Import Geant4 9.6.0 source tree
This commit is contained in:
Gabriele Cosmo
+289
-292
@@ -24,6 +24,8 @@
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// ********************************************************************
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//
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#include "G4QGSMSplitableHadron.hh"
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#include "G4PhysicalConstants.hh"
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#include "G4SystemOfUnits.hh"
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#include "G4ParticleTable.hh"
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#include "G4PionPlus.hh"
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#include "G4PionMinus.hh"
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@@ -48,386 +50,381 @@
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void G4QGSMSplitableHadron::InitParameters()
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{
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// changing rapidity distribution for all
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alpha = -0.5; // Note that this number is still assumed in the algorithm
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// needs to be generalized.
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// changing rapidity distribution for projectile like
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beta = 2.5;// Note that this number is still assumed in the algorithm
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// needs to be generalized.
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theMinPz = 0.5*G4PionMinus::PionMinus()->GetPDGMass();
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// theMinPz = 0.1*G4PionMinus::PionMinus()->GetPDGMass();
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// theMinPz = G4PionMinus::PionMinus()->GetPDGMass();
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// as low as possible, otherwise, we have unphysical boundary conditions in the sampling.
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StrangeSuppress = 0.48;
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sigmaPt = 0.*GeV; // widens eta slightly, if increased to 1.7,
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// but Maxim's algorithm breaks energy conservation
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// to be revised.
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widthOfPtSquare = 0.01*GeV*GeV;
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Direction = FALSE;
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minTransverseMass = 1*keV;
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// changing rapidity distribution for all
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alpha = -0.5; // Note that this number is still assumed in the algorithm
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// needs to be generalized.
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// changing rapidity distribution for projectile like
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beta = 2.5;// Note that this number is still assumed in the algorithm
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// needs to be generalized.
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theMinPz = 0.5*G4PionMinus::PionMinus()->GetPDGMass();
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// theMinPz = 0.1*G4PionMinus::PionMinus()->GetPDGMass();
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// theMinPz = G4PionMinus::PionMinus()->GetPDGMass();
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// as low as possible, otherwise, we have unphysical boundary conditions in the sampling.
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StrangeSuppress = 0.48;
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sigmaPt = 0.*GeV; // widens eta slightly, if increased to 1.7,
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// but Maxim's algorithm breaks energy conservation
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// to be revised.
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widthOfPtSquare = 0.01*GeV*GeV;
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Direction = FALSE;
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minTransverseMass = 1*keV;
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}
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G4QGSMSplitableHadron::G4QGSMSplitableHadron()
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{
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InitParameters();
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InitParameters();
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}
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G4QGSMSplitableHadron::G4QGSMSplitableHadron(const G4ReactionProduct & aPrimary, G4bool aDirection)
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:G4VSplitableHadron(aPrimary)
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:G4VSplitableHadron(aPrimary)
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{
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InitParameters();
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Direction = aDirection;
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InitParameters();
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Direction = aDirection;
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}
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G4QGSMSplitableHadron::G4QGSMSplitableHadron(const G4ReactionProduct & aPrimary)
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: G4VSplitableHadron(aPrimary)
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: G4VSplitableHadron(aPrimary)
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{
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InitParameters();
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InitParameters();
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}
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G4QGSMSplitableHadron::G4QGSMSplitableHadron(const G4Nucleon & aNucleon)
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: G4VSplitableHadron(aNucleon)
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: G4VSplitableHadron(aNucleon)
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{
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InitParameters();
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InitParameters();
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}
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G4QGSMSplitableHadron::G4QGSMSplitableHadron(const G4Nucleon & aNucleon, G4bool aDirection)
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: G4VSplitableHadron(aNucleon)
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: G4VSplitableHadron(aNucleon)
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{
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InitParameters();
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Direction = aDirection;
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InitParameters();
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Direction = aDirection;
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}
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G4QGSMSplitableHadron::~G4QGSMSplitableHadron(){}
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const G4QGSMSplitableHadron & G4QGSMSplitableHadron::operator=(const G4QGSMSplitableHadron &)
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{
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throw G4HadronicException(__FILE__, __LINE__, "G4QGSMSplitableHadron::operator= meant to not be accessable");
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return *this;
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}
