// // ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // ------------------------------------------------------------ // GEANT 4 class header file // // History: // 01 August 2007 P.Gumplinger // Reference: TRIUMF PIENU Technote: // M. Blecher - "Inclusion of pi->enug in MC " // Rate is for gammas > 100keV // // ------------------------------------------------------------ // // // #include "G4PionRadiativeDecayChannel.hh" #include "G4PhysicalConstants.hh" #include "G4SystemOfUnits.hh" #include "Randomize.hh" #include "G4DecayProducts.hh" #include "G4LorentzVector.hh" G4PionRadiativeDecayChannel::G4PionRadiativeDecayChannel() : G4VDecayChannel(), beta(0.),cib(0.),csdp(0.),csdm(0.),cif(0.),cig(0.), xl(0.), yl(0.), xu(0.), yu(0.), d2wmax(0.) { } G4PionRadiativeDecayChannel:: G4PionRadiativeDecayChannel(const G4String& theParentName, G4double theBR) : G4VDecayChannel("Radiative Pion Decay",1) { // set names for daughter particles if (theParentName == "pi+") { SetBR(theBR); SetParent("pi+"); SetNumberOfDaughters(3); SetDaughter(0, "e+"); SetDaughter(1, "gamma"); SetDaughter(2, "nu_e"); } else if (theParentName == "pi-") { SetBR(theBR); SetParent("pi-"); SetNumberOfDaughters(3); SetDaughter(0, "e-"); SetDaughter(1, "gamma"); SetDaughter(2, "anti_nu_e"); } else { #ifdef G4VERBOSE if (GetVerboseLevel()>0) { G4cout << "G4RadiativePionDecayChannel:: constructor :"; G4cout << " parent particle is not charged pion but "; G4cout << theParentName << G4endl; } #endif } beta = 3.6612e-03; cib = 1.16141e-03; csdp = 3.45055e-02; csdm = 5.14122e-03; cif = 4.63543e-05; cig = 1.78928e-05; xl = 2.*0.1*MeV/139.57*MeV; yl = ((1.-xl) + std::sqrt((1-xl)*(1-xl)+4*beta*beta))/2.; xu = 1. - (yl - std::sqrt(yl*yl-4.*beta*beta))/2.; yu = 1. + beta*beta; d2wmax = D2W(xl,yl); } G4PionRadiativeDecayChannel::~G4PionRadiativeDecayChannel() { } G4PionRadiativeDecayChannel::G4PionRadiativeDecayChannel(const G4PionRadiativeDecayChannel &right) :G4VDecayChannel(right), beta(right.beta),cib(right.cib),csdp(right.csdp), csdm(right.csdm),cif(right.cif),cig(right.cig), xl(right.xl), yl(right.yl), xu(right.xu), yu(right.yu), d2wmax(right.d2wmax) { } G4PionRadiativeDecayChannel & G4PionRadiativeDecayChannel::operator=(const G4PionRadiativeDecayChannel & right) { if (this != &right) { kinematics_name = right.kinematics_name; verboseLevel = right.verboseLevel; rbranch = right.rbranch; // copy parent name parent_name = new G4String(*right.parent_name); // clear daughters_name array ClearDaughtersName(); // recreate array numberOfDaughters = right.numberOfDaughters; if ( numberOfDaughters >0 ) { if (daughters_name !=0) ClearDaughtersName(); daughters_name = new G4String*[numberOfDaughters]; //copy daughters name for (G4int index=0; index < numberOfDaughters; index++) { daughters_name[index] = new G4String(*right.daughters_name[index]); } } beta = right.beta; cib = right.cib; csdp = right.csdp; csdm = right.csdm; cif = right.cif; cig = right.cig; xl = right.xl; yl = right.yl; xu = right.xu; yu = right.yu; d2wmax = right.d2wmax; } return *this; } G4DecayProducts *G4PionRadiativeDecayChannel::DecayIt(G4double) { #ifdef G4VERBOSE if (GetVerboseLevel()>1) G4cout << "G4PionRadiativeDecayChannel::DecayIt "; #endif if (G4MT_parent == 0) FillParent(); if (G4MT_daughters == 0) FillDaughters(); // parent mass G4double parentmass = G4MT_parent->GetPDGMass(); G4double EMPI = parentmass; //daughters'mass const G4int N_DAUGHTER=3; G4double daughtermass[N_DAUGHTER]; G4double sumofdaughtermass = 0.0; for (G4int index=0; indexGetPDGMass(); sumofdaughtermass += daughtermass[index]; } G4double EMASS = daughtermass[0]; //create parent G4DynamicParticle at rest G4ThreeVector dummy; G4DynamicParticle * parentparticle = new G4DynamicParticle( G4MT_parent, dummy, 0.0); //create G4Decayproducts G4DecayProducts *products = new G4DecayProducts(*parentparticle); delete parentparticle; G4double x, y; const size_t MAX_LOOP=1000; for (size_t loop_counter1=0; loop_counter1 1.) break; } G4double d2w = D2W(x,y); if (d2w > G4UniformRand()*d2wmax) break; } //----------------------------------------------------------------------- // // Calculate the angle between positron and photon (cosine) // G4double cthetaGE = (y*(x-2.)+2.*(1.-x+beta*beta)) / (x*std::sqrt(y*y-4.*beta*beta)); // //----------------------------------------------------------------------- // G4double G = x * EMPI/2.; G4double E = y * EMPI/2.; // //----------------------------------------------------------------------- // if (E < EMASS) E = EMASS; // calculate daughter momentum G4double daughtermomentum[2]; daughtermomentum[0] = std::sqrt(E*E - EMASS*EMASS); G4double cthetaE = 2.*G4UniformRand()-1.; G4double sthetaE = std::sqrt(1.-cthetaE*cthetaE); G4double phiE = twopi*G4UniformRand()*rad; G4double cphiE = std::cos(phiE); G4double sphiE = std::sin(phiE); //Coordinates of the decay positron G4double px = sthetaE*cphiE; G4double py = sthetaE*sphiE; G4double pz = cthetaE; G4ThreeVector direction0(px,py,pz); G4DynamicParticle * daughterparticle0 = new G4DynamicParticle( G4MT_daughters[0], daughtermomentum[0]*direction0); products->PushProducts(daughterparticle0); daughtermomentum[1] = G; G4double sthetaGE = std::sqrt(1.-cthetaGE*cthetaGE); G4double phiGE = twopi*G4UniformRand()*rad; G4double cphiGE = std::cos(phiGE); G4double sphiGE = std::sin(phiGE); //Coordinates of the decay gamma with respect to the decay positron px = sthetaGE*cphiGE; py = sthetaGE*sphiGE; pz = cthetaGE; G4ThreeVector direction1(px,py,pz); direction1.rotateUz(direction0); G4DynamicParticle * daughterparticle1 = new G4DynamicParticle( G4MT_daughters[1], daughtermomentum[1]*direction1); products->PushProducts(daughterparticle1); // output message #ifdef G4VERBOSE if (GetVerboseLevel()>1) { G4cout << "G4PionRadiativeDecayChannel::DecayIt "; G4cout << " create decay products in rest frame " <DumpInfo(); } #endif return products; }