| 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 7 | // * conditions of the Geant4 Software License, included in the file * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // |
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| 27 | // |
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| 28 | // $Id: G4QString.hh,v 1.11 2009/08/24 14:41:49 mkossov Exp $ |
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| 29 | // GEANT4 tag $Name: hadr-chips-V09-03-08 $ |
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| 30 | |
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| 31 | #ifndef G4QString_h |
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| 32 | #define G4QString_h 1 |
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| 33 | |
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| 34 | // ------------------------------------------------------------ |
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| 35 | // GEANT 4 class header file |
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| 36 | // |
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| 37 | // ---------------- G4QString ---------------- |
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| 38 | // by Mikhail Kosov, October 2006. |
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| 39 | // class for an excited string used by Parton String Models |
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| 40 | // For comparison mirror member functions are taken from G4 classes: |
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| 41 | // G4FragmentingString |
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| 42 | // G4ExcitedStringDecay |
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| 43 | // |
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| 44 | // ------------------------------------------------------------ |
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| 45 | // Short description: If partons from the G4QPartonPair are close in |
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| 46 | // rapidity, they create Quasmons, but if they are far in the rapidity |
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| 47 | // space, they can not interact directly. Say the bottom parton (quark) |
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| 48 | // has rapidity 0, and the top parton (antiquark) has rapidity 8, then |
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| 49 | // the top quark splits in two by radiating gluon, and each part has |
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| 50 | // rapidity 4, then the gluon splits in quark-antiquark pair (rapidity |
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| 51 | // 2 each), and then the quark gadiates anothe gluon and reachs rapidity |
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| 52 | // 1. Now it can interact with the bottom antiquark, creating a Quasmon |
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| 53 | // or a hadron. The intermediate partons is the string ladder. |
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| 54 | // --------------------------------------------------------------------- |
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| 55 | |
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| 56 | #include "G4ios.hh" |
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| 57 | #include "globals.hh" |
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| 58 | #include "G4ThreeVector.hh" |
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| 59 | #include "G4LorentzVector.hh" |
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| 60 | #include "G4LorentzRotation.hh" |
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| 61 | #include "G4QHadronVector.hh" |
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| 62 | #include "G4QPartonPair.hh" |
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| 63 | #include "G4QPartonVector.hh" |
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| 64 | #include <algorithm> |
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| 65 | |
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| 66 | class G4QString |
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| 67 | { |
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| 68 | public: |
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| 69 | |
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| 70 | enum {PROJECTILE = 1, TARGET = -1}; // The same as in quark-pair (@@ ? M.K.) |
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| 71 | |
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| 72 | G4QString(); // formal creation of the string with future excitation |
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| 73 | G4QString(G4QParton* Color,G4QParton* Gluon, G4QParton* AntiColor, G4int Dir=PROJECTILE); |
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| 74 | G4QString(G4QParton* Col, G4QParton* AntiCol, G4int Dir=PROJECTILE); |
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| 75 | G4QString(G4QPartonPair* ColAntiCol); |
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| 76 | G4QString(const G4QString &right); |
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| 77 | G4QString(const G4QString &old, G4QParton* newdecay, const G4LorentzVector *momentum); |
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| 78 | G4QString(const G4QString &old, G4QParton* newdecay); |
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| 79 | G4QString(G4QParton* newdecay, const G4LorentzVector* momentum); |
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| 80 | |
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| 81 | ~G4QString(); |
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| 82 | |
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| 83 | // Selectors |
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| 84 | G4int operator==(const G4QString &right) const {return this == &right;} |
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| 85 | G4int operator!=(const G4QString &right) const {return this != &right;} |
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| 86 | const G4ThreeVector& GetPosition() const {return thePosition;} |
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| 87 | const G4QPartonVector* GetPartonList() const {return &thePartons;} |
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| 88 | G4QParton* GetLeftParton() const {return *thePartons.begin();} |
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| 89 | G4QParton* GetRightParton() const {return *(thePartons.end()-1);} |
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| 90 | G4int GetDirection() const {return theDirection;} |
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| 91 | G4LorentzVector Get4Momentum() const; |
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| 92 | G4QContent GetQC() const {return GetLeftParton()->GetQC()+GetRightParton()->GetQC();} |
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| 93 | G4int GetCharge() const {return GetQC().GetCharge();} |
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| 94 | G4int GetBaryonNumber() const {return GetQC().GetBaryonNumber();} |
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| 95 | G4int GetStrangeness() const {return GetQC().GetStrangeness();} |
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| 96 | G4int GetDecayDirection() const; |
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| 97 | G4bool DecayIsQuark() const {return theDecayParton->GetType()==1;} |
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| 98 | G4bool StableIsQuark() const {return theStableParton->GetType()==1;} |
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| 99 | G4ThreeVector DecayPt(); // Get Pt of the decaying quark @@ Called once |
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| 100 | G4double Mass2() const { return Pplus*Pminus-(Ptleft+Ptright).mag2();} |
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| 101 | G4double Mass() const // @@ Very dangerous! USE ONLY FORE THE LIGHT CONE ALGORITHM !! |
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| 102 | { |
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| 103 | G4double m2=Mass2(); |
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| 104 | if(m2>0) return std::sqrt(Mass2()); |
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| 105 | else return 0.; // @@ Make Warning |
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| 106 | } |
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| 107 | G4bool StopFragmentation() |
