//--------------------------------------------------------------------------
// File and Version Information:
//
// Description:
//	Class TTotalMomentum - a simple object to calculate the total 
//                               4 momentum in an event
//
// Environment:
//	Software developed for the BaBar Detector at the SLAC B-Factory.
//
// Author List:
//      Paul Harrison                         Original author
//
// Copyright Information:
//	Copyright (C) 1997	              Hedgehog Concepts
//
// ROOT Version by Marcel Kunze, RUB
//------------------------------------------------------------------------
#ifndef TTOTALMOMENTUM_H
#define TTOTALMOMENTUM_H

//------------------------------------
// Collaborating Class Declarations --
//------------------------------------
class TEventInfo;
class TCandidate;
#include "RhoBase/TCandList.h"
#include "TVector3.h"
#include "TLorentzVector.h"

//		---------------------
// 		-- Class Interface --
//		---------------------
 
class TTotalMomentum : public TObject {

//--------------------
// Instance Members --
//--------------------

public:

    // Constructors
    TTotalMomentum(TCandList&, const TEventInfo&);

    // Destructor
    virtual ~TTotalMomentum();

    // accessors to get at results

    inline double TotalEnergy() const { return _total4Momentum.T(); }
    inline double TotalMomentum() const { return TVector3(_total4Momentum.X(),_total4Momentum.Y(),_total4Momentum.Z()).Mag(); }
    inline TVector3 Total3Momentum() const { return TVector3(_total4Momentum.X(),_total4Momentum.Y(),_total4Momentum.Z()); }
    inline TLorentzVector Total4Momentum() const { return _total4Momentum; }

    inline double TotalEnergyCms() const { return _total4MomentumCms.T(); }
    inline double TotalMomentumCms() const { return TVector3(_total4MomentumCms.X(),_total4MomentumCms.Y(),_total4MomentumCms.Z()).Mag(); }
    inline TVector3 Total3MomentumCms() const { return TVector3(_total4MomentumCms.X(),_total4MomentumCms.Y(),_total4MomentumCms.Z()); }
    inline TLorentzVector Total4MomentumCms() const { return _total4MomentumCms; }

    inline double TotalMass() const { return _total4Momentum.Mag(); }

    inline double MissingEnergy() const { return _missing4Momentum.T(); }
    inline double MissingMomentum() const { return TVector3(_missing4Momentum.X(),_missing4Momentum.Y(),_missing4Momentum.Z()).Mag(); }
    inline TVector3 Missing3Momentum() const { return TVector3(_missing4Momentum.X(),_missing4Momentum.Y(),_missing4Momentum.Z()); }
    inline TLorentzVector Missing4Momentum() const { return _missing4Momentum; }

    inline double MissingEnergyCms() const { return _missing4MomentumCms.T(); }
    inline double MissingMomentumCms() const { return TVector3(_missing4MomentumCms.X(),_missing4MomentumCms.Y(),_missing4MomentumCms.Z()).Mag(); }
    inline TVector3 Missing3MomentumCms() const { return TVector3(_missing4MomentumCms.X(),_missing4MomentumCms.Y(),_missing4MomentumCms.Z()); }
    inline TLorentzVector Missing4MomentumCms() const { return _missing4MomentumCms; }

    inline double MissingMass() const { return _missing4Momentum.Mag(); }

protected:

    // Member data
    TLorentzVector _total4Momentum; //!
    TLorentzVector _total4MomentumCms; //!
    
    TLorentzVector _missing4Momentum; //!
    TLorentzVector _missing4MomentumCms; //!

public:
    ClassDef(TTotalMomentum,1) // A simple object to calculate the total 4 momentum in an event
};

#endif