#include <PythiaDecays.h>

Public Member Functions
const DaughterParticleList &	particleDaughtersPy6 (ParticlePropagator &particle)
const DaughterParticleList &	particleDaughtersPy8 (ParticlePropagator &particle)
	PythiaDecays (std::string program)
	~PythiaDecays ()
Private Attributes
std::auto_ptr< Pythia8::Pythia >	decayer
std::string	program_
Pythia6jets *	pyjets
gen::Pythia6Service *	pyservice
std::auto_ptr< Pythia8::Pythia >	pythia
DaughterParticleList	theList

Detailed Description

Definition at line 27 of file PythiaDecays.h.

Constructor & Destructor Documentation

PythiaDecays::PythiaDecays ( std::string program )

Definition at line 21 of file PythiaDecays.cc.

References gather_cfg::cout, decayer, program_, pyjets, pyservice, pythia, and Pythia6jets::Pythia6jets().

{
  program_=program;
  if (program_ == "pythia6") {
    pyjets = new Pythia6jets();
    pyservice = new gen::Pythia6Service();
    // The PYTHIA decay tables will be initialized later 
  } else if (program_ == "pythia8") {
    pythia.reset(new Pythia8::Pythia);
    decayer.reset(new Pythia8::Pythia);

    RandomP8* RP8 = new RandomP8();
    pythia->setRndmEnginePtr(RP8);
    decayer->setRndmEnginePtr(RP8);
  } else {
    std::cout << "WARNING: you are requesting an option which is not available in PythiaDecays::PythiaDecays " << std::endl;
  }

}

PythiaDecays::~PythiaDecays ( )

Definition at line 43 of file PythiaDecays.cc.

References program_, pyjets, and pyservice.

                            {
  if (program_ == "pythia6") {
    delete pyjets;
    delete pyservice;
  }
}

Member Function Documentation

const DaughterParticleList & PythiaDecays::particleDaughtersPy6 ( ParticlePropagator & particle )

Definition at line 108 of file PythiaDecays.cc.

References i, Pythia6jets::k(), RawParticle::mass(), max(), Pythia6jets::n(), Pythia6jets::p(), RawParticle::pid(), pyjets, pyservice, PYTHIA6PYDECY, RawParticle::T(), theList, Pythia6jets::v(), RawParticle::X(), RawParticle::Y(), and RawParticle::Z().

Referenced by TrajectoryManager::updateWithDaughters().

{
  gen::Pythia6Service::InstanceWrapper guard(pyservice); // grab Py6 context

  //  Pythia6jets pyjets;
  int ip;

  pyjets->k(1,1) = 1;
  pyjets->k(1,2) = particle.pid();
  pyjets->p(1,1) = particle.Px();
  pyjets->p(1,2) = particle.Py();
  pyjets->p(1,3) = particle.Pz();
  pyjets->p(1,4) = std::max(particle.mass(),particle.e());
  pyjets->p(1,5) = particle.mass();
  pyjets->v(1,1) = particle.X();
  pyjets->v(1,2) = particle.Y();
  pyjets->v(1,3) = particle.Z();
  pyjets->v(1,4) = particle.T();
  pyjets->n() = 1;
  
  ip = 1;
  PYTHIA6PYDECY(&ip);

  // Fill the list of daughters
  theList.clear();
  if ( pyjets->n()==1 ) return theList; 

  theList.resize(pyjets->n()-1,RawParticle());

  for (int i=2;i<=pyjets->n();++i) {
    
    theList[i-2].SetXYZT(pyjets->p(i,1),pyjets->p(i,2),
                         pyjets->p(i,3),pyjets->p(i,4)); 
    theList[i-2].setVertex(pyjets->v(i,1),pyjets->v(i,2),
                           pyjets->v(i,3),pyjets->v(i,4));
    theList[i-2].setID(pyjets->k(i,2));
    theList[i-2].setMass(pyjets->p(i,5));

  }

  return theList;
  
}

const DaughterParticleList & PythiaDecays::particleDaughtersPy8 ( ParticlePropagator & particle )

Definition at line 51 of file PythiaDecays.cc.

References decayer, RawParticle::mass(), RawParticle::momentum(), RawParticle::pid(), RawParticle::T(), theList, RawParticle::X(), RawParticle::Y(), and RawParticle::Z().

Referenced by TrajectoryManager::updateWithDaughters().

{

  theList.clear();

  /*
  std::cout << "###" << std::endl;
  std::cout << "particle.PDGname() == " << particle.PDGname() << std::endl; 
  std::cout << "particle.status() == " << particle.status() << std::endl;
  std::cout << "particle.pid() == " << particle.pid() << std::endl;
  std::cout << "particle.momentum().x() == " << particle.momentum().x() << std::endl;
  std::cout << "particle.Px() == " << particle.Px() << std::endl;
  std::cout << "particle.X() == " << particle.X() << std::endl;
  std::cout << "particle.mass() == " << particle.mass() << std::endl;
  std::cout << "particle.PDGmass() == " << particle.PDGmass() << std::endl;
  std::cout << "particle.PDGcTau() == " << particle.PDGcTau() << std::endl;
  std::cout << "(decayer->particleData).tau0( particle.pid() ) == " << (decayer->particleData).tau0( particle.pid() ) << std::endl;
  */

  // inspired by method Pythia8Hadronizer::residualDecay() in GeneratorInterface/Pythia8Interface/src/Pythia8Hadronizer.cc
  decayer->event.reset();
  Pythia8::Particle py8part(  particle.pid(), 93, 0, 0, 0, 0, 0, 0,
                     particle.momentum().x(), // note: momentum().x() and Px() are the same
                     particle.momentum().y(),
                     particle.momentum().z(),
                     particle.momentum().t(),
                     particle.mass() );
  py8part.vProd( particle.X(), particle.Y(), 
                 particle.Z(), particle.T() );
  py8part.tau( (decayer->particleData).tau0( particle.pid() ) );
  decayer->event.append( py8part );

  int nentries = decayer->event.size();
  if ( !decayer->event[nentries-1].mayDecay() ) return theList;
  decayer->next();
  int nentries1 = decayer->event.size();
  if ( nentries1 <= nentries ) return theList; //same number of particles, no decays...
  Pythia8::Particle& py8daughter = decayer->event[nentries]; // the 1st daughter // DO I NEED THIS LINE?

  theList.resize(nentries,RawParticle());

  for ( int ipart=nentries+1; ipart<nentries1; ipart++ )
    {
      py8daughter = decayer->event[ipart];
      theList[ipart-nentries-1].SetXYZT( py8daughter.px(), py8daughter.py(), py8daughter.pz(), py8daughter.e() );
      theList[ipart-nentries-1].setVertex( py8daughter.xProd(),
                                           py8daughter.yProd(),
                                           py8daughter.zProd(),
                                           py8daughter.tProd() );
      theList[ipart-nentries-1].setID( py8daughter.id() );
      theList[ipart-nentries-1].setMass( py8daughter.m() );
    }

  return theList;
}