include/Geant4/G4VHadDecayAlgorithm.hh

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0025 //
0026 //
0027 // Abstract base class for multibody "phase space" generators.  Subclasses
0028 // implement a specific algorithm, such as Kopylov, GENBOD, or Makoto's
0029 // NBody.  Subclasses are used by G4HadPhaseSpaceGenerator.
0030 //
0031 // Author:  Michael Kelsey (SLAC) <kelsey@slac.stanford.edu>
0032
0033 #ifndef G4VHadDecayAlgorithm_HH
0034 #define G4VHadDecayAlgorithm_HH 1
0035
0036 #include "globals.hh"
0037 #include "G4LorentzVector.hh"
0038 #include "G4ThreeVector.hh"
0039 #include <vector>
0040 #include <iosfwd>
0041
0042 class G4VHadDecayAlgorithm {
0043 public:
0044   G4VHadDecayAlgorithm(const G4String& algName, G4int verbose=0)
0045     : name(algName), verboseLevel(verbose) {;}
0046   virtual ~G4VHadDecayAlgorithm() {;}
0047
0048   // Initial state (rest mass) and list of final masses
0049   void Generate(G4double initialMass,
0050         const std::vector<G4double>& masses,
0051         std::vector<G4LorentzVector>& finalState);
0052
0053   // Enable (or disable if 0) diagnostic messages (subclass may overload)
0054   virtual void  SetVerboseLevel(G4int verbose) { verboseLevel = verbose; }
0055   G4int GetVerboseLevel() const { return verboseLevel; }
0056   const G4String& GetName() const { return name; }
0057
0058 protected:
0059   // Subclasses MUST implement these functions
0060   virtual void GenerateTwoBody(G4double initialMass,
0061                    const std::vector<G4double>& masses,
0062                    std::vector<G4LorentzVector>& finalState) = 0;
0063
0064   virtual void GenerateMultiBody(G4double initialMass,
0065                  const std::vector<G4double>& masses,
0066                  std::vector<G4LorentzVector>& finalState) = 0;
0067
0068   // Validate kinematics (e.g., limit number of final state particles)
0069   // Subclasses may override or call back to this function
0070   virtual G4bool IsDecayAllowed(G4double initialMass,
0071                 const std::vector<G4double>& masses) const;
0072
0073   // Two-body momentum function (c.f. PDK from CERNLIB W505)
0074   G4double TwoBodyMomentum(G4double M0, G4double M1, G4double M2) const;
0075
0076   // Convenience functions for uniform angular distributions
0077   G4double UniformTheta() const;
0078   G4double UniformPhi() const;
0079
0080   // Utility to dump vector contents to line of output
0081   void PrintVector(const std::vector<G4double>& v, const G4String& name,
0082            std::ostream& os) const;
0083
0084 private:
0085   G4String name;
0086   G4int verboseLevel;
0087 };
0088
0089 #endif  /* G4VHadDecayAlgorithm_HH */