Minor correction
[u/mrichter/AliRoot.git] / TPC / AliTPCtrackerParam.cxx
1 /**************************************************************************
2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3  *                                                                        *
4  * Author: The ALICE Off-line Project.                                    *
5  * Contributors are mentioned in the code where appropriate.              *
6  *                                                                        *
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  **************************************************************************
15  **************************************************************************
16  *                                                                        *
17  * This class builds AliTPCtrack objects from generated tracks to feed    *
18  * ITS tracking (V2). The AliTPCtrack is built from its first hit in      *
19  * the TPC. The track is assigned a Kalman-like covariance matrix         *
20  * depending on its pT and pseudorapidity and track parameters are        *
21  * smeared according to this covariance matrix.                           *
22  * Output file contains sorted tracks, ready for matching with ITS        *
23  *                                                                        *
24  * Test macro is: AliBarrelRec_TPCparam.C                                 * 
25  *                                                                        *
26  *  Origin: Andrea Dainese, Padova - e-mail: andrea.dainese@pd.infn.it    * 
27  *                                                                        *
28  **************************************************************************/
29 #include "AliTPCtrackerParam.h"
30 #include "alles.h"
31 #include "AliMagF.h"
32 #include "AliTPCtrack.h"
33 #include "TMatrixD.h"
34 #include "AliKalmanTrack.h"
35 #include "AliMagFCM.h"
36 #include "AliGausCorr.h"
37
38
39
40
41 ClassImp(AliTPCtrackerParam)
42
43 //-----------------------------------------------------------------
44 AliTPCtrackerParam::AliTPCtrackerParam(const Int_t coll,const Double_t Bz) 
45 {
46   fColl = coll; // collision code (0: PbPb6000)
47   fBz = Bz;     // value of the z component of L3 field (Tesla)
48   
49 }
50 //-----------------------------------------------------------------
51 AliTPCtrackerParam::~AliTPCtrackerParam() 
52 {}
53 //-----------------------------------------------------------------
54
55 Int_t AliTPCtrackerParam::BuildTPCtracks(const TFile *inp, TFile *out, Int_t n)
56 {
57  
58   if(fColl!=0) { 
59     cerr<<"AliTPCtrackerParam::BuildTPCtracks:  Invalid collision!\n";
60     cerr<<"      Available:  0   ->   PbPb6000"<<endl; return 0; 
61   }
62   if(fBz!=0.4) {
63     cerr<<"AliTPCtrackerParam::BuildTPCtracks:  Invalid field!\n";
64     cerr<<"      Available:  0.4"<<endl; return 0;
65   }
66
67   TFile *infile=(TFile*)inp;
68
69   // Get gAlice object from file
70   if(!(gAlice=(AliRun*)infile->Get("gAlice"))) {
