FermionSpinInfo.h

// -*- C++ -*-
//
// FermionSpinInfo.h is a part of ThePEG - Toolkit for HEP Event Generation
// Copyright (C) 2003-2019 Peter Richardson, Leif Lonnblad
//
// ThePEG is licenced under version 3 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef ThePEG_FermionSpinInfo_H
#define ThePEG_FermionSpinInfo_H
// This is the declaration of the FermionSpinInfo class.
 
#include "ThePEG/EventRecord/SpinInfo.h"
#include "ThePEG/Helicity/LorentzSpinor.h"
#include "FermionSpinInfo.fh"
#include <array>
 
namespace ThePEG {
namespace Helicity {
 
class FermionSpinInfo: public SpinInfo {
 
public:
 
  FermionSpinInfo()
    : SpinInfo(PDT::Spin1Half), _decaycalc(false) {}
 
  FermionSpinInfo(const Lorentz5Momentum & p, bool time)
    : SpinInfo(PDT::Spin1Half, p, time), _decaycalc(false) {}
 
public:
 
  void setBasisState(unsigned int hel,
                     const LorentzSpinor<SqrtEnergy> & in) const {
    assert(hel<2);
    _productionstates[hel] = in;
    _currentstates   [hel] = in;
  }
 
  void setDecayState(unsigned int hel,
                     const LorentzSpinor<SqrtEnergy> & in) const {
    assert(hel<2);
    _decaycalc = true;
    _decaystates[hel] = in;
  }
 
  const LorentzSpinor<SqrtEnergy> & getProductionBasisState(unsigned int hel) const {
    assert(hel<2);
    return _productionstates[hel];
  }
 
  const LorentzSpinor<SqrtEnergy> & getCurrentBasisState(unsigned int hel) const {
    assert(hel<2);
    return _currentstates[hel];
  }
 
  const LorentzSpinor<SqrtEnergy> & getDecayBasisState(unsigned int hel) const {
    assert(hel<2);
    if(!_decaycalc) {
      for(unsigned int ix=0;ix<2;++ix) _decaystates[ix]=_currentstates[ix];
      _decaycalc=true;
    }
    return _decaystates[hel];
  }
 
  virtual void transform(const LorentzMomentum &,const LorentzRotation &);
 
  virtual void undecay() const {
    _decaycalc=false;
    SpinInfo::undecay();
  }
 
  virtual void reset() {
    undecay();
    _currentstates = _productionstates;
    SpinInfo::reset();
  }
 
public:
 
  static void Init();
 
  virtual EIPtr clone() const;
 
private:
 
  FermionSpinInfo & operator=(const FermionSpinInfo &) = delete;
 
private:
 
  mutable std::array<LorentzSpinor<SqrtEnergy>,2> _productionstates;
 
  mutable std::array<LorentzSpinor<SqrtEnergy>,2> _currentstates;
 
  mutable std::array<LorentzSpinor<SqrtEnergy>,2> _decaystates;
 
  mutable bool _decaycalc;
 
};
 
}
}
 
namespace ThePEG {
 
}
#endif /* ThePEG_FermionSpinInfo_H */