Module to analyze the performance of muon reconstruction on the example of Z->mumu events. More...

#include <PhysicsTools/PatExamples/plugins/PatZToMuMuAnalyzer.h>

Inheritance diagram for PatZToMuMuAnalyzer:

Public Types
typedef math::XYZTLorentzVector	LorentzVector
typedef math::XYZVector	Vector
	typedef's to simplify get functions
Public Member Functions
	PatZToMuMuAnalyzer (const edm::ParameterSet &cfg)
	default constructor
	~PatZToMuMuAnalyzer ()
	default destructor
Private Member Functions
virtual void	analyze (const edm::Event &event, const edm::EventSetup &setup)
	everything that needs to be done during the event loop
bool	booked (const std::string histName) const
	check if histogram was booked
void	fill (const std::string histName, double value) const
	fill histogram if it had been booked before
void	fill (std::string hists, const reco::TrackRef &t1, const reco::TrackRef &t2) const
	fill a predefined set of histograms from inner outer or global tracks for first and second mu candidate
double	mass (const math::XYZVector &t1, const math::XYZVector &t2) const
	calculate the mass of the Z boson from the tracker momenta by hand
Private Attributes
std::map< std::string, TH1D * >	hists_
	management of 1d histograms
edm::InputTag	muons_
	input for muons
double	shift_

Detailed Description

Module to analyze the performance of muon reconstruction on the example of Z->mumu events.

Module to analyze the performance of muon reconstruction on the example of Z->mumu events: transverse momentum and eta of the muon candidates and the mass of the Z boson candidate are plotted from inner, outer and global tracks. The mass is recalculated by an extra finction. The difference of the outer track and the global track are plotted for the transverse momentum, eta and phi of the two muon candi- dates, for global muons as far as available. The only input parameters are:

_muons_ --> indicating the muon collection of choice. _shift_ --> indicating the relative shift of the transverse momentum for the estimate of the effect on the invariant mass.

The shift is applied to all mass calculations.

Definition at line 33 of file PatZToMuMuAnalyzer.cc.

Member Typedef Documentation

typedef math::XYZTLorentzVector PatZToMuMuAnalyzer::LorentzVector

Definition at line 38 of file PatZToMuMuAnalyzer.cc.

typedef math::XYZVector PatZToMuMuAnalyzer::Vector

typedef's to simplify get functions

Definition at line 37 of file PatZToMuMuAnalyzer.cc.

Constructor & Destructor Documentation

PatZToMuMuAnalyzer::PatZToMuMuAnalyzer ( const edm::ParameterSet & cfg ) [explicit]

default constructor

Definition at line 76 of file PatZToMuMuAnalyzer.cc.

References fileService, and hists_.

                                                                :
  muons_(cfg.getParameter< edm::InputTag >("muons")),
  shift_(cfg.getParameter< double >("shift"))
{
  edm::Service< TFileService > fileService;
  
  // mass plot around Z peak from global tracks
  hists_[ "globalMass"] = fileService->make< TH1D >( "globalMass" , "Mass_{Z} (global) (GeV)",   90,    30.,   120.);
  // eta from global tracks
  hists_[ "globalEta" ] = fileService->make< TH1D >( "globalEta"  , "#eta (global)"          ,   48,   -2.4,    2.4);
  // pt from global tracks
  hists_[ "globalPt"  ] = fileService->make< TH1D >( "globalPt"   , "p_{T} (global) (GeV)"   ,  100,     0.,   100.);
  // mass plot around Z peak from inner tracks
  hists_[ "innerMass" ] = fileService->make< TH1D >( "innerMass"  , "Mass_{Z} (inner) (GeV)" ,   90,    30.,   120.);
  // eta from inner tracks
  hists_[ "innerEta"  ] = fileService->make< TH1D >( "innerEta"   , "#eta (inner)"           ,   48,   -2.4,    2.4);
  // pt from inner tracks
  hists_[ "innerPt"   ] = fileService->make< TH1D >( "innerPt"    , "p_{T} (inner) (GeV)"    ,  100,     0.,   100.);
  // mass plot around Z peak from outer tracks
  hists_[ "outerMass" ] = fileService->make< TH1D >( "outerMass"  , "Mass_{Z} (outer) (GeV)" ,   90,    30.,   120.);
  // eta from outer tracks
  hists_[ "outerEta"  ] = fileService->make< TH1D >( "outerEta"   , "#eta (outer)"           ,   48,   -2.4,    2.4);
  // pt from outer tracks
  hists_[ "outerPt"   ] = fileService->make< TH1D >( "outerPt"    , "p_{T} (outer) (GeV)"    ,  100,     0.,   100.);
  // delta pt between global and outer track
  hists_[ "deltaPt"   ] = fileService->make< TH1D >( "deltaPt"    , "#Delta p_{T} (GeV)"     ,  100,   -20.,    20.);
  // delta eta between global and outer track
  hists_[ "deltaEta"  ] = fileService->make< TH1D >( "deltaEta"   , "#Delta #eta"            ,  100,   -0.2,    0.2);
  // delta phi between global and outer track
  hists_[ "deltaPhi"  ] = fileService->make< TH1D >( "deltaPhi"   , "#Delta #phi"            ,  100,   -0.2,    0.2);
}

PatZToMuMuAnalyzer::~PatZToMuMuAnalyzer ( ) [inline]

default destructor

Definition at line 43 of file PatZToMuMuAnalyzer.cc.

