EvtVubBLNPHybrid.hh

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#ifndef EVTVUBBLNPHYBRID_HH
#define EVTVUBBLNPHYBRID_HH

#include "EvtGenBase/EvtDecayIncoherent.hh"

#include <vector>

class EvtParticle;

// tripleDiff from BLNPHybrid's notebook, based on hep-ph/0504071
//
// Description:
// Class to generate inclusive B to X_u l nu decays.
// This class is based on EvtVubBLNP by Sheila Mclachlin with an update to
// generate the inclusive decays in such a way that the right
// mix of inclusive and exclusive decays is obtained.
//
//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

class EvtVubBLNPHybrid : public EvtDecayIncoherent {
  public:
    std::string getName() override;

    EvtDecayBase* clone() override;

    void initProbMax() override;

    void init() override;

    void decay( EvtParticle* Bmeson ) override;

    void readWeights( int startArg = 0 );

    double getWeight( double mX, double q2, double El );

  private:
    //Input for hybrid modell
    enum
    {
        nParameters = 10,
        nVariables = 3
    };
    bool _noHybrid = false;
    bool _storeWhat = true;
    int _nbins = 0;
    double _masscut = 0.28;
    std::vector<double> _bins_mX;
    std::vector<double> _bins_q2;
    std::vector<double> _bins_El;
    std::vector<double> _weights;

    // Input parameters
    double mBB;
    double lambda2;

    // Shape function parameters
    double b;
    double Lambda;
    double Ecut;
    double wzero;

    // SF and SSF modes
    int itype;
    double dtype;
    int isubl;

    // flags
    int flag1;
    int flag2;
    int flag3;

    // Quark mass
    double mb;

    // Matching scales
    double muh;
    double mui;
    double mubar;

    // Perturbative quantities
    double CF;
    double CA;

    double beta0;
    double beta1;
    double beta2;

    double zeta3;

    double Gamma0;
    double Gamma1;
    double Gamma2;

    double gp0;
    double gp1;

    double Lbar;
    double mupisq;
    double moment2;

    int flagpower;
    int flag2loop;

    int maxLoop;
    double precision;

    std::vector<double> gvars;

    double rate3( double Pp, double Pl, double Pm );
    double F1( double Pp, double Pm, double muh, double mui, double mubar,
               double doneJS, double done1 );
    double F2( double Pp, double Pm, double muh, double mui, double mubar,
               double done3 );
    double F3( double Pp, double Pm, double muh, double mui, double mubar,
               double done2 );
    double DoneJS( double Pp, double Pm, double mui );
    double Done1( double Pp, double Pm, double mui );
    double Done2( double Pp, double Pm, double mui );
    double Done3( double Pp, double Pm, double mui );
    static double IntJS( double what, const std::vector<double>& vars );
    static double Int1( double what, const std::vector<double>& vars );
    static double Int2( double what, const std::vector<double>& vars );
    static double Int3( double what, const std::vector<double>& vars );
    static double g1( double w, const std::vector<double>& vars );
    static double g2( double w, const std::vector<double>& vars );
    static double g3( double w, const std::vector<double>& vars );
    static double Shat( double w, const std::vector<double>& vars );
    static double Mzero( double muf, double mu, double mupisq,
                         const std::vector<double>& vars );
    double wS( double w );
    double t( double w );
    double u( double w );
    double v( double w );
    double myfunction( double w, double Lbar, double mom2 );
    double myfunctionBIK( double w, double Lbar, double mom2 );
    double dU1nlo( double muh, double mui );
    double U1lo( double muh, double mui );
    double Sfun( double mu1, double mu2, double epsilon );
    double S0( double a1, double r );
    double S1( double a1, double r );
    double S2( double a1, double r );
    double aGamma( double mu1, double mu2, double epsilon );
    double agp( double mu1, double mu2, double epsilon );
    double alo( double muh, double mui );
    double anlo( double muh, double mui );    // d/depsilon of aGamma
    static double alphas( double mu, const std::vector<double>& vars );
    double PolyLog( double v, double z );
    static double Gamma( double z );
    static double Gamma( double a, double x );
    static double gamser( double a, double x, double LogGamma );
    static double gammcf( double a, double x, double LogGamma );
    double findBLNPWhat();
    std::vector<double> _pf;
};

#endif