#include <hepmcoutput.h>

SMASH output to HepMC file.

This class writes a vertex connecting all intial particles with all final particles into a HepMC outputfile. In collider mode, projectile and target are combined into single intial particles with a nuclear pdg code. The output file is a human-readable ASCII file. HepMC version 3 is used.

More details of the output format can be found in the User Guide.

Definition at line 41 of file hepmcoutput.h.

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Public Member Functions
	HepMcOutput (const bf::path &path, std::string name, const OutputParameters &out_par, const int total_N, const int proj_N)
	Create HepMC particle output. More...

	~HepMcOutput ()
	Destructor renames file. More...

void	at_eventstart (const Particles &particles, const int event_number, const EventInfo &) override
	Add the initial particles information of an event to the central vertex. More...

void	at_eventend (const Particles &particles, const int32_t event_number, const EventInfo &event) override
	Add the final particles information of an event to the central vertex. More...

Public Member Functions inherited from smash::OutputInterface
	OutputInterface (std::string name)
	Construct output interface. More...

virtual	~OutputInterface ()=default

virtual void	at_eventend (const Particles &particles, const int event_number, const EventInfo &info)=0
	Output launched at event end. More...

virtual void	at_interaction (const Action &action, const double density)
	Called whenever an action modified one or more particles. More...

virtual void	at_intermediate_time (const Particles &particles, const std::unique_ptr< Clock > &clock, const DensityParameters &dens_param, const EventInfo &info)
	Output launched after every N'th timestep. More...

virtual void	thermodynamics_output (const ThermodynamicQuantity tq, const DensityType dt, RectangularLattice< DensityOnLattice > &lattice)
	Output to write thermodynamics from the lattice. More...

virtual void	thermodynamics_output (const ThermodynamicQuantity tq, const DensityType dt, RectangularLattice< EnergyMomentumTensor > &lattice)
	Output to write energy-momentum tensor and related quantities from the lattice. More...

virtual void	thermodynamics_output (const GrandCanThermalizer &gct)
	Output to write energy-momentum tensor and related quantities from the thermalizer class. More...

bool	is_dilepton_output () const
	Get, whether this is the dilepton output? More...

bool	is_photon_output () const
	Get, whether this is the photon output? More...

bool	is_IC_output () const
	Get, whether this is the IC output? More...

const char *	to_string (const ThermodynamicQuantity tq)
	Convert thermodynamic quantities to strings. More...

const char *	to_string (const DensityType dens_type)
	Convert density types to strings. More...

Private Member Functions
int	construct_nuclear_pdg_code (int na, int nz) const
	Construct nulcear pdg code for porjectile and target, see PDG chapter "Monte Carlo particle numbering scheme" for details. More...

Private Attributes
const bf::path	filename_
	Filename of output. More...

bf::path	filename_unfinished_
	Filename of output as long as simulation is still running. More...

const int	total_N_
	Total number of nucleons in projectile and target, needed for converting nuclei to single particles. More...

const int	proj_N_
	Total number of nucleons in projectile, needed for converting nuclei to single particles. More...

std::unique_ptr< HepMC3::WriterAscii >	output_file_
	Pointer to Ascii HepMC3 output file. More...

std::unique_ptr< HepMC3::GenEvent >	current_event_
	HepMC3::GenEvent pointer for current event. More...

HepMC3::GenVertexPtr	vertex_
	HepMC3::GenVertex pointer for central vertex in event. More...

Static Private Attributes
static const int	status_code_for_beam_particles = 4
	HepMC convention: status code for target and projecticle particles. More...

static const int	status_code_for_final_particles = 1
	HepMC convention: status code for final particles. More...

Additional Inherited Members
Protected Attributes inherited from smash::OutputInterface
const bool	is_dilepton_output_
	Is this the dilepton output? More...

const bool	is_photon_output_
	Is this the photon output? More...

const bool	is_IC_output_
	Is this the IC output? More...

Constructor & Destructor Documentation

◆ HepMcOutput()

smash::HepMcOutput::HepMcOutput	(	const bf::path &	path,
		std::string	name,
		const OutputParameters &	out_par,
		const int	total_N,
		const int	proj_N
	)

Create HepMC particle output.

Parameters

[in]	path	Output path.
[in]	name	Name of the output.
[in]	out_par	Unused, needed since inhertied.
[in]	total_N	Total number of particles in both nuclei.
[in]	proj_N	Number of particles in projectile.

Definition at line 51 of file hepmcoutput.cc.

     : OutputInterface(name),
       filename_(path / (name + ".asciiv3")),
       total_N_(total_N),
       proj_N_(proj_N) {
   filename_unfinished_ = filename_;
   filename_unfinished_ += +".unfinished";
   output_file_ =
       make_unique<HepMC3::WriterAscii>(filename_unfinished_.string());
 }

◆ ~HepMcOutput()

smash::HepMcOutput::~HepMcOutput ( )

Destructor renames file.

