EvtEvalHelAmp.hh

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#ifndef EVTEVALHELAMP_HH
#define EVTEVALHELAMP_HH
 
#include "EvtGenBase/EvtDecayAmp.hh"
#include "EvtGenBase/EvtId.hh"
#include "EvtGenBase/EvtSpinType.hh"
 
class EvtParticle;
class EvtAmp;
 
class EvtEvalHelAmp {
  public:
    EvtEvalHelAmp( EvtId idA, EvtId idB, EvtId idC, EvtComplexPtrPtr HBC );
 
    virtual ~EvtEvalHelAmp();
 
    double probMax();
 
    void evalAmp( EvtParticle* p, EvtAmp& amp );
 
  private:
    void fillHelicity( int* lambda2, int n, int J2, EvtId id );
    void setUpRotationMatrices( EvtParticle* p, double theta, double phi );
    void applyRotationMatrices();
 
    //spins states available for particle A, B, and C.
    int m_nA, m_nB, m_nC;
 
    //helicity amplitudes
    EvtComplexPtrPtr m_HBC;
 
    //2 times spin for each of the particles
    int m_JA2, m_JB2, m_JC2;
 
    //2 times the helicity for the states
    int *m_lambdaA2, *m_lambdaB2, *m_lambdaC2;
 
    //Rotation matrices
    EvtComplexPtrPtr m_RA, m_RB, m_RC;
 
    //temporary array for amplitudes
    EvtComplexPtrPtrPtr m_amp, m_amp1, m_amp3;
};
 
#endif