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 "AliITStrackMI.h"
31 ClassImp(AliITStrackMI)
35 //____________________________________________________________________________
36 AliITStrackMI::AliITStrackMI():AliITStrackV2(),
40 fDeadZoneProbability(0),
41 fReconstructed(kFALSE),
44 for(Int_t i=0; i<kMaxLayer; i++) fClIndex[i]=-1;
45 for(Int_t i=0; i<6; i++) { fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
46 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0; fChi2MIP[i]=0;}
54 //____________________________________________________________________________
55 AliITStrackMI::AliITStrackMI(AliESDtrack& t,Bool_t c) throw (const Char_t *) :
57 //------------------------------------------------------------------
58 // Conversion ESD track -> ITS track.
59 // If c==kTRUE, create the ITS track out of the constrained params.
60 //------------------------------------------------------------------
62 fReconstructed = kFALSE;
65 fDeadZoneProbability = 0;
66 for(Int_t i=0; i<6; i++) {fClIndex[i]=-1; fNy[i]=0; fNz[i]=0; fNormQ[i]=0; fNormChi2[i]=1000;}
67 for(Int_t i=0; i<12; i++) {fDy[i]=0; fDz[i]=0; fSigmaY[i]=0; fSigmaZ[i]=0;fChi2MIP[i]=0;}
74 //if (!Invariant()) throw "AliITStrackV2: conversion failed !\n";
78 void AliITStrackMI::UpdateESDtrack(ULong_t flags) {
79 fESDtrack->UpdateTrackParams(this,flags);
80 if (flags == AliESDtrack::kITSin) fESDtrack->SetITSChi2MIP(fChi2MIP);
83 //____________________________________________________________________________
84 AliITStrackMI::AliITStrackMI(const AliITStrackMI& t) : AliITStrackV2(t) {
85 //------------------------------------------------------------------
87 //------------------------------------------------------------------
89 fReconstructed = t.fReconstructed;
90 fNSkipped = t.fNSkipped;
91 fNDeadZone = t.fNDeadZone;
92 fDeadZoneProbability = t.fDeadZoneProbability;
94 fFakeRatio = t.fFakeRatio;
95 fdEdxMismatch = t.fdEdxMismatch;
99 fD[0]=t.fD[0]; fD[1]=t.fD[1];
100 fDnorm[0] = t.fDnorm[0]; fDnorm[1]=t.fDnorm[1];
102 for(Int_t i=0; i<6; i++) {
103 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];
105 for(Int_t i=0; i<12; i++) {fDy[i]=t.fDy[i]; fDz[i]=t.fDz[i];
106 fSigmaY[i]=t.fSigmaY[i]; fSigmaZ[i]=t.fSigmaZ[i];fChi2MIP[i]=t.fChi2MIP[i];}
107 fConstrain = t.fConstrain;
108 //memcpy(fDy,t.fDy,6*sizeof(Float_t));
109 //memcpy(fDz,t.fDz,6*sizeof(Float_t));
110 //memcpy(fSigmaY,t.fSigmaY,6*sizeof(Float_t));
111 //memcpy(fSigmaZ,t.fSigmaZ,6*sizeof(Float_t));
112 //memcpy(fChi2MIP,t.fChi2MIP,12*sizeof(Float_t));
115 //_____________________________________________________________________________
116 Int_t AliITStrackMI::Compare(const TObject *o) const {
117 //-----------------------------------------------------------------
118 // This function compares tracks according to the their curvature
119 //-----------------------------------------------------------------
120 AliITStrackMI *t=(AliITStrackMI*)o;
121 //Double_t co=TMath::Abs(t->Get1Pt());
122 //Double_t c =TMath::Abs(Get1Pt());
123 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]));
124 Double_t c =GetSigmaY2()*GetSigmaZ2()*(0.5+TMath::Sqrt(0.5*fD[0]*fD[0]+fD[1]*fD[1]));
126 else if (c<co) return -1;
131 Double_t AliITStrackMI::GetPredictedChi2MI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz) const
133 //-----------------------------------------------------------------
134 // This function calculates a predicted chi2 increment.
