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25 //
26 //
27 //
28 // --------------------------------------------------------------------
29 // GEANT4 class header file
30 //
31 // Class Description:
32 // Base class for a clipboard for communicating between quantum entangled tracks.
33 //
34 // ------------------ G4VEntanglementClipBoard ------------------
35 //
36 // Author: J.Allison, May 2017
37 //
38 // --------------------------------------------------------------------
39
40 // Usage:
41 //
42 // In the method that generates entangled secondaries
43 // (See, for example, G4eplusAnnihilation::AtRestDoIt)
44 // Make a shared pointer to a clip board and attach it to the tracks through
45 // G4EntanglementAuxInfo. That way the clip board lasts the life of both tracks.
46 // (G4XXXEntanglementClipBoard is your class inherited from this class)
47 // (See, for example, G4eplusAnnihilationEntanglementClipBoard)
48 // auto clipBoard = std::make_shared<G4XXXEntanglementClipBoard>();
49 // For each secondary
50 // G4Track* track = new G4Track(...
51 // ...
52 // clipBoard->SetTrackA(track);
53 // track->SetAuxiliaryTrackInformation(0,new G4EntanglementAuxInfo(clipBoard));
54 // Then repeat for track B
55 //
56 // In the method that does the quantum "measurement"
57 // (See, for example, G4LivermorePolarizedComptonModel::SampleSecondaries)
58 // const auto* auxInfo = fParticleChange->GetCurrentTrack()->GetAuxiliaryTrackInformation(0);
59 // if (auxInfo) {
60 // const auto* entanglementAuxInfo = dynamic_cast<const G4EntanglementAuxInfo*>(auxInfo);
61 // if (entanglementAuxInfo) {
62 // auto* clipBoard = dynamic_cast<G4XXXEntanglementClipBoard*>
63 // (entanglementAuxInfo->GetEntanglementClipBoard());
64 // if (clipBoard) {
65 // if (clipBoard->IsTrack1Measurement()) {
66 // if (clipBoard->GetTrackB() == fParticleChange->GetCurrentTrack()) {
67 // clipBoard->ResetTrack1Measurement();
68 // // Store information
69 // ...
70 // }
71 // } else if (clipBoard->IsTrack2Measurement()) {
72 // if (clipBoard->GetTrackA() == fParticleChange->GetCurrentTrack()) {
73 // clipBoard->ResetTrack2Measurement();
74 // // Retrieve information and apply quantum mechanics
75 // ...
76 // }
77 // }
78 // }
79 // }
80 // }
81
82 #ifndef G4VEntanglementClipBoard_hh
83 #define G4VEntanglementClipBoard_hh
84
85 #include "globals.hh"
86
87 class G4ParticleDefinition;
88 class G4Track;
89
90 class G4VEntanglementClipBoard {
91
92 public:
93
94 G4VEntanglementClipBoard()
95 : fpParentParticleDefinition(0)
96 , fTrackA(0)
97 , fTrackB(0)
98 , fTrack1Measurement(true)
99 , fTrack2Measurement(true)
100 {}
101 virtual ~G4VEntanglementClipBoard() {}
102
103 void SetParentParticleDefinition(G4ParticleDefinition* p)
104 {fpParentParticleDefinition = p;}
105 G4ParticleDefinition* GetParentParticleDefinition() const
106 {return fpParentParticleDefinition;}
107
108 void SetTrackA(const G4Track* track) {fTrackA = track;}
109 void SetTrackB(const G4Track* track) {fTrackB = track;}
110 const G4Track* GetTrackA() const {return fTrackA;}
111 const G4Track* GetTrackB() const {return fTrackB;}
112
113 // The entanglement-sensitive process is responsible for setting this.
114 void ResetTrack1Measurement() {fTrack1Measurement = false;}
115 void ResetTrack2Measurement() {fTrack2Measurement = false;}
116 G4bool IsTrack1Measurement() const {return fTrack1Measurement;}
117 G4bool IsTrack2Measurement() const {return fTrack2Measurement;}
118
119 private:
120
121 G4ParticleDefinition* fpParentParticleDefinition;
122
123 // Use pointer values to identify tracks. We don't know in which order the
124 // tracks will be processed so let us call them A & B.
125 const G4Track* fTrackA;
126 const G4Track* fTrackB;
127
128 // False until first measurement...
129 G4bool fTrack1Measurement; // ...of the first encountered track
130 G4bool fTrack2Measurement; // ...of the second encountered track
131
132 };
133
134 #endif
135