DerivationFramework::TruthBornLeptonCollectionMaker Class Reference

#include <TruthBornLeptonCollectionMaker.h>

Inheritance diagram for DerivationFramework::TruthBornLeptonCollectionMaker:

Collaboration diagram for DerivationFramework::TruthBornLeptonCollectionMaker:

Public Member Functions
	TruthBornLeptonCollectionMaker (const std::string &t, const std::string &n, const IInterface *p)
	~TruthBornLeptonCollectionMaker ()
StatusCode	initialize ()
virtual StatusCode	addBranches () const

Private Member Functions
bool	hasBareDescendent (const xAOD::TruthParticle *p) const
	Helper function for finding bare descendents of born leptons. More...

Private Attributes
SG::ReadHandleKey< xAOD::TruthParticleContainer >	m_particlesKey {this, "ParticlesKey", "TruthParticles", "Name of TruthParticle key for input"}
	< Input particle collection key More...
SG::WriteHandleKey< xAOD::TruthParticleContainer >	m_collectionName {this, "NewCollectionName", "", "Name of TruthParticle key for output"}
SG::WriteDecorHandleKey< xAOD::TruthParticleContainer >	m_originDecoratorKey {this, "classifierParticleOrigin", "TruthParticles.classifierParticleOrigin", "Particle origin decoration, set at initialisation"}
SG::WriteDecorHandleKey< xAOD::TruthParticleContainer >	m_typeDecoratorKey {this, "classifierParticleType","TruthParticles.classifierParticleType", "Particle type decoration, set at initialisation"}
SG::WriteDecorHandleKey< xAOD::TruthParticleContainer >	m_outcomeDecoratorKey {this, "classifierParticleOutCome", "TruthParticles.classifierParticleOutCome", "Particle outcome decoration, set at initialisation"}
SG::WriteDecorHandleKey< xAOD::TruthParticleContainer >	m_classificationDecoratorKey {this, "Classification", "TruthParticles.Classification", "Classification code decorator, set at initialisation"}
ServiceHandle< StoreGateSvc >	m_metaStore
	Handle on the metadata store for init. More...

Detailed Description

Definition at line 31 of file TruthBornLeptonCollectionMaker.h.

Constructor & Destructor Documentation

TruthBornLeptonCollectionMaker()

DerivationFramework::TruthBornLeptonCollectionMaker::TruthBornLeptonCollectionMaker	(	const std::string &	t,
		const std::string &	n,
		const IInterface *	p
	)

Definition at line 27 of file TruthBornLeptonCollectionMaker.cxx.

  : base_class(t,n,p)
  , m_metaStore( "MetaDataStore", n )
{
  declareProperty( "MetaDataStore", m_metaStore );
}

~TruthBornLeptonCollectionMaker()

DerivationFramework::TruthBornLeptonCollectionMaker::~TruthBornLeptonCollectionMaker

(

)

Definition at line 37 of file TruthBornLeptonCollectionMaker.cxx.

                                                                                   {
}

Member Function Documentation

addBranches()

StatusCode DerivationFramework::TruthBornLeptonCollectionMaker::addBranches ( ) const

virtual

Definition at line 73 of file TruthBornLeptonCollectionMaker.cxx.

{
  // Event context
  const EventContext& ctx = Gaudi::Hive::currentContext();
  
  // Set up for some metadata handling
  static const bool is_sherpa = [this]() {
    bool is_sherpa = false;
    // TODO: needs to be made MT-friendly
    if (m_metaStore->contains<xAOD::TruthMetaDataContainer>("TruthMetaData")){
      // Note that I'd like to get this out of metadata in general, but it seems that the
      // metadata isn't fully available in initialize, and since this is a const function
      // I can only do the retrieve every event, rather than lazy-initializing, since this
      // metadata ought not change during a run
      const xAOD::TruthMetaDataContainer* truthMetaData(nullptr);
      // Shamelessly stolen from the file meta data tool
 
