Create Pythia8_Monash2013_Rsn004.C for Ps analysis

Create a generator to inject multiple strange pentaquark states into 13 TeV pp collisions to study efficiency

MC/CustomGenerators/PWGLF/Pythia8_Monash2013_Rsn004.C

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+struct particle_inj {
+  int n;
+  char name[32];
+  int pdg;
+  double maxpt;
+  double maxy;
+};
+
+AliGenerator* GeneratorCustom()
+{
+  AliGenCocktail *ctl = (AliGenCocktail*) GeneratorCocktail("Monash2013_RsnNcl002");
+  // pythia8
+  AliGenerator   *py8 = GeneratorPythia8(kPythia8Tune_Monash2013);
+  ctl->AddGenerator(py8, "Pythia8 (Monash2013)", 1.);
+
+  // randomly injected particles
+  const int nParticles = 16;
+  particle_inj particleList[16] = { // {name,pdgcode,maxpt,maxy},
+      {1,"Ps(1870)+",9322132,10.,0.55},
+      {1,"Ps_Bar(1870)-",-9322132,10.,0.55},
+      {1,"Ps(2065)+",9322312,10.,0.55},
+      {1,"Ps_Bar(2065)-",-9322312,10.,0.55},
+      {1,"Ps(2255)+",9323212,10.,0.55},
+      {1,"Ps_Bar(2255)-",-9323212,10.,0.55},
+      {1,"Ps(2455)+",9332212,10.,0.55},
+      {1,"Ps_Bar(2455)-",-9332212,10.,0.55},
+      {1,"Ps(1870)0",9322131,10.,0.55},
+      {1,"Ps_Bar(1870)0",-9322131,10.,0.55},
+      {1,"Ps(2065)0",9322311,10.,0.55},
+      {1,"Ps_Bar(2065)0",-9322311,10.,0.55},
+      {1,"Ps(2255)0",9323211,10.,0.55},
+      {1,"Ps_Bar(2255)0",-9323211,10.,0.55},
+      {1,"Ps(2455)0",9332211,10.,0.55},
+      {1,"Ps_Bar(2455)0",-9332211,10.,0.55}
+  };
+
+    AliDecayerPythia *dec = new AliDecayerPythia;
+    AliPDG::AddParticlesToPdgDataBase();
+
+    //ctl->UseSingleInjectionPerEvent();
+    for (int idx = 0; idx < nParticles; ++idx) {
+      AliGenerator   *inj = GeneratorParam(particleList[idx].n, particleList[idx].pdg, 1., particleList[idx].maxpt,-particleList[idx].maxy, particleList[idx].maxy,dec);
+      ctl->AddGenerator(inj, (TString(particleList[idx].name) + " injector").Data(), 1.);
+    }
+    return ctl;
+  }
+