HepMC::Pythia8ToHepMCA Class Reference

#include <HepMCA2.h>

Inheritance diagram for HepMC::Pythia8ToHepMCA:

Public Member Functions
bool	append_event (Pythia8::Event &pyev, GenEvent *evt, GenParticle *rootpart, int ibarcode=-1, Pythia8::Info *pyinfo=0, Pythia8::Settings *pyset=0)
bool	convert_gluon_to_0 () const
bool	crash_on_problem () const
bool	free_parton_warnings () const
bool	print_inconsistency () const
	Pythia8ToHepMCA ()
void	set_convert_gluon_to_0 (bool b=false)
void	set_crash_on_problem (bool b=false)
void	set_free_parton_warnings (bool b=true)
void	set_print_inconsistency (bool b=true)
virtual	~Pythia8ToHepMCA ()

Private Member Functions
virtual bool	fill_next_event (GenEvent *)
	Pythia8ToHepMCA (const Pythia8ToHepMCA &)
virtual void	write_event (const GenEvent *)

Private Attributes
bool	m_convert_gluon_to_0
bool	m_crash_on_problem
bool	m_free_parton_warnings
int	m_internal_event_number
bool	m_print_inconsistency

Detailed Description

Definition at line 26 of file HepMCA2.h.

Constructor & Destructor Documentation

HepMC::Pythia8ToHepMCA::Pythia8ToHepMCA ( )

inline

Definition at line 31 of file HepMCA2.h.

                    : m_internal_event_number(0),
    m_print_inconsistency(true), m_free_parton_warnings(true),
    m_crash_on_problem(false),   m_convert_gluon_to_0(false) {;}

virtual HepMC::Pythia8ToHepMCA::~Pythia8ToHepMCA ( )

inlinevirtual

Definition at line 34 of file HepMCA2.h.

{;}

HepMC::Pythia8ToHepMCA::Pythia8ToHepMCA ( const Pythia8ToHepMCA &  )

inlineprivate

Definition at line 59 of file HepMCA2.h.

: IO_BaseClass() {;}

Member Function Documentation

bool HepMC::Pythia8ToHepMCA::append_event ( Pythia8::Event &  pyev, GenEvent *  evt, GenParticle *  rootpart, int  ibarcode = -1, Pythia8::Info *  pyinfo = 0, Pythia8::Settings *  pyset = 0  )

inline

Definition at line 74 of file HepMCA2.h.

References funct::abs(), ecal_dqm_sourceclient-live_cfg::cerr, cuy::col, alignCSCRings::e, cmsRelvalreport::exit, GenParticle::GenParticle, i, visualization-live-secondInstance_cfg::m, m_crash_on_problem, m_free_parton_warnings, m_print_inconsistency, HWWFunctions::MM, and AlCaHLTBitMon_ParallelJobs::p.

Referenced by gen::Py8GunBase::residualDecay(), and Pythia8Hadronizer::residualDecay().

                                                             {

  // 1. Error if no event passed.
  if (!evt) {
    std::cerr << "Pythia8ToHepMCA::fill_next_event error - passed null event."
              << std::endl;
    return 0;
  }

  // Conversion factors from Pythia units GeV and mm to HepMC ones.
  double momFac = HepMC::Units::conversion_factor(HepMC::Units::GEV,
    evt->momentum_unit());
  double lenFac = HepMC::Units::conversion_factor(HepMC::Units::MM,
    evt->length_unit());
    
  int NewBarcode = evt->particles_size();
  if (ibarcode > -1) NewBarcode = ibarcode;

  GenVertex* prod_vtx0 = new GenVertex();
  prod_vtx0->add_particle_in( rootpart );
  evt->add_vertex( prod_vtx0 );

  // 2. Create a particle instance for each entry and fill a map, and
  // a vector which maps from the particle index to the GenParticle address.
  std::vector<GenParticle*> hepevt_particles( pyev.size() );
  for (int i = 2; i < pyev.size(); ++i) {

    // Fill the particle.

