EIC code displayed by LXR master/​include/​Herwig/​Decay/​ScalarMeson/​PseudoScalar2FermionsDecayer.h	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2026-08-06 09:24:02

 // -*- C++ -*-
 #ifndef Herwig_PseudoScalar2FermionsDecayer_H
 #define Herwig_PseudoScalar2FermionsDecayer_H
 //
 // This is the declaration of the PseudoScalar2FermionsDecayer class.
 //
 
 #include "Herwig/Decay/DecayIntegrator.h"
 #include "Herwig/Decay/PhaseSpaceMode.h"
 #include "ThePEG/Helicity/LorentzSpinorBar.h"
 
 namespace Herwig {
 
 using namespace ThePEG;
 
 /**
  * The PseudoScalar2FermionsDecayer class is designed for the decay of a pseudoscalar meson to
  * two fermions, in reality this is always the decay of the \f$\eta_c\f$ to a baryon
  * antibaryon pair.
  *
  * @see \ref PseudoScalar2FermionsDecayerInterfaces "The interfaces"
  * defined for PseudoScalar2FermionsDecayer.
  */
 class PseudoScalar2FermionsDecayer: public DecayIntegrator {
 
 public:
 
   /**
    * The default constructor.
    */
   PseudoScalar2FermionsDecayer();
 
   /**
    * 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;
 
   /**
    * Return the matrix element squared for a given mode and phase-space channel.
    * @param ichan The channel we are calculating the matrix element for. 
    * @param part The decaying Particle.
    * @param outgoing The particles produced in the decay
    * @param momenta  The momenta of the particles produced in the decay
    * @param meopt Option for the calculation of the matrix element
    * @return The matrix element squared for the phase-space configuration.
    */
   double me2(const int ichan,const Particle & part,
          const tPDVector & outgoing,
          const vector<Lorentz5Momentum> & momenta,
          MEOption meopt) const;
 
   /**
    *   Construct the SpinInfos for the particles produced in the decay
    */
   virtual void constructSpinInfo(const Particle & part,
                  ParticleVector outgoing) const;
 
   /**
    * Specify the \f$1\to2\f$ matrix element to be used in the running width calculation.
    * @param dm The DecayMode
    * @param mecode The code for the matrix element as described
    *               in the GenericWidthGenerator class, in this case 2.
    * @param coupling The coupling for the matrix element.
    * @return True or False if this mode can be handled.
    */
   bool twoBodyMEcode(const DecayMode & dm, int & mecode, double & coupling) 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);
   //@}
 
   /**
    * The standard Init function used to initialize the interfaces.
    * Called exactly once for each class by the class description system
    * before the main function starts or
    * when this class is dynamically loaded.
    */
   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;
 
   /** 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;
   //@}
 
 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:
 
   /**
    * The assignment operator is private and must never be called.
    * In fact, it should not even be implemented.
    */
   PseudoScalar2FermionsDecayer & operator=(const PseudoScalar2FermionsDecayer &) = delete;
 
 public:
 
   /**
    *   Set the parameters for a decay mode
    */
   string setUpDecayMode(string arg);
 
 private:
 
   /**
    * coupling for a decay
    */
   vector<double> coupling_;
 
   /**
    * the PDG codes for the incoming particles
    */
   vector<long> incoming_;
 
   /**
    * the PDG codes for the outgoing fermion-antifermion
    */
   vector<pair<long,long>> outgoing_;
 
   /**
    * maximum weight for a decay
    */
   vector<double> maxweight_;
 
   /**
    *  Spin density matrix
    */
   mutable RhoDMatrix rho_;
 
   /**
    *  Spinors for the decay products
    */
   mutable vector<Helicity::LorentzSpinor   <SqrtEnergy> > wave_;
 
   /**
    *  barred spinors for the decay products
    */
   mutable vector<Helicity::LorentzSpinorBar<SqrtEnergy> > wavebar_;
 
 };
 
 }
 
 #endif /* Herwig_PseudoScalar2FermionsDecayer_H */

This page was automatically generated by the 2.3.7 LXR engine. The LXR team