JadeDistanceTagger.hh

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#ifndef __FASTJET_JADE_DISTANCE_TAGGER_HH__
#define __FASTJET_JADE_DISTANCE_TAGGER_HH__

#include <fastjet/tools/Transformer.hh>
#include <fastjet/CompositeJetStructure.hh>

FASTJET_BEGIN_NAMESPACE

class JadeDistanceTagger;
class JadeDistanceStructure;

//----------------------------------------------------------------------
/// @ingroup tools_taggers
/// \class JadeDistanceTagger
/// Class that helps perform 2-pronged boosted tagging searching the
/// clustring with maximal Jade distance
///
/// <FULL DESCRIPTION TO BE ADDED>
///
/// \section desc Options
/// 
/// The constructor has the following arguments:
///  - The first argument is the minimal mass drop requested
///  - The second argument is the maximal mass of the subjets
///
/// \section input Input conditions
/// 
///  - the original jet must have constituents
///
/// \section output Output/interface
/// 
///  - the 2 subjets are kept as pieces if some substructure is found,
///    otherwise a single 0-momentum piece
///  - the 'mdrop' and 'jade distance' values corresponding to the
///    unclustering step that passed the tagger's cuts
///
class JadeDistanceTagger : public Transformer{
public:
  /// default ctor
  JadeDistanceTagger(const double mdrop=0.9, const double mcut=40.0)
    : _mdrop(mdrop), _mcut(mcut){};

  /// description of the tagger
  virtual std::string description() const;

  /// the tagging itself
  ///  \param jet   the PseudoJet to tag
  virtual PseudoJet apply(const PseudoJet & jet) const;

  /// the type of the associated structure
  typedef JadeDistanceStructure StructureType;

protected:
  void _recursively_find_subjets(const PseudoJet &jet, std::vector<PseudoJet> &subjets) const;

  double _mdrop, _mcut;
};


//------------------------------------------------------------------------
/// @ingroup tools_taggers
/// \class JadeDistanceStructure
/// the structure returned by the JadeDistanceTagger transformer.
///
/// See the JadeDistanceTagger class description for the details of what
/// is inside this structure
///
class JadeDistanceStructure : public CompositeJetStructure{
public:
  /// ctor with pieces initialisation
  JadeDistanceStructure(std::vector<PseudoJet> pieces) :
    CompositeJetStructure(pieces), _mdrop(0.0), _jade_distance(0.0){}

  /// access to the associated N-subjettiness
  inline double mdrop() const{return _mdrop;}

  /// access to the associated angle with the boosted axis
  inline double jade_distance() const {return _jade_distance;}

protected:
  mutable double _mdrop;         ///< the value of the mass-drop parameter
  mutable double _jade_distance; ///< the value of the jade distance

  // allow the tagger to set these
  friend class JadeDistanceTagger;
};



FASTJET_END_NAMESPACE

#endif  //  __FASTJET_JADE_DISTANCE_TAGGER_HH__