Geant4  10.03.p02
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
G4eeToTwoPiModel.cc
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: G4eeToTwoPiModel.cc 91869 2015-08-07 15:21:02Z gcosmo $
27 //
28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class header file
31 //
32 //
33 // File name: G4eeToTwoPiModel
34 //
35 // Author: Vladimir Ivanchenko
36 //
37 // Creation date: 25.10.2003
38 //
39 // Modifications:
40 //
41 //
42 // -------------------------------------------------------------------
43 //
44 
45 
46 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
47 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
48 
49 #include "G4eeToTwoPiModel.hh"
50 #include "Randomize.hh"
51 #include "G4PhysicalConstants.hh"
52 #include "G4SystemOfUnits.hh"
53 #include "G4PionPlus.hh"
54 #include "G4PionMinus.hh"
55 #include "G4DynamicParticle.hh"
56 #include "G4PhysicsVector.hh"
57 #include "G4PhysicsLinearVector.hh"
58 #include "G4eeCrossSections.hh"
59 
60 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
61 
62 using namespace std;
63 
65  G4double maxkinEnergy,
66  G4double binWidth)
67 : G4Vee2hadrons(cr,
68  2.0*G4PionPlus::PionPlus()->GetPDGMass(),
69  maxkinEnergy,
70  binWidth)
71 {
72  G4cout << "#####G4eeToTwoPiModel####" << G4endl;
73 
74  massPi = G4PionPlus::PionPlus()->GetPDGMass();
75  massRho = 775.5*MeV;
76 }
77 
78 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
79 
81 {}
82 
83 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
84 
86 {
87  return massRho;
88 }
89 
90 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
91 
93 {
94  return cross->CrossSection2pi(e);
95 }
96 
97 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
98 
99 void G4eeToTwoPiModel::SampleSecondaries(std::vector<G4DynamicParticle*>* newp,
100  G4double e, const G4ThreeVector& direction)
101 {
102 
103  G4double tkin = 0.5*e - massPi;
104  if(tkin < 0.0) tkin = 0.0;
105  G4double cost;
106  do {
107  cost = 2.0*G4UniformRand() - 1.0;
108  // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
109  } while( G4UniformRand() > 1.0 - cost*cost );
110 
111  G4double sint = sqrt(1.0 - cost*cost);
112  G4double phi = twopi * G4UniformRand();
113 
114  G4ThreeVector dir(sint*cos(phi),sint*sin(phi), cost);
115  dir.rotateUz(direction);
116 
117  // create G4DynamicParticle objects
119  new G4DynamicParticle(G4PionPlus::PionPlus(),dir,tkin);
120  G4DynamicParticle* pin =
121  new G4DynamicParticle(G4PionMinus::PionMinus(),-dir,tkin);
122  newp->push_back(pip);
123  newp->push_back(pin);
124 }
125 
126 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
127 
G4double CrossSection2pi(G4double)
static constexpr double twopi
Definition: G4SIunits.hh:76
#define G4UniformRand()
Definition: Randomize.hh:97
G4GLOB_DLL std::ostream G4cout
Hep3Vector & rotateUz(const Hep3Vector &)
Definition: ThreeVector.cc:38
static G4PionPlus * PionPlus()
Definition: G4PionPlus.cc:98
G4double GetPDGMass() const
static G4PionMinus * PionMinus()
Definition: G4PionMinus.cc:98
virtual ~G4eeToTwoPiModel()
virtual void SampleSecondaries(std::vector< G4DynamicParticle * > *, G4double, const G4ThreeVector &) override
G4eeCrossSections * cross
#define G4endl
Definition: G4ios.hh:61
G4eeToTwoPiModel(G4eeCrossSections *, G4double, G4double)
static constexpr double MeV
Definition: G4SIunits.hh:214
double G4double
Definition: G4Types.hh:76
virtual G4double ComputeCrossSection(G4double) const override
virtual G4double PeakEnergy() const override