class AliDielectronSignalExt: public AliDielectronSignalBase

Dielectron SignalExt



  Class used for extracting the signal from an invariant mass spectrum.
  Used invariant mass spectra are provided via an array of histograms. There are serveral method
  to estimate the background and to extract the raw yield from the background subtracted spectra.

  Example usage:

  AliDielectronSignalExt *sig = new AliDielectronSignalExt();


  1) invariant mass input spectra

  1.1) Assuming a AliDielectronCF container as data format (check class for more details)
  AliDielectronCFdraw *cf = new AliDielectronCFdraw("path/to/the/output/file.root");
  TObjArray *arrHists = cf->CollectMinvProj(cf->FindStep("Config"));

  1.2) Assuming a AliDielectronHF grid as data format (check class for more details)
  AliDielectronHFhelper *hf = new AliDielectronHFhelper("path/to/the/output/file.root", "ConfigName");
  TObjArray *arrHists = hf->CollectHistos(AliDielectronVarManager::kM);

  1.3) Assuming a single histograms
  TObjArray *histoArray = new TObjArray();
  arrHists->Add(signalPP);            // add the spectrum histograms to the array
  arrHists->Add(signalPM);            // the order is important !!!
  arrHists->Add(signalMM);


  2) background estimation

  2.1) set the method for the background estimation (methods can be found in AliDielectronSignalBase)
  sig->SetMethod(AliDielectronSignalBase::kEventMixing);
  2.2) rebin the spectras if needed
  //  sig->SetRebin(2);
  2.3) normalize the backgound spectum to the odd-sign spectrum in the desired range(s)
  sig->SetScaleRawToBackground(minScale, maxScale);
  //  sig->SetScaleRawToBackground(minScale, maxScale, minScale2, maxScale2);


  3) configure the signal extraction

  3.1) set the method for the signal extraction (methods can be found in AliDielectronSignalBase)
  depending on the method serveral inputs are needed (e.g. MC shape, PDG code of the particle of interest)
  //  sig->SetParticleOfInterest(443); //default is jpsi
  //  sig->SetMCSignalShape(signalMC);
  sig->SetIntegralRange(minInt, maxInt);  // range for bin counting
  sig->SetExtractionMethod(AliDielectronSignal::BinCounting); // this is the default


  4) start the processing

  sig->Process(arrHists);
  sig->Print(""); // print values and errors extracted


  5) access the spectra and values created

  5.1) standard spectras
  TH1F *hsign = (TH1F*) sig->GetUnlikeSignHistogram();  // same as the input (rebinned)
  TH1F *hbgrd = (TH1F*) sig->GetBackgroundHistogram();  // scaled input      (rebinned)
  TH1F *hextr = (TH1F*) sig->GetSignalHistogram();      // after backgound extraction (rebinned)
  TObject *oPeak = (TObject*) sig->GetPeakShape();      // can be a TF1 or TH1 depending on the extraction method
  TH1F *hrfac = (TH1F*) sig->GetRfactorHistogram();     // if like-sign correction was activated, o.w. 0x0
  5.2) access the extracted values and errors
  sig->GetValues();     or GetErrors();                 // yield extraction