child0 != nullptr && child1 != nullptr) {
+                    // check for parent-child relations
+                    auto pdg0 = child0->GetPdgCode();
+                    auto pdg1 = child1->GetPdgCode();
+                    std::cout << "First and last children of parent " << checkPdgSignal << " are PDG0: " << pdg0 << " PDG1: " << pdg1 << "\n";
+                    if (std::abs(pdg0) == checkPdgDecay && std::abs(pdg1) == checkPdgDecay && pdg0 == -pdg1) {
+                        nLeptonPairs++;
+                        if (child0->getToBeDone() && child1->getToBeDone()) {
+                            nLeptonPairsToBeDone++;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    std::cout << "#events: " << nEvents << "\n"
+              << "#leptons: " << nLeptons << "\n"
+              << "#antileptons: " << nAntileptons << "\n"
+              << "#signal (prompt Jpsi): " << nSignalJpsi << "; within acceptance (|y| < 1): " << nSignalJpsiWithinAcc << "\n"
+              << "#signal (prompt Psi(2S)): " << nSignalPsi2S << "; within acceptance (|y| < 1): " << nSignalPsi2SWithinAcc << "\n"
+              << "#lepton pairs: " << nLeptonPairs << "\n"
+              << "#lepton pairs to be done: " << nLeptonPairs << "\n";
+
+
+    if (nLeptonPairs == 0 || nLeptons == 0 || nAntileptons == 0) {
+        std::cerr << "Number of leptons, number of anti-leptons as well as number of lepton pairs should all be greater than 1.\n";
+        return 1;
+    }
+    if (nLeptonPairs != nLeptonPairsToBeDone) {
+        std::cerr << "The number of lepton pairs should be the same as the number of lepton pairs which should be transported.\n";
+        return 1;
+    }
+
+    return 0;
+}