Gabriele Cosmo
153 lines
5.1 KiB
C++
153 lines
5.1 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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// ------------------------------------------------------------
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// GEANT 4 class header file
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//
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// History:
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// 25 July 2007 P.Gumplinger
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// Samples Radiative Muon Decay
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// Reference:
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// TRIUMF/TWIST Technote:
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// "Radiative muon decay" by P. Depommier and A. Vacheret
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//
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// ------------------------------------------------------------
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//
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//
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//
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//
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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#ifndef G4MuonRadiativeDecayChannelWithSpin_h
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#define G4MuonRadiativeDecayChannelWithSpin_h 1
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#include "globals.hh"
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#include "Randomize.hh"
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#include "G4ThreeVector.hh"
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#include "G4VDecayChannel.hh"
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class G4MuonRadiativeDecayChannelWithSpin : public G4VDecayChannel
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{
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// Class Decription
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// This class describes radiative muon decay kinemtics, but
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// gives incorrect energy spectrum for neutrinos
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public: // With Description
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//Constructors
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G4MuonRadiativeDecayChannelWithSpin(const G4String& theParentName,
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G4double theBR);
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// Destructor
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virtual ~G4MuonRadiativeDecayChannelWithSpin();
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public: // With Description
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virtual G4DecayProducts *DecayIt(G4double);
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void SetPolarization(G4ThreeVector);
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const G4ThreeVector& GetPolarization() const;
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private:
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G4ThreeVector parent_polarization;
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G4double fron(G4double Pmu, G4double x, G4double y,
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G4double cthetaE, G4double cthetaG, G4double cthetaEG);
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// rn3dim generates random vectors, uniformly distributed over the surface
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// of a sphere of given radius.
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// See http://wwwinfo.cern.ch/asdoc/shortwrupsdir/v131/top.html
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void rn3dim(G4double& x, G4double& y, G4double& z, G4double xlong);
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G4double atan4(G4double x, G4double y);
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G4double EMMU;
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G4double EMASS;
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};
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inline void G4MuonRadiativeDecayChannelWithSpin::
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SetPolarization(G4ThreeVector polar)
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{
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parent_polarization = polar;
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}
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inline const G4ThreeVector& G4MuonRadiativeDecayChannelWithSpin::
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GetPolarization() const
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{
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return parent_polarization;
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}
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inline void G4MuonRadiativeDecayChannelWithSpin::rn3dim(G4double& x,
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G4double& y,
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G4double& z,
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G4double xlong)
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{
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G4double a = 0.; G4double b = 0.; G4double c = 0.; G4double r = 0.;
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do {
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a = G4UniformRand() - 0.5;
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b = G4UniformRand() - 0.5;
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c = G4UniformRand() - 0.5;
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r = a*a + b*b + c*c;
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} while (r > 0.25);
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G4double rinv = xlong/(std::sqrt(r));
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x = a * rinv;
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y = b * rinv;
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z = c * rinv;
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return;
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}
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inline G4double G4MuonRadiativeDecayChannelWithSpin::atan4(G4double x,
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G4double y)
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{
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G4double phi = 0.;
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G4double pi = 4.*std::atan(1.);
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if (x==0. && y>0.){
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phi = 0.5*pi;
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} else if (x==0. && y<0.){
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phi = 1.5*pi;
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} else if (y==0. && x>0.){
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phi = 0.;
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} else if (y==0. && x<0.){
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phi = pi;
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} else if (x>0. ){
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phi = std::atan(y/x);
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} else if (x<0. ){
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phi = std::atan(y/x) + pi;
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}
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return phi;
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}
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#endif
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