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//**************************************************************************************************************************
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void G4QGSMSplitableHadron::SplitUp()
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{
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if (IsSplit()) return;
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Splitting();
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if (Color.size()!=0) return;
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if (GetSoftCollisionCount() == 0)
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{
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DiffractiveSplitUp();
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}
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else
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{
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SoftSplitUp();
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}
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if (IsSplit()) return;
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Splitting();
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if (Color.size()!=0) return;
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if (GetSoftCollisionCount() == 0)
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{
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DiffractiveSplitUp();
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}
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else
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{
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SoftSplitUp();
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}
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}
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void G4QGSMSplitableHadron::DiffractiveSplitUp()
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{
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// take the particle definitions and get the partons HPW
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G4Parton * Left = NULL;
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G4Parton * Right = NULL;
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GetValenceQuarkFlavors(GetDefinition(), Left, Right);
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Left->SetPosition(GetPosition());
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Right->SetPosition(GetPosition());
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G4LorentzVector HadronMom = Get4Momentum();
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//std::cout << "DSU 1 - "<<HadronMom<<std::endl;
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// take the particle definitions and get the partons HPW
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G4Parton * Left = NULL;
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G4Parton * Right = NULL;
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GetValenceQuarkFlavors(GetDefinition(), Left, Right);
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Left->SetPosition(GetPosition());
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Right->SetPosition(GetPosition());
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// momenta of string ends
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G4double pt2 = HadronMom.perp2();
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G4double transverseMass2 = HadronMom.plus()*HadronMom.minus();
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G4double maxAvailMomentum2 = sqr(std::sqrt(transverseMass2) - std::sqrt(pt2));
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G4ThreeVector pt(minTransverseMass, minTransverseMass, 0);
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if(maxAvailMomentum2/widthOfPtSquare>0.01) pt = GaussianPt(widthOfPtSquare, maxAvailMomentum2);
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//std::cout << "DSU 1.1 - "<< maxAvailMomentum2<< pt <<std::endl;
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G4LorentzVector HadronMom = Get4Momentum();
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//std::cout << "DSU 1 - "<<HadronMom<<std::endl;
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G4LorentzVector LeftMom(pt, 0.);
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G4LorentzVector RightMom;
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RightMom.setPx(HadronMom.px() - pt.x());
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RightMom.setPy(HadronMom.py() - pt.y());
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//std::cout << "DSU 2 - "<<RightMom<<" "<< LeftMom <<std::endl;
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// momenta of string ends
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G4double pt2 = HadronMom.perp2();
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G4double transverseMass2 = HadronMom.plus()*HadronMom.minus();
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G4double maxAvailMomentum2 = sqr(std::sqrt(transverseMass2) - std::sqrt(pt2));
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G4ThreeVector pt(minTransverseMass, minTransverseMass, 0);
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if(maxAvailMomentum2/widthOfPtSquare>0.01) pt = GaussianPt(widthOfPtSquare, maxAvailMomentum2);
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//std::cout << "DSU 1.1 - "<< maxAvailMomentum2<< pt <<std::endl;
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G4double Local1 = HadronMom.minus() + (RightMom.perp2() - LeftMom.perp2())/HadronMom.plus();
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G4double Local2 = std::sqrt(std::max(0., sqr(Local1) - 4.*RightMom.perp2()*HadronMom.minus()/HadronMom.plus()));
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//std::cout << "DSU 3 - "<< Local1 <<" "<< Local2 <<std::endl;
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if (Direction) Local2 = -Local2;
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G4double RightMinus = 0.5*(Local1 + Local2);
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G4double LeftMinus = HadronMom.minus() - RightMinus;
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//std::cout << "DSU 4 - "<< RightMinus <<" "<< LeftMinus << " "<<HadronMom.minus() <<std::endl;
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G4LorentzVector LeftMom(pt, 0.);
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G4LorentzVector RightMom;
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RightMom.setPx(HadronMom.px() - pt.x());
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RightMom.setPy(HadronMom.py() - pt.y());
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//std::cout << "DSU 2 - "<<RightMom<<" "<< LeftMom <<std::endl;
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G4double LeftPlus = LeftMom.perp2()/LeftMinus;
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G4double RightPlus = HadronMom.plus() - LeftPlus;
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//std::cout << "DSU 5 - "<< RightPlus <<" "<< LeftPlus <<std::endl;
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LeftMom.setPz(0.5*(LeftPlus - LeftMinus));
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LeftMom.setE (0.5*(LeftPlus + LeftMinus));
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RightMom.setPz(0.5*(RightPlus - RightMinus));
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RightMom.setE (0.5*(RightPlus + RightMinus));
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//std::cout << "DSU 6 - "<< LeftMom <<" "<< RightMom <<std::endl;
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Left->Set4Momentum(LeftMom);
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Right->Set4Momentum(RightMom);
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Color.push_back(Left);
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AntiColor.push_back(Right);
