add new generator for material budget systematics study

MC/CustomGenerators/PWGLF/Hijing_muB_pileup_002.C

@@ -0,0 +1,83 @@
+#if !defined(__CINT__) || defined(__MAKECINT__)
+//For ROOT6
+R__ADD_INCLUDE_PATH($ALIDPG_ROOT)
+#include "Utils/GetTriggerBCMaskAndMu.C"
+#endif
+
+AliGenerator *GeneratorCustom()
+{
+
+#if defined(__CINT__)
+  // For ROOT5
+  gROOT->LoadMacro("$ALIDPG_ROOT/Utils/GetTriggerBCMaskAndMu.C++");
+#endif
+
+  Double_t mu = 0.001;
+  TString bcm = GetTriggerBCMaskAndMu(mu);
+
+  //printf("   BC mask = %s\n",bcm.Data());
+  //printf("   mu = %f\n",mu);
+  //printf("   Energy = %f\n",energyConfig);
+
+  // Set the pileup interaction generator
+  // The second argument is the pileup rate
+  // in terms of event rate per bunch crossing
+  AliGenCocktail *ctl = (AliGenCocktail *)GeneratorCocktail("Hijing_muB_pileup_002");
+
+  const Int_t pdgcodes[3] = {
+      2212,
+      1000010020,
+      1000020030};
+
+  const Char_t *names[3] = {
+      "Proton",
+      "Deuteron"
+      "He3"};
+
+  int npart[3] = {40, 10, 10};
+
+  double maxpt[3] = {3.5, 10.0, 10.0}; /// large pt range for Lambda for the mass measurement
+
+  for (Int_t ipart = 0; ipart < 3; ++ipart)
+  {
+    for (Int_t negative = 0; negative < 2; negative++)
+    {
+
+      AliGenBox *box = new AliGenBox(npart[ipart]);
+      Int_t pdg = pdgcodes[ipart];
+      if (negative)
+        pdg = -pdg;
+      box->SetPart(pdg);
+      box->SetPtRange(0.2, maxpt[ipart]);
+      box->SetPhiRange(0., 360.);
+      box->SetYRange(-1., 1.);
+      ctl->AddGenerator(box, Form("%s%i", names[ipart], negative), 1);
+    }
+  }
+
+  // this is the Hijing generator for the trigger event,
+  // which could contain an impact parameter cut
+  TString simulation = gSystem->Getenv("CONFIG_SIMULATION");
+  if (!simulation.Contains("Embed"))
+  {
+    AliGenHijing *hijingC = (AliGenHijing *)GeneratorHijing();
+
+    AliGenPileup *genpil = new AliGenPileup();
+    // this is the Hijing generator for the pileup events,
+    // which is configured wihtout impact parameter cuts
+    AliGenHijing *hijing = (AliGenHijing *)GeneratorHijing();
+    hijing->SetImpactParameterRange(0., 15.);
+    genpil->SetGenerator(hijing, mu);
+    // Set the beam time structure
+    // Details on the syntax in STEER/AliTriggerBCMask
+    genpil->SetBCMask(bcm.Data());
+    // Do not generate the trigger interaction!
+    genpil->GenerateTrigInteraction(kFALSE);
+    genpil->Print();
+
+    ctl->AddGenerator(genpil, "Pileup", 1.);
+    ctl->AddGenerator(hijingC, "Hijing", 1.);
+  }
+
+  return ctl;
+}