ReferenceFrame.h

/**************************************************************************
 * BASF2 (Belle Analysis Framework 2)                                     *
 * Copyright(C) 2015 - Belle II Collaboration                             *
 *                                                                        *
 * Author: The Belle II Collaboration                                     *
 * Contributors: Thomas Keck, Dennis Weyland                              *
 *                                                                        *
 * This software is provided "as is" without any warranty.                *
 **************************************************************************/
 
#pragma once
 
#include <TLorentzRotation.h>
#include <TRotation.h>
#include <TLorentzVector.h>
#include <analysis/dataobjects/Particle.h>
#include <analysis/utility/PCmsLabTransform.h>
 
#include <stack>
 
namespace Belle2 {
  class ReferenceFrame {
  public:
    virtual TVector3 getVertex(const TVector3& vector) const = 0;
 
    virtual TVector3 getVertex(const Particle* particle) const
    {
      return getVertex(particle->getVertex());
    }
 
    virtual TLorentzVector getMomentum(const TLorentzVector& vector) const = 0;
 
    virtual TLorentzVector getMomentum(const Particle* particle) const
    {
      return getMomentum(particle->get4Vector());
    }
 
    virtual TMatrixFSym getMomentumErrorMatrix(const TMatrixFSym& matrix) const = 0;
 
    virtual TMatrixFSym getMomentumErrorMatrix(const Particle* particle) const
    {
      return getMomentumErrorMatrix(particle->getMomentumErrorMatrix());
    }
 
    virtual TMatrixFSym getVertexErrorMatrix(const TMatrixFSym& matrix) const = 0;
 
    virtual TMatrixFSym getVertexErrorMatrix(const Particle* particle) const
    {
      return getVertexErrorMatrix(particle->getVertexErrorMatrix());
    }
 
    static const ReferenceFrame& GetCurrent();
 
  private:
    static void Push(const ReferenceFrame* frame)
    {
      m_reference_frames.push(frame);
    }
 
    static void Pop()
    {
      m_reference_frames.pop();
    }
 
    static std::stack<const ReferenceFrame*> m_reference_frames; 
    template<class T>
    friend class UseReferenceFrame;
  };
 
  class RestFrame : public ReferenceFrame {
 
  public:
    explicit RestFrame(const Particle* particle);
 
    virtual TVector3 getVertex(const TVector3& vector) const override;
 
    virtual TLorentzVector getMomentum(const TLorentzVector& vector) const override;
 
    virtual TMatrixFSym getMomentumErrorMatrix(const TMatrixFSym& matrix) const override;
 
    virtual TMatrixFSym getVertexErrorMatrix(const TMatrixFSym& matrix) const override;
 
  private:
    TLorentzVector m_momentum;         
    TVector3 m_displacement;           
    TVector3 m_boost;                  
    TLorentzRotation m_lab2restframe;  
  };
 
  class LabFrame : public ReferenceFrame {
 
  public:
 
    virtual TVector3 getVertex(const TVector3& vector) const override;
 
    virtual TLorentzVector getMomentum(const TLorentzVector& vector) const override;
 
    virtual TMatrixFSym getMomentumErrorMatrix(const TMatrixFSym& matrix) const override;
 
    virtual TMatrixFSym getVertexErrorMatrix(const TMatrixFSym& matrix) const override;
 
  };
 
  class CMSFrame : public ReferenceFrame {
 
  public:
    virtual TVector3 getVertex(const TVector3& vector) const override;
 
    virtual TLorentzVector getMomentum(const TLorentzVector& vector) const override;
 
    virtual TMatrixFSym getMomentumErrorMatrix(const TMatrixFSym& matrix) const override;
 
    virtual TMatrixFSym getVertexErrorMatrix(const TMatrixFSym& matrix) const override;
 
  private:
    PCmsLabTransform m_transform; 
  };
 
  class RotationFrame : public ReferenceFrame {
 
  public:
    explicit RotationFrame(const TVector3& newX, const TVector3& newY, const TVector3& newZ);
 
    virtual TVector3 getVertex(const TVector3& vector) const override;
 
    virtual TLorentzVector getMomentum(const TLorentzVector& vector) const override;
 
    virtual TMatrixFSym getMomentumErrorMatrix(const TMatrixFSym& matrix) const override;
 
    virtual TMatrixFSym getVertexErrorMatrix(const TMatrixFSym& matrix) const override;
 
  private:
    TRotation m_rotation; 
  };
 
  class CMSRotationFrame : public ReferenceFrame {
 
  public:
    explicit CMSRotationFrame(const TVector3& newX, const TVector3& newY, const TVector3& newZ);
 
    virtual TVector3 getVertex(const TVector3& vector) const override;
 
    virtual TLorentzVector getMomentum(const TLorentzVector& vector) const override;
 
    virtual TMatrixFSym getMomentumErrorMatrix(const TMatrixFSym& matrix) const override;
 
    virtual TMatrixFSym getVertexErrorMatrix(const TMatrixFSym& matrix) const override;
 
  private:
    CMSFrame cmsframe; 
    RotationFrame rotationframe; 
  };
 
  template<class T>
  class UseReferenceFrame {
  public:
    template<class ...Args>
    explicit UseReferenceFrame(Args&& ... params) : m_frame(std::forward<Args>(params)...)
    {
      ReferenceFrame::Push(&m_frame);
    }
 
    ~UseReferenceFrame()
    {
      ReferenceFrame::Pop();
    }
  private:
    T m_frame; 
  };
 
} // Belle2 namespace