TtDecayChannelSelector Class Reference

#include <TtDecayChannelSelector.h>

Public Types
enum	{ Elec = 0, Muon = 1, Tau = 2 }
	leafs of leptonic decay channel vector decay_ More...
typedef std::vector< int >	Decay
	typedef to simplify the decay vectors More...

Public Member Functions
bool	operator() (const reco::GenParticleCollection &parts, std::string_view inputType) const
	operator for decay channel selection More...
	TtDecayChannelSelector (const edm::ParameterSet &)
	std contructor More...

Private Member Functions
unsigned int	checkSum (const Decay &vec) const
unsigned int	countProngs (const reco::Candidate &part) const
	count the number of charged particles for tau decays More...
unsigned int	decayChannel () const
	return decay channel to select for from configuration More...
bool	search (reco::GenParticleCollection::const_iterator &part, int pdgId, std::string_view inputType) const
	search for particle with pdgId in given listing (for top) More...
bool	search (reco::GenParticle::const_iterator &part, int pdgId, std::string_view inputType) const
	search for particle with pdgId in given listing (for top daughters) More...
bool	tauDecay (const reco::Candidate &) const
	check tau decay to be leptonic, 1-prong or 3-prong More...

Private Attributes
bool	allow1Prong_
	allow 1-prong tau decays More...
bool	allow3Prong_
	allow 2-prong tau decays More...
Decay	allowedDecays_
bool	allowElectron_
	allow tau decays into electron More...
bool	allowMuon_
	allow tau decays into muon More...
Decay	decayBranchA_
	top decay branch 1 More...
Decay	decayBranchB_
	top decay branch 2 More...
bool	invert_
	invert selection More...
bool	restrictTauDecays_
	restrict tau decays More...

Detailed Description

Definition at line 9 of file TtDecayChannelSelector.h.

Member Typedef Documentation

Decay

typedef std::vector<int> TtDecayChannelSelector::Decay

typedef to simplify the decay vectors

Definition at line 14 of file TtDecayChannelSelector.h.

Member Enumeration Documentation

anonymous enum

anonymous enum

leafs of leptonic decay channel vector decay_

Enumerator
Elec
Muon
Tau

Definition at line 12 of file TtDecayChannelSelector.h.

{ Elec = 0, Muon = 1, Tau = 2 };

Constructor & Destructor Documentation

TtDecayChannelSelector()

TtDecayChannelSelector::TtDecayChannelSelector

(

const edm::ParameterSet &

cfg

)

std contructor

Definition at line 15 of file TtDecayChannelSelector.cc.

References allow1Prong_, allow3Prong_, allowedDecays_, TtDecayChannelFilter_cfi::allowedTopDecays, allowElectron_, allowMuon_, looper::cfg, ztail::d, TtDecayChannelFilter_cfi::decayBranchA, decayBranchA_, TtDecayChannelFilter_cfi::decayBranchB, decayBranchB_, edm::ParameterSet::existsAs(), edm::ParameterSet::getParameter(), kDecayChannels, and restrictTauDecays_.

    : invert_(cfg.getParameter<bool>("invert")),
      allowElectron_(false),
      allowMuon_(false),
      allow1Prong_(false),
      allow3Prong_(false) {
  // tau decays are not restricted if this PSet does not exist at all
  restrictTauDecays_ = cfg.existsAs<edm::ParameterSet>("restrictTauDecays");
  // determine allowed tau decays
  if (restrictTauDecays_) {
    edm::ParameterSet allowedTauDecays = cfg.getParameter<edm::ParameterSet>("restrictTauDecays");
    // tau decays are not restricted if none of the following parameters exists
    restrictTauDecays_ = (allowedTauDecays.existsAs<bool>("electron") || allowedTauDecays.existsAs<bool>("muon") ||
                          allowedTauDecays.existsAs<bool>("oneProng") || allowedTauDecays.existsAs<bool>("threeProng"));
    // specify the different possible restrictions of the tau decay channels
    allowElectron_ =
        (allowedTauDecays.existsAs<bool>("electron") ? allowedTauDecays.getParameter<bool>("electron") : false);
    allowMuon_ = (allowedTauDecays.existsAs<bool>("muon") ? allowedTauDecays.getParameter<bool>("muon") : false);
    allow1Prong_ =
        (allowedTauDecays.existsAs<bool>("oneProng") ? allowedTauDecays.getParameter<bool>("oneProng") : false);
    allow3Prong_ =
        (allowedTauDecays.existsAs<bool>("threeProng") ? allowedTauDecays.getParameter<bool>("threeProng") : false);
  }
  // allowed top decays PSet
  edm::ParameterSet allowedTopDecays = cfg.getParameter<edm::ParameterSet>("allowedTopDecays");

