EvtVubHybrid.hh

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//--------------------------------------------------------------------------
//
// Environment:
//      This software is part of the EvtGen package developed jointly
//      for the BaBar and CLEO collaborations.  If you use all or part
//      of it, please give an appropriate acknowledgement.
//
// Copyright Information: See EvtGen/COPYRIGHT
//      Copyright (C) 1998      Caltech, UCSB
//
// Module: EvtGen/EvtVubHybrid.hh
//
// Description:
// Class to generate inclusive B to X_u l nu decays.
// This class is based on EvtVub by Sven Menke with an update to
// generate the inclusive decays in such a way that the right
// mix of inclusive and exclusive decays is obtained:
// "Hybrid Model" by Dominique Fortin.
// NOTE:
// - A set of weights (for bins in the kinematic variables mX, q2, El)
//   is read from DECAY.DEC. This set of weights must be consistent
//   with the other parameters specified (excl. BF, non-res BF, mb, a).
// - If no binning/weights are specified in DECAY.DEC the hybrid
//   reweighting is not activated
//
// Modification history:
//
//   Jochen Dingfelder February 1, 2005  Created Module as update of
//                                       the module EvtVub including
//                                       hybrid model.
//------------------------------------------------------------------------
 
#ifndef EVTVUBHYBRID_HH
#define EVTVUBHYBRID_HH
 
#include "../EvtGenBase/EvtDecayIncoherent.hh"
 
#include <vector>
 
class EvtParticle;
class EvtVubdGamma;
class RandGeneral;
 
class EvtVubHybrid : public EvtDecayIncoherent {
 
public:
  EvtVubHybrid();
  virtual ~EvtVubHybrid();
 
  void getName( std::string& name );
 
  EvtDecayBase* clone();
 
  void initProbMax();
 
  void init();
 
  void decay( EvtParticle* p );
 
  void readWeights( int startArg = 0 );
 
  double getWeight( double mX, double q2, double El );
 
private:
  double findPFermi();
 
  enum { nParameters = 3, nVariables = 3 };
 
  bool _noHybrid;
  bool _storeQplus;
 
  double              _mb;     // the b-quark pole mass in GeV (try 4.65 to 4.9)
  double              _a;      // Parameter for the Fermi Motion (1.29 is good)
  double              _alphas; // Strong Coupling at m_b (around 0.24)
  double              _dGMax;  // max dGamma*p2 value;
  int                 _nbins_mX;
  int                 _nbins_q2;
  int                 _nbins_El;
  int                 _nbins;
  double              _masscut;
  double*             _bins_mX;
  double*             _bins_q2;
  double*             _bins_El;
  double*             _weights;
  EvtVubdGamma*       _dGamma; // calculates the decay rate
  std::vector<double> _pf;
};
 
#endif