AliAODRecoDecayHF3Prong.cxx

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 * Author: The ALICE Off-line Project.                                    *
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 * about the suitability of this software for any purpose. It is          *
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/* $Id$ */

//
// Base class for AOD reconstructed heavy-flavour 3-prong decay
//
// Author: E.Bruna bruna@to.infn.it, F.Prino prino@to.infn.it

#include <TDatabasePDG.h>
#include "AliAODRecoDecayHF.h"
#include "AliAODRecoDecayHF3Prong.h"
#include "AliAODTrack.h"
#include "AliESDtrack.h"
#include "AliVertexerTracks.h"
#include "TVector3.h"
#include "TLorentzVector.h"

ClassImp(AliAODRecoDecayHF3Prong);

//--------------------------------------------------------------------------
AliAODRecoDecayHF3Prong::AliAODRecoDecayHF3Prong() :
  AliAODRecoDecayHF(), 
  fSigmaVert(0),
  fDist12toPrim(0),
  fDist23toPrim(0)
{
  //
  //
}
//--------------------------------------------------------------------------
AliAODRecoDecayHF3Prong::AliAODRecoDecayHF3Prong(AliAODVertex *vtx2,
             Double_t *px,Double_t *py,Double_t *pz,
             Double_t *d0,Double_t *d0err,
             Double_t *dca, Double_t sigvert,
             Double_t dist12,Double_t dist23,Short_t charge) :
  AliAODRecoDecayHF(vtx2,3,charge,px,py,pz,d0,d0err),
  fSigmaVert(sigvert),
  fDist12toPrim(dist12),
  fDist23toPrim(dist23)
{
  //
  //
  SetDCAs(3,dca);
}
//--------------------------------------------------------------------------
AliAODRecoDecayHF3Prong::AliAODRecoDecayHF3Prong(AliAODVertex *vtx2,
             Double_t *d0,Double_t *d0err,
             Double_t *dca, Double_t sigvert,
             Double_t dist12,Double_t dist23, Short_t charge) :
  AliAODRecoDecayHF(vtx2,3,charge,d0,d0err),
  fSigmaVert(sigvert),
  fDist12toPrim(dist12),
  fDist23toPrim(dist23)
{
  //
  //
  SetDCAs(3,dca);
}
//--------------------------------------------------------------------------
AliAODRecoDecayHF3Prong::AliAODRecoDecayHF3Prong(const AliAODRecoDecayHF3Prong &source) :
  AliAODRecoDecayHF(source),
  fSigmaVert(source.fSigmaVert),
  fDist12toPrim(source.fDist12toPrim),
  fDist23toPrim(source.fDist23toPrim)
{
  //
  //
}
//--------------------------------------------------------------------------
AliAODRecoDecayHF3Prong &AliAODRecoDecayHF3Prong::operator=(const AliAODRecoDecayHF3Prong &source)
{
  //
  //
  if(&source == this) return *this;

  AliAODRecoDecayHF::operator=(source);

  fDist12toPrim= source.fDist12toPrim;
  fDist23toPrim= source.fDist23toPrim;
  fSigmaVert= source.fSigmaVert;

  return *this;
}
//--------------------------------------------------------------------------
Bool_t AliAODRecoDecayHF3Prong::SelectDplus(const Double_t *cuts)
  const {

  Double_t mDplusPDG = TDatabasePDG::Instance()->GetParticle(411)->Mass();
  Double_t mDplus=InvMassDplus();
  if(TMath::Abs(mDplus-mDplusPDG)>cuts[0])return kFALSE;
  //single track
  if(TMath::Abs(PtProng(1)) < cuts[1] || TMath::Abs(Getd0Prong(1))<cuts[3])return kFALSE;//Kaon
  if(TMath::Abs(PtProng(0)) < cuts[2] || TMath::Abs(Getd0Prong(0))<cuts[4])return kFALSE;//Pion1
  if(TMath::Abs(PtProng(2)) < cuts[2] || TMath::Abs(Getd0Prong(2))<cuts[4])return kFALSE;//Pion2

