EvtDalitzReso.hh

/*****************************************************************************
 * Project: BaBar detector at the SLAC PEP-II B-factory
 * Package: EvtGenBase
 *    File: $Id: EvtDalitzReso.hh,v 1.1 2016/09/23 18:37:30 jwebb Exp $
 *
 * Description:
 *   Class to compute Dalitz amplitudes based on many models that cannot be
 *     handled with EvtResonance.
 *
 * Modification history:
 *   Jordi Garra Ticó     2008/07/03         File created
 *****************************************************************************/

#ifndef __EVTDALITZRESO_HH__
#define __EVTDALITZRESO_HH__

#include <string>
#include <vector>
#include <map>

#include "EvtGenBase/EvtComplex.hh"
#include "EvtGenBase/EvtCyclic3.hh"
#include "EvtGenBase/EvtSpinType.hh"
#include "EvtGenBase/EvtTwoBodyVertex.hh"
#include "EvtGenBase/EvtDalitzPoint.hh"
#include "EvtGenBase/EvtDecayAmp.hh"
#include "EvtGenBase/EvtBlattWeisskopf.hh"
#include "EvtGenBase/EvtFlatte.hh"

using std::vector;
using std::map;

class EvtBlattWeisskopf;

class EvtDalitzReso
{
public:
  // Numerator type
  enum NumType { NBW            = 0 , RBW_ZEMACH        = 1 , RBW_KUEHN  = 2 , RBW_CLEO        = 3 ,
                 RBW_ZEMACH2    = 4 , GS_CLEO           = 5 , K_MATRIX   = 6 , RBW_CLEO_ZEMACH = 7 ,
                 GS_CLEO_ZEMACH = 8 , LASS              = 9 , K_MATRIX_I = 10, K_MATRIX_II     = 11,
                 GAUSS_CLEO     = 12, GAUSS_CLEO_ZEMACH = 13, FLATTE = 14, NON_RES = 15,
     NON_RES_LIN    = 16, NON_RES_EXP       = 17 };

  // Coupling type
  //  ChgPion : pi+ pi-
  //  NeuPion : pi0 pi0
  //  Pion    : 0.5*[(pi+ pi-) + (pi0 pi0)]
  //  ChgKaon : K+ K-
  //  NeuKaon : K0 K0
  //  Kaon    : 0.5*[(K+ K-) + (K0 K0)]
  //  EtaPion : eta pi0
  enum CouplingType {Undefined=0,PicPic=1,PizPiz,PiPi,KcKc,KzKz,KK,EtaPic,EtaPiz,PicPicKK,WA76};

  EvtDalitzReso() : _typeN(NON_RES) {};

  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairRes, NumType typeN, double alpha=0.0) : _dp(dp), _pairRes(pairRes), _typeN(typeN), _alpha(alpha) {};

  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairAng, EvtCyclic3::Pair pairRes, 
                EvtSpinType::spintype spin, double m0, double g0, NumType typeN, double f_b=0.0, double f_d=1.5);

  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairAng, EvtCyclic3::Pair pairRes, 
                EvtSpinType::spintype spin, double m0, double g0, NumType typeN,
                double m0_mix, double g0_mix, double delta_mix, EvtComplex amp_mix);

  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairAng, EvtCyclic3::Pair pairRes, 
                EvtSpinType::spintype spin, double m0, NumType typeN, double g1, double g2, CouplingType coupling2);

  // K-matrix
  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairRes, std::string nameIndex, NumType typeN,
                EvtComplex fr12prod, EvtComplex fr13prod, EvtComplex fr14prod, EvtComplex fr15prod, double s0prod);

  // LASS
  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairRes, double m0, double g0,
                double a, double r, double B, double phiB, double R, double phiR, double cutoff=-1, bool scaleByMOverQ=false);

  //Flatte
  EvtDalitzReso(const EvtDalitzPlot& dp, EvtCyclic3::Pair pairRes, double m0);

  EvtDalitzReso(const EvtDalitzReso& other);

  ~EvtDalitzReso();

  EvtDalitzReso* clone() const { return new EvtDalitzReso(*this); }

  EvtComplex evaluate(const EvtDalitzPoint& p);

  void set_fd( double R ) { _vd.set_f( R ); }
  void set_fb( double R ) { _vb.set_f( R ); }

  void addFlatteParam(const EvtFlatteParam& param) { _flatteParams.push_back(param); }

private:
  EvtComplex psFactor(double& ma, double& mb, double& m);
  EvtComplex psFactor(double& ma1, double& mb1, double& ma2, double& mb2, double& m);
  EvtComplex propGauss(const double& m0, const double& s0, const double& m);
  EvtComplex propBreitWigner(const double& m0, const double& g0, const double& m); 
  EvtComplex propBreitWignerRel(const double& m0, const double& g0, const double& m);
  EvtComplex propBreitWignerRel(const double& m0, const EvtComplex& g0, const double& m);
  EvtComplex propBreitWignerRelCoupled(const double& m0, const EvtComplex& g1, const EvtComplex& g2, const double& m); 
  EvtComplex propGounarisSakurai(const double& m0, const double& g0, const double& k0, 
                                 const double& m, const double& g, const double& k);
  inline double GS_f(const double& m0, const double& g0, const double& k0, const double& m, const double& k);
  inline double GS_h(const double& m, const double& k);
  inline double GS_dhods(const double& m0, const double& k0); 
  inline double GS_d(const double& m0, const double& k0); 

  EvtComplex numerator(const EvtDalitzPoint& p, const EvtTwoBodyKine& vb, const EvtTwoBodyKine& vd);
  double angDep(const EvtDalitzPoint& p);
  EvtComplex mixFactor(EvtComplex prop, EvtComplex prop_mix);
  EvtComplex Fvector( double s, int index );
  EvtComplex lass(double s);
  EvtComplex flatte(const double& m);

  inline EvtComplex sqrtCplx(double in) { return (in > 0) ? EvtComplex(sqrt(in), 0) : EvtComplex(0, sqrt(-in)); }

  // Dalitz plot
  EvtDalitzPlot _dp; 

  // Pairing indices:
  EvtCyclic3::Pair _pairAng;    // angular  
  EvtCyclic3::Pair _pairRes;    // resonance

  // Spin
  EvtSpinType::spintype _spin;                                  

  // Numerator type
  NumType _typeN;

  // Nominal mass and width
  double _m0,_g0; 

  // Vertices
  EvtTwoBodyVertex _vb;
  EvtTwoBodyVertex _vd;

  // Daughter masses
  double _massFirst,_massSecond;

  // variables for electromagnetic mass mixing 
  double _m0_mix,_g0_mix,_delta_mix;
  EvtComplex _amp_mix;   

  // variables for coupled Breit-Wigner
  double _g1,_g2;
  CouplingType _coupling2;

  // variables for Blatt-Weisskopf form factors
  double _f_b, _f_d;

  // K-matrix 
  int _kmatrix_index;
  EvtComplex _fr12prod,_fr13prod,_fr14prod,_fr15prod;
  double _s0prod;

  // LASS
  double _a;
  double _r;
  double _Blass;
  double _phiB;
  double _R;
  double _phiR;
  double _cutoff;
  bool _scaleByMOverQ;

  //Nonresonant
  double _alpha;

  // Flatte
  std::vector<EvtFlatteParam> _flatteParams;

};

#endif