      if (m_metaStore->retrieve(truthMetaData).isSuccess() && !truthMetaData->empty()){
        // Let's just be super sure...
        const std::string gens = truthMetaData->at(0)->generators();
        is_sherpa = (gens.find("sherpa")==std::string::npos &&
                     gens.find("Sherpa")==std::string::npos &&
                     gens.find("SHERPA")==std::string::npos) ? false : true;
      } // Seems to be the only sure way...
      else {
        ATH_MSG_WARNING("Found xAODTruthMetaDataContainer empty! Configuring to be NOT Sherpa.");
      }
      ATH_MSG_INFO("From metadata configured: Sherpa? " << is_sherpa);
    } 
    else {
      ATH_MSG_WARNING("Could not find metadata container in storegate; assuming NOT Sherpa");
    }
    return is_sherpa;
  }();
 
  // Retrieve truth collections
  SG::ReadHandle<xAOD::TruthParticleContainer> truthParticles(m_particlesKey,ctx);    
  if (!truthParticles.isValid()) {        
    ATH_MSG_ERROR("Couldn't retrieve TruthParticle collection with name " << m_particlesKey);        
    return StatusCode::FAILURE;    
  }
 
  // Create the new particle containers and WriteHandles
  SG::WriteHandle<xAOD::TruthParticleContainer> newParticlesWriteHandle(m_collectionName, ctx);
  ATH_CHECK(newParticlesWriteHandle.record(std::make_unique<xAOD::TruthParticleContainer>(),
                                           std::make_unique<xAOD::TruthParticleAuxContainer>()));
  ATH_MSG_DEBUG( "Recorded new TruthParticleContainer with key: " << (m_collectionName.key()));
 
  // Set up decorators
  SG::WriteDecorHandle<xAOD::TruthParticleContainer, unsigned int > originDecorator(m_originDecoratorKey, ctx);
  SG::WriteDecorHandle<xAOD::TruthParticleContainer, unsigned int > typeDecorator(m_typeDecoratorKey, ctx);
  SG::WriteDecorHandle<xAOD::TruthParticleContainer, unsigned int > outcomeDecorator(m_outcomeDecoratorKey, ctx);
  SG::WriteDecorHandle<xAOD::TruthParticleContainer, unsigned int > classificationDecorator(m_classificationDecoratorKey, ctx);
 
  static const SG::ConstAccessor<unsigned int> classifierParticleTypeAcc("classifierParticleType");
  static const SG::ConstAccessor<unsigned int> classifierParticleOriginAcc("classifierParticleOrigin");
  static const SG::ConstAccessor<unsigned int> classifierParticleOutComeAcc("classifierParticleOutCome");
  static const SG::ConstAccessor<unsigned int> ClassificationAcc("Classification");
 
  // add relevant particles to new collection
  for (unsigned int i=0; i<truthParticles->size(); ++i) {
    // Grab the particle
    const xAOD::TruthParticle* theParticle = (*truthParticles)[i];
    if (!theParticle) continue; // Protection against null pointers
    if (!theParticle->isLepton()) continue; // Only include leptons!
 
    if (is_sherpa) {
      // For Sherpa, skip is not status 11
      if (MC::isPhysical(theParticle)) continue;
      // Sherpa may have two sets of status == 11 leptons. Here we take the first set.
      // To do so, we check the first status == 11 leptons, 
      //   check that it has a child a parent barecode corresponding the the lepton's uniqueID
      // If so, then save this parent uniqueID and skip all status 11 leptons with this parent uniqueID.
      bool has_parent_of_same_flavour = false;
      if (theParticle->prodVtx())
      for (size_t p = 0; p < theParticle->prodVtx()->nIncomingParticles(); ++p){
          if (theParticle->parent(p)->pdg_id() == theParticle->pdg_id()) has_parent_of_same_flavour = true;
      }
      if (has_parent_of_same_flavour) continue;
    } else {
      // Some generators, look for leptons  coming from vertices with other leptons
      bool physical = false, has_V = false;
      if (!MC::isPhysical(theParticle) && theParticle->hasProdVtx()){
        const xAOD::TruthVertex * prod = theParticle->prodVtx();
        // Look for other leptons in the production vertex and check if those are physical
        for (size_t p = 0; p < prod->nOutgoingParticles(); ++p){
          if (prod->outgoingParticle(p) && prod->outgoingParticle(p)->isLepton() && MC::isPhysical(prod->outgoingParticle(p))){
              physical = true; 
              break;
            }
          }
          // See if there was a boson going *into* the vertex
        for (size_t p = 0; p < prod->nIncomingParticles(); ++p){
          if (prod->incomingParticle(p) && (prod->incomingParticle(p)->isZ() || prod->incomingParticle(p)->isW() || prod->incomingParticle(p)->isHiggs()) ){
            has_V = true;  // Found a vector boson
            break;
          }
        } 
      }
 
