Line data    Source code

       1             : // ResonanceDecays.h is a part of the PYTHIA event generator.
       2             : // Copyright (C) 2015 Torbjorn Sjostrand.
       3             : // PYTHIA is licenced under the GNU GPL version 2, see COPYING for details.
       4             : // Please respect the MCnet Guidelines, see GUIDELINES for details.
       5             : 
       6             : // This file contains the main class for performing resonance decays.
       7             : // ResonanceDecays: handles the sequential decay of resonances in process.
       8             : 
       9             : #ifndef Pythia8_ResonanceDecays_H
      10             : #define Pythia8_ResonanceDecays_H
      11             : 
      12             : #include "Pythia8/Basics.h"
      13             : #include "Pythia8/Event.h"
      14             : #include "Pythia8/Info.h"
      15             : #include "Pythia8/ParticleData.h"
      16             : #include "Pythia8/PythiaStdlib.h"
      17             : #include "Pythia8/ResonanceWidths.h"
      18             : #include "Pythia8/Settings.h"
      19             : 
      20             : namespace Pythia8 {
      21             : 
      22             : //==========================================================================
      23             : 
      24             : // The ResonanceDecays class handles the sequential decay of resonances
      25             : // that are part of the hard process (t, W, Z, H, SUSY,...).
      26             : 
      27           0 : class ResonanceDecays {
      28             : 
      29             : public:
      30             : 
      31             :   // Constructor.
      32           0 :   ResonanceDecays() {}
      33             : 
      34             :   // Store pointers to Info and Rndm for error messages and random numbers.
      35             :   void init(Info* infoPtrIn,  ParticleData* particleDataPtrIn,
      36           0 :     Rndm* rndmPtrIn) {infoPtr = infoPtrIn;
      37           0 :     particleDataPtr = particleDataPtrIn; rndmPtr = rndmPtrIn;}
      38             : 
      39             :   // Generate the next decay sequence.
      40             :   bool next( Event& process, int iDecNow = 0);
      41             : 
      42             : private:
      43             : 
      44             :   // Constants: could only be changed in the code itself.
      45             :   static const int    NTRYCHANNEL, NTRYMASSES;
      46             :   static const double MSAFETY, WIDTHCUT, TINY, TINYBWRANGE,
      47             :                       WTCORRECTION[11];
      48             : 
      49             :   // Pointer to various information on the generation.
      50             :   Info*         infoPtr;
      51             : 
      52             :   // Pointer to the particle data table.
      53             :   ParticleData* particleDataPtr;
      54             : 
      55             :   // Pointer to the random number generator.
      56             :   Rndm*         rndmPtr;
      57             : 
      58             :   // Select masses of decay products.
      59             :   bool pickMasses();
      60             : 
      61             :   // Select colours of decay products.
      62             :   bool pickColours(int iDec, Event& process);
      63             : 
      64             :   // Select kinematics isotropic in phase space.
      65             :   bool pickKinematics();
      66             : 
      67             :   // Flavour, colour and momentum information.
      68             :   int            id0, mult;
      69             :   double         m0;
      70             :   vector<int>    idProd, cols, acols;
      71             :   vector<double> mProd;
      72             :   vector<Vec4>   pProd;
      73             : 
      74             : };
      75             : 
      76             : //==========================================================================
      77             : 
      78             : } // end namespace Pythia8
      79             : 
      80             : #endif // Pythia8_ResonanceDecays_H