{};

Member Function Documentation

void PatZToMuMuAnalyzer::analyze	(	const edm::Event &	event,
		const edm::EventSetup &	setup
	)		`[private, virtual]`

everything that needs to be done during the event loop

Implements edm::EDAnalyzer.

Definition at line 128 of file PatZToMuMuAnalyzer.cc.

References fill(), patZpeak::muons, and muons_.

{
  // pat candidate collection
  edm::Handle< edm::View<pat::Muon> > muons;
  event.getByLabel(muons_, muons);

  // Fill some basic muon quantities as 
  // reconstructed from inner and outer 
  // tack 
  for(edm::View<pat::Muon>::const_iterator mu1=muons->begin(); mu1!=muons->end(); ++mu1){
    for(edm::View<pat::Muon>::const_iterator mu2=muons->begin(); mu2!=muons->end(); ++mu2){
      if(mu2>mu1){ // prevent double conting
        if( mu1->charge()*mu2->charge()<0 ){ // check only muon pairs of unequal charge 
          fill(std::string("inner" ), mu1->innerTrack (), mu2->innerTrack ());
          fill(std::string("outer" ), mu1->outerTrack (), mu2->outerTrack ());
          fill(std::string("global"), mu1->globalTrack(), mu2->globalTrack());
          
          if(mu1->isGlobalMuon()){
            fill("deltaPt" , mu1->outerTrack()->pt ()-mu1->globalTrack()->pt ());
            fill("deltaEta", mu1->outerTrack()->eta()-mu1->globalTrack()->eta());
            fill("deltaPhi", mu1->outerTrack()->phi()-mu1->globalTrack()->phi());
          }
          if(mu2->isGlobalMuon()){
            fill("deltaPt" , mu2->outerTrack()->pt ()-mu2->globalTrack()->pt ());
            fill("deltaEta", mu2->outerTrack()->eta()-mu2->globalTrack()->eta());
            fill("deltaPhi", mu2->outerTrack()->phi()-mu2->globalTrack()->phi());
          }
        }
      }
    }
  }
}

bool PatZToMuMuAnalyzer::booked ( const std::string histName ) const [inline, private]

check if histogram was booked

Definition at line 52 of file PatZToMuMuAnalyzer.cc.

References hists_.

Referenced by fill().

{ return hists_.find(histName.c_str())!=hists_.end(); };

void PatZToMuMuAnalyzer::fill	(	const std::string	histName,
		double	value
	)		const `[inline, private]`

fill histogram if it had been booked before

Definition at line 54 of file PatZToMuMuAnalyzer.cc.

References booked(), hists_, and edm::second().

Referenced by analyze(), and fill().

{ if(booked(histName.c_str())) hists_.find(histName.c_str())->second->Fill(value); };

void PatZToMuMuAnalyzer::fill	(	std::string	hists,
		const reco::TrackRef &	t1,
		const reco::TrackRef &	t2
	)		const `[private]`

fill a predefined set of histograms from inner outer or global tracks for first and second mu candidate

Definition at line 108 of file PatZToMuMuAnalyzer.cc.

References python::multivaluedict::append(), fill(), edm::Ref< C, T, F >::isAvailable(), and mass().

{
  if( t1.isAvailable() ){
    // fill pt from global track for first muon
    fill( std::string(hists).append("Pt") , t1->pt() );
    // fill pt from global track for second muon
    fill( std::string(hists).append("Eta"), t1->eta() );
  }
  if( t2.isAvailable() ){
    // fill eta from global track for first muon
    fill( std::string(hists).append("Pt") , t2->pt() );
    // fill eta from global track for second muon
    fill( std::string(hists).append("Eta"), t2->eta() );
  }
  if( t1.isAvailable() && t2.isAvailable() ){
    // fill invariant mass of the Z boson candidate
    fill( std::string(hists).append("Mass"), mass(t1->momentum(), t2->momentum()));
  }
}

double PatZToMuMuAnalyzer::mass	(	const math::XYZVector &	t1,
		const math::XYZVector &	t2
	)		const `[inline, private]`

calculate the mass of the Z boson from the tracker momenta by hand

Definition at line 68 of file PatZToMuMuAnalyzer.cc.

References shift_, and mathSSE::sqrt().

Referenced by fill().

{
  return (LorentzVector(shift_*t1.x(), shift_*t1.y(), t1.z(), sqrt((0.1057*0.1057)+t1.mag2())) + LorentzVector(shift_*t2.x(), shift_*t2.y(), t2.z(), sqrt((0.1057*0.1057)+t2.mag2()))).mass();
}