class AliDielectronV0Cuts: public AliDielectronVarCuts

Cut class providing cuts to V0 candidates
Selection or deselection of V0 candiates can be done.

Authors:
Julian Book <Julian.Book@cern.ch>


Class to provide some V0 selection using exactley the same cuts in ESDs as in AODs.
It implements the PID cut class AliDielectronPID and the standard AliDielectronVarCuts for
the configuration of leg respective pair cuts. These pair cuts are applied on the KFparticle
build by the legs.

Some QA cuts for the tracks are applied before the V0 pair is build. These cuts are:
AliDielectronVarCuts dauQAcuts1;
dauQAcuts1.AddCut(AliDielectronVarManager::kPt,            0.05, 100.0);
dauQAcuts1.AddCut(AliDielectronVarManager::kEta,          -0.9,    0.9);
dauQAcuts1.AddCut(AliDielectronVarManager::kNclsTPC,      50.0,  160.0);
dauQAcuts1.AddCut(AliDielectronVarManager::kTPCchi2Cl,     0.0,    4.0);
AliDielectronTrackCuts dauQAcuts2;
dauQAcuts2.SetRequireTPCRefit(kTRUE);



Example configuration:

  AliDielectronV0Cuts *gammaV0Cuts = new AliDielectronV0Cuts("IsGamma","IsGamma");

  // which V0 finder you want to use
  gammaV0Cuts->SetV0finder(kOnTheFly);  // kAll(default), kOffline or kOnTheFly

  // add some pdg codes (they are used then by the KF package and important for gamma conversions)
  gammaV0Cuts->SetPdgCodes(22,11,11); // mother, daughter1 and 2

  // add default PID cuts (defined in AliDielectronPID)
  // requirement can be set to at least one(kAny) of the tracks or to both(kBoth)
  gammaV0Cuts->SetDefaultPID(16, AliDielectronV0Cuts::kAny);

  // add the pair cuts for V0 candidates
  gammaV0Cuts->AddCut(AliDielectronVarManager::kCosPointingAngle, TMath::Cos(0.02),   1.0, kFALSE);
  gammaV0Cuts->AddCut(AliDielectronVarManager::kChi2NDF,                       0.0,  10.0, kFALSE);
  gammaV0Cuts->AddCut(AliDielectronVarManager::kLegDist,                       0.0,   0.25, kFALSE);
  gammaV0Cuts->AddCut(AliDielectronVarManager::kR,                             3.0,  90.0, kFALSE);
  gammaV0Cuts->AddCut(AliDielectronVarManager::kPsiPair,                       0.0,   0.05, kFALSE);
  gammaV0Cuts->AddCut(AliDielectronVarManager::kM,                             0.0,   0.05, kFALSE);
  gammaV0Cuts->AddCut(AliDielectronVarManager::kArmPt,                         0.0,   0.05, kFALSE);

  // selection or rejection of V0 tracks
  gammaV0Cuts->SetExcludeTracks(kTRUE);

  // add the V0cuts directly to the track filter or to some cut group of it