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G4double Local1 = HadronMom.minus() + (RightMom.perp2() - LeftMom.perp2())/HadronMom.plus();
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G4double Local2 = std::sqrt(std::max(0., sqr(Local1) - 4.*RightMom.perp2()*HadronMom.minus()/HadronMom.plus()));
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//std::cout << "DSU 3 - "<< Local1 <<" "<< Local2 <<std::endl;
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if (Direction) Local2 = -Local2;
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G4double RightMinus = 0.5*(Local1 + Local2);
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G4double LeftMinus = HadronMom.minus() - RightMinus;
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//std::cout << "DSU 4 - "<< RightMinus <<" "<< LeftMinus << " "<<HadronMom.minus() <<std::endl;
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G4double LeftPlus = LeftMom.perp2()/LeftMinus;
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G4double RightPlus = HadronMom.plus() - LeftPlus;
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//std::cout << "DSU 5 - "<< RightPlus <<" "<< LeftPlus <<std::endl;
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LeftMom.setPz(0.5*(LeftPlus - LeftMinus));
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LeftMom.setE (0.5*(LeftPlus + LeftMinus));
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RightMom.setPz(0.5*(RightPlus - RightMinus));
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RightMom.setE (0.5*(RightPlus + RightMinus));
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//std::cout << "DSU 6 - "<< LeftMom <<" "<< RightMom <<std::endl;
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Left->Set4Momentum(LeftMom);
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Right->Set4Momentum(RightMom);
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Color.push_back(Left);
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AntiColor.push_back(Right);
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}
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void G4QGSMSplitableHadron::SoftSplitUp()
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{
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//... sample transversal momenta for sea and valence quarks
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G4double phi, pts;
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G4double SumPy = 0.;
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G4double SumPx = 0.;
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G4ThreeVector Pos = GetPosition();
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G4int nSeaPair = GetSoftCollisionCount()-1;
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// here the condition,to ensure viability of splitting, also in cases
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// where difractive excitation occured together with soft scattering.
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// G4double LightConeMomentum = (Direction)? Get4Momentum().plus() : Get4Momentum().minus();
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// G4double Xmin = theMinPz/LightConeMomentum;
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G4double Xmin = theMinPz/( Get4Momentum().e() - GetDefinition()->GetPDGMass() );
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while(Xmin>=1-(2*nSeaPair+1)*Xmin) Xmin*=0.95;
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//... sample transversal momenta for sea and valence quarks
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G4double phi, pts;
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G4double SumPy = 0.;
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G4double SumPx = 0.;
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G4ThreeVector Pos = GetPosition();
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G4int nSeaPair = GetSoftCollisionCount()-1;
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G4int aSeaPair;
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for (aSeaPair = 0; aSeaPair < nSeaPair; aSeaPair++)
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{
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// choose quark flavour, d:u:s = 1:1:(1/StrangeSuppress-2)
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// here the condition,to ensure viability of splitting, also in cases
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// where difractive excitation occured together with soft scattering.
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// G4double LightConeMomentum = (Direction)? Get4Momentum().plus() : Get4Momentum().minus();
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// G4double Xmin = theMinPz/LightConeMomentum;
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G4double Xmin = theMinPz/( Get4Momentum().e() - GetDefinition()->GetPDGMass() );
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while(Xmin>=1-(2*nSeaPair+1)*Xmin) Xmin*=0.95;
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G4int aPDGCode = 1 + (G4int)(G4UniformRand()/StrangeSuppress);
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G4int aSeaPair;
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for (aSeaPair = 0; aSeaPair < nSeaPair; aSeaPair++)
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{
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// choose quark flavour, d:u:s = 1:1:(1/StrangeSuppress-2)
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// BuildSeaQuark() determines quark spin, isospin and colour
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// via parton-constructor G4Parton(aPDGCode)
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G4int aPDGCode = 1 + (G4int)(G4UniformRand()/StrangeSuppress);
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G4Parton * aParton = BuildSeaQuark(false, aPDGCode, nSeaPair);
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// BuildSeaQuark() determines quark spin, isospin and colour
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// via parton-constructor G4Parton(aPDGCode)
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// G4cerr << "G4QGSMSplitableHadron::SoftSplitUp()" << G4endl;
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G4Parton * aParton = BuildSeaQuark(false, aPDGCode, nSeaPair);
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// G4cerr << "Parton 1: "
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// << " PDGcode: " << aPDGCode
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// << " - Name: " << aParton->GetDefinition()->GetParticleName()
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// << " - Type: " << aParton->GetDefinition()->GetParticleType()
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// << " - Spin-3: " << aParton->GetSpinZ()
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// << " - Colour: " << aParton->GetColour() << G4endl;
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// G4cerr << "G4QGSMSplitableHadron::SoftSplitUp()" << G4endl;
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// save colour a spin-3 for anti-quark
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// G4cerr << "Parton 1: "
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// << " PDGcode: " << aPDGCode
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// << " - Name: " << aParton->GetDefinition()->GetParticleName()
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// << " - Type: " << aParton->GetDefinition()->GetParticleType()
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// << " - Spin-3: " << aParton->GetSpinZ()
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// << " - Colour: " << aParton->GetColour() << G4endl;
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G4int firstPartonColour = aParton->GetColour();
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G4double firstPartonSpinZ = aParton->GetSpinZ();
