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 //-------------------------------------------------------------------------
27 #include "AliCluster.h"
28 #include "AliESDtrack.h"
29 #include "AliITSgeomTGeo.h"
30 #include "AliITStrackMI.h"
32 ClassImp(AliITStrackMI)
36 //____________________________________________________________________________
37 AliITStrackMI::AliITStrackMI():AliITStrackV2(),
41 fDeadZoneProbability(0),
42 fReconstructed(kFALSE),
50 for(Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fClIndex[i]=-1;
51 for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
52 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fChi2MIP[i]=0;}
54 fDnorm[0]=0; fDnorm[1]=0;
57 //____________________________________________________________________________
58 AliITStrackMI::AliITStrackMI(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
63 fDeadZoneProbability(0),
64 fReconstructed(kFALSE),
70 //------------------------------------------------------------------
71 // Conversion ESD track -> ITS track.
72 // If c==kTRUE, create the ITS track out of the constrained params.
73 //------------------------------------------------------------------
74 for(Int_t i=0; i<6; i++) {fClIndex[i]=-1; fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
75 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;fChi2MIP[i]=0;}
77 fDnorm[0]=0; fDnorm[1]=0;
78 //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
82 void AliITStrackMI::UpdateESDtrack(ULong_t flags) {
83 fESDtrack->UpdateTrackParams(this,flags);
84 //if (flags == AliESDtrack::kITSin) fESDtrack->SetITSChi2MIP(fChi2MIP);
87 //____________________________________________________________________________
88 AliITStrackMI::AliITStrackMI(const AliITStrackMI& t) : AliITStrackV2(t),
90 fNSkipped(t.fNSkipped),
91 fNDeadZone(t.fNDeadZone),
92 fDeadZoneProbability(t.fDeadZoneProbability),
93 fReconstructed(t.fReconstructed),
96 fdEdxMismatch(t.fdEdxMismatch),
97 fConstrain(t.fConstrain),
99 //------------------------------------------------------------------
101 //------------------------------------------------------------------
103 fFakeRatio = t.fFakeRatio;
105 fD[0]=t.fD[0]; fD[1]=t.fD[1];
106 fDnorm[0] = t.fDnorm[0]; fDnorm[1]=t.fDnorm[1];
107 for(Int_t i=0; i<6; i++) {
108 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];
110 for(Int_t i=0; i<12; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i];
111 fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i];fChi2MIP[i]=t.fChi2MIP[i];}
112 //memcpy(fDy,t.fDy,6*sizeof(Float_t));
113 //memcpy(fDz,t.fDz,6*sizeof(Float_t));
114 //memcpy(fSigmaY,t.fSigmaY,6*sizeof(Float_t));
115 //memcpy(fSigmaZ,t.fSigmaZ,6*sizeof(Float_t));
116 //memcpy(fChi2MIP,t.fChi2MIP,12*sizeof(Float_t));
119 //_____________________________________________________________________________
120 Int_t AliITStrackMI::Compare(const TObject *o) const {
121 //-----------------------------------------------------------------
122 // This function compares tracks according to the their curvature
123 //-----------------------------------------------------------------
124 AliITStrackMI *t=(AliITStrackMI*)o;
125 //Double_t co=TMath::Abs(t->Get1Pt());
126 //Double_t c =TMath::Abs(Get1Pt());
127 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]));
128 Double_t c =GetSigmaY2()*GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*fD[0]*fD[0]+fD[1]*fD[1]));
130 else if (c<co) return -1;
135 Double_t AliITStrackMI::GetPredictedChi2MI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz) const
137 //-----------------------------------------------------------------
138 // This function calculates a predicted chi2 increment.