71     cerr<<"gAlice has not been found on galice.root !\n";
72     return 1;
73   }
74
75   AliMagFCM *fiel = (AliMagFCM*)gAlice->Field();
76   Double_t fieval=(Double_t)fiel->SolenoidField()/10.;
77   printf("Magnetic field is %6.2f Tesla\n",fieval);
78   if(fBz!=fieval) {
79     cerr<<"AliTPCtrackerParam::BuildTPCtracks:  Invalid field!"<<endl;
80     cerr<<"Field selected is: "<<fBz<<" T\n";
81     cerr<<"Field found on file is: "<<fieval<<" T\n";
82     return 0;
83   }
84
85   AliKalmanTrack::SetConvConst(100/0.299792458/fBz);
86
87
88   // loop over first n events in file
89   for(Int_t evt=0; evt<n; evt++){
90     cerr<<"+++\n+++ Processing event "<<evt<<"\n+++\n";
91
92     AliTPCtrack *tpctrack=0;
93
94     // tree for TPC tracks
95     Char_t tname[100];
96     sprintf(tname,"TreeT_TPC_%d",evt);
97     TTree *tracktree = new TTree(tname,"Tree with TPC tracks");
98     tracktree->Branch("tracks","AliTPCtrack",&tpctrack,20000,0);
99
100     // array for TPC tracks
101     TObjArray tarray(20000);
102
103
104     Int_t nparticles=gAlice->GetEvent(evt);   
105
106     Bool_t done[500000];
107     for(Int_t l=0; l<500000; l++) { done[l]=kFALSE; }
108
109
110     // Get TPC detector 
111     AliTPC *TPC=(AliTPC*)gAlice->GetDetector("TPC");
112     Int_t ver = TPC->IsVersion(); 
113     cerr<<"+++ TPC version "<<ver<<" has been found !\n";
114     AliTPCParam *digp=(AliTPCParam*)infile->Get("75x40_100x60");
115     if(!digp) { cerr<<"TPC parameters have not been found !\n"; return 1; }
116     TPC->SetParam(digp);
117
118     // Get TreeH with hits
119     TTree *TH=gAlice->TreeH(); 
120     Int_t ntracks=(Int_t)TH->GetEntries();
121     cerr<<"+++\n+++ Number of particles in event "<<evt<<":  "<<nparticles<<"\n+++\n+++ Number of \"primary tracks\" (entries in TreeH): "<<ntracks<<"\n+++\n\n";
122
123     TParticle* Part;
124     AliTPChit* tpcHit;
125     Double_t hPx,hPy,hPz,hPt,xg,yg,zg,xl,yl,zl;
126     Double_t Alpha;
127     Float_t cosAlpha,sinAlpha;
128     Int_t label,Pdg,charge,bin;
129     Int_t tracks=0;
130     //Int_t N1=0,N2=0;
131
132     // loop over entries in TreeH
133     for(Int_t i=0; i<ntracks; i++) {
134       if(i%1000==0) cerr<<"  --- Processing primary track "<<i<<" of "<<ntracks<<" ---\r";
135       TPC->ResetHits();
136       TH->GetEvent(i);
137       // Get FirstHit
138       tpcHit=(AliTPChit*)TPC->FirstHit(-1);
139       for( ; tpcHit; tpcHit=(AliTPChit*)TPC->NextHit() ) {
140         if(tpcHit->fQ !=0.) continue;
141         // Get particle momentum at hit
142         hPx=tpcHit->X(); hPy=tpcHit->Y(); hPz=tpcHit->Z();
143         hPt=TMath::Sqrt(hPx*hPx+hPy*hPy);
144         // reject hits with Pt<mag*0.45 GeV/c
145         if(hPt<(fBz*0.45)) continue;
146
147         // Get track label
148         label=tpcHit->Track();
149         // check if this track has already been processed
150         if(done[label]) continue;
151         // electric charge
152         Part = gAlice->Particle(label);
153         Pdg = Part->GetPdgCode();