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// save colour a spin-3 for anti-quark
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SumPx += aParton->Get4Momentum().px();
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SumPy += aParton->Get4Momentum().py();
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Color.push_back(aParton);
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G4int firstPartonColour = aParton->GetColour();
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G4double firstPartonSpinZ = aParton->GetSpinZ();
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// create anti-quark
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SumPx += aParton->Get4Momentum().px();
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SumPy += aParton->Get4Momentum().py();
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Color.push_back(aParton);
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aParton = BuildSeaQuark(true, aPDGCode, nSeaPair);
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aParton->SetSpinZ(-firstPartonSpinZ);
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aParton->SetColour(-firstPartonColour);
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// create anti-quark
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// G4cerr << "Parton 2: "
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// << " PDGcode: " << -aPDGCode
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// << " - Name: " << aParton->GetDefinition()->GetParticleName()
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// << " - Type: " << aParton->GetDefinition()->GetParticleType()
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// << " - Spin-3: " << aParton->GetSpinZ()
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// << " - Colour: " << aParton->GetColour() << G4endl;
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// G4cerr << "------------" << G4endl;
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aParton = BuildSeaQuark(true, aPDGCode, nSeaPair);
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aParton->SetSpinZ(-firstPartonSpinZ);
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aParton->SetColour(-firstPartonColour);
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SumPx += aParton->Get4Momentum().px();
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SumPy += aParton->Get4Momentum().py();
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AntiColor.push_back(aParton);
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}
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// Valence quark
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G4Parton* pColorParton = NULL;
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G4Parton* pAntiColorParton = NULL;
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GetValenceQuarkFlavors(GetDefinition(), pColorParton, pAntiColorParton);
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G4int ColorEncoding = pColorParton->GetPDGcode();
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pts = sigmaPt*std::sqrt(-std::log(G4UniformRand()));
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phi = 2.*pi*G4UniformRand();
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G4double Px = pts*std::cos(phi);
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G4double Py = pts*std::sin(phi);
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SumPx += Px;
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SumPy += Py;
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// G4cerr << "Parton 2: "
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// << " PDGcode: " << -aPDGCode
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// << " - Name: " << aParton->GetDefinition()->GetParticleName()
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// << " - Type: " << aParton->GetDefinition()->GetParticleType()
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// << " - Spin-3: " << aParton->GetSpinZ()
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// << " - Colour: " << aParton->GetColour() << G4endl;
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// G4cerr << "------------" << G4endl;
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if (ColorEncoding < 0) // use particle definition
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{
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G4LorentzVector ColorMom(-SumPx, -SumPy, 0, 0);
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pColorParton->Set4Momentum(ColorMom);
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G4LorentzVector AntiColorMom(Px, Py, 0, 0);
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pAntiColorParton->Set4Momentum(AntiColorMom);
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}
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else
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{
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G4LorentzVector ColorMom(Px, Py, 0, 0);
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pColorParton->Set4Momentum(ColorMom);
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G4LorentzVector AntiColorMom(-SumPx, -SumPy, 0, 0);
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pAntiColorParton->Set4Momentum(AntiColorMom);
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}
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Color.push_back(pColorParton);
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AntiColor.push_back(pAntiColorParton);
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SumPx += aParton->Get4Momentum().px();
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SumPy += aParton->Get4Momentum().py();
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AntiColor.push_back(aParton);
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}
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// Valence quark
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G4Parton* pColorParton = NULL;
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G4Parton* pAntiColorParton = NULL;
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GetValenceQuarkFlavors(GetDefinition(), pColorParton, pAntiColorParton);
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G4int ColorEncoding = pColorParton->GetPDGcode();
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// Sample X
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G4int nAttempt = 0;
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G4double SumX = 0;
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G4double aBeta = beta;
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G4double ColorX, AntiColorX;
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if (GetDefinition() == G4PionMinus::PionMinusDefinition()) aBeta = 1.;
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if (GetDefinition() == G4Gamma::GammaDefinition()) aBeta = 1.;
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if (GetDefinition() == G4PionPlus::PionPlusDefinition()) aBeta = 1.;
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if (GetDefinition() == G4PionZero::PionZeroDefinition()) aBeta = 1.;
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if (GetDefinition() == G4KaonPlus::KaonPlusDefinition()) aBeta = 0.;
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if (GetDefinition() == G4KaonMinus::KaonMinusDefinition()) aBeta = 0.;
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do
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{
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SumX = 0;
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nAttempt++;
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G4int NumberOfUnsampledSeaQuarks = 2*nSeaPair;
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ColorX = SampleX(Xmin, NumberOfUnsampledSeaQuarks, 2*nSeaPair, aBeta);
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Color.back()->SetX(SumX = ColorX);// this is the valenz quark.