135 //-----------------------------------------------------------------
136 Double_t r00=cerry*cerry, r01=0., r11=cerrz*cerrz;
137 r00+=fC00; r01+=fC10; r11+=fC11;
139 Double_t det=r00*r11 - r01*r01;
140 if (TMath::Abs(det) < 1.e-30) {
141 Int_t n=GetNumberOfClusters();
143 Warning("GetPredictedChi2","Singular matrix (%d) !\n",n);
146 Double_t tmp=r00; r00=r11; r11=tmp; r01=-r01;
148 Double_t dy=cy - fP0, dz=cz - fP1;
150 return (dy*r00*dy + 2*r01*dy*dz + dz*r11*dz)/det;
153 //____________________________________________________________________________
154 Int_t AliITStrackMI::CorrectForMaterial(Double_t d, Double_t x0) {
155 //------------------------------------------------------------------
156 //This function corrects the track parameters for crossed material
157 //------------------------------------------------------------------
158 // Double_t p2=(1.+ GetTgl()*GetTgl())/(Get1Pt()*Get1Pt());
159 Double_t p2=(1.+ fP3*fP3)/(Get1Pt()*Get1Pt());
160 Double_t et = p2 + GetMass()*GetMass();
161 Double_t beta2=p2/et;
163 d*=TMath::Sqrt((1.+ fP3*fP3)/(1.- fP2*fP2));
164 //d*=TMath::Sqrt(1.+ fP3*fP3 +fP2*fP2/(1.- fP2*fP2));
166 //Multiple scattering******************
168 Double_t theta2=14.1*14.1/(beta2*p2*1e6)*TMath::Abs(d);
169 //Double_t theta2=1.0259e-6*14*14/28/(beta2*p2)*TMath::Abs(d)*9.36*2.33;
170 fC22 += theta2*(1.- fP2*fP2)*(1. + fP3*fP3);
171 fC33 += theta2*(1. + fP3*fP3)*(1. + fP3*fP3);
172 fC43 += theta2*fP3*fP4*(1. + fP3*fP3);
173 fC44 += theta2*fP3*fP4*fP3*fP4;
176 //Energy losses************************
179 // Double_t dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
181 Double_t dE = 0.265*0.153e-3*(39.2-55.6*beta2+28.7*beta2*beta2+27.41/beta2)*d;
183 if (beta2/(1-beta2)>3.5*3.5){
184 dE=0.153e-3/beta2*(log(3.5*5940)+0.5*log(beta2/(1-beta2)) - beta2)*d;
187 dE=0.153e-3/beta2*(log(5940*beta2/(1-beta2)) - beta2)*d;
188 dE+=0.06e-3/(beta2*beta2)*d;
192 Double_t delta44 = (dE*fP4*et/p2);
197 if (!Invariant()) return 0;
202 //____________________________________________________________________________
203 Int_t AliITStrackMI::UpdateMI(Double_t cy, Double_t cz, Double_t cerry, Double_t cerrz, Double_t chi2,UInt_t index) {
204 //------------------------------------------------------------------
205 //This function updates track parameters
206 //------------------------------------------------------------------
207 Double_t p0=fP0,p1=fP1,p2=fP2,p3=fP3,p4=fP4;
209 Double_t c10=fC10, c11=fC11;
210 Double_t c20=fC20, c21=fC21, c22=fC22;
211 Double_t c30=fC30, c31=fC31, c32=fC32, c33=fC33;
212 Double_t c40=fC40, c41=fC41, c42=fC42, c43=fC43, c44=fC44;
215 Double_t r00=cerry*cerry, r01=0., r11=cerrz*cerrz;
216 r00+=fC00; r01+=fC10; r11+=fC11;
217 Double_t det=r00*r11 - r01*r01;
