Geant4  10.03.p02
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G4VHadPhaseSpaceAlgorithm.cc
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25 //
26 // $Id$
27 //
28 // Abstract base class for multibody uniform phase space generators.
29 // Subclasses implement a specific algorithm, such as Kopylov, GENBOD,
30 // or Makoto's NBody. Subclasses are used by G4HadDecayGenerator.
31 //
32 // Author: Michael Kelsey (SLAC) <kelsey@slac.stanford.edu>
33 
35 #include "G4HadronicException.hh"
36 #include "G4PhysicalConstants.hh"
37 #include "G4SystemOfUnits.hh"
38 #include "G4ThreeVector.hh"
39 #include "Randomize.hh"
40 #include <algorithm>
41 #include <iostream>
42 #include <iterator>
43 #include <numeric>
44 #include <vector>
45 
46 
47 
48 
49 // Two body decay with uniform angular distribution
50 
53  const std::vector<G4double>& masses,
54  std::vector<G4LorentzVector>& finalState) {
55  if (GetVerboseLevel()>1)
56  G4cout << " >>> G4HadDecayGenerator::FillTwoBody" << G4endl;
57 
58  // Initialization and sanity check
59  finalState.clear();
60  if (masses.size() != 2U) return; // Should not have been called
61 
62  // Momentum of final state (energy balance has already been checked)
63  G4double p = TwoBodyMomentum(initialMass,masses[0],masses[1]);
64  if (GetVerboseLevel()>2) G4cout << " finalState momentum = " << p << G4endl;
65 
66  finalState.resize(2); // Allows filling by index
67  finalState[0].setVectM(UniformVector(p), masses[0]);
68  finalState[1].setVectM(-finalState[0].vect(), masses[1]);
69 }
70 
71 
72 // Samples a random vector with given magnitude
73 
75  // FIXME: Should this be made a static thread-local buffer?
78  return v;
79 }
G4double UniformTheta() const
const char * p
Definition: xmltok.h:285
G4int GetVerboseLevel() const
G4GLOB_DLL std::ostream G4cout
void setRThetaPhi(double r, double theta, double phi)
tuple v
Definition: test.py:18
virtual void GenerateTwoBody(G4double initialMass, const std::vector< G4double > &masses, std::vector< G4LorentzVector > &finalState)
G4double UniformPhi() const
G4double TwoBodyMomentum(G4double M0, G4double M1, G4double M2) const
#define G4endl
Definition: G4ios.hh:61
double G4double
Definition: G4Types.hh:76
G4ThreeVector UniformVector(G4double mag=1.) const