      // Now we have all the information for the special case of V->l(born) l(bare) l(born) l(bare)
      // AV: The comment above, most likely is related to the case when the event is passed to PHOTOS with an option to keep 
      // the "documentation" particles, i.e. particles before the photon emission. 
      // These particles in PHOTOS are attached to the same vertex, but have different status, e.g. 3. 
      // The momentum conservation, is, of course, violated.  
      if ( !(physical && has_V && !MC::isPhysical(theParticle)) && !MC::Pythia8::isConditionB(theParticle)){
        // Skip if it has no boson parent, or has no descendent that is a bare lepton
        if (!hasBareDescendent( theParticle ) ) continue;
        const xAOD::TruthVertex * prod = theParticle->prodVtx();
        if (!prod) continue;
        if (prod->nIncomingParticles() < 1) continue;
        size_t bad_parent = 0;
        for (size_t p = 0; p < prod->nIncomingParticles(); ++p){
          if (!theParticle->parent(p)) { bad_parent++; continue;}
          if (!theParticle->parent(p)->isZ() && !theParticle->parent(p)->isW() && !theParticle->parent(p)->isHiggs()) bad_parent++;
        }
        if (bad_parent != 0) continue;
 
      }
    } // End of treatment for generators that are not Sherpa
 
    // Add this particle to the new collection
    xAOD::TruthParticle* xTruthParticle = new xAOD::TruthParticle();
    newParticlesWriteHandle->push_back( xTruthParticle );
    // Fill with numerical content
    *xTruthParticle=*theParticle;
    // Copy over the decorations if they are available
    typeDecorator(*xTruthParticle) = classifierParticleTypeAcc.withDefault(*theParticle, 0);
    originDecorator(*xTruthParticle) = classifierParticleOriginAcc.withDefault(*theParticle, 0);
    outcomeDecorator(*xTruthParticle) = classifierParticleOutComeAcc.withDefault(*theParticle, 0);
    classificationDecorator(*xTruthParticle) = ClassificationAcc.withDefault(*theParticle, 0);
  } // Loop over all particles
 
  return StatusCode::SUCCESS;
}

hasBareDescendent()

bool DerivationFramework::TruthBornLeptonCollectionMaker::hasBareDescendent ( const xAOD::TruthParticle *  p ) const

private

Helper function for finding bare descendents of born leptons.

Definition at line 210 of file TruthBornLeptonCollectionMaker.cxx.

{
  // Null pointer check
  if (!p) return false;
  // If we hit a bare descendent, then we're a winnner
  if (p->isLepton() && MC::isStable(p) ) return true;
  // Otherwise look through all the children
  for (size_t c=0;c<p->nChildren();++c){
    if (!p->child(c)) continue; // Null pointer protection
    if (p->pdgId()!=p->child(c)->pdgId()) continue; // Different particle child
    if (hasBareDescendent( p->child(c) )) return true;
  }
  // No luck -- this branch is a dead end
  return false;
}

initialize()

StatusCode DerivationFramework::TruthBornLeptonCollectionMaker::initialize

(

)

Definition at line 41 of file TruthBornLeptonCollectionMaker.cxx.

