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26 //
27 // -------------------------------------------------------------------
28 // GEANT4 Class file
29 //
30 // For information related to this code contact:
31 //
32 // File name: G4XAqmTotal
33 //
34 // Author:
35 //
36 // Creation date: 15 April 1999
37 //
38 // Modifications:
39 //
40 // Additive Quark Model total cross section
41 // (H.J. Lipkin and F. Scheck, Phys.Rev. 16 (1966) 71
42 //
43 // -------------------------------------------------------------------
44
45 #include "globals.hh"
46 #include "G4ios.hh"
47 #include "G4Pow.hh"
48 #include "G4SystemOfUnits.hh"
49 #include "G4XAqmTotal.hh"
50 #include "G4KineticTrack.hh"
51 #include "G4ParticleDefinition.hh"
52
53
54 // Validity range of this cross-section
55 const G4double G4XAqmTotal::_lowLimit = 0.;
56 const G4double G4XAqmTotal::_highLimit = DBL_MAX;
57
58 G4XAqmTotal::G4XAqmTotal()
59 {
60 // As a first approximation the model is assumed to be valid over
61 // the entire energy range
62 }
63
64
65 G4XAqmTotal::~G4XAqmTotal()
66 { }
67
68
69 G4bool G4XAqmTotal::operator==(const G4XAqmTotal &right) const
70 {
71 return (this == (G4XAqmTotal *) &right);
72 }
73
74
75 G4bool G4XAqmTotal::operator!=(const G4XAqmTotal &right) const
76 {
77 return (this != (G4XAqmTotal *) &right);
78 }
79
80
81 G4double G4XAqmTotal::CrossSection(const G4KineticTrack& trk1, const G4KineticTrack& trk2) const
82 {
83 G4double sigma = 0.;
84
85 // Get strangeness content
86 const G4ParticleDefinition* def1 = trk1.GetDefinition();
87 G4int sTrk1 = def1->GetQuarkContent(3) + def1->GetAntiQuarkContent(3);
88 const G4ParticleDefinition* def2 = trk2.GetDefinition();
89 G4int sTrk2 = def2->GetQuarkContent(3) + def2->GetAntiQuarkContent(3);
90
91 // Get non-strange quark content
92 G4int qTrk1 = def1->GetQuarkContent(1) + def1->GetAntiQuarkContent(1) +
93 def1->GetQuarkContent(2) + def1->GetAntiQuarkContent(2) +
94 def1->GetQuarkContent(4) + def1->GetAntiQuarkContent(4) +
95 def1->GetQuarkContent(5) + def1->GetAntiQuarkContent(5) +
96 def1->GetQuarkContent(6) + def1->GetAntiQuarkContent(6);
97
98 G4int qTrk2 = def2->GetQuarkContent(1) + def2->GetAntiQuarkContent(1) +
99 def2->GetQuarkContent(2) + def2->GetAntiQuarkContent(2) +
100 def2->GetQuarkContent(4) + def2->GetAntiQuarkContent(4) +
101 def2->GetQuarkContent(5) + def2->GetAntiQuarkContent(5) +
102 def2->GetQuarkContent(6) + def2->GetAntiQuarkContent(6);
103
104 G4double sRatio1 = 0.;
105 if (qTrk1 != 0) sRatio1 = sTrk1 / qTrk1;
106
107 G4double sRatio2 = 0.;
108 if (qTrk2 != 0) sRatio2 = sTrk2 / qTrk2;
109
110 // Calculate the number of colliding mesons
111 G4int nMesons = 0;
112 G4int nQ1 = sTrk1 + qTrk1;
113
114 if (nQ1 == 2) nMesons++;
115 G4int nQ2 = sTrk2 + qTrk2;
116 if (nQ2 == 2) nMesons++;
117
118 // Cross-section (units to be checked!)
119 sigma = 40. * G4Pow::GetInstance()->powN((2.0/3.0),nMesons) * (1. - 0.4 * sRatio1) * (1. - 0.4 * sRatio2) * millibarn;
120
121 return sigma;
122 }
123
124
125 G4String G4XAqmTotal::Name() const
126 {
127 G4String name("AqmTotalCrossSection");
128 return name;
129 }
130
131
132
133 G4bool G4XAqmTotal::IsValid(G4double e) const
134 {
135 G4bool answer = InLimits(e,_lowLimit,_highLimit);
136
137 return answer;
138 }
139