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File indexing completed on 2021-02-14 14:28:16

0001 #ifndef KinematicTree_H
0002 #define KinematicTree_H
0003 
0004 #include "RecoVertex/KinematicFitPrimitives/interface/RefCountedKinematicParticle.h"
0005 #include "RecoVertex/KinematicFitPrimitives/interface/RefCountedKinematicVertex.h"
0006 #include "DataFormats/GeometrySurface/interface/ReferenceCounted.h"
0007 #include "DataFormats/Math/interface/Graph.h"
0008 #include "DataFormats/Math/interface/GraphWalker.h"
0009 
0010 /**
0011  * Class describing the decay
0012  * chain inside the kinematic fit.
0013  * Uses the boost graph based DDD
0014  * library. KinematicVertices are
0015  * vertices, kinemtaic particles become nodes.
0016  *
0017  * Kirill Prokofiev, April 2003
0018  */
0019 /** 
0020  * WARNING:  before using any of these
0021  * methods please make sure you _understand correctly_
0022  * what part of tree are you looking at now and
0023  * where the pointer will be after the desiring 
0024  * operation.
0025  *
0026  * "Left" and "Right" notation reflects the order
0027  * of creating a three: from bottom to top,
0028  * from left to right
0029  * EXAMPLE: Bs->J/Psi Phi -> mumu KK
0030  * First creating a mumu branch, fit it to J/Psi,
0031  * Then adding Phi->KK and reconstructing a Bs will
0032  * look like: left bottom particle: muon, top of
0033  * the tree is Bs, right bottom is K.
0034  */
0035 
0036 class KinematicTree : public ReferenceCounted {
0037 public:
0038   /**
0039  * Constructor initializing
0040  * everything and setting all values to 0 
0041  */
0042   KinematicTree();
0043 
0044   ~KinematicTree() override;
0045 
0046   /**
0047  * Access methods
0048  */
0049   bool isEmpty() const;
0050   bool isValid() const { return !empt; }
0051 
0052   /**
0053  * This method checks if the tree
0054  * is consistent, i.e. the top vertex is
0055  * only one.
0056  */
0057 
0058   bool isConsistent() const;
0059 
0060   /**
0061  * Methods adding nodes and 
0062  * edges to the graph representation 
0063  * of the Kinematic Tree
0064  */
0065   void addParticle(RefCountedKinematicVertex prodVtx,
0066                    RefCountedKinematicVertex decVtx,
0067                    RefCountedKinematicParticle part);
0068 
0069   /**
0070  * Kinematic Tree  navigation methods
0071  */
0072 
0073   /** 
0074  * Returns the complete vector of final state
0075  * particles for the whole decay tree.
0076  * Pointer is NOT moved after this operation
0077  */
0078   std::vector<RefCountedKinematicParticle> finalStateParticles() const;
0079 
0080   /**
0081  * Returns the top particle of
0082  * decay. Pointer is moved to the
0083  * TOP of the decay tree.
0084  */
0085   RefCountedKinematicParticle topParticle() const;
0086 
0087   /**
0088  * Returns a current decay vertex
0089  * pointer is NOT moved
0090  */
0091   RefCountedKinematicVertex currentDecayVertex() const;
0092 
0093   /**
0094  * Returns a current production vertex
0095  * pointer is NOT moved
0096  */
0097   RefCountedKinematicVertex currentProductionVertex() const;
0098 
0099   /**
0100  * Returns a current particle
0101  * pointer is NOT moved
0102  */
0103   RefCountedKinematicParticle currentParticle() const;
0104 
0105   /**
0106  * Returns _true_ and state of mother particle
0107  * if successfull, _false_ and state of current particle
0108  * in case of failure
0109  * Pointer is NOT moved.
0110  */
0111   std::pair<bool, RefCountedKinematicParticle> motherParticle() const;
0112 
0113   /**
0114  * Returns a non-zero vector in case of success and
0115  * 0 vector in case of failure  
0116  * Pointer is NOT moved
0117  */
0118   std::vector<RefCountedKinematicParticle> daughterParticles() const;
0119 
0120   /**
0121  *  Puts the pointer to the top (root)
0122  *  of the tree. The  Graph walker
0123  * object gets recreated inside the tree.
0124  */
0125   void movePointerToTheTop() const;
0126 
0127   /**
0128  * Pointer goes to the mother
0129  * particle (if any) with respest to
0130  * the current one
0131  */
0132   bool movePointerToTheMother() const;
0133 
0134   /**
0135  * Pointer goes to the first 
0136  * child(if any) in the list
0137  */
0138   bool movePointerToTheFirstChild() const;
0139 
0140   /**
0141  * Pointer goes to the next 
0142  * child in the list (if any)
0143  */
0144   bool movePointerToTheNextChild() const;
0145 
0146   /**
0147  * Pointer goes to the needed
0148  * particle inside the tree if
0149  * found (true). Pointer goes
0150  * to the top of the tree if not 
0151  * found (false)
0152  */
0153   bool findParticle(const RefCountedKinematicParticle part) const;
0154 
0155   /**
0156  * Pointer goes to the particle
0157  * for which the neede vertex will be 
0158  * the decay one (true case)
0159  * Or pointer stays at the top of teh tree
0160  * if search is unsuccessfull (false case). 
0161  */
0162   bool findDecayVertex(const RefCountedKinematicVertex vert) const;
0163   bool findDecayVertex(KinematicVertex* vert) const;
0164 
0165   /**
0166  * Methods replacing Particles and Vertices
0167  * inside the tree during the refit. Methods
0168  * should used by corresponding KinematicFitter
0169  * classe only. Replace the current track or
0170  * current (decay) vertex 
0171  * WARNING: replace methods are not available
0172  * at this version of KinematicFitPrimitives.
0173  */
0174   void replaceCurrentParticle(RefCountedKinematicParticle newPart) const;
0175 
0176   /**
0177  * Replaces _decay_ vertex of the 
0178  * current particle with the given value
0179  */
0180   void replaceCurrentVertex(RefCountedKinematicVertex newVert) const;
0181 
0182   /**
0183  * Method adding a tree _tr_ to the vertex vtx
0184  * of current tree in such a way, that vtx become a 
0185  * production vertex for the top particle of the _tr_.
0186  * The whole contetnts of _tr_ is the rewritten to
0187  * current tree. This method is purely technical
0188  * and contains no mathematics. To be used by
0189  * KinematicParticleVertexFitter after the corresponding fit.
0190  */
0191   void addTree(RefCountedKinematicVertex vtx, KinematicTree* tr);
0192 
0193 private:
0194   /**
0195  * Private methods to  walk around the tree:
0196  * Needed to collect final state or 
0197  * particle search.
0198  */
0199 
0200   bool leftBranchSearch(RefCountedKinematicParticle part) const;
0201 
0202   bool leftBranchVertexSearch(RefCountedKinematicVertex vtx) const;
0203 
0204   bool leftFinalParticle() const;
0205 
0206   void leftBranchAdd(KinematicTree* otherTree, RefCountedKinematicVertex vtx);
0207 
0208   mutable bool empt;
0209 
0210   mutable math::Graph<RefCountedKinematicVertex, RefCountedKinematicParticle> treeGraph;
0211   mutable math::GraphWalker<RefCountedKinematicVertex, RefCountedKinematicParticle>* treeWalker;
0212 };
0213 #endif