Definition at line 64 of file hepmcoutput.cc.

64 { bf::rename(filename_unfinished_, filename_); }

Member Function Documentation

◆ at_eventstart()

void smash::HepMcOutput::at_eventstart	(	const Particles &	particles,
		const int	event_number,
		const EventInfo &
	)

overridevirtual

Add the initial particles information of an event to the central vertex.

Construct projectile and target particles with nuclear pdg code if collider.

Parameters

[in]	particles	Current list of all particles.
[in]	event_number	Current event number

Exceptions

std::invalid_argument if nuclei with non-nucleon particle (like hypernuclei) are tried to be constructed

Implements smash::OutputInterface.

Definition at line 80 of file hepmcoutput.cc.

                                                                            {
   current_event_ =
       make_unique<HepMC3::GenEvent>(HepMC3::Units::GEV, HepMC3::Units::MM);
  
   /* Rivet needs a value for the cross section, but SMASH only knows about
    * nucleon cross sections, not about cross sections between nuclei,
    * so a dummy is used. */
   std::shared_ptr<HepMC3::GenCrossSection> cross_section =
       std::make_shared<HepMC3::GenCrossSection>();
   current_event_->add_attribute("GenCrossSection", cross_section);
   const double dummy_xs = 1.0;
   cross_section->set_cross_section(dummy_xs, dummy_xs);
  
   current_event_->set_event_number(event_number);
   vertex_ = std::make_shared<HepMC3::GenVertex>();
   current_event_->add_vertex(vertex_);
  
   if (proj_N_ > 0) {
     // Collider modus: Construct and write projectile and target as two intial
     // particles
     int targ_N = total_N_ - proj_N_;
     int proj_Z = 0;
     int targ_Z = 0;
     FourVector total_mom_proj;
     FourVector total_mom_targ;
     for (const ParticleData &data : particles) {
       if (data.id() < proj_N_) {
         total_mom_proj += data.momentum();
         if (data.is_proton()) {
           proj_Z += 1;
         } else if (!data.is_neutron()) {
           throw std::invalid_argument(
               "HepMC output in SMASH only supports colliding nuclei consisting "
               "of p and n.");
         }
       } else {
         total_mom_targ += data.momentum();
         if (data.is_proton()) {
           targ_Z += 1;
         } else if (!data.is_neutron()) {
           throw std::invalid_argument(
               "HepMC output in SMASH only supports colliding nuclei consisting "
               "of p and n.");
         }
       }
     }
  
     const int proj_nuclear_pdg_code =
         construct_nuclear_pdg_code(proj_N_, proj_Z);
     const int targ_nuclear_pdg_code =
         construct_nuclear_pdg_code(targ_N, targ_Z);
  
     HepMC3::GenParticlePtr projectile_p = std::make_shared<HepMC3::GenParticle>(
         HepMC3::FourVector(total_mom_proj.x1(), total_mom_proj.x2(),
                            total_mom_proj.x3(), total_mom_proj.x0()),
         proj_nuclear_pdg_code, status_code_for_beam_particles);
     vertex_->add_particle_in(projectile_p);
     HepMC3::GenParticlePtr target_p = std::make_shared<HepMC3::GenParticle>(
         HepMC3::FourVector(total_mom_targ.x1(), total_mom_targ.x2(),
                            total_mom_targ.x3(), total_mom_targ.x0()),
         targ_nuclear_pdg_code, status_code_for_beam_particles);
     vertex_->add_particle_in(target_p);
  
   } else {
     // Other modi (not collider): Write all inital particles into output
     for (const ParticleData &data : particles) {
       const FourVector mom = data.momentum();
       HepMC3::GenParticlePtr p = std::make_shared<HepMC3::GenParticle>(
           HepMC3::FourVector(mom.x1(), mom.x2(), mom.x3(), mom.x0()),
           data.pdgcode().get_decimal(), status_code_for_beam_particles);
       vertex_->add_particle_in(p);
     }
   }
 }

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◆ at_eventend()

void smash::HepMcOutput::at_eventend	(	const Particles &	particles,
		const int32_t	event_number,
		const EventInfo &	event
	)

override

Add the final particles information of an event to the central vertex.

Store impact paramter and write event.

Parameters

[in]	particles	Current list of particles.
[in]	event_number	Number of event.
[in]	event	Event info, see event_info

Definition at line 156 of file hepmcoutput.cc.

