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 // -*- C++ -*-
 #ifndef HERWIG_BaryonThreeQuarkModelFormFactor_H
 #define HERWIG_BaryonThreeQuarkModelFormFactor_H
 //
 // This is the declaration of the BaryonThreeQuarkModelFormFactor class.
 //
 #include "BaryonFormFactor.h"
 #include "ThePEG/PDT/ParticleData.h"
 
 namespace Herwig {
 using namespace ThePEG;
 
 /** \ingroup Decay
  *
  *  The BaryonThreeQuarkModelFormFactor class implements the 
  *  form factors for the semi-leptonic decay of baryons containing a heavy quark
  *  from the relativistic three-quark model calculation of PRD56, 348.
  *
  *  As the only formulae in the paper are for the heavy-to-heavy i.e. bottom
  *  to charm decay this there are the only modes included, although the paper
  *  also includes charm decays and bottom decays to light quarks.
  *
  *  The form factors are calculated by numerical computing the integrals from
  *  PRD56, 348 to obtain the coefficients for the expansion of the form factors.
  *
  * @see BaryonFormFactor
  */
 class BaryonThreeQuarkModelFormFactor: public BaryonFormFactor {
   
 public:
 
   /**
    * Default constructor
    */
   BaryonThreeQuarkModelFormFactor();
 
   /** @name Functions used by the persistent I/O system. */
   //@{
   /**
    * Function used to write out object persistently.
    * @param os the persistent output stream written to.
    */
   void persistentOutput(PersistentOStream & os) const;
 
   /**
    * Function used to read in object persistently.
    * @param is the persistent input stream read from.
    * @param version the version number of the object when written.
    */
   void persistentInput(PersistentIStream & is, int version);
   //@}
 
   /**
    * Standard Init function used to initialize the interfaces.
    */
   static void Init();
 
 protected:
 
   /** @name Clone Methods. */
   //@{
   /**
    * Make a simple clone of this object.
    * @return a pointer to the new object.
    */
   virtual IBPtr clone() const {return new_ptr(*this);}
 
   /** Make a clone of this object, possibly modifying the cloned object
    * to make it sane.
    * @return a pointer to the new object.
    */
   virtual IBPtr fullclone() const {return new_ptr(*this);}
   //@}
 
 public:
 
   /** @name Form Factors */
   //@{
   /**
    * The form factor for the weak decay of a spin \f$\frac12\f$ baryon to a 
    * spin \f$\frac12\f$ baryon.  
    * @param q2 The scale \f$q^2\f$.
    * @param iloc The location in the form factor list.
    * @param id0 The PDG code of the incoming baryon.
    * @param id1 The PDG code of the outgoing baryon.
    * @param m0 The mass of the incoming baryon.
    * @param m1 The mass of the outgoing baryon.
    * @param f1v The form factor \f$F^V_1\f$.
    * @param f2v The form factor \f$F^V_2\f$.
    * @param f3v The form factor \f$F^V_3\f$.
    * @param f1a The form factor \f$F^A_1\f$.
    * @param f2a The form factor \f$F^A_2\f$.
    * @param f3a The form factor \f$F^A_3\f$.
    * @param virt Whether the q2 is space or timelike
    */
   virtual void SpinHalfSpinHalfFormFactor(Energy2 q2,int iloc, int id0, int id1,
                       Energy m0, Energy m1,
                       Complex & f1v,Complex & f2v,Complex & f3v,
                       Complex & f1a,Complex & f2a,Complex & f3a,
                       FlavourInfo flavour,
                       Virtuality virt=SpaceLike);
 
   /**
    * The form factor for the weak decay of a spin \f$\frac12\f$ baryon to a 
    * spin \f$\frac32\f$ baryon.  
    * @param q2 The scale \f$q^2\f$.
    * @param iloc The location in the form factor list.
    * @param id0 The PDG code of the incoming baryon.
    * @param id1 The PDG code of the outgoing baryon.
    * @param m0 The mass of the incoming baryon.
    * @param m1 The mass of the outgoing baryon.
    * @param g1v The form factor \f$G^V_1\f$.
    * @param g2v The form factor \f$G^V_2\f$.
    * @param g3v The form factor \f$G^V_3\f$.
    * @param g4v The form factor \f$G^V_4\f$.
    * @param g1a The form factor \f$G^A_1\f$.
    * @param g2a The form factor \f$G^A_2\f$.
    * @param g3a The form factor \f$G^A_3\f$.
    * @param g4a The form factor \f$G^A_4\f$.
    * @param virt Whether the q2 is space or timelike
    */
   virtual void SpinHalfSpinThreeHalfFormFactor(Energy2 q2,int iloc, int id0, int id1,
                            Energy m0, Energy m1,
                            Complex & g1v,Complex & g2v,Complex & g3v,
                            Complex & g4v,Complex & g1a,Complex & g2a,
                            Complex & g3a,Complex & g4a,
                            FlavourInfo flavour,
                            Virtuality virt=SpaceLike);
   //@}
 