{
  ATH_MSG_VERBOSE("initialize() ...");
 
   // Input truth particles
   ATH_CHECK( m_particlesKey.initialize() );
   ATH_MSG_INFO("Using " << m_particlesKey.key() << " as the input truth container key");
 
  // Output truth particles
  if (m_collectionName.empty()) {
    ATH_MSG_FATAL("No key provided for the new truth particle collection");
    return StatusCode::FAILURE;
  } else {ATH_MSG_INFO("New truth particle collection key: " << m_collectionName.key() );}
  ATH_CHECK( m_collectionName.initialize());
 
  // Decoration keys
  m_originDecoratorKey = m_collectionName.key() + ".classifierParticleOrigin";
  ATH_CHECK(m_originDecoratorKey.initialize());
  m_typeDecoratorKey = m_collectionName.key() + ".classifierParticleType";
  ATH_CHECK(m_typeDecoratorKey.initialize());
  m_outcomeDecoratorKey = m_collectionName.key() + ".classifierParticleOutCome";
  ATH_CHECK(m_outcomeDecoratorKey.initialize());
  m_classificationDecoratorKey = m_collectionName.key() + ".Classification";
  ATH_CHECK(m_classificationDecoratorKey.initialize());
  
  // TODO: needs to be made MT-friendly
  ATH_CHECK( m_metaStore.retrieve() );
 
  return StatusCode::SUCCESS;
}

Member Data Documentation

m_classificationDecoratorKey

SG::WriteDecorHandleKey<xAOD::TruthParticleContainer> DerivationFramework::TruthBornLeptonCollectionMaker::m_classificationDecoratorKey {this, "Classification", "TruthParticles.Classification", "Classification code decorator, set at initialisation"}

private

Definition at line 52 of file TruthBornLeptonCollectionMaker.h.

m_collectionName

SG::WriteHandleKey<xAOD::TruthParticleContainer> DerivationFramework::TruthBornLeptonCollectionMaker::m_collectionName {this, "NewCollectionName", "", "Name of TruthParticle key for output"}

private

Definition at line 43 of file TruthBornLeptonCollectionMaker.h.

m_metaStore

ServiceHandle<StoreGateSvc> DerivationFramework::TruthBornLeptonCollectionMaker::m_metaStore

private

Handle on the metadata store for init.

Definition at line 55 of file TruthBornLeptonCollectionMaker.h.

m_originDecoratorKey

SG::WriteDecorHandleKey<xAOD::TruthParticleContainer> DerivationFramework::TruthBornLeptonCollectionMaker::m_originDecoratorKey {this, "classifierParticleOrigin", "TruthParticles.classifierParticleOrigin", "Particle origin decoration, set at initialisation"}

private

Definition at line 46 of file TruthBornLeptonCollectionMaker.h.

m_outcomeDecoratorKey

SG::WriteDecorHandleKey<xAOD::TruthParticleContainer> DerivationFramework::TruthBornLeptonCollectionMaker::m_outcomeDecoratorKey {this, "classifierParticleOutCome", "TruthParticles.classifierParticleOutCome", "Particle outcome decoration, set at initialisation"}

private

Definition at line 50 of file TruthBornLeptonCollectionMaker.h.

m_particlesKey

SG::ReadHandleKey<xAOD::TruthParticleContainer> DerivationFramework::TruthBornLeptonCollectionMaker::m_particlesKey {this, "ParticlesKey", "TruthParticles", "Name of TruthParticle key for input"}

private

< Input particle collection key

Output particle collection key

Definition at line 40 of file TruthBornLeptonCollectionMaker.h.

m_typeDecoratorKey

SG::WriteDecorHandleKey<xAOD::TruthParticleContainer> DerivationFramework::TruthBornLeptonCollectionMaker::m_typeDecoratorKey {this, "classifierParticleType","TruthParticles.classifierParticleType", "Particle type decoration, set at initialisation"}

private

Definition at line 48 of file TruthBornLeptonCollectionMaker.h.

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

• TruthBornLeptonCollectionMaker.h
• TruthBornLeptonCollectionMaker.cxx