EvtWHad.hh

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#ifndef EvtWHad_HH
#define EvtWHad_HH

#include "EvtGenBase/EvtComplex.hh"
#include "EvtGenBase/EvtVector4C.hh"
#include "EvtGenBase/EvtVector4R.hh"

#include <vector>

// Description: Routine to calculate W -> (n pi) + (m K) current
//                      according to [Kuhn, Was, Acta.Phys.Polon B39 (2008) 147]

class EvtWHad {
  public:
    EvtWHad();

    EvtVector4C WCurrent( const EvtVector4R& q1 ) const;

    EvtVector4C WCurrent( const EvtVector4R& q1, const EvtVector4R& q2 ) const;

    EvtVector4C WCurrent( const EvtVector4R& q1, const EvtVector4R& q2,
                          const EvtVector4R& q3 ) const;

    EvtVector4C WCurrent( const EvtVector4R& q1, const EvtVector4R& q2,
                          const EvtVector4R& q3, const EvtVector4R& q4,
                          const EvtVector4R& q5 ) const;

    EvtVector4C WCurrent_KKP( const EvtVector4R& pKplus,
                              const EvtVector4R& pKminus,
                              const EvtVector4R& pPiPlus ) const;

    EvtVector4C WCurrent_KPP( const EvtVector4R& pKplus,
                              const EvtVector4R& pPiPlus,
                              const EvtVector4R& pPiMinus ) const;

    EvtVector4C WCurrent_KSK( const EvtVector4R& pKS,
                              const EvtVector4R& pKplus ) const;

  protected:
    EvtVector4C JB( const EvtVector4R& q1, const EvtVector4R& q2,
                    const EvtVector4R& q3, const EvtVector4R& q4,
                    const EvtVector4R& q5 ) const;

    EvtComplex BWa( const EvtVector4R& q ) const;

    EvtComplex BWf( const EvtVector4R& q ) const;

    EvtComplex BWr( const EvtVector4R& q ) const;

    EvtComplex BWKK( double s, int i ) const;

    double pi3G( double Q2 ) const;

    EvtComplex pcm( double s ) const;

  private:
    std::vector<double> mRho_, gamma0_, cK_;
};

#endif