1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
16 //-------------------------------------------------------------------------
17 // Implementation of the ITS track class
19 // Origin: Marian Ivanov, CERN, Marian.Ivanov@cern.ch
20 // dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
21 //-------------------------------------------------------------------------
29 #include "AliITSRecoParam.h"
30 #include "AliCluster.h"
31 #include "AliESDtrack.h"
32 #include "AliITSgeomTGeo.h"
33 #include "AliITStrackMI.h"
35 ClassImp(AliITStrackMI)
39 //____________________________________________________________________________
40 AliITStrackMI::AliITStrackMI():AliITStrackV2(),
44 fReconstructed(kFALSE),
54 for(Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fClIndex[i]=-1;
55 for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000; fDeadZoneProbability[i]=0;}
56 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fSigmaYZ[i]=0; fChi2MIP[i]=0;}
58 fDnorm[0]=0; fDnorm[1]=0;
61 //____________________________________________________________________________
62 AliITStrackMI::AliITStrackMI(AliESDtrack& t,Bool_t c):
67 fReconstructed(kFALSE),
74 //------------------------------------------------------------------
75 // Conversion ESD track -> ITS track.
76 // If c==kTRUE, create the ITS track out of the constrained params.
77 //------------------------------------------------------------------
78 for(Int_t i=0; i<6; i++) {fClIndex[i]=-1; fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000; fDeadZoneProbability[i]=0;}
79 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fSigmaYZ[i]=0; fChi2MIP[i]=0;}
81 fDnorm[0]=0; fDnorm[1]=0;
85 //____________________________________________________________________________
86 AliITStrackMI::AliITStrackMI(const AliITStrackMI& t) : AliITStrackV2(t),
88 fNSkipped(t.fNSkipped),
89 fNDeadZone(t.fNDeadZone),
90 fReconstructed(t.fReconstructed),
93 fdEdxMismatch(t.fdEdxMismatch),
94 fConstrain(t.fConstrain),
97 //------------------------------------------------------------------
99 //------------------------------------------------------------------
101 fFakeRatio = t.fFakeRatio;
103 fD[0]=t.fD[0]; fD[1]=t.fD[1];
104 fDnorm[0] = t.fDnorm[0]; fDnorm[1]=t.fDnorm[1];
105 for(Int_t i=0; i<6; i++) {
106 fClIndex[i]= t.fClIndex[i]; fNy[i]=t.fNy[i]; fNz[i]=t.fNz[i]; fNormQ[i]=t.fNormQ[i]; fNormChi2[i] = t.fNormChi2[i]; fDeadZoneProbability[i]=t.fDeadZoneProbability[i];
108 for(Int_t i=0; i<12; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i];
109 fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i]; fSigmaYZ[i]=t.fSigmaYZ[i]; fChi2MIP[i]=t.fChi2MIP[i];}
110 //memcpy(fDy,t.fDy,6*sizeof(Float_t));
111 //memcpy(fDz,t.fDz,6*sizeof(Float_t));
112 //memcpy(fSigmaY,t.fSigmaY,6*sizeof(Float_t));
113 //memcpy(fSigmaZ,t.fSigmaZ,6*sizeof(Float_t));
114 //memcpy(fChi2MIP,t.fChi2MIP,12*sizeof(Float_t));
117 //_____________________________________________________________________________
118 Int_t AliITStrackMI::Compare(const TObject *o) const {
119 //-----------------------------------------------------------------
120 // This function compares tracks according to the their curvature
121 //-----------------------------------------------------------------
122 AliITStrackMI *t=(AliITStrackMI*)o;
123 //Double_t co=TMath::Abs(t->Get1Pt());
124 //Double_t c =TMath::Abs(Get1Pt());
125 Double_t co=t->GetSigmaY2()*t->GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*t->fD[0]*t->fD[0]+t->fD[1]*t->fD[1]));
126 Double_t c =GetSigmaY2()*GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*fD[0]*fD[0]+fD[1]*fD[1]));
128 else if (c<co) return -1;
133 Double_t AliITStrackMI::GetPredictedChi2MI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz, Double_t covyz) const
135 //-----------------------------------------------------------------
136 // This function calculates a predicted chi2 increment.
137 //-----------------------------------------------------------------
138 Double_t p[2]={cy, cz};
139 Double_t cov[3]={cerry*cerry, covyz, cerrz*cerrz};
140 return AliExternalTrackParam::GetPredictedChi2(p,cov);
143 //____________________________________________________________________________
144 Bool_t AliITStrackMI::UpdateMI(const AliCluster *c, Double_t chi2, Int_t index) {
145 //------------------------------------------------------------------
146 //This function updates track parameters
147 //------------------------------------------------------------------
148 Double_t dy=c->GetY() - GetY(), dz=c->GetZ() - GetZ();
149 Int_t layer = (index & 0xf0000000) >> 28;
152 fSigmaY[layer] = TMath::Sqrt(c->GetSigmaY2()+GetSigmaY2());
153 fSigmaZ[layer] = TMath::Sqrt(c->GetSigmaZ2()+GetSigmaZ2());
154 fSigmaYZ[layer] = c->GetSigmaYZ()+GetSigmaZY();
157 return Update(c,chi2,index);
160 Int_t AliITStrackMI::GetProlongationFast(Double_t alp, Double_t xk,Double_t &y, Double_t &z)
162 //-----------------------------------------------------------------------------
163 //get fast prolongation
164 //-----------------------------------------------------------------------------
165 Double_t ca=TMath::Cos(alp-GetAlpha()), sa=TMath::Sin(alp-GetAlpha());
166 Double_t cf=TMath::Sqrt((1.-GetSnp())*(1.+GetSnp()));
167 // **** rotation **********************
168 y= -GetX()*sa + GetY()*ca;
169 // **** translation ******************
170 Double_t dx = xk- GetX()*ca - GetY()*sa;
171 Double_t f1=GetSnp()*ca - cf*sa, f2=f1 + GetC()*dx;
172 if (TMath::Abs(f2) >= 0.9999) {
175 Double_t r1=TMath::Sqrt((1.-f1)*(1.+f1)), r2=TMath::Sqrt((1.-f2)*(1.+f2));
176 y += dx*(f1+f2)/(r1+r2);
177 z = GetZ()+dx*(f1+f2)/(f1*r2 + f2*r1)*GetTgl();
182 Bool_t AliITStrackMI::IsGoldPrimary()
185 // Indicates gold pimary track
188 if (!fConstrain) return kFALSE; //
189 if (fNDeadZone+fNDeadZone<5.5) isGold = kFALSE; // short track
191 if (fChi2MIP[0]*fChi2MIP[3]>2) isGold = kFALSE; // RS: cut on chi2*interpolated_chi2
192 if (fChi2/Float_t(fN)>2.){
193 if (fChi2MIP[0]+fNUsed>3.5) isGold = kFALSE;
195 if (fChi2MIP[2]>4.5) isGold = kFALSE; //back propagation chi2
197 if (fDnorm[0]>0&&fDnorm[1]>0){
198 const Float_t distcut2 =2.5*2.5; //normalize distance cut
199 Float_t dist2 = fD[0]*fD[0]/(fDnorm[0]*fDnorm[0])+fD[1]*fD[1]/(fDnorm[1]*fDnorm[1]); //normalize distance to the vertex (pools)
200 if (dist2>distcut2) isGold = kFALSE;