   /**
    * Output the setup information for the particle database
    * @param os The stream to output the information to
    * @param header Whether or not to output the information for MySQL
    * @param create Whether or not to add a statement creating the object
    */
   virtual void dataBaseOutput(ofstream & os,bool header,bool create) const;
 
   /**
    *  The integrand for the coefficients of the expansion. This is a function of the
    * integration variable \f$x\f$ which is chosen to transform the integrand over \f$y\f$
    * which is from \f$0\f$ to \f$\infty\f$ to an integral between 0 and 1. This means
    * that \f$y=\frac{1-x}{x}\f$.
    * @param x The integration variable.
    */
   double operator ()(double x) const;
   /** Argument type for GaussianIntegrator */
   typedef double ArgType;
   /** Return type for GaussianIntegrator */
   typedef double ValType;
 
   /**
    * The integrand for the semi-analytic calculation of the semi-leptonic width.
    * This is included for testing purposes.
    * @param omega The \f$\omega\f$ parameter of the heavy quark form-factors.
    * @param m0 The mass of the incoming baryon.
    * @param m1 The mass of the outgoing baryon.
    * @param type The type of the decay 
    * @param imass The baryonic mass parameter to use.
    * @param id0 PDG code for the decaying particle
    * @param id1 PDG code for the decay product
    */
   Energy widthIntegrand(double omega,Energy m0, Energy m1, int type, int imass,
             int id0,int id1);
 
 protected:
 
   /** @name Function needed to calculate the form factors */
   //@{
   /**
    * Returns the function \f$\Phi_N\f$ function of PRD56, 348 as a function
    * of \f$\omega\f$. 
    */
   vector<double> phiFunction(double);
 
   /**
    * The integral of a power of the the \f$S\f$ function of PRD56, 348 with respect
    * to \f$\theta\f$. This is used to 
    * calculate the coefficients of the expansion to compute the form factors.
    * The integral is calculated by computing a low power of the integrand and then
    * using recursion relations to calculate the pwoer requested.
    * @param y The \f$y\f$ variable of the function which is integrate over numerically.
    * @param N The power to which the integrand is raised.
    * @param SNm2 The integral with the function raised to the power \f$N/2-1\f$.
    * @param SN The integral with the function raised to the power \f$N\f$.  
    */
   void SN(double y,int N,double & SNm2,double & SN) const;
   //@}
 
 protected:
 
   /** @name Standard Interfaced functions. */
   //@{
 
   /**
    * Initialize this object after the setup phase before saving and
    * EventGenerator to disk.
    * @throws InitException if object could not be initialized properly.
    */
   virtual void doinit();
   //@}
 
 private:
 
   /**
    * Private and non-existent assignment operator.
    */
   BaryonThreeQuarkModelFormFactor & operator=(const BaryonThreeQuarkModelFormFactor &) = delete;
 
 private:
 
   /** @name Parameters for the form factors */
   //@{
   /**
    * Initialization of the expansion coefficients
    */
   bool _initialize;
 
   /**
    * Order of the expansion for the form factors.
    */
   unsigned int _order;
 
   /**
    *  Mass of the light quarks used in the calculation of the form factors.
    */
   Energy _mlight;
 
   /**
    *  Mass of the strange quark used in the calculation of the form factors.
    */
   Energy _mstrange;
 
   /**
    *  The heavy quark \f$\Lambda_Q\f$ parameter for the calculation of the form factors.
    */
   Energy _LambdaQ;
 
   /**
    *  The \f$\Lambda_{qq}\f$ parameter for the calculation of the form factors.
    */
   Energy _Lambdaqq;
 
   /**
    *  The \f$\Lambda_{sq}\f$ parameter for the calculation of the form factors.
    */
   Energy _Lambdasq;
 
 
   /**
    *  The \f$\Lambda_{ss}\f$ parameter for the calculation of the form factors.
    */
   Energy _Lambdass;
 
   /**
    *  Coefficients for the expansion of the \f$\xi(\omega)\f$ form factor.
    */
   vector<double> _C0;
 
   /**
    *  Coefficients for the expansion of the \f$\xi_1(\omega)\f$ form factor.
    */
   vector<double> _C1;
 
   /**
    *  Coefficients for the expansion of the \f$\xi_2(\omega)\f$ form factor.
    */
   vector<double> _C2;
 
   /**
    *  Coefficient of the first term in the integrand for the coefficient calculation.
    */
   double _a;
 
   /**
    *  Coefficient of the second term in the integrand for the coefficient calculation.
    */
   double _b;
 
   /**
    *  The \f$\mu^2\f$ parameter for the coefficient calculation.
    */
   double _mu2;
 
   /**
    *  the order of the coefficient being calculated.
    */
   int _N;
   //@}
 };
 
 }
 
 #endif /* HERWIG_BaryonThreeQuarkModelFormFactor_H */

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