  //DCA
  for(Int_t i=0;i<3;i++) if(GetDCA(i)>cuts[11])return kFALSE;

  //2track cuts
  if(fDist12toPrim<cuts[5] || fDist23toPrim<cuts[5])return kFALSE;
  if(Getd0Prong(0)*Getd0Prong(1)<0. && Getd0Prong(2)*Getd0Prong(1)<0.)return kFALSE;

  //sec vert
  if(fSigmaVert>cuts[6])return kFALSE;

  if(DecayLength()<cuts[7])return kFALSE;

  if(TMath::Abs(PtProng(0))<cuts[8] && TMath::Abs(PtProng(1))<cuts[8] && TMath::Abs(PtProng(2))<cuts[8])return kFALSE;
  if(CosPointingAngle()   < cuts[9])return kFALSE;
  Double_t sum2=Getd0Prong(0)*Getd0Prong(0)+Getd0Prong(1)*Getd0Prong(1)+Getd0Prong(2)*Getd0Prong(2);
  if(sum2<cuts[10])return kFALSE;
  return kTRUE;
}
//--------------------------------------------------------------------------
Bool_t AliAODRecoDecayHF3Prong::SelectDs(const Double_t *cuts,Int_t &okDsKKpi,Int_t &okDspiKK, Int_t &okMassPhi, Int_t &okMassK0star)
  const {
  Double_t mDsKKpi,mDspiKK;
  okDsKKpi=1; okDspiKK=1;
  okMassPhi=0; okMassK0star=0;

  Double_t mDsPDG = TDatabasePDG::Instance()->GetParticle(431)->Mass();

  mDsKKpi=InvMassDsKKpi();
  mDspiKK=InvMassDspiKK();

  if(TMath::Abs(mDsKKpi-mDsPDG)>cuts[0]) okDsKKpi = 0;
  if(TMath::Abs(mDspiKK-mDsPDG)>cuts[0]) okDspiKK = 0;
  if(!okDsKKpi && !okDspiKK) return kFALSE;

  //single track
  if(TMath::Abs(PtProng(0)) < cuts[1] || TMath::Abs(Getd0Prong(0))<cuts[3])return kFALSE;//Kaon1
  if(TMath::Abs(PtProng(1)) < cuts[1] || TMath::Abs(Getd0Prong(1))<cuts[3])return kFALSE;//Kaon2
  if(TMath::Abs(PtProng(2)) < cuts[2] || TMath::Abs(Getd0Prong(2))<cuts[4])return kFALSE;//Pion

  // cuts on resonant decays (via Phi or K0*)
  Double_t mPhiPDG = TDatabasePDG::Instance()->GetParticle(333)->Mass();
  Double_t mK0starPDG = TDatabasePDG::Instance()->GetParticle(313)->Mass();
  if(okDsKKpi){
    Double_t mass01phi=InvMass2Prongs(0,1,321,321);
    Double_t mass12K0s=InvMass2Prongs(1,2,321,211);
    if(TMath::Abs(mass01phi-mPhiPDG)<cuts[12]) okMassPhi=1;
    if(TMath::Abs(mass12K0s-mK0starPDG)<cuts[13]) okMassK0star = 1;
    if(!okMassPhi && !okMassK0star) okDsKKpi=kFALSE;
  }
  if(okDspiKK){
    Double_t mass01K0s=InvMass2Prongs(0,1,211,321);
    Double_t mass12phi=InvMass2Prongs(1,2,321,321);
    if(TMath::Abs(mass01K0s-mK0starPDG)<cuts[13]) okMassK0star = 1;
    if(TMath::Abs(mass12phi-mPhiPDG)<cuts[12]) okMassPhi=1;
    if(!okMassPhi && !okMassK0star) okDspiKK=kFALSE;
  }
  if(!okDsKKpi && !okDspiKK) return kFALSE;



  
  //DCA
  for(Int_t i=0;i<3;i++) if(GetDCA(i)>cuts[11])return kFALSE;

  //2track cuts
  if(fDist12toPrim<cuts[5] || fDist23toPrim<cuts[5])return kFALSE;

