EvtTwoBodyKine.hh

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#ifndef EVT_TWO_BODY_KINE_HH
#define EVT_TWO_BODY_KINE_HH

#include <iostream>

// Descriptions of the kinematics of a two-body decay.

class EvtTwoBodyKine {
  public:
    enum Index
    {
        A,
        B,
        AB
    };

    EvtTwoBodyKine();
    EvtTwoBodyKine( double mA, double mB, double mAB );

    // Accessors

    inline double mA() const { return _mA; }
    inline double mB() const { return _mB; }
    inline double mAB() const { return _mAB; }
    double m( Index i ) const;

    // Momentum of the other two particles in the
    // rest-frame of particle i.

    double p( Index i = AB ) const;

    // Energy of particle i in the rest frame of particle j

    double e( Index i, Index j ) const;

    void print( std::ostream& os ) const;

  private:
    double _mA;
    double _mB;
    double _mAB;
};

std::ostream& operator<<( std::ostream& os, const EvtTwoBodyKine& p );

#endif