139 //-----------------------------------------------------------------
140 Double_t p[2]={cy, cz};
141 Double_t cov[3]={cerry*cerry, 0., cerrz*cerrz};
142 return AliExternalTrackParam::GetPredictedChi2(p,cov);
145 //____________________________________________________________________________
146 Int_t AliITStrackMI::CorrectForMaterial(Double_t d, Double_t x0) {
147 //------------------------------------------------------------------
148 //This function corrects the track parameters for crossed material
149 //------------------------------------------------------------------
152 Double_t p2=(1.+ GetTgl()*GetTgl())/(GetSigned1Pt()*GetSigned1Pt());
153 Double_t et = p2 + GetMass()*GetMass();
154 Double_t beta2=p2/et;
156 d*=TMath::Sqrt((1.+ GetTgl()*GetTgl())/(1.- GetSnp()*GetSnp()));
158 //Multiple scattering******************
160 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d);
161 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33;
162 Cov(5) += theta2*(1.- GetSnp()*GetSnp())*(1. + GetTgl()*GetTgl());
163 Cov(9) += theta2*(1. + GetTgl()*GetTgl())*(1. + GetTgl()*GetTgl());
164 Cov(13)+= theta2*GetTgl()*GetSigned1Pt()*(1. + GetTgl()*GetTgl());
165 Cov(14)+= theta2*GetTgl()*GetSigned1Pt()*GetTgl()*GetSigned1Pt();
168 //Energy losses************************
171 // Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
173 Double_t dE = 0.265*0.153e-3*(39.2-55.6*beta2+28.7*beta2*beta2+27.41/beta2)*d;
174 //if (beta2/(1-beta2)>3.5*3.5){
175 // dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d;
178 // dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
179 // dE+=0.06e-3/(beta2*beta2)*d;
182 Par(4)*=(1.- et/p2*dE);
183 Double_t delta44 = (dE*GetSigned1Pt()*et/p2);
185 Cov(14)+= delta44/400.;
188 if (!Invariant()) return 0;
193 //____________________________________________________________________________
194 Bool_t AliITStrackMI::UpdateMI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz, Double_t chi2, Int_t index) {
195 //------------------------------------------------------------------
196 //This function updates track parameters
197 //------------------------------------------------------------------
198 Double_t dy=cy - GetY(), dz=cz - GetZ();
199 Int_t layer = (index & 0xf0000000) >> 28;
202 fSigmaY[layer] = TMath::Sqrt(cerry*cerry+GetSigmaY2());
203 fSigmaZ[layer] = TMath::Sqrt(cerrz*cerrz+GetSigmaZ2());
205 Double_t p[2]={cy, cz};
206 Double_t cov[3]={cerry*cerry, 0., cerrz*cerrz};
207 if (!AliExternalTrackParam::Update(p,cov)) return kFALSE;
210 AliWarning("Wrong invariant !");
214 if (chi2<0) return 1;
215 Int_t n=GetNumberOfClusters();
217 SetNumberOfClusters(n+1);
218 SetChi2(GetChi2()+chi2);
223 Int_t AliITStrackMI::GetProlongationFast(Double_t alp, Double_t xk,Double_t &y, Double_t &z)
225 //-----------------------------------------------------------------------------
226 //get fast prolongation
227 //-----------------------------------------------------------------------------
228 Double_t ca=TMath::Cos(alp-GetAlpha()), sa=TMath::Sin(alp-GetAlpha());
229 Double_t cf=TMath::Sqrt(1.- GetSnp()*GetSnp());
230 // **** rotation **********************
231 y= -GetX()*sa + GetY()*ca;
232 // **** translation ******************
233 Double_t dx = xk- GetX()*ca - GetY()*sa;
234 Double_t f1=GetSnp()*ca - cf*sa, f2=f1 + GetC()*dx;
235 if (TMath::Abs(f2) >= 0.9999) {
238 Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
239 y += dx*(f1+f2)/(r1+r2);
240 z = GetZ()+dx*(f1+f2)/(f1*r2 + f2*r1)*GetTgl();
245 Bool_t AliITStrackMI::IsGoldPrimary()
248 // Indicates gold pimary track
251 if (!fConstrain) return kFALSE; //
252 if (fNDeadZone+fNDeadZone<5.5) isGold = kFALSE; // short track
254 if (fChi2/Float_t(fN)>2.){
255 if (fChi2MIP[0]+fNUsed>3.5) isGold = kFALSE;
257 if (fChi2MIP[2]>4.5) isGold = kFALSE; //back propagation chi2
259 if (fDnorm[0]>0&&fDnorm[1]>0){
260 const Float_t distcut2 =2.5*2.5; //normalize distance cut
261 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)
262 if (dist2>distcut2) isGold = kFALSE;