Gabriele Cosmo
191 lines
7.1 KiB
C++
191 lines
7.1 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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// INCL++ intra-nuclear cascade model
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// Alain Boudard, CEA-Saclay, France
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// Joseph Cugnon, University of Liege, Belgium
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// Jean-Christophe David, CEA-Saclay, France
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// Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
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// Sylvie Leray, CEA-Saclay, France
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// Davide Mancusi, CEA-Saclay, France
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//
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#define INCLXX_IN_GEANT4_MODE 1
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#include "globals.hh"
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#include "G4INCLNDeltaToDeltaLKChannel.hh"
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#include "G4INCLKinematicsUtils.hh"
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#include "G4INCLBinaryCollisionAvatar.hh"
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#include "G4INCLRandom.hh"
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#include "G4INCLGlobals.hh"
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#include "G4INCLLogger.hh"
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#include <algorithm>
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#include "G4INCLPhaseSpaceGenerator.hh"
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namespace G4INCL {
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const G4double NDeltaToDeltaLKChannel::angularSlope = 2.;
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NDeltaToDeltaLKChannel::NDeltaToDeltaLKChannel(Particle *p1, Particle *p2)
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: particle1(p1), particle2(p2)
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{}
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NDeltaToDeltaLKChannel::~NDeltaToDeltaLKChannel(){}
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G4double NDeltaToDeltaLKChannel::sampleDeltaMass(G4double ecm) {
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const G4double maxDeltaMass = ecm - ParticleTable::effectiveLambdaMass - ParticleTable::effectiveKaonMass - 1.0;
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const G4double maxDeltaMassRndm = std::atan((maxDeltaMass-ParticleTable::effectiveDeltaMass)*2./ParticleTable::effectiveDeltaWidth);
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const G4double deltaMassRndmRange = maxDeltaMassRndm - ParticleTable::minDeltaMassRndm;
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// assert(deltaMassRndmRange>0.);
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G4double y=ecm*ecm;
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G4double q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2 = (mNucleon + mPion)^2, 6.4E5 = 800^2 = (mNucleon - mPion)^2
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G4double q3=std::pow(std::sqrt(q2), 3.);
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const G4double f3max=q3/(q3+5.832E6); // 5.832E6 = 180^3 = ???^3
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G4double x;
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G4int nTries = 0;
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G4bool success = false;
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while(!success) { /* Loop checking, 10.07.2015, D.Mancusi */
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if(++nTries >= 100000) {
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INCL_WARN("NDeltaToDeltaLKChannel::sampleDeltaMass loop was stopped because maximum number of tries was reached. Minimum delta mass "
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<< ParticleTable::minDeltaMass << " MeV with CM energy " << ecm << " MeV may be unphysical." << '\n');
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return ParticleTable::minDeltaMass;
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}
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G4double rndm = ParticleTable::minDeltaMassRndm + Random::shoot() * deltaMassRndmRange;
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y = std::tan(rndm);
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x = ParticleTable::effectiveDeltaMass + 0.5*ParticleTable::effectiveDeltaWidth*y;
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// assert(x>=ParticleTable::minDeltaMass && ecm >= x + ParticleTable::effectiveLambdaMass + ParticleTable::effectiveKaonMass + 1.0);
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// generation of the delta mass with the penetration factor
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// (see prc56(1997)2431)
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y=x*x;
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q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2 = (mNucleon + mPion)^2, 6.4E5 = 800^2 = (mNucleon - mPion)^2
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q3=std::pow(std::sqrt(q2), 3.);
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const G4double f3=q3/(q3+5.832E6); // 5.832E6 = 180^3 = ???^3
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rndm = Random::shoot();
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if (rndm*f3max < f3)
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success = true;
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}
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return x;
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}
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void NDeltaToDeltaLKChannel::fillFinalState(FinalState *fs) {
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// D++ p -> L K+ D++ (4)
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//
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// D++ n -> L K+ D+ (3)
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// D++ n -> L K0 D++ (4)
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//
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// D+ p -> L K0 D++ (3)
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// D+ p -> L K+ D+ (2)
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//
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// D+ n -> L K+ D0 (4)
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// D+ n -> L K0 D+ (2)
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Particle *delta;
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Particle *nucleon;
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if (particle1->isResonance()) {
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delta = particle1;
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nucleon = particle2;
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}
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else {
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delta = particle2;
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nucleon = particle1;
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}
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const G4double sqrtS = KinematicsUtils::totalEnergyInCM(particle1, particle2);
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const G4int iso = ParticleTable::getIsospin(particle1->getType()) + ParticleTable::getIsospin(particle2->getType());
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const G4int iso_d = ParticleTable::getIsospin(delta->getType());
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const G4double rdm = Random::shoot();
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/* const G4double m1 = particle1->getMass();
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const G4double m2 = particle2->getMass();
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const G4double pLab = KinematicsUtils::momentumInLab(particle1, particle2);*/
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ParticleType KaonType;
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ParticleType DeltaType;
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nucleon->setType(Lambda);
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if(std::abs(iso) == 4){// D++ p
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KaonType = ParticleTable::getKaonType(iso/4);
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DeltaType = ParticleTable::getDeltaType(3*iso/4);
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}
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else if(iso == 0){// D+ n
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if(rdm*3 < 2){
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KaonType = ParticleTable::getKaonType(iso_d);
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DeltaType = ParticleTable::getDeltaType(-iso_d);
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}
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else{
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KaonType = ParticleTable::getKaonType(-iso_d);
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DeltaType = ParticleTable::getDeltaType(iso_d);
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}
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}
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else if(ParticleTable::getIsospin(particle1->getType()) == ParticleTable::getIsospin(particle2->getType())){// D+ p
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if(rdm*5 < 3){
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KaonType = ParticleTable::getKaonType(-iso/2);
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DeltaType = ParticleTable::getDeltaType(3*iso/2);
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}
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else{
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KaonType = ParticleTable::getKaonType(iso/2);
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DeltaType = ParticleTable::getDeltaType(iso/2);
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}
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}
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else{// D++ n
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if(rdm*7 < 3){
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KaonType = ParticleTable::getKaonType(iso/2);
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DeltaType = ParticleTable::getDeltaType(iso/2);
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}
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else{
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KaonType = ParticleTable::getKaonType(-iso/2);
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DeltaType = ParticleTable::getDeltaType(3*iso/2);
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}
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}
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delta->setType(DeltaType);
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delta->setMass(sampleDeltaMass(sqrtS));
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ParticleList list;
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list.push_back(delta);
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list.push_back(nucleon);
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const ThreeVector &rcol = nucleon->getPosition();
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const ThreeVector zero;
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Particle *kaon = new Particle(KaonType,zero,rcol);
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list.push_back(kaon);
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if(Random::shoot()<0.5) PhaseSpaceGenerator::generateBiased(sqrtS, list, 0, angularSlope);
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else PhaseSpaceGenerator::generateBiased(sqrtS, list, 1, angularSlope);
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fs->addModifiedParticle(delta);
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fs->addModifiedParticle(nucleon);
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fs->addCreatedParticle(kaon);
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}
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}
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