EvtVubHybrid.hh

//--------------------------------------------------------------------------
//
// 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();

  std::string getName();

  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