                                                       {
   // Set heavy ion attribute, only the impact parameter is known
   std::shared_ptr<HepMC3::GenHeavyIon> heavy_ion =
       std::make_shared<HepMC3::GenHeavyIon>();
   current_event_->add_attribute("GenHeavyIon", heavy_ion);
   // Impact paramter has to converted to mm (x1E-12), since fm not a supported
   // unit in HepMC, -1(.0) are placeholders
   heavy_ion->set(-1, -1, -1, -1, -1, -1, -1, -1, -1,
                  event.impact_parameter * 1E-12, -1.0, -1.0, -1.0, -1.0, -1.0);
  
   for (const ParticleData &data : particles) {
     const FourVector mom = data.momentum();
     HepMC3::GenParticlePtr p = std::make_shared<HepMC3::GenParticle>(
         HepMC3::FourVector(mom.x1(), mom.x2(), mom.x3(), mom.x0()),
         data.pdgcode().get_decimal(), status_code_for_final_particles);
     vertex_->add_particle_out(p);
   }
  
   output_file_->write_event(*current_event_);
 }

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◆ construct_nuclear_pdg_code()

int smash::HepMcOutput::construct_nuclear_pdg_code	(	int	na,
		int	nz
	)		const

private

Construct nulcear pdg code for porjectile and target, see PDG chapter "Monte Carlo particle numbering scheme" for details.

Parameters

[in]	na	Number of all particles in nucleus (A)
[in]	nz	Number of all charged particles in nucleus (Z).

Note: Isomers and hypernuclei are not supported. Also note that one would usually create a PdgCode object to store the PDG code of the nuclei. This PdgCode object however would be first constructed with the integer determined here and then directly returned again with a method of the PdgCode class, making the creation of a PdgCode class instance overkill. A possible improvement would be the inclusion of this function in the PdgCode class.

Definition at line 66 of file hepmcoutput.cc.

                                                                 {
   const int pdg_nuclear_code_prefix = 10 * 1E8;
   // Hypernuclei not supported here
   const int pdg_nuclear_code_lambda = 0 * 1E7;
   const int pdg_nuclear_code_charge = nz * 1E4;
   const int pdg_nuclear_code_baryon = na * 1E1;
   // SMASH does not do isomers
   const int pdg_nuclear_code_isomer = 0 * 1E0;
  
   return pdg_nuclear_code_prefix + pdg_nuclear_code_lambda +
          pdg_nuclear_code_charge + pdg_nuclear_code_baryon +
          pdg_nuclear_code_isomer;
 }

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Member Data Documentation

◆ status_code_for_beam_particles

const int smash::HepMcOutput::status_code_for_beam_particles = 4

staticprivate

HepMC convention: status code for target and projecticle particles.

Definition at line 84 of file hepmcoutput.h.

◆ status_code_for_final_particles

const int smash::HepMcOutput::status_code_for_final_particles = 1

staticprivate

HepMC convention: status code for final particles.

Definition at line 86 of file hepmcoutput.h.

◆ filename_

const bf::path smash::HepMcOutput::filename_

private

Filename of output.

Definition at line 89 of file hepmcoutput.h.

◆ filename_unfinished_

bf::path smash::HepMcOutput::filename_unfinished_

private

Filename of output as long as simulation is still running.

Definition at line 91 of file hepmcoutput.h.

◆ total_N_

const int smash::HepMcOutput::total_N_

private

Total number of nucleons in projectile and target, needed for converting nuclei to single particles.

Definition at line 97 of file hepmcoutput.h.

◆ proj_N_

const int smash::HepMcOutput::proj_N_

private

Total number of nucleons in projectile, needed for converting nuclei to single particles.

Definition at line 102 of file hepmcoutput.h.

◆ output_file_

std::unique_ptr<HepMC3::WriterAscii> smash::HepMcOutput::output_file_

private

Pointer to Ascii HepMC3 output file.

Definition at line 122 of file hepmcoutput.h.

◆ current_event_

std::unique_ptr<HepMC3::GenEvent> smash::HepMcOutput::current_event_

private

HepMC3::GenEvent pointer for current event.

Definition at line 125 of file hepmcoutput.h.

◆ vertex_

HepMC3::GenVertexPtr smash::HepMcOutput::vertex_

private

HepMC3::GenVertex pointer for central vertex in event.

Definition at line 128 of file hepmcoutput.h.

The documentation for this class was generated from the following files:

src/include/smash/hepmcoutput.h
src/hepmcoutput.cc

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ HepMcOutput()

◆ ~HepMcOutput()

Member Function Documentation

◆ at_eventstart()

◆ at_eventend()

◆ construct_nuclear_pdg_code()

Member Data Documentation

◆ status_code_for_beam_particles

◆ status_code_for_final_particles

◆ filename_

◆ filename_unfinished_

◆ total_N_

◆ proj_N_

◆ output_file_

◆ current_event_

◆ vertex_