source: trunk/source/processes/electromagnetic/highenergy/src/G4eeToTwoPiModel.cc

Last change on this file was 1337, checked in by garnier, 14 years ago

tag geant4.9.4 beta 1 + modifs locales
File size: 4.6 KB
Line 
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,v 1.7 2009/02/20 16:38:33 vnivanch Exp $
27// GEANT4 tag $Name: geant4-09-04-beta-01 $
28//
29// -------------------------------------------------------------------
30//
31// GEANT4 Class header file
32//
33//
34// File name:     G4eeToTwoPiModel
35//
36// Author:        Vladimir Ivanchenko
37//
38// Creation date: 25.10.2003
39//
40// Modifications:
41//
42//
43// -------------------------------------------------------------------
44//
45
46
47//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
48//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
49
50#include "G4eeToTwoPiModel.hh"
51#include "Randomize.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
61using namespace std;
62
63G4eeToTwoPiModel::G4eeToTwoPiModel(G4eeCrossSections* cr):
64  cross(cr)
65{
66  massPi = G4PionPlus::PionPlus()->GetPDGMass();
67  massRho = 775.5*MeV;
68}
69
70//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
71
72G4eeToTwoPiModel::~G4eeToTwoPiModel()
73{}
74
75//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
76
77G4double G4eeToTwoPiModel::ThresholdEnergy() const
78{
79  return 2.0*massPi;
80}
81
82//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
83
84G4double G4eeToTwoPiModel::PeakEnergy() const
85{
86  return massRho;
87}
88
89//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
90
91G4double G4eeToTwoPiModel::ComputeCrossSection(G4double e) const
92{
93  G4double ee = std::min(HighEnergy(),e);
94  return cross->CrossSection2pi(ee);
95}
96
97//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
98
99G4PhysicsVector* G4eeToTwoPiModel::PhysicsVector(G4double emin, 
100                                                 G4double emax) const
101{
102  G4double tmin = std::max(emin, 2.0*massPi);
103  G4double tmax = std::max(tmin, emax);
104  G4int nbins = (G4int)((tmax - tmin)/(5.*MeV));
105  G4PhysicsVector* v = new G4PhysicsLinearVector(emin,emax,nbins);
106  v->SetSpline(true);
107  return v;
108}
109
110//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
111
112void G4eeToTwoPiModel::SampleSecondaries(std::vector<G4DynamicParticle*>* newp,
113            G4double e, const G4ThreeVector& direction)
114{
115
116  G4double tkin = 0.5*e - massPi;
117  if(tkin < 0.0) tkin = 0.0;
118  G4double cost;
119  do {
120    cost = 2.0*G4UniformRand() - 1.0;
121  } while( G4UniformRand() > 1.0 - cost*cost );
122
123  G4double sint = sqrt(1.0 - cost*cost);
124  G4double phi  = twopi * G4UniformRand();
125
126  G4ThreeVector dir(sint*cos(phi),sint*sin(phi), cost);
127  dir.rotateUz(direction);
128
129  // create G4DynamicParticle objects
130  G4DynamicParticle* pip = 
131     new G4DynamicParticle(G4PionPlus::PionPlus(),dir,tkin);
132  G4DynamicParticle* pin = 
133     new G4DynamicParticle(G4PionMinus::PionMinus(),-dir,tkin);
134  newp->push_back(pip);
135  newp->push_back(pin);
136}
137
138//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
139
Note: See TracBrowser for help on using the repository browser.