Add G4HepEm to CMSSW

The new EMH physics list replaces the EM processes for electrons,
positrons, and gammas with G4HepEm. Note that gamma-lepto-nuclear
interactions are NOT implemented yet, and disabled for this physics
list (by removing G4EmExtraPhysics).

BigProducts/Simulation/BuildFile.xml

@@ -31,7 +31,9 @@
 <use name="Validation/HcalHits"/>
 <use name="Validation/HGCalValidation"/>
 <use name="geant4static"/>
+<use name="g4hepemstatic"/>
 <flags DROP_DEP="geant4core"/>
+<flags DROP_DEP="g4hepemcore"/>
 <ifrelease name="!_LTO_">
   <!-- Disable LTO in BigLibs, as it seems to clash with debugging symbols with gcc 4.9.X -->
   <flags REM_BIGOBJ_CXXFLAGS="-flto"/>

SimG4Core/PhysicsLists/BuildFile.xml

@@ -1,6 +1,7 @@
 <use name="boost"/>
 <use name="clhep"/>
 <use name="geant4core"/>
+<use name="g4hepemcore"/>
 <use name="heppdt"/>
 <use name="FWCore/MessageLogger"/>
 <use name="SimG4Core/MagneticField"/>

SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsEMH.h

@@ -0,0 +1,26 @@
+#ifndef SimG4Core_PhysicsLists_CMSEmStandardPhysicsEMH_h
+#define SimG4Core_PhysicsLists_CMSEmStandardPhysicsEMH_h
+
+#include "G4VPhysicsConstructor.hh"
+#include "globals.hh"
+#include "G4MscStepLimitType.hh"
+
+#include "FWCore/ParameterSet/interface/ParameterSet.h"
+
+class CMSEmStandardPhysicsEMH : public G4VPhysicsConstructor {
+public:
+  CMSEmStandardPhysicsEMH(G4int ver, const edm::ParameterSet& p);
+  ~CMSEmStandardPhysicsEMH() override;
+
+  void ConstructParticle() override;
+  void ConstructProcess() override;
+
+private:
+  G4double fRangeFactor;
+  G4double fGeomFactor;
+  G4double fSafetyFactor;
+  G4double fLambdaLimit;
+  G4MscStepLimitType fStepLimitType;
+};
+
+#endif

SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_EMH.cc

@@ -0,0 +1,44 @@
+#include "FTFPCMS_BERT_EMH.h"
+#include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsEMH.h"
+#include "SimG4Core/PhysicsLists/interface/CMSHadronPhysicsFTFP_BERT.h"
+#include "FWCore/MessageLogger/interface/MessageLogger.h"
+
+#include "G4DecayPhysics.hh"
+#include "G4IonPhysics.hh"
+#include "G4StoppingPhysics.hh"
+#include "G4HadronElasticPhysics.hh"
+
+FTFPCMS_BERT_EMH::FTFPCMS_BERT_EMH(const edm::ParameterSet& p) : PhysicsList(p) {
+  int ver = p.getUntrackedParameter<int>("Verbosity", 0);
+  bool emPhys = p.getUntrackedParameter<bool>("EMPhysics", true);
+  bool hadPhys = p.getUntrackedParameter<bool>("HadPhysics", true);
+  double minFTFP = p.getParameter<double>("EminFTFP") * CLHEP::GeV;
+  double maxBERT = p.getParameter<double>("EmaxBERT") * CLHEP::GeV;
+  double maxBERTpi = p.getParameter<double>("EmaxBERTpi") * CLHEP::GeV;
+  edm::LogVerbatim("PhysicsList") << "CMS Physics List FTFP_BERT_EMH: "
+                                  << "\n Flags for EM Physics: " << emPhys << "; Hadronic Physics: " << hadPhys
+                                  << "\n Transition energy Bertini/FTFP from " << minFTFP / CLHEP::GeV << " to "
+                                  << maxBERT / CLHEP::GeV << "; for pions to " << maxBERTpi / CLHEP::GeV << " GeV";
+
+  if (emPhys) {
+    // EM Physics
+    RegisterPhysics(new CMSEmStandardPhysicsEMH(ver, p));
+  }
+
+  // Decays
+  this->RegisterPhysics(new G4DecayPhysics(ver));
+
+  if (hadPhys) {
+    // Hadron Elastic scattering
+    RegisterPhysics(new G4HadronElasticPhysics(ver));
+
+    // Hadron Physics
+    RegisterPhysics(new CMSHadronPhysicsFTFP_BERT(minFTFP, maxBERT, maxBERTpi, minFTFP, maxBERT));
+
+    // Stopping Physics
+    RegisterPhysics(new G4StoppingPhysics(ver));
+
+    // Ion Physics
+    RegisterPhysics(new G4IonPhysics(ver));
+  }
+}

SimG4Core/PhysicsLists/plugins/FTFPCMS_BERT_EMH.h

@@ -0,0 +1,12 @@
+#ifndef SimG4Core_PhysicsLists_FTFPCMS_BERT_EMH_H
+#define SimG4Core_PhysicsLists_FTFPCMS_BERT_EMH_H
+
+#include "SimG4Core/Physics/interface/PhysicsList.h"
+#include "FWCore/ParameterSet/interface/ParameterSet.h"
+
+class FTFPCMS_BERT_EMH : public PhysicsList {
+public:
+  FTFPCMS_BERT_EMH(const edm::ParameterSet& p);
+};
+
+#endif