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for(G4int aPair = 0; aPair < nSeaPair; aPair++)
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{
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NumberOfUnsampledSeaQuarks--;
|
||||
ColorX = SampleX(Xmin, NumberOfUnsampledSeaQuarks, 2*nSeaPair, aBeta);
|
||||
Color[aPair]->SetX(ColorX);
|
||||
SumX += ColorX;
|
||||
NumberOfUnsampledSeaQuarks--;
|
||||
AntiColorX = SampleX(Xmin, NumberOfUnsampledSeaQuarks, 2*nSeaPair, aBeta);
|
||||
AntiColor[aPair]->SetX(AntiColorX); // the 'sea' partons
|
||||
SumX += AntiColorX;
|
||||
if (1. - SumX <= Xmin) break;
|
||||
}
|
||||
}
|
||||
while (1. - SumX <= Xmin);
|
||||
pts = sigmaPt*std::sqrt(-std::log(G4UniformRand()));
|
||||
phi = 2.*pi*G4UniformRand();
|
||||
G4double Px = pts*std::cos(phi);
|
||||
G4double Py = pts*std::sin(phi);
|
||||
SumPx += Px;
|
||||
SumPy += Py;
|
||||
|
||||
(*(AntiColor.end()-1))->SetX(1. - SumX); // the di-quark takes the rest, then go to momentum
|
||||
G4double lightCone = ((!Direction) ? Get4Momentum().minus() : Get4Momentum().plus());
|
||||
G4double lightCone2 = ((!Direction) ? Get4Momentum().plus() : Get4Momentum().minus());
|
||||
for(aSeaPair = 0; aSeaPair < nSeaPair+1; aSeaPair++)
|
||||
{
|
||||
G4Parton* aParton = Color[aSeaPair];
|
||||
aParton->DefineMomentumInZ(lightCone, lightCone2, Direction);
|
||||
if (ColorEncoding < 0) // use particle definition
|
||||
{
|
||||
G4LorentzVector ColorMom(-SumPx, -SumPy, 0, 0);
|
||||
pColorParton->Set4Momentum(ColorMom);
|
||||
G4LorentzVector AntiColorMom(Px, Py, 0, 0);
|
||||
pAntiColorParton->Set4Momentum(AntiColorMom);
|
||||
}
|
||||
else
|
||||
{
|
||||
G4LorentzVector ColorMom(Px, Py, 0, 0);
|
||||
pColorParton->Set4Momentum(ColorMom);
|
||||
G4LorentzVector AntiColorMom(-SumPx, -SumPy, 0, 0);
|
||||
pAntiColorParton->Set4Momentum(AntiColorMom);
|
||||
}
|
||||
Color.push_back(pColorParton);
|
||||
AntiColor.push_back(pAntiColorParton);
|
||||
|
||||
aParton = AntiColor[aSeaPair];
|
||||
aParton->DefineMomentumInZ(lightCone, lightCone2, Direction);
|
||||
}
|
||||
return;
|
||||
// Sample X
|
||||
G4int nAttempt = 0;
|
||||
G4double SumX = 0;
|
||||
G4double aBeta = beta;
|
||||
G4double ColorX, AntiColorX;
|
||||
if (GetDefinition() == G4PionMinus::PionMinusDefinition()) aBeta = 1.;
|
||||
if (GetDefinition() == G4Gamma::GammaDefinition()) aBeta = 1.;
|
||||
if (GetDefinition() == G4PionPlus::PionPlusDefinition()) aBeta = 1.;
|
||||
if (GetDefinition() == G4PionZero::PionZeroDefinition()) aBeta = 1.;
|
||||
if (GetDefinition() == G4KaonPlus::KaonPlusDefinition()) aBeta = 0.;
|
||||
if (GetDefinition() == G4KaonMinus::KaonMinusDefinition()) aBeta = 0.;
|
||||
do
|
||||
{
|
||||
SumX = 0;
|
||||
nAttempt++;
|
||||
G4int NumberOfUnsampledSeaQuarks = 2*nSeaPair;
|
||||
ColorX = SampleX(Xmin, NumberOfUnsampledSeaQuarks, 2*nSeaPair, aBeta);
|
||||
Color.back()->SetX(SumX = ColorX);// this is the valenz quark.