  //sec vert
  if(fSigmaVert>cuts[6])return kFALSE;

  if(DecayLength()<cuts[7])return kFALSE;

  if(TMath::Abs(PtProng(0))<cuts[8] && TMath::Abs(PtProng(1))<cuts[8] && TMath::Abs(PtProng(2))<cuts[8])return kFALSE;
  if(CosPointingAngle()   < cuts[9])return kFALSE;
  Double_t sum2=Getd0Prong(0)*Getd0Prong(0)+Getd0Prong(1)*Getd0Prong(1)+Getd0Prong(2)*Getd0Prong(2);
  if(sum2<cuts[10])return kFALSE;

  return kTRUE;
}
//--------------------------------------------------------------------------
Bool_t AliAODRecoDecayHF3Prong::SelectLc(const Double_t *cuts,Int_t &okLcpKpi,Int_t &okLcpiKp)
  const {
  Double_t mLcpKpi,mLcpiKp;
  okLcpKpi=1; okLcpiKp=1;

  Double_t mLcPDG = TDatabasePDG::Instance()->GetParticle(4122)->Mass();

  mLcpKpi=InvMassLcpKpi();
  mLcpiKp=InvMassLcpiKp();

  if(TMath::Abs(mLcpKpi-mLcPDG)>cuts[0]) okLcpKpi = 0;
  if(TMath::Abs(mLcpiKp-mLcPDG)>cuts[0]) okLcpiKp = 0;
  if(!okLcpKpi && !okLcpiKp) return kFALSE;

  //single track
  if(TMath::Abs(PtProng(0)) < cuts[1] || TMath::Abs(Getd0Prong(0))<cuts[3])return kFALSE;//Proton
  if(TMath::Abs(PtProng(1)) < cuts[2] || TMath::Abs(Getd0Prong(1))<cuts[4])return kFALSE;//Kaon
  if(TMath::Abs(PtProng(2)) < cuts[2] || TMath::Abs(Getd0Prong(2))<cuts[4])return kFALSE;//Pion

  //DCA
  for(Int_t i=0;i<3;i++) if(GetDCA(i)>cuts[11])return kFALSE;

  //2track cuts
  if(fDist12toPrim<cuts[5] || fDist23toPrim<cuts[5])return kFALSE;
  if(Getd0Prong(0)*Getd0Prong(1)<0. && Getd0Prong(2)*Getd0Prong(1)<0.)return kFALSE;

  //sec vert
  if(fSigmaVert>cuts[6])return kFALSE;

  if(DecayLength()<cuts[7])return kFALSE;

  if(TMath::Abs(PtProng(0))<cuts[8] && TMath::Abs(PtProng(1))<cuts[8] && TMath::Abs(PtProng(2))<cuts[8])return kFALSE;
  if(CosPointingAngle()   < cuts[9])return kFALSE;
  Double_t sum2=Getd0Prong(0)*Getd0Prong(0)+Getd0Prong(1)*Getd0Prong(1)+Getd0Prong(2)*Getd0Prong(2);
  if(sum2<cuts[10])return kFALSE;

  return kTRUE;
}


//----------------------------------------------------------------------
Double_t AliAODRecoDecayHF3Prong::CosPiKPhiRFrame(Int_t option)
const {

 Int_t indexPi;
 Int_t indexK1;
 Int_t indexK2;

  if (option==0){ //KKpi
    indexPi=2;
    indexK1=0;
    indexK2=1;
  }else if (option==1){   //piKK
    indexPi=0;
    indexK1=1;
    indexK2=2;
  }else{  //KpiK
    indexPi=1;
    indexK1=0;
    indexK2=2;
  }
          
  Double_t ePhi=EProng(indexK1,321)+EProng(indexK2,321);
  Double_t pxPhi=PxProng(indexK1)+PxProng(indexK2);
  Double_t pyPhi=PyProng(indexK1)+PyProng(indexK2);
  Double_t pzPhi=PzProng(indexK1)+PzProng(indexK2);
  Double_t bxPhi=pxPhi/ePhi;
  Double_t byPhi=pyPhi/ePhi;
  Double_t bzPhi=pzPhi/ePhi;
 
