HepMC Reference Documentation HepMC

GenParticle.cc

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// Matt.Dobbs@Cern.CH, September 1999
// Updated: 07.02.2000 no longer does particle point to ParticleData, 
//                     but rather it uses an int id which can be looked up
// particle within an event coming in/out of a vertex
#include "HepMC/GenEvent.h"
#include "HepMC/GenVertex.h"
#include "HepMC/GenParticle.h"
#include <iomanip>       // needed for formatted output

namespace HepMC {

    GenParticle::GenParticle( void ) :
        m_momentum(0), m_pdg_id(0), m_status(0), m_flow(this),
        m_polarization(0), m_production_vertex(0), m_end_vertex(0),
        m_barcode(0), m_generated_mass(0.)
    {
        s_counter++;
    }

    GenParticle::GenParticle( const FourVector& momentum, 
                        int pdg_id, int status, 
                        const Flow& itsflow,
                        const Polarization& polar ) : 
        m_momentum(momentum), m_pdg_id(pdg_id), m_status(status), m_flow(this),
        m_polarization(polar), m_production_vertex(0), m_end_vertex(0),
        m_barcode(0), m_generated_mass(momentum.m())
    {
        // Establishing *this as the owner of m_flow is done above,
        // then we set it equal to the other flow pattern (subtle)
        set_flow(itsflow);
        s_counter++;
    }

    GenParticle::GenParticle( const GenParticle& inparticle ) : 
        m_momentum( inparticle.momentum() ),
        m_pdg_id( inparticle.pdg_id() ), 
        m_status( inparticle.status() ), 
        m_flow(this),
        m_polarization( inparticle.polarization() ),
        m_production_vertex(0), 
        m_end_vertex(0), 
        m_barcode(0), 
        m_generated_mass( inparticle.generated_mass() )
    {
        set_production_vertex_( 0 );
        set_end_vertex_( 0 );
        suggest_barcode( inparticle.barcode() );
        s_counter++;
    }

    GenParticle::~GenParticle() {    
        if ( parent_event() ) parent_event()->remove_barcode(this);
        s_counter--;
    }

    void GenParticle::swap( GenParticle & other)
    {
        // if a container has a swap method, use that for improved performance
        m_momentum.swap( other.m_momentum );
        std::swap( m_pdg_id, other.m_pdg_id );
        std::swap( m_status, other.m_status );
        m_flow.swap( other.m_flow );
        m_polarization.swap( other.m_polarization );
        std::swap( m_production_vertex, other.m_production_vertex );
        std::swap( m_end_vertex, other.m_end_vertex );
        std::swap( m_barcode, other.m_barcode );
        std::swap( m_generated_mass, other.m_generated_mass );
    }

    GenParticle& GenParticle::operator=( const GenParticle& inparticle ) {

        // best practices implementation
        GenParticle tmp( inparticle );
        swap( tmp );
        return *this;
    }

    bool GenParticle::operator==( const GenParticle& a ) const {
        if ( a.momentum() != this->momentum() ) return 0;
        if ( a.generated_mass() != this->generated_mass() ) return 0;
        if ( a.pdg_id() != this->pdg_id() ) return 0;
        if ( a.status() != this->status() ) return 0;
        if ( a.m_flow != this->m_flow ) return 0;
        if ( a.polarization() != this->polarization() ) return 0;
        return 1;
    }

    bool GenParticle::operator!=( const GenParticle& a ) const {
        return !( a == *this );
    }

    void GenParticle::print( std::ostream& ostr ) const {
        ostr << "GenParticle: " 
             << barcode() << " ID:" << pdg_id()
             << " (P,E)=" << momentum().px() << "," << momentum().py() 
             << "," << momentum().pz() << "," << momentum().e()
             << " Stat:" << status();
        if ( production_vertex() && production_vertex()->barcode()!=0 ) {
            ostr << " PV:" << production_vertex()->barcode();
        } else ostr << " PV:" << production_vertex();
        if ( end_vertex() && end_vertex()->barcode()!=0 ) {
            ostr << " EV:" << end_vertex()->barcode();
        } else ostr << " EV:" << end_vertex();
        ostr << " Pol:" << polarization() << " F:" << m_flow << std::endl;
    }

