Geant4  10.02
G4HadPhaseSpaceGenbod.hh
Go to the documentation of this file.
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 // $Id$
27 //
28 // Multibody "phase space" generator using GENBOD (CERNLIB W515) method.
29 //
30 // Author: Michael Kelsey (SLAC) <kelsey@slac.stanford.edu>
31 
32 #ifndef G4HadPhaseSpaceGenbod_HH
33 #define G4HadPhaseSpaceGenbod_HH 1
34 
36 
37 
39 public:
40  G4HadPhaseSpaceGenbod(G4int verbose=0);
41  virtual ~G4HadPhaseSpaceGenbod() {;}
42 
43 protected:
44  virtual void GenerateMultiBody(G4double initialMass,
45  const std::vector<G4double>& masses,
46  std::vector<G4LorentzVector>& finalState);
47 
48 protected:
49  void Initialize(G4double initialMass,
50  const std::vector<G4double>& masses);
51 
52  void FillRandomBuffer();
53 
54  void ComputeWeightScale(const std::vector<G4double>& masses);
55 
56  void FillEnergySteps(G4double initialMass,
57  const std::vector<G4double>& masses);
58 
59  void GenerateMomenta(const std::vector<G4double>& masses,
60  std::vector<G4LorentzVector>& finalState);
61 
62  void AccumulateFinalState(size_t i,
63  const std::vector<G4double>& masses,
64  std::vector<G4LorentzVector>& finalState);
65 
66  G4bool AcceptEvent() const; // Use accept-reject to generate distribution
67  G4double ComputeWeight() const;
68 
69 private:
70  size_t nFinal; // Number of final state particles
71  G4double totalMass; // Sum of final state masses
72  G4double massExcess; // Available kinetic energy
73  G4double weightMax; // Maximum possible weight
74  G4int nTrials; // Accept/reject cycles taken
75 
76  std::vector<G4double> msum; // Cumulative sum of masses
77  std::vector<G4double> msq; // Final state squared masses
78  std::vector<G4double> rndm; // Random sequence for effective masses
79  std::vector<G4double> meff; // Random final-state effective masses
80  std::vector<G4double> pd; // Random momentum magnitudes
81 };
82 
83 #endif /* G4HadPhaseSpaceGenbod_HH */
void FillEnergySteps(G4double initialMass, const std::vector< G4double > &masses)
void GenerateMomenta(const std::vector< G4double > &masses, std::vector< G4LorentzVector > &finalState)
void ComputeWeightScale(const std::vector< G4double > &masses)
void AccumulateFinalState(size_t i, const std::vector< G4double > &masses, std::vector< G4LorentzVector > &finalState)
G4double ComputeWeight() const
virtual void GenerateMultiBody(G4double initialMass, const std::vector< G4double > &masses, std::vector< G4LorentzVector > &finalState)
int G4int
Definition: G4Types.hh:78
G4HadPhaseSpaceGenbod(G4int verbose=0)
bool G4bool
Definition: G4Types.hh:79
std::vector< G4double > msq
void Initialize(G4double initialMass, const std::vector< G4double > &masses)
std::vector< G4double > pd
std::vector< G4double > rndm
std::vector< G4double > msum
std::vector< G4double > meff
double G4double
Definition: G4Types.hh:76