  TVector3 vecK1Phiframe;
  TLorentzVector vecK1(PxProng(indexK1),PyProng(indexK1),PzProng(indexK1),EProng(indexK1,321));
  vecK1.Boost(-bxPhi,-byPhi,-bzPhi);
  vecK1.Boost(vecK1Phiframe);
  vecK1Phiframe=vecK1.BoostVector();
    
  TVector3 vecPiPhiframe;
  TLorentzVector vecPi(PxProng(indexPi),PyProng(indexPi),PzProng(indexPi),EProng(indexPi,211));
  vecPi.Boost(-bxPhi,-byPhi,-bzPhi);
  vecPi.Boost(vecPiPhiframe);
  vecPiPhiframe=vecPi.BoostVector();
                                                             
  Double_t innera=vecPiPhiframe.Dot(vecK1Phiframe);
  Double_t norm1a=TMath::Sqrt(vecPiPhiframe.Dot(vecPiPhiframe));
  Double_t norm2a=TMath::Sqrt(vecK1Phiframe.Dot(vecK1Phiframe));
  Double_t cosK1PhiFrame=innera/(norm1a*norm2a);                                                      

  return cosK1PhiFrame;

}

//----------------------------------------------------------------------
Double_t AliAODRecoDecayHF3Prong::CosPiDsLabFrame(Int_t option)
const {

 Int_t indexPi;

  if (option==0){ //KKpi
    indexPi=2;
  }else if (option==1){//piKK
    indexPi=0;
  }else{ //KpiK
    indexPi=1;
  }

 
  Double_t bxD=Px()/E(431);
  Double_t byD=Py()/E(431);
  Double_t bzD=Pz()/E(431);

  TVector3 piDsframe;
  TLorentzVector vecPi(PxProng(indexPi),PyProng(indexPi),PzProng(indexPi),EProng(indexPi,211));
  vecPi.Boost(-bxD,-byD,-bzD);
  vecPi.Boost(piDsframe);
  piDsframe=vecPi.BoostVector();
 
  TVector3 vecDs(Px(),Py(),Pz());
      
  Double_t inner=vecDs.Dot(piDsframe);
  Double_t norm1=TMath::Sqrt(vecDs.Dot(vecDs));
  Double_t norm2=TMath::Sqrt(piDsframe.Dot(piDsframe));
  Double_t cosPiDsFrame=inner/(norm1*norm2);  
 

  return cosPiDsFrame;

}

//----------------------------------------------------------------------
Double_t AliAODRecoDecayHF3Prong::ComputeSigmaVert(const AliAODEvent* aod) const{

  AliVertexerTracks vertexer(aod->GetMagneticField());
  Double_t pos[3],cov[6];
  AliAODVertex* aodV=aod->GetPrimaryVertex();
  aodV->GetXYZ(pos);
  aodV->GetCovarianceMatrix(cov);
  Double_t chi2=aodV->GetChi2();
  Int_t nC=aodV->GetNContributors();
  AliESDVertex vprim(pos,cov,chi2,nC);
  vertexer.SetVtxStart(&vprim);
  TObjArray threeTrackArray(3);

  for(Int_t iDau=0; iDau<GetNDaughters(); iDau++){
    AliVTrack* at=(AliVTrack*)GetDaughter(iDau);
    threeTrackArray.AddAt(new AliESDtrack(at),iDau);
  }

  AliESDVertex* secVert=vertexer.VertexForSelectedESDTracks(&threeTrackArray,kFALSE,kTRUE,kFALSE);
  Double_t disp=secVert->GetDispersion();
  
  threeTrackArray.Delete();
  delete secVert;
  return disp;
  
}
//--------------------------------------------------------------------------
void AliAODRecoDecayHF3Prong::DeleteRecoD(){
  //Delete data member to reduce size of AliAOD.VertexingHF.root
  //They will be recomputed at the analysis level
  AliAODRecoDecayHF::DeleteRecoD();//delete data members of AliAODRecoDecayHF
  if(fSigmaVert) fSigmaVert =0.;
}