|
||||
for(G4int aPair = 0; aPair < nSeaPair; aPair++)
|
||||
{
|
||||
NumberOfUnsampledSeaQuarks--;
|
||||
ColorX = SampleX(Xmin, NumberOfUnsampledSeaQuarks, 2*nSeaPair, aBeta);
|
||||
Color[aPair]->SetX(ColorX);
|
||||
SumX += ColorX;
|
||||
NumberOfUnsampledSeaQuarks--;
|
||||
AntiColorX = SampleX(Xmin, NumberOfUnsampledSeaQuarks, 2*nSeaPair, aBeta);
|
||||
AntiColor[aPair]->SetX(AntiColorX); // the 'sea' partons
|
||||
SumX += AntiColorX;
|
||||
if (1. - SumX <= Xmin) break;
|
||||
}
|
||||
}
|
||||
while (1. - SumX <= Xmin);
|
||||
|
||||
(*(AntiColor.end()-1))->SetX(1. - SumX); // the di-quark takes the rest, then go to momentum
|
||||
G4double lightCone = ((!Direction) ? Get4Momentum().minus() : Get4Momentum().plus());
|
||||
G4double lightCone2 = ((!Direction) ? Get4Momentum().plus() : Get4Momentum().minus());
|
||||
for(aSeaPair = 0; aSeaPair < nSeaPair+1; aSeaPair++)
|
||||
{
|
||||
G4Parton* aParton = Color[aSeaPair];
|
||||
aParton->DefineMomentumInZ(lightCone, lightCone2, Direction);
|
||||
|
||||
aParton = AntiColor[aSeaPair];
|
||||
aParton->DefineMomentumInZ(lightCone, lightCone2, Direction);
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
void G4QGSMSplitableHadron::GetValenceQuarkFlavors(const G4ParticleDefinition * aPart, G4Parton *& Parton1, G4Parton *& Parton2)
|
||||
{
|
||||
// Note! convention aEnd = q or (qq)bar and bEnd = qbar or qq.
|
||||
G4int aEnd;
|
||||
G4int bEnd;
|
||||
G4int HadronEncoding = aPart->GetPDGEncoding();
|
||||
if (aPart->GetBaryonNumber() == 0)
|
||||
{
|
||||
theMesonSplitter.SplitMeson(HadronEncoding, &aEnd, &bEnd);
|
||||
}
|
||||
else
|
||||
{
|
||||
theBaryonSplitter.SplitBarion(HadronEncoding, &aEnd, &bEnd);
|
||||
}
|
||||
// Note! convention aEnd = q or (qq)bar and bEnd = qbar or qq.
|
||||
G4int aEnd;
|
||||
G4int bEnd;
|
||||
G4int HadronEncoding = aPart->GetPDGEncoding();
|
||||
if (aPart->GetBaryonNumber() == 0)
|
||||
{
|
||||
theMesonSplitter.SplitMeson(HadronEncoding, &aEnd, &bEnd);
|
||||
}
|
||||
else
|
||||
{
|
||||
theBaryonSplitter.SplitBarion(HadronEncoding, &aEnd, &bEnd);
|
||||
}
|
||||
|
||||
Parton1 = new G4Parton(aEnd);
|
||||
Parton1->SetPosition(GetPosition());
|
||||
Parton1 = new G4Parton(aEnd);
|
||||
Parton1->SetPosition(GetPosition());
|
||||
|
||||
// G4cerr << "G4QGSMSplitableHadron::GetValenceQuarkFlavors()" << G4endl;
|
||||
// G4cerr << "Parton 1: "
|
||||
// << " PDGcode: " << aEnd
|
||||
// << " - Name: " << Parton1->GetDefinition()->GetParticleName()
|
||||
// << " - Type: " << Parton1->GetDefinition()->GetParticleType()
|
||||
// << " - Spin-3: " << Parton1->GetSpinZ()
|
||||
// << " - Colour: " << Parton1->GetColour() << G4endl;
|
||||
// G4cerr << "G4QGSMSplitableHadron::GetValenceQuarkFlavors()" << G4endl;
|
||||
// G4cerr << "Parton 1: "
|
||||
// << " PDGcode: " << aEnd
|
||||
// << " - Name: " << Parton1->GetDefinition()->GetParticleName()
|
||||
// << " - Type: " << Parton1->GetDefinition()->GetParticleType()
|
||||
// << " - Spin-3: " << Parton1->GetSpinZ()
|
||||
// << " - Colour: " << Parton1->GetColour() << G4endl;
|
||||
|
||||
Parton2 = new G4Parton(bEnd);
|
||||
Parton2->SetPosition(GetPosition());
|
