[u/mrichter/AliRoot.git] / PYTHIA8 / pythia8140 / include / MiniStringFragmentation.h

// MiniStringFragmentation.h is a part of the PYTHIA event generator.
// Copyright (C) 2010 Torbjorn Sjostrand.
// PYTHIA is licenced under the GNU GPL version 2, see COPYING for details.
// Please respect the MCnet Guidelines, see GUIDELINES for details.

// This file contains the class for "cluster" fragmentation.
// MiniStringFragmentation: handle the fragmentation of low-mass systems.

#ifndef Pythia8_MiniStringFragmentation_H
#define Pythia8_MiniStringFragmentation_H

#include "Basics.h"
#include "Event.h"
#include "FragmentationFlavZpT.h"
#include "FragmentationSystems.h"
#include "Info.h"
#include "ParticleData.h"
#include "PythiaStdlib.h"
#include "Settings.h"

namespace Pythia8 {

//==========================================================================

// The MiniStringFragmentation class contains the routines to fragment 
// occasional low-mass colour singlet partonic systems, where the string 
// approach is not directly applicable (for technical reasons).

class MiniStringFragmentation {

public:

  // Constructor. 
  MiniStringFragmentation() {}

  // Initialize and save pointers.
  void init(Info* infoPtrIn, Settings& settings,  
    ParticleData* particleDataPtrIn, Rndm* rndmPtrIn, 
    StringFlav* flavSelPtrIn);

  // Do the fragmentation: driver routine.
  bool fragment( int iSub, ColConfig& colConfig, Event& event, 
    bool isDiff = false);

private: 

  // Constants: could only be changed in the code itself.
  static const int    NTRYDIFFRACTIVE, NTRYLASTRESORT, NTRYFLAV;
  static const double SIGMAMIN;

  // Pointer to various information on the generation.
  Info*         infoPtr;

  // Pointer to the particle data table.
  ParticleData* particleDataPtr;

  // Pointer to the random number generator.
  Rndm*         rndmPtr;

  // Pointer to class for flavour generation.
  StringFlav*   flavSelPtr;

  // Initialization data, read from Settings.
  int    nTryMass;
  double sigma, sigma2Had, bLund;

  // Data members.
  bool   isClosed;
  double mSum, m2Sum;
  Vec4   pSum;
  vector<int> iParton;
  FlavContainer flav1, flav2;

  // Attempt to produce two particles from a cluster.
  bool ministring2two( int nTry, Event& event);

  // Attempt to produce one particle from a cluster.
  bool ministring2one( int iSub, ColConfig& colConfig, Event& event);

};

//==========================================================================

} // end namespace Pythia8

#endif // Pythia8_MiniStringFragmentation_H
Commit	Line	Data
b584e2f5	1	// MiniStringFragmentation.h is a part of the PYTHIA event generator.
	2	// Copyright (C) 2010 Torbjorn Sjostrand.
	3	// PYTHIA is licenced under the GNU GPL version 2, see COPYING for details.
	4	// Please respect the MCnet Guidelines, see GUIDELINES for details.
	5
	6	// This file contains the class for "cluster" fragmentation.
	7	// MiniStringFragmentation: handle the fragmentation of low-mass systems.
	8
	9	#ifndef Pythia8_MiniStringFragmentation_H
	10	#define Pythia8_MiniStringFragmentation_H
	11
	12	#include "Basics.h"
	13	#include "Event.h"
	14	#include "FragmentationFlavZpT.h"
	15	#include "FragmentationSystems.h"
	16	#include "Info.h"
	17	#include "ParticleData.h"
	18	#include "PythiaStdlib.h"
	19	#include "Settings.h"
	20
	21	namespace Pythia8 {
	22
	23	//==========================================================================
	24
	25	// The MiniStringFragmentation class contains the routines to fragment
	26	// occasional low-mass colour singlet partonic systems, where the string
	27	// approach is not directly applicable (for technical reasons).
	28
	29	class MiniStringFragmentation {
	30
	31	public:
	32
	33	// Constructor.
	34	MiniStringFragmentation() {}
	35
	36	// Initialize and save pointers.
	37	void init(Info* infoPtrIn, Settings& settings,
	38	ParticleData* particleDataPtrIn, Rndm* rndmPtrIn,
	39	StringFlav* flavSelPtrIn);
	40
	41	// Do the fragmentation: driver routine.
	42	bool fragment( int iSub, ColConfig& colConfig, Event& event,
	43	bool isDiff = false);
	44
	45	private:
	46
	47	// Constants: could only be changed in the code itself.
	48	static const int NTRYDIFFRACTIVE, NTRYLASTRESORT, NTRYFLAV;
	49	static const double SIGMAMIN;
	50
	51	// Pointer to various information on the generation.
	52	Info* infoPtr;
	53
	54	// Pointer to the particle data table.
	55	ParticleData* particleDataPtr;
	56
	57	// Pointer to the random number generator.
	58	Rndm* rndmPtr;
	59
	60	// Pointer to class for flavour generation.
	61	StringFlav* flavSelPtr;
	62
	63	// Initialization data, read from Settings.
	64	int nTryMass;
65	double sigma, sigma2Had, bLund;
66
67	// Data members.
68	bool isClosed;
69	double mSum, m2Sum;
70	Vec4 pSum;
71	vector<int> iParton;
72	FlavContainer flav1, flav2;
73
74	// Attempt to produce two particles from a cluster.
75	bool ministring2two( int nTry, Event& event);
76
77	// Attempt to produce one particle from a cluster.
78	bool ministring2one( int iSub, ColConfig& colConfig, Event& event);
79
80	};
81
82	//==========================================================================
83
84	} // end namespace Pythia8
85
86	#endif // Pythia8_MiniStringFragmentation_H