154         if(Pdg>200 || Pdg==-11 || Pdg==-13) { charge=1; }
155         else if(Pdg<-200 || Pdg==11 || Pdg==13) { charge=-1; }
156         else continue;
157
158
159         if((tpcHit=(AliTPChit*)TPC->NextHit())==0) break;
160         if(tpcHit->fQ != 0.) continue;
161         // Get global coordinates of hit
162         xg=tpcHit->X(); yg=tpcHit->Y(); zg=tpcHit->Z();
163         if(TMath::Sqrt(xg*xg+yg*yg)>90.) continue;
164
165         // Get TPC sector, Alpha angle and local coordinates
166         // printf("Sector %d\n",tpcHit->fSector);
167         digp->AdjustCosSin(tpcHit->fSector,cosAlpha,sinAlpha);
168         Alpha = TMath::ATan2(sinAlpha,cosAlpha);
169         xl = xg*cosAlpha + yg*sinAlpha;
170         yl =-xg*sinAlpha + yg*cosAlpha;
171         zl = zg;
172         //printf("Alpha %f   xl %f  yl %f  zl %f\n",Alpha,xl,yl,zl);
173
174         // reject tracks which are not in the TPC acceptance
175         if(TMath::Abs(zl+(244.-xl)*hPz/hPt)>252.) continue;
176
177         // Get bin in pT,eta
178         bin = GetBin(hPt,Part->Eta());
179
180         // Apply selection according to TPC efficiency
181         //if(abs(Pdg)==211) N1++;
182         if(!SelectedTrack(Pdg,hPt,Part->Eta())) continue; 
183         //if(abs(Pdg)==211) N2++;
184
185         // Mark track as "done"
186         done[label]=kTRUE; tracks++;
187  
188         // create AliTPCtrack object
189         tpctrack = BuildTrack(Alpha,xl,yl,zl,hPx,hPy,hPz,hPt,charge,label);
190
191         // put track in array
192         tarray.AddLast(tpctrack);
193
194       }
195  
196     } // loop over entries in TreeH
197
198     TObjArray newtarray(20000);
199
200     // assing covariance matrixes and smear track parameters
201     CookTracks(tarray,newtarray);
202
203     // sort array with TPC tracks (decreasing pT)
204     newtarray.Sort();
205
206
207     Int_t arrentr = newtarray.GetEntriesFast();
208     //printf("\n  %d  \n\n",arrentr);
209     for(Int_t l=0; l<arrentr; l++) {
210       tpctrack=(AliTPCtrack*)newtarray.UncheckedAt(l);
211       tracktree->Fill();
212     }
213
214     // write the tree with tracks in the output file
215     out->cd();
216     tracktree->Write();
217
218     delete tracktree;
219
220     printf("\n\n+++\n+++ Number of TPC tracks: %d\n+++\n",tracks);
221     //printf("Average Eff: %f\n",(Float_t)N2/N1);
222
223   } // loop on events
224
225   return 0;
226 }
227
228 //-----------------------------------------------------------------
229 AliTPCtrack* AliTPCtrackerParam::BuildTrack(Double_t alpha,Double_t x,
230                                             Double_t y,Double_t z,Double_t Px,
231                                             Double_t Py,Double_t Pz,Double_t Pt,
232                                             Int_t ch,Int_t lab) 
233 {  
234   Double_t xref = x;
235   Double_t xx[5],cc[15];
236   cc[0]=cc[2]=cc[5]=cc[9]=cc[14]=10.;
237   cc[1]=cc[3]=cc[4]=cc[6]=cc[7]=cc[8]=cc[10]=cc[11]=cc[12]=cc[13]=0.;
238   
239   // Magnetic field
