PCmsLabTransform.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
#pragma once
 
#include <mdst/dbobjects/CollisionBoostVector.h>
#include <mdst/dbobjects/CollisionInvariantMass.h>
#include <mdst/dbobjects/CollisionAxisCMS.h>
#include <framework/database/DBObjPtr.h>
#include <framework/utilities/LabToCms.h>
 
#include <Math/LorentzRotation.h>
#include <Math/Vector4D.h>
 
namespace Belle2 {

  class PCmsLabTransform {
 
  public:

    PCmsLabTransform();

    ROOT::Math::XYZVector getBoostVector() const
    {
      return ROOT::Math::XYZVector(m_boostVectorDB->getBoost());
    }

    double getCMSEnergy() const
    {
      return m_invariantMassDB->getMass();
    }

    ROOT::Math::PxPyPzEVector getBeamFourMomentum() const
    {
      return rotateCmsToLab() * ROOT::Math::PxPyPzEVector(0, 0, 0, getCMSEnergy());
    }

    const ROOT::Math::LorentzRotation rotateLabToCms() const
    {
      return LabToCms::rotateLabToCms(getBoostVector(), m_axisCmsDB->getAngleXZ(), m_axisCmsDB->getAngleYZ());
    }

    const ROOT::Math::LorentzRotation rotateCmsToLab() const
    {
      return rotateLabToCms().Inverse();
    }

    static ROOT::Math::PxPyPzMVector labToCms(const ROOT::Math::PxPyPzMVector& vec);

    static ROOT::Math::PxPyPzMVector cmsToLab(const ROOT::Math::PxPyPzMVector& vec);

    static ROOT::Math::PxPyPzEVector labToCms(const ROOT::Math::PxPyPzEVector& vec);

    static ROOT::Math::PxPyPzEVector cmsToLab(const ROOT::Math::PxPyPzEVector& vec);
 
  private:
    const DBObjPtr<CollisionInvariantMass> m_invariantMassDB; 
    const DBObjPtr<CollisionBoostVector> m_boostVectorDB; 
    const DBObjPtr<CollisionAxisCMS> m_axisCmsDB; 
  };

} // Belle2 namespace