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25 //
26 //
27 //
28 // ------------------------------------------------------------
29 // GEANT 4 class implementation file
30 //
31 // ---------------- G4Parton ----------------
32 // by Gunter Folger, June 1998.
33 // class for Parton (inside a string) used by Parton String Models
34 // ------------------------------------------------------------
35
36 #include "G4Parton.hh"
37 #include "G4HadronicException.hh"
38
39 G4Parton::G4Parton(G4int PDGcode)
40 {
41 PDGencoding=PDGcode;
42 theX = 0;
43 theDefinition=G4ParticleTable::GetParticleTable()->FindParticle(PDGencoding);
44 if (theDefinition == NULL)
45 {
46 G4cout << "Encoding = "<<PDGencoding<<G4endl;
47 const G4String& text = "G4Parton::GetDefinition(): Encoding not in particle table";
48 throw G4HadronicException(__FILE__, __LINE__, text);
49 }
50 //
51 // colour by random in (1,2,3)=(R,G,B) for quarks and
52 // in (-1,-2,-3)=(Rbar,Gbar,Bbar) for anti-quarks:
53 //
54 if (theDefinition->GetParticleType() == "quarks") {
55 theColour = ((G4int)(3.*G4UniformRand())+1)*(std::abs(PDGencoding)/PDGencoding) ;
56 }
57 //
58 // colour by random in (-1,-2,-3)=(Rbar,Gbar,Bbar)=(GB,RB,RG) for di-quarks and
59 // in (1,2,3)=(R,G,B)=(GB,RB,RG) for anti-di-quarks:
60 //
61 else if (theDefinition->GetParticleType() == "diquarks") {
62 theColour = -((G4int)(3.*G4UniformRand())+1)*(std::abs(PDGencoding)/PDGencoding);
63 }
64 //
65 // colour by random in (-11,-12,...,-33)=(RRbar,RGbar,RBbar,...,BBbar) for gluons:
66 //
67 else if (theDefinition->GetParticleType() == "gluons") {
68 theColour = -(((G4int)(3.*G4UniformRand())+1)*10 + ((G4int)(3.*G4UniformRand())+1));
69 }
70 else {
71 G4cout << "Encoding = "<<PDGencoding<<G4endl;
72 const G4String& text = "G4Parton::GetDefinition(): Particle is not a parton";
73 throw G4HadronicException(__FILE__, __LINE__, text);
74 }
75 //
76 // isospin-z from PDG-encoded isospin-z for
77 // quarks, anti-quarks, di-quarks, and anti-di-quarks:
78 //
79 if ((theDefinition->GetParticleType() == "quarks") || (theDefinition->GetParticleType() == "diquarks")){
80 theIsoSpinZ = theDefinition->GetPDGIsospin3();
81 }
82 //
83 // isospin-z choosen at random from PDG-encoded isospin for gluons (should be zero):
84 //
85 else {
86 G4int thisPDGiIsospin=theDefinition->GetPDGiIsospin();
87 if (thisPDGiIsospin == 0) {
88 theIsoSpinZ = 0;
89 }
90 else {
91 theIsoSpinZ = ((G4int)((thisPDGiIsospin+1)*G4UniformRand()))-thisPDGiIsospin*0.5;
92 }
93 }
94 //
95 // spin-z choosen at random from PDG-encoded spin:
96 //
97 G4int thisPDGiSpin=theDefinition->GetPDGiSpin();
98 if (thisPDGiSpin == 0) {
99 theSpinZ = 0;
100 }
101 else {
102 G4int rand=((G4int)((thisPDGiSpin+1)*G4UniformRand()));
103 theSpinZ = rand-thisPDGiSpin*0.5;;
104 }
105 }
106
107 G4Parton::G4Parton(const G4Parton &right)
108 {
109 PDGencoding = right.PDGencoding;
110 theMomentum = right.theMomentum;
111 thePosition = right.thePosition;
112 theX = right.theX;
113 theDefinition = right.theDefinition;
114 theColour = right.theColour;
115 theIsoSpinZ = right.theIsoSpinZ;
116 theSpinZ = right.theSpinZ;
117 }
118
119 G4Parton & G4Parton::operator=(const G4Parton &right)
120 {
121 if (this != &right)
122 {
123 PDGencoding=right.GetPDGcode();
124 theMomentum=right.Get4Momentum();
125 thePosition=right.GetPosition();
126 theX = right.theX;
127 theDefinition = right.theDefinition;
128 theColour = right.theColour;
129 theIsoSpinZ = right.theIsoSpinZ;
130 theSpinZ = right.theSpinZ;
131 }
132
133 return *this;
134 }
135
136 G4Parton::~G4Parton()
137 {
138 // cout << "G4Parton::~G4Parton(): this = "<<this <<endl;
139 // cout << "break here"<<this <<endl;
140 }
141
142 void G4Parton::DefineMomentumInZ(G4double aLightConeMomentum, G4bool aDirection)
143 {
144 G4double Mass = GetMass();
145 G4LorentzVector a4Momentum = Get4Momentum();
146 aLightConeMomentum*=theX;
147 G4double TransverseMass2 = sqr(a4Momentum.px()) + sqr(a4Momentum.py()) + sqr(Mass);
148 a4Momentum.setPz(0.5*(aLightConeMomentum - TransverseMass2/aLightConeMomentum)*(aDirection? 1: -1));
149 a4Momentum.setE( 0.5*(aLightConeMomentum + TransverseMass2/aLightConeMomentum));
150 Set4Momentum(a4Momentum);
151 }
152
153 void G4Parton::DefineMomentumInZ(G4double aLightConeMomentum,G4double aLightConeE, G4bool aDirection)
154 {
155 G4double Mass = GetMass();
156 G4LorentzVector a4Momentum = Get4Momentum();
157 aLightConeMomentum*=theX;
158 aLightConeE*=theX;
159 G4double TransverseMass2 = sqr(a4Momentum.px()) + sqr(a4Momentum.py()) + sqr(Mass);
160 a4Momentum.setPz(0.5*(aLightConeMomentum - aLightConeE - TransverseMass2/aLightConeMomentum)*(aDirection? 1: -1));
161 a4Momentum.setE( 0.5*(aLightConeMomentum + aLightConeE + TransverseMass2/aLightConeMomentum));
162 Set4Momentum(a4Momentum);
163 }
164