    hepevt_particles[i] = new GenParticle(
      FourVector( momFac * pyev[i].px(), momFac * pyev[i].py(),
                  momFac * pyev[i].pz(), momFac * pyev[i].e()  ),
      pyev[i].id(), pyev[i].statusHepMC() );
    if (ibarcode !=0) NewBarcode++;
    hepevt_particles[i]->suggest_barcode(NewBarcode);
    hepevt_particles[i]->set_generated_mass( momFac * pyev[i].m() );

    // Colour flow uses index 1 and 2.
    int colType = pyev[i].colType();
    if (colType ==  1 || colType == 2)
      hepevt_particles[i]->set_flow(1, pyev[i].col());
    if (colType == -1 || colType == 2)
      hepevt_particles[i]->set_flow(2, pyev[i].acol());
  }

  // 3. Loop over particles AGAIN, this time creating vertices.
  // We build the production vertex for each entry in hepevt.
  // The HEPEVT pointers are bi-directional, so gives decay vertices as well.
  for (int i = 2; i < pyev.size(); ++i) {
    GenParticle* p = hepevt_particles[i];

    // 3a. Search to see if a production vertex already exists.
    std::vector<int> mothers = pyev[i].motherList();

    unsigned int imother = 0;
    int mother = -1; // note that in Pythia8 there is a particle number 0!
    if ( !mothers.empty() ) mother = mothers[imother];
    GenVertex* prod_vtx = p->production_vertex();
    while ( !prod_vtx && mother > 0 ) {
      if(mother == 1) {
        prod_vtx = rootpart->end_vertex();
      } else {
        prod_vtx = hepevt_particles[mother]->end_vertex();
      }
      if ( prod_vtx ) prod_vtx->add_particle_out( p );
      mother = ( ++imother < mothers.size() ) ? mothers[imother] : -1;
    }

    // 3b. If no suitable production vertex exists - and the particle has
    // at least one mother or position information to store - make one.
    FourVector prod_pos( lenFac * pyev[i].xProd(), lenFac * pyev[i].yProd(),
                         lenFac * pyev[i].zProd(), lenFac * pyev[i].tProd() );
    if ( !prod_vtx && ( mothers.size() > 0 || prod_pos != FourVector() ) ) {
      prod_vtx = new GenVertex();
      prod_vtx->add_particle_out( p );
      evt->add_vertex( prod_vtx );
    }

    // 3c. If prod_vtx doesn't already have position specified, fill it.
    if ( prod_vtx && prod_vtx->position() == FourVector() )
      prod_vtx->set_position( prod_pos );

    // 3d. loop over mothers to make sure their end_vertices are consistent.
    imother = 0;
    mother = -1;
    if ( !mothers.empty() ) mother = mothers[imother];
    while ( prod_vtx && mother > 0 ) {

      // If end vertex of the mother isn't specified, do it now.
      GenParticle* ppp;
      if(mother == 1) ppp = rootpart;
      if(mother > 1) ppp = hepevt_particles[mother];

      if ( !ppp->end_vertex() ) {
        prod_vtx->add_particle_in( ppp );

      // Problem scenario: the mother already has a decay vertex which
      // differs from the daughter's production vertex. This means there is
      // internal inconsistency in the HEPEVT event record. Print an error.
      // Note: we could provide a fix by joining the two vertices with a
      // dummy particle if the problem arises often.
      } else if (ppp->end_vertex() != prod_vtx ) {
       if ( m_print_inconsistency ) std::cerr
          << "HepMC::Pythia8ToHepMC: inconsistent mother/daugher "
          << "information in Pythia8 event " << std::endl
          << "i = " << i << " mother = " << mother
          << "\n This warning can be turned off with the "
          << "Pythia8ToHepMC::print_inconsistency switch." << std::endl;
      }

      // End of vertex-setting loops.
      mother = ( ++imother < mothers.size() ) ? mothers[imother] : -1;
    }
  }

  // If hadronization switched on then no final coloured particles.
  bool doHadr = (pyset == 0) ? m_free_parton_warnings
    : pyset->flag("HadronLevel:all") && pyset->flag("HadronLevel:Hadronize");