  // fill decayBranchA_
  edm::ParameterSet decayBranchA = allowedTopDecays.getParameter<edm::ParameterSet>("decayBranchA");
  decayBranchA_.push_back(decayBranchA.getParameter<bool>("electron"));
  decayBranchA_.push_back(decayBranchA.getParameter<bool>("muon"));
  decayBranchA_.push_back(decayBranchA.getParameter<bool>("tau"));

  // fill decay branchB_
  edm::ParameterSet decayBranchB = allowedTopDecays.getParameter<edm::ParameterSet>("decayBranchB");
  decayBranchB_.push_back(decayBranchB.getParameter<bool>("electron"));
  decayBranchB_.push_back(decayBranchB.getParameter<bool>("muon"));
  decayBranchB_.push_back(decayBranchB.getParameter<bool>("tau"));

  // fill allowedDecays_
  for (unsigned int d = 0; d < kDecayChannels; ++d) {
    allowedDecays_.push_back(decayBranchA_[d] + decayBranchB_[d]);
  }
}

Member Function Documentation

checkSum()

unsigned int TtDecayChannelSelector::checkSum ( const Decay &  vec ) const

inlineprivate

Definition at line 68 of file TtDecayChannelSelector.h.

References ztail::d.

Referenced by operator()().

                                                                           {
  unsigned int sum = 0;
  for (unsigned int d = 0; d < vec.size(); ++d) {
    sum += vec[d];
  }
  return sum;
}

countProngs()

unsigned int TtDecayChannelSelector::countProngs ( const reco::Candidate &  part ) const

private

count the number of charged particles for tau decays

Definition at line 186 of file TtDecayChannelSelector.cc.

Referenced by tauDecay().

                                                                                {
  // if stable, return 1 or 0
  if (part.status() == 1) {
    return (part.charge() != 0);
  }
  // if unstable, call recursively on daughters
  int prong = 0;
  for (reco::Candidate::const_iterator daughter = part.begin(); daughter != part.end(); ++daughter) {
    prong += countProngs(*daughter);
  }
  return prong;
}

decayChannel()

unsigned int TtDecayChannelSelector::decayChannel ( ) const

inlineprivate

return decay channel to select for from configuration

Definition at line 57 of file TtDecayChannelSelector.h.

References submitPVResolutionJobs::count, decayBranchA_, and decayBranchB_.

Referenced by operator()().

                                                               {
  unsigned int channel = 0;
  if (std::count(decayBranchA_.begin(), decayBranchA_.end(), 1) > 0) {
    ++channel;
  }
  if (std::count(decayBranchB_.begin(), decayBranchB_.end(), 1) > 0) {
    ++channel;
  }
  return channel;
}

operator()()

bool TtDecayChannelSelector::operator()	(	const reco::GenParticleCollection &	parts,
		std::string_view	inputType
	)		const

operator for decay channel selection

Definition at line 59 of file TtDecayChannelSelector.cc.

References funct::abs(), accept(), allowedDecays_, reco::Candidate::begin(), TopDecayID::bID, checkSum(), decayBranchA_, decayBranchB_, decayChannel(), Elec, TopDecayID::elecID, reco::Candidate::end(), createfilelist::int, invert_, CrabHelper::log, Muon, TopDecayID::muonID, restrictTauDecays_, search(), Tau, tauDecay(), TopDecayID::tauID, TopDecayID::tID, verbose, and TopDecayID::WID.