SimG4Core/PhysicsLists/plugins/module.cc

@@ -3,6 +3,7 @@
 #include "DummyPhysics.h"
 #include "FTFCMS_BIC.h"
 #include "FTFPCMS_BERT.h"
+#include "FTFPCMS_BERT_EMH.h"
 #include "FTFPCMS_BERT_EML.h"
 #include "FTFPCMS_BERT_EMM.h"
 #include "G4Version.hh"
@@ -33,6 +34,8 @@ typedef FTFCMS_BIC FTF_BIC;
 DEFINE_PHYSICSLIST(FTF_BIC);
 typedef FTFPCMS_BERT FTFP_BERT;
 DEFINE_PHYSICSLIST(FTFP_BERT);
+typedef FTFPCMS_BERT_EMH FTFP_BERT_EMH;
+DEFINE_PHYSICSLIST(FTFP_BERT_EMH);
 typedef FTFPCMS_BERT_EML FTFP_BERT_EML;
 DEFINE_PHYSICSLIST(FTFP_BERT_EML);
 typedef FTFPCMS_BERT_EMM FTFP_BERT_EMM;

SimG4Core/PhysicsLists/src/CMSEmStandardPhysicsEMH.cc

@@ -0,0 +1,94 @@
+#include "SimG4Core/PhysicsLists/interface/CMSEmStandardPhysicsEMH.h"
+#include "FWCore/MessageLogger/interface/MessageLogger.h"
+
+#include "G4SystemOfUnits.hh"
+#include "G4ParticleDefinition.hh"
+#include "G4EmParameters.hh"
+#include "G4EmBuilder.hh"
+
+#include "G4MscStepLimitType.hh"
+
+#include "G4hIonisation.hh"
+#include "G4hMultipleScattering.hh"
+#include "G4ionIonisation.hh"
+
+#include "G4ParticleTable.hh"
+#include "G4Gamma.hh"
+#include "G4Electron.hh"
+#include "G4Positron.hh"
+#include "G4GenericIon.hh"
+
+#include "G4PhysicsListHelper.hh"
+#include "G4BuilderType.hh"
+#include "G4ProcessManager.hh"
+
+#include "G4HepEmProcess.hh"
+
+#include <string>
+
+CMSEmStandardPhysicsEMH::CMSEmStandardPhysicsEMH(G4int ver, const edm::ParameterSet& p)
+    : G4VPhysicsConstructor("CMSEmStandard_emh") {
+  SetVerboseLevel(ver);
+  G4EmParameters* param = G4EmParameters::Instance();
+  param->SetDefaults();
+  param->SetVerbose(ver);
+  param->SetApplyCuts(true);
+  param->SetStepFunction(0.8, 1 * CLHEP::mm);
+  param->SetMscRangeFactor(0.2);
+  param->SetMscStepLimitType(fUseSafety);
+  param->SetFluo(false);
+  SetPhysicsType(bElectromagnetic);
+  fRangeFactor = p.getParameter<double>("G4MscRangeFactor");
+  fGeomFactor = p.getParameter<double>("G4MscGeomFactor");
+  fSafetyFactor = p.getParameter<double>("G4MscSafetyFactor");
+  fLambdaLimit = p.getParameter<double>("G4MscLambdaLimit") * CLHEP::mm;
+  std::string msc = p.getParameter<std::string>("G4MscStepLimit");
+  fStepLimitType = fUseSafety;
+  if (msc == "UseSafetyPlus") {
+    fStepLimitType = fUseSafetyPlus;
+  }
+  if (msc == "Minimal") {
+    fStepLimitType = fMinimal;
+  }
+  double tcut = p.getParameter<double>("G4TrackingCut") * CLHEP::MeV;
+  param->SetLowestElectronEnergy(tcut);
+  param->SetLowestMuHadEnergy(tcut);
+}
+
+CMSEmStandardPhysicsEMH::~CMSEmStandardPhysicsEMH() {}
+
+void CMSEmStandardPhysicsEMH::ConstructParticle() {
+  // minimal set of particles for EM physics
+  G4EmBuilder::ConstructMinimalEmSet();
+}
+
+void CMSEmStandardPhysicsEMH::ConstructProcess() {
+  if (verboseLevel > 0) {
+    edm::LogVerbatim("PhysicsList") << "### " << GetPhysicsName() << " Construct EM Processes";
+  }
+
+  // This EM builder takes default models of Geant4 10 EMV.
+  // Multiple scattering by WentzelVI for all particles except:
+  //   a) e+e- below 100 MeV for which the Urban model is used
+  //   b) ions for which Urban model is used
+  G4EmBuilder::PrepareEMPhysics();
+
+  G4PhysicsListHelper* ph = G4PhysicsListHelper::GetPhysicsListHelper();
+  // processes used by several particles
+  G4hMultipleScattering* hmsc = new G4hMultipleScattering("ionmsc");
+  G4NuclearStopping* pnuc(nullptr);
+
+  G4HepEmProcess* hepEmProcess = new G4HepEmProcess();
+  G4Electron::Electron()->GetProcessManager()->AddProcess(hepEmProcess, -1, -1, 1);
+  G4Positron::Positron()->GetProcessManager()->AddProcess(hepEmProcess, -1, -1, 1);
+  G4Gamma::Gamma()->GetProcessManager()->AddProcess(hepEmProcess, -1, -1, 1);
+
+  // generic ion
+  G4ParticleDefinition* particle = G4GenericIon::GenericIon();
+  G4ionIonisation* ionIoni = new G4ionIonisation();
+  ph->RegisterProcess(hmsc, particle);
+  ph->RegisterProcess(ionIoni, particle);
+
+  // muons, hadrons ions
+  G4EmBuilder::ConstructCharged(hmsc, pnuc);
+}