CMSSW Reference Manual

00001 #include "PhysicsTools/CandUtils/interface/zMCLeptonDaughters.h"
00002 #include "DataFormats/Candidate/interface/Candidate.h"
00003 #include "FWCore/Utilities/interface/EDMException.h"
00004 #include <cassert>
00005 using namespace std;
00006 using namespace reco;
00007 
00008 pair<const Candidate*, const Candidate*> zMCLeptonDaughters(const Candidate & z, int leptonPdgId) {
00009   if(z.numberOfDaughters()<2)
00010     throw cms::Exception("RuntimeError") <<
00011       "calling helper function reco::zMCLeptonDaughters passing a Z candidate"
00012       "with less than 2 daughters (" << z.numberOfDaughters() << ").\n";
00013   const Candidate * dau0 = z.daughter(0);
00014   const Candidate * dau1 = z.daughter(1);
00015   for(size_t i0 = 0; i0 < dau0->numberOfDaughters(); ++i0) {
00016     const Candidate * ddau0 = dau0->daughter(i0);
00017     if(abs(ddau0->pdgId())==leptonPdgId && ddau0->status()==1) {
00018       dau0 = ddau0; break;
00019     }
00020   }
00021   for(size_t i1 = 0; i1 < dau1->numberOfDaughters(); ++i1) {
00022     const Candidate * ddau1 = dau1->daughter(i1);
00023     if(abs(ddau1->pdgId())==leptonPdgId && ddau1->status()==1) {
00024       dau1 = ddau1; break;
00025     }
00026   }
00027   assert(abs(dau0->pdgId())==leptonPdgId && dau0->status()==1);
00028   assert(abs(dau1->pdgId())==leptonPdgId && dau1->status()==1);
00029   return make_pair(dau0, dau1);
00030 }
zMCLeptonDaughters.cc