                                                                                                              {
  bool verbose =
      false;  // set this to true for debugging and add TtDecayChannelSelector category to the MessageLogger in your cfg file
  unsigned int iLep = 0;
  unsigned int iTop = 0, iBeauty = 0, iElec = 0, iMuon = 0, iTau = 0;
  for (reco::GenParticleCollection::const_iterator top = parts.begin(); top != parts.end(); ++top) {
    if (search(top, TopDecayID::tID, inputType)) {
      ++iTop;
      for (reco::GenParticle::const_iterator td = top->begin(); td != top->end(); ++td) {
        if (search(td, TopDecayID::bID, inputType)) {
          ++iBeauty;
        }
        if (search(td, TopDecayID::WID, inputType)) {
          for (reco::GenParticle::const_iterator wd = td->begin(); wd != td->end(); ++wd) {
            if (std::abs(wd->pdgId()) == TopDecayID::elecID) {
              ++iElec;
            }
            if (std::abs(wd->pdgId()) == TopDecayID::muonID) {
              ++iMuon;
            }
            if (std::abs(wd->pdgId()) == TopDecayID::tauID) {
              if (restrictTauDecays_) {
                // count as iTau if it is leptonic, one-prong
                // or three-prong and ignore increasing iLep
                // though else
                if (tauDecay(*wd)) {
                  ++iTau;
                } else {
                  ++iLep;
                }
              } else {
                ++iTau;
              }
            }
          }
        }
      }
    }
  }
  if (verbose) {
    edm::LogVerbatim log("TtDecayChannelSelector");
    log << "----------------------"
        << "\n"
        << " iTop    : " << iTop << "\n"
        << " iBeauty : " << iBeauty << "\n"
        << " iElec   : " << iElec << "\n"
        << " iMuon   : " << iMuon << "\n"
        << " iTau    : " << iTau + iLep;
    if (restrictTauDecays_ && (iTau + iLep) > 0) {
      log << " (" << iTau << ")\n";
    } else {
      log << "\n";
    }
    log << "- - - - - - - - - - - "
        << "\n";
  }
  iLep += iElec + iMuon + iTau;

  bool accept = false;
  unsigned int channel = decayChannel();
  if ((iTop == 2) && (iBeauty == 2)) {
    if (channel == iLep) {
      if (channel == 0) {
        // no lepton: accept without restriction we already
        // know that the number of leptons is correct
        accept = true;
      }
      if (channel == 1) {
        // one lepton: check that this one is allowed
        accept = (iElec && allowedDecays_[Elec]) || (iMuon && allowedDecays_[Muon]) || (iTau && allowedDecays_[Tau]);
      }
      if (channel == 2) {
        if (checkSum(allowedDecays_) == channel) {
          // no redundancy
          accept = (allowedDecays_[Elec] == (int)iElec) && (allowedDecays_[Muon] == (int)iMuon) &&
                   (allowedDecays_[Tau] == (int)iTau);
        } else {
          // reject events with wrong tau decays
          if (iElec + iMuon + iTau != channel) {
            accept = false;
          } else {
            if ((iElec == 2) || (iMuon == 2) || (iTau == 2)) {
              // same lepton twice: check that this is allowed.
              accept = (allowedDecays_[Elec] == (int)iElec) || (allowedDecays_[Muon] == (int)iMuon) ||
                       (allowedDecays_[Tau] == (int)iTau);
            } else {
              // two different leptons: look if there is a possible combination
              accept = (((iElec && decayBranchA_[Elec]) &&
                         ((iMuon && decayBranchB_[Muon]) || (iTau && decayBranchB_[Tau]))) ||
                        ((iMuon && decayBranchA_[Muon]) &&
                         ((iElec && decayBranchB_[Elec]) || (iTau && decayBranchB_[Tau]))) ||
                        ((iTau && decayBranchA_[Tau]) &&
                         ((iElec && decayBranchB_[Elec]) || (iMuon && decayBranchB_[Muon]))));
            }
          }
        }
      }
    }
    accept = ((!invert_ && accept) || (!(!invert_) && !accept));
  } else {
    edm::LogWarning("NoVtbDecay") << "Decay is not via Vtb";
  }
  if (verbose)
    edm::LogVerbatim("TtDecayChannelSelector") << " accept  : " << accept;
  return accept;
}

search() [1/2]

bool TtDecayChannelSelector::search ( reco::GenParticleCollection::const_iterator &  part, int  pdgId, std::string_view  inputType  ) const

private

search for particle with pdgId in given listing (for top)

Definition at line 166 of file TtDecayChannelSelector.cc.

References funct::abs(), kGenParticles, EgammaValidation_cff::pdgId, funct::true, and TopDecayID::unfrag.

Referenced by operator()().