218 Double_t tmp=r00; r00=r11/det; r11=tmp/det; r01=-r01/det;
221 Double_t k00=fC00*r00+fC10*r01, k01=fC00*r01+fC10*r11;
222 Double_t k10=fC10*r00+fC11*r01, k11=fC10*r01+fC11*r11;
223 Double_t k20=fC20*r00+fC21*r01, k21=fC20*r01+fC21*r11;
224 Double_t k30=fC30*r00+fC31*r01, k31=fC30*r01+fC31*r11;
225 Double_t k40=fC40*r00+fC41*r01, k41=fC40*r01+fC41*r11;
227 Double_t dy=cy - fP0, dz=cz - fP1;
228 Int_t layer = (index & 0xf0000000) >> 28;
231 fSigmaY[layer] = TMath::Sqrt(cerry*cerry+fC00);
232 fSigmaZ[layer] = TMath::Sqrt(cerrz*cerrz+fC11);
234 Double_t sf=fP2 + k20*dy + k21*dz;
236 fP0 += k00*dy + k01*dz;
237 fP1 += k10*dy + k11*dz;
239 fP3 += k30*dy + k31*dz;
240 fP4 += k40*dy + k41*dz;
242 Double_t c01=fC10, c02=fC20, c03=fC30, c04=fC40;
243 Double_t c12=fC21, c13=fC31, c14=fC41;
245 fC00-=k00*fC00+k01*fC10; fC10-=k00*c01+k01*fC11;
246 fC20-=k00*c02+k01*c12; fC30-=k00*c03+k01*c13;
247 fC40-=k00*c04+k01*c14;
249 fC11-=k10*c01+k11*fC11;
250 fC21-=k10*c02+k11*c12; fC31-=k10*c03+k11*c13;
251 fC41-=k10*c04+k11*c14;
253 fC22-=k20*c02+k21*c12; fC32-=k20*c03+k21*c13;
254 fC42-=k20*c04+k21*c14;
256 fC33-=k30*c03+k31*c13;
257 fC43-=k30*c04+k31*c14;
259 fC44-=k40*c04+k41*c14;
262 fP0=p0; fP1=p1; fP2=p2; fP3=p3; fP4=p4;
265 fC20=c20; fC21=c21; fC22=c22;
266 fC30=c30; fC31=c31; fC32=c32; fC33=c33;
267 fC40=c40; fC41=c41; fC42=c42; fC43=c43; fC44=c44;
271 if (chi2<0) return 1;
272 Int_t n=GetNumberOfClusters();
274 SetNumberOfClusters(n+1);
275 SetChi2(GetChi2()+chi2);
280 Int_t AliITStrackMI::GetProlongationFast(Double_t alp, Double_t xk,Double_t &y, Double_t &z)
282 //-----------------------------------------------------------------------------
283 //get fast prolongation
284 //-----------------------------------------------------------------------------
285 Double_t ca=TMath::Cos(alp-fAlpha), sa=TMath::Sin(alp-fAlpha);
286 Double_t cf=TMath::Sqrt(1.- fP2*fP2);
287 // **** rotation **********************
289 // **** translation ******************
290 Double_t dx = xk- fX*ca - fP0*sa;
291 Double_t f1=fP2*ca - cf*sa, f2=f1 + fP4*dx;
292 if (TMath::Abs(f2) >= 0.9999) {
295 Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
296 y += dx*(f1+f2)/(r1+r2);
297 z = fP1+dx*(f1+f2)/(f1*r2 + f2*r1)*fP3;
302 Bool_t AliITStrackMI::IsGoldPrimary()
305 // Indicates gold pimary track
308 if (!fConstrain) return kFALSE; //
309 if (fNDeadZone+fNDeadZone<5.5) isGold = kFALSE; // short track
311 if (fChi2/Float_t(fN)>2.){
312 if (fChi2MIP[0]+fNUsed>3.5) isGold = kFALSE;
314 if (fChi2MIP[2]>4.5) isGold = kFALSE; //back propagation chi2
316 if (fDnorm[0]>0&&fDnorm[1]>0){
317 const Float_t distcut2 =2.5*2.5; //normalize distance cut
318 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)
319 if (dist2>distcut2) isGold = kFALSE;