||||
Parton2 = new G4Parton(bEnd);
|
||||
Parton2->SetPosition(GetPosition());
|
||||
|
||||
// G4cerr << "Parton 2: "
|
||||
// << " PDGcode: " << bEnd
|
||||
// << " - Name: " << Parton2->GetDefinition()->GetParticleName()
|
||||
// << " - Type: " << Parton2->GetDefinition()->GetParticleType()
|
||||
// << " - Spin-3: " << Parton2->GetSpinZ()
|
||||
// << " - Colour: " << Parton2->GetColour() << G4endl;
|
||||
// G4cerr << "... now checking for color and spin conservation - yielding: " << G4endl;
|
||||
// G4cerr << "Parton 2: "
|
||||
// << " PDGcode: " << bEnd
|
||||
// << " - Name: " << Parton2->GetDefinition()->GetParticleName()
|
||||
// << " - Type: " << Parton2->GetDefinition()->GetParticleType()
|
||||
// << " - Spin-3: " << Parton2->GetSpinZ()
|
||||
// << " - Colour: " << Parton2->GetColour() << G4endl;
|
||||
// G4cerr << "... now checking for color and spin conservation - yielding: " << G4endl;
|
||||
|
||||
// colour of parton 1 choosen at random by G4Parton(aEnd)
|
||||
// colour of parton 2 is the opposite:
|
||||
// colour of parton 1 choosen at random by G4Parton(aEnd)
|
||||
// colour of parton 2 is the opposite:
|
||||
|
||||
Parton2->SetColour(-(Parton1->GetColour()));
|
||||
Parton2->SetColour(-(Parton1->GetColour()));
|
||||
|
||||
// isospin-3 of both partons is handled by G4Parton(PDGCode)
|
||||
|
||||
// spin-3 of parton 1 and 2 choosen at random by G4Parton(aEnd)
|
||||
// spin-3 of parton 2 may be constrained by spin of original particle:
|
||||
|
||||
if ( std::abs(Parton1->GetSpinZ() + Parton2->GetSpinZ()) > aPart->GetPDGSpin())
|
||||
{
|
||||
if ( std::abs(Parton1->GetSpinZ() + Parton2->GetSpinZ()) > aPart->GetPDGSpin())
|
||||
{
|
||||
Parton2->SetSpinZ(-(Parton2->GetSpinZ()));
|
||||
}
|
||||
}
|
||||
|
||||
// G4cerr << "Parton 2: "
|
||||
// << " PDGcode: " << bEnd
|
||||
// << " - Name: " << Parton2->GetDefinition()->GetParticleName()
|
||||
// << " - Type: " << Parton2->GetDefinition()->GetParticleType()
|
||||
// << " - Spin-3: " << Parton2->GetSpinZ()
|
||||
// << " - Colour: " << Parton2->GetColour() << G4endl;
|
||||
// G4cerr << "------------" << G4endl;
|
||||
// G4cerr << "Parton 2: "
|
||||
// << " PDGcode: " << bEnd
|
||||
// << " - Name: " << Parton2->GetDefinition()->GetParticleName()
|
||||
// << " - Type: " << Parton2->GetDefinition()->GetParticleType()
|
||||
// << " - Spin-3: " << Parton2->GetSpinZ()
|
||||
// << " - Colour: " << Parton2->GetColour() << G4endl;
|
||||
// G4cerr << "------------" << G4endl;
|
||||
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
G4ThreeVector G4QGSMSplitableHadron::GaussianPt(G4double widthSquare, G4double maxPtSquare)
|
||||
{
|
||||
G4double R;
|
||||
while((R = -widthSquare*std::log(G4UniformRand())) > maxPtSquare) {;}
|
||||
R = std::sqrt(R);
|
||||
G4double phi = twopi*G4UniformRand();
|
||||
return G4ThreeVector (R*std::cos(phi), R*std::sin(phi), 0.);
|
||||
G4double R;
|
||||
while((R = -widthSquare*std::log(G4UniformRand())) > maxPtSquare) {;}
|
||||
R = std::sqrt(R);
|
||||
G4double phi = twopi*G4UniformRand();
|
||||
return G4ThreeVector (R*std::cos(phi), R*std::sin(phi), 0.);
|
||||
}
|
||||
|
||||
