EvtFlatte.hh

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#ifndef EVTFLATTE_HH
#define EVTFLATTE_HH
 
#include "EvtGenBase/EvtComplex.hh"
#include "EvtGenBase/EvtVector4R.hh"
 
#include <vector>
 
using std::vector;
 
// Helper class
 
class EvtFlatteParam {
  public:
    EvtFlatteParam( double m1, double m2, double g ) :
        m_m1( m1 ), m_m2( m2 ), m_g( g )
    {
    }
 
    inline double m1() const { return m_m1; }
    inline double m2() const { return m_m2; }
    inline double g() const { return m_g; }
 
  private:
    double m_m1, m_m2, m_g;
};
 
//class declaration
 
class EvtFlatte final {
  public:
    //operator
    EvtFlatte& operator=( const EvtFlatte& );
 
    //constructor with all information about the resonance
    EvtFlatte( const EvtVector4R& p4_p, const EvtVector4R& p4_d1,
               const EvtVector4R& p4_d2, double ampl, double theta, double mass,
               vector<EvtFlatteParam>& params );
 
    //accessors
    //return 4-momenta of the particles involved
    inline const EvtVector4R& p4_p() { return m_p4_p; }
    inline const EvtVector4R& p4_d1() { return m_p4_d1; }
    inline const EvtVector4R& p4_d2() { return m_p4_d2; }
 
    //return amplitude
    inline double amplitude() { return m_ampl; }
 
    //return theta
    inline double theta() { return m_theta; }
 
    //return bwm
    inline double mass() { return m_mass; }
 
    //functions
 
    //calculate amplitude for this resonance
    EvtComplex resAmpl();
 
  private:
    inline EvtComplex sqrtCplx( double in )
    {
        return ( in > 0 ) ? EvtComplex( sqrt( in ), 0 )
                          : EvtComplex( 0, sqrt( -in ) );
    }
 
    EvtVector4R m_p4_p, m_p4_d1, m_p4_d2;
    double m_ampl, m_theta, m_mass;
    vector<EvtFlatteParam> m_params;
};
 
#endif