240   TVector3 Bfield(0.,0.,fBz);
241   
242   
243   // radius [cm] of track projection in (x,y) 
244   Double_t rho = Pt*100/0.299792458/Bfield.Z();
245   // center of track projection in local reference frame
246   TVector3 MomH,PosH;
247
248
249   // position (local) and momentum (local) at the hit
250   // in the bending plane (z=0)
251   PosH.SetXYZ(x,y,0.);
252   MomH.SetXYZ(Px*TMath::Cos(alpha)+Py*TMath::Sin(alpha),-Px*TMath::Sin(alpha)+Py*TMath::Cos(alpha),0.);
253   TVector3 Vrho = MomH.Cross(Bfield);
254   Vrho *= ch;
255   Vrho.SetMag(rho);
256
257   TVector3 Vcenter = PosH+Vrho;
258
259   Double_t x0 = Vcenter.X();
260
261   // fX     = xref         X-coordinate of this track (reference plane)
262   // fAlpha = Alpha        Rotation angle the local (TPC sector) 
263   // fP0    = YL           Y-coordinate of a track
264   // fP1    = ZG           Z-coordinate of a track
265   // fP2    = C*x0         x0 is center x in rotated frame
266   // fP3    = Tgl          tangent of the track momentum dip angle
267   // fP4    = C            track curvature
268   xx[0] = y;
269   xx[1] = z;
270   xx[3] = Pz/Pt;
271   xx[4] = -ch/rho;
272   xx[2] = xx[4]*x0;
273
274   // create the object AliTPCtrack    
275   AliTPCtrack* track = new AliTPCtrack(0,xx,cc,xref,alpha);
276   // set the label
277   track->SetLabel(lab);
278
279   return track;
280 }
281
282 //-----------------------------------------------------------------
283 Bool_t AliTPCtrackerParam::SelectedTrack(Int_t pdg,Double_t pt,Double_t eta) 
284 {
285   Double_t eff=0.;
286   
287   //eff computed with | zl+(244-xl)*pz/pt | < 252
288   Double_t effPi[27] = {0.724587,0.743389,0.619273,0.798477,0.812036,0.823195,0.771437,0.775826,0.784136,0.809071,0.762001,0.774576,0.848834,0.787201,0.792548,0.942089,0.951631,0.951085,0.960885,0.971451,0.969103,0.983245,0.978939,0.988706,0.990852,0.985679,0.993606};
289   Double_t effK[18]  = {0.377934,0.363962,0.321721,0.518784,0.547459,0.517878,0.612704,0.619101,0.620894,0.733411,0.732128,0.750373,0.790630,0.806565,0.791353,0.967486,0.970483,0.974527};
290   Double_t effP[15]  = {0.131173,0.165114,0.229658,0.365357,0.412989,0.483297,0.454614,0.505173,0.658615,0.694753,0.730661,0.815680,0.873461,0.887227,0.899324};
291   Double_t effEl[15] = {0.835549,0.853746,0.718207,0.835230,0.831489,0.862222,0.757783,0.747301,0.824096,0.867949,0.871891,0.808480,0.890625,0.911765,0.973684};
292   Double_t effMu[15] = {0.553486,0.641392,0.609932,0.591126,0.706729,0.750755,0.747952,0.729051,0.760849,0.898810,0.737500,0.830357,0.735294,0.800000,0.882353};
293  
294
295   if(TMath::Abs(pdg)==211)  eff = LinearInterpolation(9,effPi,pt,eta);
296   if(TMath::Abs(pdg)==321)  eff = LinearInterpolation(6,effK,pt,eta);
297   if(TMath::Abs(pdg)==2212) eff = LinearInterpolation(5,effP,pt,eta);
298   if(TMath::Abs(pdg)==11)   eff = LinearInterpolation(5,effEl,pt,eta);
299   if(TMath::Abs(pdg)==13)   eff = LinearInterpolation(5,effMu,pt,eta);
300
301   if(gRandom->Rndm() < eff) return kTRUE;
302
303   return kFALSE;
304 }