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| 108 | { |
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| 109 | G4LorentzVector mom(Ptleft+Ptright, 0.5*(Pplus+Pminus)); |
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| 110 | mom.setPz(0.5*(Pplus-Pminus)); |
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| 111 | return FragmentationMass(1) + MassCut > mom.mag(); |
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| 112 | } |
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| 113 | G4bool IsFragmentable() {return FragmentationMass() + MassCut < Mass();} // @@ Mass() ? |
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| 114 | G4ThreeVector SampleQuarkPt(); // @@ Called once |
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| 115 | G4QHadron* CreateHadron(G4QParton* black, G4QParton* white); |
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| 116 | G4QHadron* CreateLowSpinHadron(G4QParton* black, G4QParton* white); |
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| 117 | G4QHadron* CreateHighSpinHadron(G4QParton* black, G4QParton* white); |
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| 118 | |
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| 119 | // Modifiers |
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| 120 | void SetPosition(const G4ThreeVector& aPosition){thePosition= aPosition;} |
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| 121 | void SetDirection(G4int dir) {if(dir==1 || dir==-1) theDirection=dir;} |
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| 122 | void SetLeftParton(G4QParton* LP) {thePartons[0]=LP;} // !! Not deleting the substituty |
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| 123 | void SetRightParton(G4QParton* RP) {thePartons.pop_back(); thePartons.push_back(RP);} |
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| 124 | void KillString() {theDirection=0;} // @@ Can be absolete |
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| 125 | void LorentzRotate(const G4LorentzRotation& rotation); |
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| 126 | //void InsertParton(G4QParton* aParton, const G4QParton* addafter = NULL); |
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| 127 | void Boost(G4ThreeVector& Velocity); |
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| 128 | G4LorentzRotation TransformToAlignedCms(); // @@ caled once |
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| 129 | //void DiffString(G4QHadron* aHadron, G4bool isProjectile); @@ Mast be used!! |
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| 130 | void ExciteString(G4QParton* Col,G4QParton* AntiCol, G4int Dir); |
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| 131 | G4QHadronVector* FragmentString(G4bool QL); // Fragment String using QGSM=true/LUND=false |
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| 132 | G4QHadronVector* LightFragmentationTest(); |
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| 133 | G4double FragmentationMass(G4int HighSpin = 0, G4QHadronPair* pdefs = 0); |
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| 134 | void SetLeftPartonStable(); |
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| 135 | void SetRightPartonStable(); |
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| 136 | G4QHadron* Splitup(G4bool QL); |
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| 137 | G4LorentzVector* SplitEandP(G4QHadron* pHadron, G4bool QL); // QGSM:QL=true,Lund:QL=false |
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| 138 | G4QPartonPair CreatePartonPair(G4int NeedParticle, G4bool AllowDiquarks=true); |
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| 139 | G4QHadron* QuarkSplitup(G4QParton* decay, G4QParton* &created); |
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| 140 | G4QHadron* DiQuarkSplitup(G4QParton* decay, G4QParton* &created); |
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| 141 | G4int SampleQuarkFlavor() {return (1+G4int(G4UniformRand()/StrangeSuppress));} // ? M.K. |
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| 142 | |
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| 143 | // Static functions |
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| 144 | static void SetParameters(G4double mCut, G4double sigQT, G4double DQSup, G4double DQBU, |
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| 145 | G4double smPar, G4double SSup, G4double SigPt); |
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| 146 | |
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| 147 | private: |
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| 148 | enum Spin {SpinZero=1, SpinHalf=2, SpinOne=3, SpinThreeHalf=4}; |
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| 149 | // Private functions |
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| 150 | G4QHadron* CreateMeson(G4QParton* black, G4QParton* white, Spin spin); |
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| 151 | G4QHadron* CreateBaryon(G4QParton* black,G4QParton* white, Spin spin); |
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| 152 | G4ThreeVector GaussianPt(G4double widthSquare, G4double maxPtSquare) const; |
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| 153 | G4double GetLundLightConeZ(G4double zmin, G4double zmax, G4int PartonEncoding, |
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| 154 | G4QHadron* pHadron, G4double Px, G4double Py); |
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| 155 | G4double GetQGSMLightConeZ(G4double zmin, G4double zmax, G4int PartonEncoding, |
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| 156 | G4QHadron* pHadron, G4double Px, G4double Py); |
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| 157 | |
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| 158 | // Static parameters |
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| 159 | // Parameters of Longitudinal String Fragmentation |
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| 160 | static G4double MassCut; // minimum mass cut for the string |
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| 161 | static G4double SigmaQT; // quark transverse momentum distribution parameter |
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| 162 | static G4double DiquarkSuppress; // is Diquark suppression parameter |
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| 163 | static G4double DiquarkBreakProb; // is Diquark breaking probability |
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| 164 | static G4double SmoothParam; // QGS model parameter |
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| 165 | static G4double StrangeSuppress; // Strangeness suppression parameter |
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| 166 | static G4double widthOfPtSquare; // width^2 of pt for string excitation |
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| 167 | |
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| 168 | // Body |
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| 169 | G4int theDirection; // must be 1 (PROJECTILE) or -1 (TARGET), 0 - DEAD |
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| 170 | G4ThreeVector thePosition; // Defined by the first quark position |
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| 171 | G4QPartonVector thePartons; // Partons on the ends of the string @@ Use PartonPair |
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| 172 | G4ThreeVector Ptleft,Ptright; // Pt (px,py) for partons (pz ignored!) |
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| 173 | G4double Pplus, Pminus; // p-, p+ of string, Plus is assigned to Left! |
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| 174 | G4QParton* theStableParton; // Parton on the stable side of the string |
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| 175 | G4QParton* theDecayParton; // Parton on the decaying part of the string |
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| 176 | enum DecaySide {None, Left, Right};// @@ To have two @@ Leav : 1=Left |
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| 177 | DecaySide decaying; // @@ it's too much @@ only : 0=Unknown |
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| 178 | G4int SideOfDecay; // @@ of a good thing @@ one! : -1=Right |
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| 179 | }; |
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| 180 | |
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| 181 | #endif |
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