                                                                    {
  if (inputType == kGenParticles) {
    return (std::abs(part->pdgId()) == pdgId && part->status() == TopDecayID::unfrag) ? true : false;
  } else {
    return (std::abs(part->pdgId()) == pdgId) ? true : false;
  }
}

search() [2/2]

bool TtDecayChannelSelector::search ( reco::GenParticle::const_iterator &  part, int  pdgId, std::string_view  inputType  ) const

private

search for particle with pdgId in given listing (for top daughters)

Definition at line 176 of file TtDecayChannelSelector.cc.

References funct::abs(), kGenParticles, EgammaValidation_cff::pdgId, funct::true, and TopDecayID::unfrag.

                                                                    {
  if (inputType == kGenParticles) {
    return (std::abs(part->pdgId()) == pdgId && part->status() == TopDecayID::unfrag) ? true : false;
  } else {
    return (std::abs(part->pdgId()) == pdgId) ? true : false;
  }
}

tauDecay()

bool TtDecayChannelSelector::tauDecay ( const reco::Candidate &  tau ) const

private

check tau decay to be leptonic, 1-prong or 3-prong

Definition at line 199 of file TtDecayChannelSelector.cc.

References funct::abs(), allow1Prong_, allow3Prong_, allowElectron_, allowMuon_, countProngs(), TopDecayID::elecID, and TopDecayID::muonID.

Referenced by operator()().

                                                                    {
  bool electronTau = false;
  bool muonTau = false;
  unsigned int nch = 0;
  // loop on tau decays, check for an elec
  // or muon and count charged particles
  for (reco::Candidate::const_iterator daughter = tau.begin(); daughter != tau.end(); ++daughter) {
    // if the tau daughter is again a tau, this means that the particle has
    // still to be propagated; in that case, return the result of the same
    // method applied on the daughter of the current particle
    if (daughter->pdgId() == tau.pdgId()) {
      return tauDecay(*daughter);
    }
    // check for electron from tau decay
    electronTau |= (std::abs(daughter->pdgId()) == TopDecayID::elecID);
    // check for muon from tau decay
    muonTau |= (std::abs(daughter->pdgId()) == TopDecayID::muonID);
    // count charged particles
    nch += countProngs(*daughter);
  }
  return ((allowElectron_ && electronTau) || (allowMuon_ && muonTau) ||
          (allow1Prong_ && !electronTau && !muonTau && nch == 1) ||
          (allow3Prong_ && !electronTau && !muonTau && nch == 3));
}

Member Data Documentation

allow1Prong_

bool TtDecayChannelSelector::allow1Prong_

private

allow 1-prong tau decays

Definition at line 45 of file TtDecayChannelSelector.h.

Referenced by tauDecay(), and TtDecayChannelSelector().

allow3Prong_

bool TtDecayChannelSelector::allow3Prong_

private

allow 2-prong tau decays

Definition at line 47 of file TtDecayChannelSelector.h.

Referenced by tauDecay(), and TtDecayChannelSelector().

allowedDecays_

Decay TtDecayChannelSelector::allowedDecays_

private

vector of allowed lepton decay channels; values may be 0,1,2 for the entries 'Elec','Muon','Tau'

Definition at line 54 of file TtDecayChannelSelector.h.

Referenced by operator()(), and TtDecayChannelSelector().

allowElectron_

bool TtDecayChannelSelector::allowElectron_

private

allow tau decays into electron

Definition at line 41 of file TtDecayChannelSelector.h.

Referenced by tauDecay(), and TtDecayChannelSelector().

allowMuon_

bool TtDecayChannelSelector::allowMuon_

private

allow tau decays into muon

Definition at line 43 of file TtDecayChannelSelector.h.

Referenced by tauDecay(), and TtDecayChannelSelector().

decayBranchA_

Decay TtDecayChannelSelector::decayBranchA_

private

top decay branch 1

Definition at line 49 of file TtDecayChannelSelector.h.

Referenced by decayChannel(), operator()(), and TtDecayChannelSelector().

decayBranchB_

Decay TtDecayChannelSelector::decayBranchB_

private

top decay branch 2

Definition at line 51 of file TtDecayChannelSelector.h.

Referenced by decayChannel(), operator()(), and TtDecayChannelSelector().

invert_

bool TtDecayChannelSelector::invert_

private

invert selection

Definition at line 37 of file TtDecayChannelSelector.h.

Referenced by operator()().

restrictTauDecays_

bool TtDecayChannelSelector::restrictTauDecays_

private

restrict tau decays

Definition at line 39 of file TtDecayChannelSelector.h.

Referenced by operator()(), and TtDecayChannelSelector().