305
306 //-----------------------------------------------------------------
307 Double_t AliTPCtrackerParam::LinearInterpolation(Int_t ptBins,Double_t *value,
308                                                  Double_t pt,Double_t eta) 
309 {
310   Double_t kValue=0,kValue1=0,kValue2=0;
311   Int_t kEtaSide = (TMath::Abs(eta)<.45 ? 0 : 1);
312   Double_t kEta[3]={0.15,0.45,0.75};
313   Double_t kPt[9]={0.244,0.390,0.676,1.190,2.36,4.,6.,10.,20.};
314   if(ptBins==6) kPt[5]=10.;
315
316   for(Int_t i=0; i<ptBins; i++) {
317     if(pt<kPt[i]) {
318       if(i==0) i=1;
319       kValue1 = value[3*i-3+kEtaSide]+(value[3*i-3+kEtaSide]-value[3*i+kEtaSide])/(kPt[i-1]-kPt[i])*(pt-kPt[i-1]);
320       kValue2 = value[3*i-3+kEtaSide+1]+(value[3*i-3+kEtaSide+1]-value[3*i+kEtaSide+1])/(kPt[i-1]-kPt[i])*(pt-kPt[i-1]);
321
322       kValue = kValue1+(kValue1-kValue2)/(kEta[kEtaSide]-kEta[kEtaSide+1])*(eta-kEta[kEtaSide]);
323       break;
324     }
325     if(i==ptBins-1) { 
326       i=ptBins-2;
327       kValue1 = value[3*i-3+kEtaSide]+(value[3*i-3+kEtaSide]-value[3*i+kEtaSide])/(kPt[i-1]-kPt[i])*(pt-kPt[i-1]);
328       kValue2 = value[3*i-3+kEtaSide+1]+(value[3*i-3+kEtaSide+1]-value[3*i+kEtaSide+1])/(kPt[i-1]-kPt[i])*(pt-kPt[i-1]);
329
330       kValue = kValue1+(kValue1-kValue2)/(kEta[kEtaSide]-kEta[kEtaSide+1])*(eta-kEta[kEtaSide]);
331       break;
332     }
333   }
334
335   return kValue;
336 }
337
338 //-----------------------------------------------------------------
339 Int_t AliTPCtrackerParam::GetBin(Double_t pt,Double_t eta) {
340
341   if(TMath::Abs(eta)<0.3) {
342     if(pt<0.3)            return 0;
343     if(pt>=0.3 && pt<0.5) return 3;
344     if(pt>=0.5 && pt<1.)  return 6;
345     if(pt>=1. && pt<1.5)  return 9;
346     if(pt>=1.5 && pt<3.)  return 12;
347     if(pt>=3. && pt<5.)   return 15;
348     if(pt>=5. && pt<7.)   return 18;
349     if(pt>=7. && pt<15.)  return 21;
350     if(pt>=15.)           return 24;
351   }
352   if(TMath::Abs(eta)>=0.3 && TMath::Abs(eta)<0.6) {
353     if(pt<0.3)            return 1;
354     if(pt>=0.3 && pt<0.5) return 4;
355     if(pt>=0.5 && pt<1.)  return 7;
356     if(pt>=1. && pt<1.5)  return 10;
357     if(pt>=1.5 && pt<3.)  return 13;
358     if(pt>=3. && pt<5.)   return 16;
359     if(pt>=5. && pt<7.)   return 19;
360     if(pt>=7. && pt<15.)  return 22;
361     if(pt>=15.)           return 25;
362   }
363   if(TMath::Abs(eta)>=0.6) {
364     if(pt<0.3)            return 2;
365     if(pt>=0.3 && pt<0.5) return 5;
366     if(pt>=0.5 && pt<1.)  return 8;
367     if(pt>=1. && pt<1.5)  return 11;
368     if(pt>=1.5 && pt<3.)  return 14;
369     if(pt>=3. && pt<5.)   return 17;
370     if(pt>=5. && pt<7.)   return 20;
371     if(pt>=7. && pt<15.)  return 23;
372     if(pt>=15.)           return 26;
373   }
374
375   return -1;
376
377 }
378
379 //-----------------------------------------------------------------
380
381 TMatrixD AliTPCtrackerParam::GetSmearingMatrix(Double_t* cc,Double_t pt,Double_t eta) 
382 {
383   TMatrixD CovMat(5,5);
