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 // -*- C++ -*-
 #ifndef HERWIG_SU3BaryonSingletOctetScalarDecayer_H
 #define HERWIG_SU3BaryonSingletOctetScalarDecayer_H
 // This is the declaration of the SU3BaryonSingletOctetScalarDecayer class.
 
 #include "Baryon1MesonDecayerBase.h"
 
 namespace Herwig {
 using namespace ThePEG;
 
 /** \ingroup Decay
  *
  * The <code>SU3BaryonSingletOctetScalarDecayer</code> class is a simple decayer for 
  * the strong decay of the excited baryon \f$SU(3)\f$ singlets to a lighter
  * baryon octet and a pseudoscalar meson from the lightest 
  * multiplet, \e i.e. \f$\pi\f$, \f$K\f$,\f$\eta\f$.
  *
  * The interaction Lagrangian is taken to have the form
  *
  * \f[\frac{2C}{f_\pi} \left[{\rm tr} (\bar{R}p_\phi\!\!\!\!\!\!\!\!\!\not\,\,\,\,\,\,\,\phi B)\right]\f]
  *  where \f$R\f$ is the field for the excited resonance, \f$\phi\f$ is the matrix
  *  field for the pseudoscalar mesons and \f$B\f$ is the matrix field for the ground
  *  state baryon octet.
  *  
  *  The above form is used for \f$\frac12^-\f$ excited
  *  baryon resonances and the above form with
  *  an additional \f$\gamma_5\f$ is used for excited \f$\frac12^+\f$ baryon resonances.
  *
  *  For the decays of the spin-\f$\frac32\f$ resonances we use the form 
  *
  * \f[\frac{2C}{f_\pi} \left[{\rm tr} (\bar{R}^\mu p_{\phi,\mu}\phi B)\right],\f]
  *  where \f$R^\mu\f$ is the field for the excited resonance. This form is used for
  * the spin\f$\frac32^+\f$ resonances and this form with an additional \f$\gamma_5\f$
  * for spin\f$\frac32^-\f$.
  * 
  *  This is one of a number of decayers based on \f$SU(3)\f$ symmetry which are
  *  intended for the decay of excited baryons.
  *
  * @see Baryon1MesonDecayerBase
  * @see SU3BaryonOctetOctetPhotonDecayer
  * @see SU3BaryonDecupletOctetPhotonDecayer
  * @see SU3BaryonDecupletOctetScalarDecayer
  * @see SU3BaryonSingletOctetPhotonDecayer
  * @see SU3BaryonSingletOctetScalarDecayer
  * @see SU3BaryonOctetDecupletScalarDecayer
  * @see SU3BaryonOctetOctetScalarDecayer
  *
  */
 class SU3BaryonSingletOctetScalarDecayer: public Baryon1MesonDecayerBase {
 
 public:
 
   /**
    * Default constructor.
    */
   SU3BaryonSingletOctetScalarDecayer();
 
   /**
    * Which of the possible decays is required
    * @param cc Is this mode the charge conjugate
    * @param parent The decaying particle
    * @param children The decay products
    */
   virtual int modeNumber(bool & cc, tcPDPtr parent, 
              const tPDVector & children) const;
 
   /**
    * 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
    */
   virtual void dataBaseOutput(ofstream & os,bool header) const;
 
 public:
 
   /** @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:
 
   /**
    *  Coupling Members.
    */
   //@{
   /**
    * Couplings for spin-\f$\frac12\f$ to spin-\f$\frac12\f$ and a scalar.
    * @param imode The mode
    * @param m0 The mass of the decaying particle.
    * @param m1 The mass of the outgoing baryon.
    * @param m2 The mass of the outgoing meson.
    * @param A The coupling \f$A\f$ described above.
    * @param B The coupling \f$B\f$ described above.
    */
   virtual void halfHalfScalarCoupling(int imode,Energy m0,Energy m1,Energy m2,
                       Complex& A,Complex& B) const;
 
   /**
    * Couplings for spin-\f$\frac12\f$ to spin-\f$\frac32\f$ and a scalar. 
    * @param imode The mode
    * @param m0 The mass of the decaying particle.
    * @param m1 The mass of the outgoing baryon.
    * @param m2 The mass of the outgoing meson.
    * @param A The coupling \f$A\f$ described above.
    * @param B The coupling \f$B\f$ described above.
    */
   virtual void threeHalfHalfScalarCoupling(int imode,Energy m0,Energy m1,Energy m2,
                        Complex& A,Complex& B) const;
   //@}
 
 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);}
   //@}
 
 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();
 
   /**
    * Initialize this object to the begining of the run phase.
    */
   virtual void doinitrun();
   //@}
 
 private:
 
   /**
    * Private and non-existent assignment operator.
    */
   SU3BaryonSingletOctetScalarDecayer & operator=(const SU3BaryonSingletOctetScalarDecayer &) = delete;
 
 private:
 
   /**
    * set-up the modes
    */
   void setupModes(unsigned int) const;
 
 private:
 
   /**
    * the coupling
    */
   double _c;
 
   /**
    * the relative parities of the two baryon multiplets
    */
   bool _parity;
 
   /**
    * the pion decay constant
    */
   Energy _fpi;
 
   /**
    * PDG codes for the various octet baryons
    */
   //@{
   /**
    *  The PDG code for the \f$p\f$-like member of the outgoing octet.
    */
   int _proton;
 
   /**
    *  The PDG code for the \f$n\f$-like member of the outgoing octet.
    */
   int _neutron;
 
   /**
    *  The PDG code for the \f$\Sigma^0\f$-like member of the outgoing octet.
    */
   int _sigma0;
 
   /**
    *  The PDG code for the  \f$\Sigma^+\f$-like member of the outgoing octet.
    */
   int _sigmap;
 
   /**
    *  The PDG code for the  \f$\Sigma^-\f$-like member of the outgoing octet.
    */
   int _sigmam;
 
   /**
    *  The PDG code for the \f$\Sigma^0\f$-like member of the outgoing octet.
    */
   int _lambda;
 
   /**
    *  The PDG code for the \f$\Xi^0\f$-like member of the outgoing octet.
    */
   int _xi0;
 
   /**
    *  The PDG code for the \f$\Xi^-\f$-like member of the outgoing octet.
    */
   int _xim;
   //@}
 
   /**
    * PDG code for the excited singlet \f$\Lambda\f$.
    */
   int _elambda;
 
   /**
    * PDG code for the outgoing baryons
    */
   mutable vector<int> _outgoingB;
 
   /**
    * PDG code for the outgoing mesons
    */
   mutable vector<int> _outgoingM;
 
   /**
    * the maximum weight for the various modes
    */
   vector<double> _maxweight;
   /**
    * The couplings for the different modes.
    */
   mutable vector<InvEnergy> _prefactor;
 };
 
 }
 
 
 #endif /* HERWIG_SU3BaryonSingletOctetScalarDecayer_H */

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