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G4eeToTwoPiModel.cc
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25 //
26 //
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class header file
30 //
31 //
32 // File name: G4eeToTwoPiModel
33 //
34 // Author: Vladimir Ivanchenko
35 //
36 // Creation date: 25.10.2003
37 //
38 // Modifications:
39 //
40 //
41 // -------------------------------------------------------------------
42 //
43 
44 
45 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
46 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
47 
48 #include "G4eeToTwoPiModel.hh"
49 #include "Randomize.hh"
50 #include "G4PhysicalConstants.hh"
51 #include "G4SystemOfUnits.hh"
52 #include "G4PionPlus.hh"
53 #include "G4PionMinus.hh"
54 #include "G4DynamicParticle.hh"
55 #include "G4PhysicsVector.hh"
56 #include "G4PhysicsLinearVector.hh"
57 #include "G4eeCrossSections.hh"
58 
59 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
60 
61 using namespace std;
62 
64  G4double maxkinEnergy,
65  G4double binWidth)
66 : G4Vee2hadrons(cr,
67  2.0*G4PionPlus::PionPlus()->GetPDGMass(),
68  maxkinEnergy,
69  binWidth)
70 {
71  G4cout << "#####G4eeToTwoPiModel####" << G4endl;
72 
74  massRho = 775.5*MeV;
75 }
76 
77 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
78 
80 {}
81 
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83 
85 {
86  return massRho;
87 }
88 
89 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
90 
92 {
93  return cross->CrossSection2pi(e);
94 }
95 
96 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
97 
98 void G4eeToTwoPiModel::SampleSecondaries(std::vector<G4DynamicParticle*>* newp,
99  G4double e, const G4ThreeVector& direction)
100 {
101 
102  G4double tkin = 0.5*e - massPi;
103  if(tkin < 0.0) tkin = 0.0;
104  G4double cost;
105  do {
106  cost = 2.0*G4UniformRand() - 1.0;
107  // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
108  } while( G4UniformRand() > 1.0 - cost*cost );
109 
110  G4double sint = sqrt(1.0 - cost*cost);
112 
113  G4ThreeVector dir(sint*cos(phi),sint*sin(phi), cost);
114  dir.rotateUz(direction);
115 
116  // create G4DynamicParticle objects
118  new G4DynamicParticle(G4PionPlus::PionPlus(),dir,tkin);
119  G4DynamicParticle* pin =
120  new G4DynamicParticle(G4PionMinus::PionMinus(),-dir,tkin);
121  newp->push_back(pip);
122  newp->push_back(pin);
123 }
124 
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126