From e4fc4766c6ab9a4907ca361e12e7ff21047831fa Mon Sep 17 00:00:00 2001
From: Daiki Sekihata <daiki.sekihata@cern.ch>
Date: Mon, 4 May 2026 10:54:33 +0200
Subject: [PATCH] PWGEM/MC: add cfg and ini for VM2ee

---
 MC/config/PWGEM/ini/pythia8_pp_5360_VM2ee.ini | 10 ++++
 .../PWGEM/ini/tests/pythia8_pp_5360_VM2ee.C   | 56 +++++++++++++++++++
 .../generator/pythia8_pp_5360_VM2ee.cfg       | 37 ++++++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 MC/config/PWGEM/ini/pythia8_pp_5360_VM2ee.ini
 create mode 100644 MC/config/PWGEM/ini/tests/pythia8_pp_5360_VM2ee.C
 create mode 100644 MC/config/PWGEM/pythia8/generator/pythia8_pp_5360_VM2ee.cfg

diff --git a/MC/config/PWGEM/ini/pythia8_pp_5360_VM2ee.ini b/MC/config/PWGEM/ini/pythia8_pp_5360_VM2ee.ini
new file mode 100644
index 000000000..5b17885ed
--- /dev/null
+++ b/MC/config/PWGEM/ini/pythia8_pp_5360_VM2ee.ini
@@ -0,0 +1,10 @@
+#NEV_TEST> 5
+[Diamond]
+width[2]=6.0
+
+[GeneratorExternal]
+fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/ALICE3/pythia8/generator_pythia8_ALICE3.C
+funcName=generator_pythia8_ALICE3()
+
+[GeneratorPythia8]
+config=${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGEM/pythia8/generator/pythia8_pp_5360_VM2ee.cfg
diff --git a/MC/config/PWGEM/ini/tests/pythia8_pp_5360_VM2ee.C b/MC/config/PWGEM/ini/tests/pythia8_pp_5360_VM2ee.C
new file mode 100644
index 000000000..aaee11ffc
--- /dev/null
+++ b/MC/config/PWGEM/ini/tests/pythia8_pp_5360_VM2ee.C
@@ -0,0 +1,56 @@
+int External() {
+  std::string path{"o2sim_Kine.root"};
+  // Check that file exists, can be opened and has the correct tree
+  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);
+
+  // Check if all events are filled
+  auto nEvents = tree->GetEntries();
+  for (Long64_t i = 0; i < nEvents; ++i)
+  {
+    tree->GetEntry(i);
+    if (tracks->empty())
+    {
+      std::cerr << "Empty entry found at event " << i << "\n";
+      return 1;
+    }
+  }
+  // // check if each event has at least two oxygen ions
+  // for (int i = 0; i < nEvents; i++)
+  // {
+  //   auto check = tree->GetEntry(i);
+  //   int count = 0;
+  //   for (int idxMCTrack = 0; idxMCTrack < tracks->size(); ++idxMCTrack)
+  //   {
+  //     auto track = tracks->at(idxMCTrack);
+  //     if (track.GetPdgCode() == 1000080160)
+  //     {
+  //       count++;
+  //     }
+  //   }
+  //   if (count < 2)
+  //   {
+  //     std::cerr << "Event " << i << " has less than 2 oxygen ions\n";
+  //     return 1;
+  //   }
+  // }
+
+  return 0;
+}
+
+int pythia8()
+{
+    return External();
+}
diff --git a/MC/config/PWGEM/pythia8/generator/pythia8_pp_5360_VM2ee.cfg b/MC/config/PWGEM/pythia8/generator/pythia8_pp_5360_VM2ee.cfg
new file mode 100644
index 000000000..b767c9ea3
--- /dev/null
+++ b/MC/config/PWGEM/pythia8/generator/pythia8_pp_5360_VM2ee.cfg
@@ -0,0 +1,37 @@
+### Specify beams
+Beams:idA = 2212
+Beams:idB = 2212            
+Beams:eCM = 5360.              ### energy
+    
+Beams:frameType = 1
+ParticleDecays:limitTau0 = on
+ParticleDecays:tau0Max = 10.      ### match alice: 1cm/c = 10.0mm/c
+
+### processes
+SoftQCD:inelastic = on # all inelastic processes
+
+# default: do nothing, Monash 2013 will do its thing
+Tune:pp = 14
+
+Random:setSeed = on
+
+# don't modify pion's PR as charged multiplicity is drived by them.
+
+# eta
+221:oneChannel = 1 1.0 0 -11 11 22
+
+# eta'
+331:oneChannel = 1 0.294 0 -11 11 111
+331:addChannel = 1 0.706 0 -11 11 223
+
+# rho
+113:oneChannel = 1 1.0 0 -11 11
+
+# omega
+223:oneChannel = 1 0.088 0 -11 11
+223:addChannel = 1 0.912 0 -11 11 111
+
+# phi
+333:oneChannel = 1 0.710 0 -11 11
+333:addChannel = 1 0.032 0 -11 11 111
+333:addChannel = 1 0.258 0 -11 11 221