83 lines
3.4 KiB
C++
83 lines
3.4 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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//
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// Multibody "phase space" generator using GENBOD (CERNLIB W515) method.
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//
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// Author: Michael Kelsey (SLAC) <kelsey@slac.stanford.edu>
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#ifndef G4HadPhaseSpaceGenbod_HH
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#define G4HadPhaseSpaceGenbod_HH 1
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#include "G4VHadPhaseSpaceAlgorithm.hh"
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class G4HadPhaseSpaceGenbod : public G4VHadPhaseSpaceAlgorithm {
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public:
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G4HadPhaseSpaceGenbod(G4int verbose=0);
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virtual ~G4HadPhaseSpaceGenbod() {;}
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protected:
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virtual void GenerateMultiBody(G4double initialMass,
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const std::vector<G4double>& masses,
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std::vector<G4LorentzVector>& finalState);
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protected:
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void Initialize(G4double initialMass,
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const std::vector<G4double>& masses);
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void FillRandomBuffer();
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void ComputeWeightScale(const std::vector<G4double>& masses);
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void FillEnergySteps(G4double initialMass,
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const std::vector<G4double>& masses);
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void GenerateMomenta(const std::vector<G4double>& masses,
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std::vector<G4LorentzVector>& finalState);
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void AccumulateFinalState(size_t i,
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const std::vector<G4double>& masses,
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std::vector<G4LorentzVector>& finalState);
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G4bool AcceptEvent() const; // Use accept-reject to generate distribution
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G4double ComputeWeight() const;
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private:
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size_t nFinal; // Number of final state particles
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G4double totalMass; // Sum of final state masses
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G4double massExcess; // Available kinetic energy
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G4double weightMax; // Maximum possible weight
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G4int nTrials; // Accept/reject cycles taken
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std::vector<G4double> msum; // Cumulative sum of masses
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std::vector<G4double> msq; // Final state squared masses
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std::vector<G4double> rndm; // Random sequence for effective masses
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std::vector<G4double> meff; // Random final-state effective masses
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std::vector<G4double> pd; // Random momentum magnitudes
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};
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#endif /* G4HadPhaseSpaceGenbod_HH */
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