    GenEvent* GenParticle::parent_event() const {
        if ( production_vertex() ) return production_vertex()->parent_event();
        if ( end_vertex() ) return end_vertex()->parent_event();
        return 0;
    }

    void GenParticle::set_production_vertex_( GenVertex* prodvertex )
    { 
        GenEvent* its_orig_event = parent_event();
        m_production_vertex = prodvertex; 
        GenEvent* its_new_event = parent_event();
        // Next bit of logic ensures the barcode maps are kept up to date
        //  in the GenEvent containers.
        if ( its_orig_event != its_new_event ) {
            if ( its_new_event ) its_new_event->set_barcode( this, barcode() );
            if ( its_orig_event ) its_orig_event->remove_barcode( this );
        }
    }

    void GenParticle::set_end_vertex_( GenVertex* decayvertex ) 
    { 
        GenEvent* its_orig_event = parent_event();
        m_end_vertex = decayvertex;
        GenEvent* its_new_event = parent_event();
        if ( its_orig_event != its_new_event ) {
            if ( its_new_event ) its_new_event->set_barcode( this, barcode() );
            if ( its_orig_event ) its_orig_event->remove_barcode( this );
        }
    }   

    bool GenParticle::suggest_barcode( int the_bar_code )
    {
        if ( the_bar_code <0 ) {
            std::cerr << "GenParticle::suggest_barcode WARNING, particle bar "
                      << "\n codes MUST be positive integers. Negative  "
                      << "\n integers are reserved for vertices only. Your "
                      << "\n suggestion has been rejected." << std::endl;
            return false;
        }
        bool success = false;
        if ( parent_event() ) {
            success = parent_event()->set_barcode( this, the_bar_code );
        } else { set_barcode_( the_bar_code ); }
        return success;
    }

    // Static  //
    unsigned int GenParticle::counter() { return s_counter; }
    unsigned int GenParticle::s_counter = 0U; 

    // Friends //

    std::ostream& operator<<( std::ostream& ostr, const GenParticle& part ) {
        ostr << " ";
        ostr.width(9);
        ostr << part.barcode();
        ostr.width(9);
        ostr << part.pdg_id() << " ";
        ostr.width(9);
        ostr.precision(2);
        ostr.setf(std::ios::scientific, std::ios::floatfield);
        ostr.setf(std::ios_base::showpos);
        ostr << part.momentum().px() << ",";
        ostr.width(9);
        ostr.precision(2);
        ostr << part.momentum().py() << ",";
        ostr.width(9);
        ostr.precision(2);
        ostr << part.momentum().pz() << ",";
        ostr.width(9);
        ostr.precision(2);
        ostr << part.momentum().e() << " ";
        ostr.setf(std::ios::fmtflags(0), std::ios::floatfield);
        ostr.unsetf(std::ios_base::showpos);
        if ( part.end_vertex() && part.end_vertex()->barcode()!=0 ) {
            ostr.width(3);
            ostr << part.status() << " ";
            ostr.width(9);
            ostr << part.end_vertex()->barcode();
        } else if ( !part.end_vertex() ) {
            // There is no valid end_vertex 
            // For consistency across different compilers, do not print anything
            ostr.width(3);
            ostr << part.status();
        } else {
            // In this case the end_vertex does not have a unique 
            //   barcode assigned, so we choose instead to print its address
            ostr.width(3);
            ostr << part.status() << " ";
            ostr.width(9);
            ostr << (void*)part.end_vertex();
        }
        return ostr;
    }


    double  GenParticle::generated_mass() const {
        return m_generated_mass;
    }

    void   GenParticle::set_generated_mass( const double & m ) {
        m_generated_mass = m;
    }

} // HepMC

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