G4Parton * G4QGSMSplitableHadron::
|
||||
BuildSeaQuark(G4bool isAntiQuark, G4int aPDGCode, G4int /* nSeaPair*/)
|
||||
{
|
||||
if (isAntiQuark) aPDGCode*=-1;
|
||||
G4Parton* result = new G4Parton(aPDGCode);
|
||||
result->SetPosition(GetPosition());
|
||||
G4ThreeVector aPtVector = GaussianPt(sigmaPt, DBL_MAX);
|
||||
G4LorentzVector a4Momentum(aPtVector, 0);
|
||||
result->Set4Momentum(a4Momentum);
|
||||
return result;
|
||||
if (isAntiQuark) aPDGCode*=-1;
|
||||
G4Parton* result = new G4Parton(aPDGCode);
|
||||
result->SetPosition(GetPosition());
|
||||
G4ThreeVector aPtVector = GaussianPt(sigmaPt, DBL_MAX);
|
||||
G4LorentzVector a4Momentum(aPtVector, 0);
|
||||
result->Set4Momentum(a4Momentum);
|
||||
return result;
|
||||
}
|
||||
|
||||
G4double G4QGSMSplitableHadron::
|
||||
SampleX(G4double anXmin, G4int nSea, G4int totalSea, G4double aBeta)
|
||||
{
|
||||
G4double result;
|
||||
G4double x1, x2;
|
||||
G4double ymax = 0;
|
||||
for(G4int ii=1; ii<100; ii++)
|
||||
{
|
||||
G4double y = std::pow(1./G4double(ii), alpha);
|
||||
y *= std::pow( std::pow(1-anXmin-totalSea*anXmin, alpha+1) - std::pow(anXmin, alpha+1), nSea);
|
||||
y *= std::pow(1-anXmin-totalSea*anXmin, aBeta+1) - std::pow(anXmin, aBeta+1);
|
||||
if(y>ymax) ymax = y;
|
||||
}
|
||||
G4double y;
|
||||
G4double xMax=1-(totalSea+1)*anXmin;
|
||||
if(anXmin > xMax)
|
||||
{
|
||||
G4cout << "anXmin = "<<anXmin<<" nSea = "<<nSea<<" totalSea = "<< totalSea<<G4endl;
|
||||
throw G4HadronicException(__FILE__, __LINE__, "G4QGSMSplitableHadron - Fatal: Cannot sample parton densities under these constraints.");
|
||||
}
|
||||
do
|
||||
{
|
||||
x1 = CLHEP::RandFlat::shoot(anXmin, xMax);
|
||||
y = std::pow(x1, alpha);
|
||||
y *= std::pow( std::pow(1-x1-totalSea*anXmin, alpha+1) - std::pow(anXmin, alpha+1), nSea);
|
||||
y *= std::pow(1-x1-totalSea*anXmin, aBeta+1) - std::pow(anXmin, aBeta+1);
|
||||
x2 = ymax*G4UniformRand();
|
||||
}
|
||||
while(x2>y);
|
||||
result = x1;
|
||||
return result;
|
||||
G4double result;
|
||||
G4double x1, x2;
|
||||
G4double ymax = 0;
|
||||
for(G4int ii=1; ii<100; ii++)
|
||||
{
|
||||
G4double y = std::pow(1./G4double(ii), alpha);
|
||||
y *= std::pow( std::pow(1-anXmin-totalSea*anXmin, alpha+1) - std::pow(anXmin, alpha+1), nSea);
|
||||
y *= std::pow(1-anXmin-totalSea*anXmin, aBeta+1) - std::pow(anXmin, aBeta+1);
|
||||
if(y>ymax) ymax = y;
|
||||
}
|
||||
G4double y;
|
||||
G4double xMax=1-(totalSea+1)*anXmin;
|
||||
if(anXmin > xMax)
|
||||
{
|
||||
G4cout << "anXmin = "<<anXmin<<" nSea = "<<nSea<<" totalSea = "<< totalSea<<G4endl;
|
||||
throw G4HadronicException(__FILE__, __LINE__, "G4QGSMSplitableHadron - Fatal: Cannot sample parton densities under these constraints.");
|
||||
}
|
||||
do
|
||||
{
|
||||
x1 = CLHEP::RandFlat::shoot(anXmin, xMax);
|
||||
y = std::pow(x1, alpha);
|
||||
y *= std::pow( std::pow(1-x1-totalSea*anXmin, alpha+1) - std::pow(anXmin, alpha+1), nSea);
|
||||
y *= std::pow(1-x1-totalSea*anXmin, aBeta+1) - std::pow(anXmin, aBeta+1);
|
||||
x2 = ymax*G4UniformRand();
|
||||
}
|
||||
while(x2>y);
|
||||
result = x1;
|
||||
return result;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user