  // 4. Check for particles which come from nowhere, i.e. are without
  // mothers or daughters. These need to be attached to a vertex, or else
  // they will never become part of the event.
  for (int i = 2; i < pyev.size(); ++i) {
    if ( !hepevt_particles[i]->end_vertex() &&
         !hepevt_particles[i]->production_vertex() ) {
      std::cerr << "hanging particle " << i << std::endl;
      GenVertex* prod_vtx = new GenVertex();
      prod_vtx->add_particle_out( hepevt_particles[i] );
      evt->add_vertex( prod_vtx );
    }

    // Also check for free partons (= gluons and quarks; not diquarks?).
    if ( doHadr && m_free_parton_warnings ) {
      if ( hepevt_particles[i]->pdg_id() == 21 &&
        !hepevt_particles[i]->end_vertex() ) {
        std::cerr << "gluon without end vertex " << i << std::endl;
        if ( m_crash_on_problem ) exit(1);
      }
      if ( abs(hepevt_particles[i]->pdg_id()) <= 6 &&
        !hepevt_particles[i]->end_vertex()         ) {
        std::cerr << "quark without end vertex " << i << std::endl;
        if ( m_crash_on_problem ) exit(1);
      }
    }
  }

  // Done.
  return true;

}

bool HepMC::Pythia8ToHepMCA::convert_gluon_to_0 ( ) const

inline

Definition at line 44 of file HepMCA2.h.

References m_convert_gluon_to_0.

{return m_convert_gluon_to_0;}

bool HepMC::Pythia8ToHepMCA::crash_on_problem ( ) const

inline

Definition at line 43 of file HepMCA2.h.

References m_crash_on_problem.

{return m_crash_on_problem;}

virtual bool HepMC::Pythia8ToHepMCA::fill_next_event ( GenEvent *  )

inlineprivatevirtual

Definition at line 55 of file HepMCA2.h.

{ return 0; }

bool HepMC::Pythia8ToHepMCA::free_parton_warnings ( ) const

inline

Definition at line 42 of file HepMCA2.h.

References m_free_parton_warnings.

{return m_free_parton_warnings;}

bool HepMC::Pythia8ToHepMCA::print_inconsistency ( ) const

inline

Definition at line 41 of file HepMCA2.h.

References m_print_inconsistency.

{return m_print_inconsistency;}

void HepMC::Pythia8ToHepMCA::set_convert_gluon_to_0 ( bool  b = false )

inline

Definition at line 50 of file HepMCA2.h.

References b, and m_convert_gluon_to_0.

{m_convert_gluon_to_0 = b;}

void HepMC::Pythia8ToHepMCA::set_crash_on_problem ( bool  b = false )

inline

Definition at line 49 of file HepMCA2.h.

References b, and m_crash_on_problem.

{m_crash_on_problem = b;}

void HepMC::Pythia8ToHepMCA::set_free_parton_warnings ( bool  b = true )

inline

Definition at line 48 of file HepMCA2.h.

References b, and m_free_parton_warnings.

{m_free_parton_warnings = b;}

void HepMC::Pythia8ToHepMCA::set_print_inconsistency ( bool  b = true )

inline

Definition at line 47 of file HepMCA2.h.

References b, and m_print_inconsistency.

{m_print_inconsistency = b;}

virtual void HepMC::Pythia8ToHepMCA::write_event ( const GenEvent *  )

inlineprivatevirtual

Definition at line 56 of file HepMCA2.h.

{;}

Member Data Documentation

bool HepMC::Pythia8ToHepMCA::m_convert_gluon_to_0

private

Definition at line 63 of file HepMCA2.h.

Referenced by convert_gluon_to_0(), and set_convert_gluon_to_0().

bool HepMC::Pythia8ToHepMCA::m_crash_on_problem

private

Definition at line 63 of file HepMCA2.h.

Referenced by append_event(), crash_on_problem(), and set_crash_on_problem().

bool HepMC::Pythia8ToHepMCA::m_free_parton_warnings

private

Definition at line 63 of file HepMCA2.h.

Referenced by append_event(), free_parton_warnings(), and set_free_parton_warnings().

int HepMC::Pythia8ToHepMCA::m_internal_event_number

private

Definition at line 62 of file HepMCA2.h.

bool HepMC::Pythia8ToHepMCA::m_print_inconsistency

private

Definition at line 63 of file HepMCA2.h.

Referenced by append_event(), print_inconsistency(), and set_print_inconsistency().