384
385   CovMat(0,0)=cc[0];
386   CovMat(1,0)=cc[1];  CovMat(0,1)=CovMat(1,0);
387   CovMat(1,1)=cc[2];
388   CovMat(2,0)=cc[3];  CovMat(0,2)=CovMat(2,0);
389   CovMat(2,1)=cc[4];  CovMat(1,2)=CovMat(2,1);
390   CovMat(2,2)=cc[5];
391   CovMat(3,0)=cc[6];  CovMat(0,3)=CovMat(3,0);
392   CovMat(3,1)=cc[7];  CovMat(1,3)=CovMat(3,1);
393   CovMat(3,2)=cc[8];  CovMat(2,3)=CovMat(3,2);
394   CovMat(3,3)=cc[9];
395   CovMat(4,0)=cc[10]; CovMat(0,4)=CovMat(4,0);
396   CovMat(4,1)=cc[11]; CovMat(1,4)=CovMat(4,1);
397   CovMat(4,2)=cc[12]; CovMat(2,4)=CovMat(4,2);
398   CovMat(4,3)=cc[13]; CovMat(3,4)=CovMat(4,3);
399   CovMat(4,4)=cc[14];
400
401   TMatrixD ScaleMat(5,5);
402   for(Int_t k=0;k<5;k++) {
403     for(Int_t l=0;l<5;l++) {
404       ScaleMat(k,l)=0.;
405     }
406   }
407
408   
409   Double_t s00[27]={1.3553,1.2973,1.2446,1.3428,1.3031,1.2345,1.3244,1.2681,1.2046,1.3046,1.2430,1.1606,1.2462,1.2104,1.1082,1.2207,1.1189,1.0789,1.2079,1.1300,1.0426,1.1502,1.1122,1.0559,1.1419,1.1072,1.0208};
410   Double_t s11[27]={1.0890,1.1463,1.2313,1.1149,1.1597,1.2280,1.1225,1.1584,1.2329,1.1149,1.1550,1.2369,1.1095,1.1353,1.2050,1.0649,1.0858,1.1546,1.0663,1.0672,1.1340,1.0416,1.0738,1.0945,1.0663,1.0654,1.0909};
411   Double_t s22[27]={1.1709,1.1367,1.0932,1.2247,1.1832,1.1247,1.2470,1.2017,1.1441,1.2202,1.1653,1.1050,1.1819,1.1269,1.0583,1.1546,1.0621,0.9928,1.1305,1.0512,0.9576,1.0995,1.0445,0.9884,1.0968,1.0368,0.9574};
412   Double_t s33[27]={0.9720,0.9869,1.0271,1.0030,1.0223,1.0479,1.0164,1.0305,1.0559,1.0339,1.0450,1.0686,1.0450,1.0507,1.0784,1.0334,1.0208,1.0863,1.0252,1.0114,1.0835,0.9854,1.0144,1.0507,1.0124,1.0159,1.0464};
413   Double_t s44[27]={1.1104,1.0789,1.0479,1.1597,1.1234,1.0728,1.2087,1.1602,1.1041,1.1942,1.1428,1.0831,1.1572,1.1036,1.0431,1.1296,1.0498,0.9844,1.1145,1.0266,0.9489,1.0959,1.0450,0.9875,1.0775,1.0266,0.9406};
414
415
416   ScaleMat(0,0) = LinearInterpolation(9,s00,pt,eta); 
417   ScaleMat(1,1) = LinearInterpolation(9,s11,pt,eta); 
418   ScaleMat(2,2) = LinearInterpolation(9,s22,pt,eta); 
419   ScaleMat(3,3) = LinearInterpolation(9,s33,pt,eta); 
420   ScaleMat(4,4) = LinearInterpolation(9,s44,pt,eta); 
421
422   TMatrixD Mat(ScaleMat,TMatrixD::kMult,CovMat);
423   TMatrixD CovMatSmear(Mat,TMatrixD::kMult,ScaleMat);
424
425
426   return CovMatSmear;
427 }
428
429 //-----------------------------------------------------------------
430 void AliTPCtrackerParam::SmearTrack(Double_t* xx,Double_t* xxsm,TMatrixD cov) {
431
432   AliGausCorr *corgen = new AliGausCorr(cov,5);
433   TArrayD corr(5);
434   corgen->GetGaussN(corr);
435   delete corgen;
436   corgen = 0;
437
438   for(Int_t l=0;l<5;l++) {
439     xxsm[l] = xx[l]+corr[l];
440   }
441
442   return;
443 }
444
445 //-----------------------------------------------------------------
446 void AliTPCtrackerParam::CookTracks(TObjArray& tarray,TObjArray& newtarray) 
447 {
448   TString* s = new TString("$ALICE_ROOT/TPC/CovMatrixDB_");
449   if(fColl==0) s->Append("PbPb6000");
450   if(fBz==0.4) s->Append("_B0.4T.root");  
451   // open file with matrixes DB
452   TFile* DBfile = new TFile(s->Data());  
453
454   AliTPCtrack* track = 0;
455   Int_t entr = (Int_t)tarray.GetEntriesFast();
456
457   for(Int_t k=0; k<entr; k++) {
458     track=(AliTPCtrack*)tarray.UncheckedAt(k);  
459
460     Double_t pt = 1/TMath::Abs(track->Get1Pt());
461     Double_t eta = -TMath::Log(TMath::Tan(0.25*TMath::Pi()-0.5*TMath::ATan(track->GetTgl())));
462
463     Int_t bin = GetBin(pt,eta);
464
465     // string with tree name
466     TString str("Tree_bin");
467     str+=bin;
468  
469     // get the right tree
470     TTree* CovTree = (TTree*)DBfile->Get(str.Data());
471     TArrayF* matrix = new TArrayF; 
472     CovTree->SetBranchAddress("matrixes",&matrix);
473
474     // get random entry from the tree
475     Int_t Entries = (Int_t)CovTree->GetEntries();
476     CovTree->GetEvent(gRandom->Integer(Entries));
477
478     Double_t xref,alpha,xx[5],xxsm[5],cc[15];
479     Int_t lab;
480     // get P and Cosl from track
481     Double_t Cosl = TMath::Cos(TMath::ATan(track->GetTgl()));
482     Double_t P = 1/TMath::Abs(track->Get1Pt())/Cosl;
483     
484     // get covariance matrix from regularized matrix
485     cc[0]=matrix->At(0)*(1.588e-3+1.911e-4/TMath::Power(P,1.5));
486     cc[1]=matrix->At(1);
487     cc[2]=matrix->At(2)*(1.195e-3+0.8102e-3/P);
488     cc[3]=matrix->At(3)*(7.275e-5+1.181e-5/TMath::Power(P,1.5));
489     cc[4]=matrix->At(4);
490     cc[5]=matrix->At(5)*(5.163e-6+1.138e-6/TMath::Power(P,2.)/Cosl);
491     cc[6]=matrix->At(6);
492     cc[7]=matrix->At(7)*(1.176e-5+1.175e-5/TMath::Power(P,1.5)/Cosl/Cosl/Cosl);
493     cc[8]=matrix->At(8);
494     cc[9]=matrix->At(9)*(1.289e-7+4.636e-7/TMath::Power(P,1.7)/Cosl/Cosl/Cosl/Cosl);
495     cc[10]=matrix->At(10)*(4.056e-7+4.379e-8/TMath::Power(P,1.5));
496     cc[11]=matrix->At(11);
497     cc[12]=matrix->At(12)*(3.049e-8+8.244e-9/TMath::Power(P,2.)/Cosl);
498     cc[13]=matrix->At(13);
499     cc[14]=matrix->At(14)*(1.847e-10+5.822e-11/TMath::Power(P,2.)/Cosl/Cosl/Cosl);
500   
501     TMatrixD CovMatSmear(5,5);
502     
503     CovMatSmear = GetSmearingMatrix(cc,pt,eta);
504
505     // get track original parameters
506     xref=track->GetX();
507     alpha=track->GetAlpha();
508     xx[0]=track->GetY();
509     xx[1]=track->GetZ();
510     xx[2]=track->GetX()*track->GetC()-track->GetSnp();
511     xx[3]=track->GetTgl();
512     xx[4]=track->GetC();
513     lab=track->GetLabel();
514
515     // use smearing matrix to smear the original parameters
516     SmearTrack(xx,xxsm,CovMatSmear);
517
518     AliTPCtrack* tpctrack = new AliTPCtrack(0,xxsm,cc,xref,alpha);
519     tpctrack->SetLabel(lab);
520
521     // fill the array
522     newtarray.AddLast(tpctrack);
523  
524    delete matrix;  
525
526   }
527
528   DBfile->Close();
529
530   delete s;
531   delete DBfile;
532
533
534   return; 
535 }
536 //-----------------------------------------------------------------
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