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 // This is a TTask that made the calculation of the Time zero using TOF.
18 // Description: The algorithm used to calculate the time zero of interaction
19 // using TOF detector is the following.
20 // We select in the MonteCarlo some primary particles - or tracks in the following -
21 // that strike the TOF detector (the larger part are pions, kaons or protons).
22 // We choose a set of 10 selected tracks, for each track You have the length
23 // of the track when the TOF is reached (a standard TOF hit does not contain this
24 // additional information, this is the reason why we implemented a new time zero
25 // dedicated TOF hit class AliTOFhitT0; in order to store this type of hit You
26 // have to use the AliTOFv4T0 as TOF class in Your Config.C. In AliTOFv4T0 the
27 // StepManager was modified in order to fill the TOF hit branch with this type
28 // of hits; in fact the AliTOF::AddT0Hit is called rather that the usual AliTOF::AddHit),
29 // the momentum at generation (from TreeK) and the time of flight
30 // given by the TOF detector.
31 // (Observe that the ctor of the AliTOF class, when the AliTOFv4T0 class is used, is called
32 // with the "tzero" option: it is in order create the fHits TClonesArray filled with
33 // AliTOFhitT0 objects, rather than with normal AliTOFhit)
34 // Then Momentum and time of flight for each track are smeared according to
35 // known experimental resolution (all sources of error have been token into account).
36 // Let consider now only one set of 10 tracks (the algorithm is the same for all sets).
37 // Assuming the (mass) hypothesis that each track can be AUT a pion, AUT a kaon, AUT a proton,
38 // we consider all the 3 at 10 possible cases.
39 // For each track in each (mass) configuration
40 // (a configuration can be e.g. pion/pion/kaon/proton/pion/proton/kaon/kaon/pion/pion)
41 // we calculate the time zero (we know in fact the velocity of the track after
42 // the assumption about its mass, the time of flight given by the TOF, and the
43 // corresponding path travelled till the TOF detector). Then for each mass configuration we have
44 // 10 time zero and we can calculate the ChiSquare for the current configuration using the
45 // weighted mean over all 10 time zero.
46 // We call the best assignment the mass configuration that gives the minimum value of the ChiSquare.
47 // We plot the weighted mean over all 10 time zero for the best assignment,
48 // the ChiSquare for the best assignment and the corresponding confidence level.
49 // The strong assumption is the MC selection of primary particles. It will be introduced
50 // in the future also some more realistic simulation about this point.
52 // root [0] AliTOFT0 * tzero = new AliTOFT0("galice.root")
53 // Warning in <TDatabasePDG::TDatabasePDG>: object already instantiated
54 // root [1] tzero->ExecuteTask()
55 // root [2] tzero->ExecuteTask("tim")
56 // // available parameters:
57 // tim - print benchmarking information
58 // all - print usefull informations about the number of misidentified tracks
59 // and a comparison about the true configuration (known from MC) and the best
61 //-- Author: F. Pierella
62 //////////////////////////////////////////////////////////////////////////////
65 #include "AliTOFhitT0.h"
67 #include "AliTOFv4T0.h"
69 #include "AliDetector.h"
81 #include "TBenchmark.h"
82 #include "TParticle.h"
83 #include "TClonesArray.h"
91 //____________________________________________________________________________
92 AliTOFT0::AliTOFT0():TTask("AliTOFT0","")
100 //____________________________________________________________________________
101 AliTOFT0::AliTOFT0(char* headerFile, Int_t nEvents):TTask("AliTOFT0","")
103 fNevents=nEvents ; // Number of events for which calculate the T0,
104 // default 0: it means all evens in current file
105 fLowerMomBound=1.5; // [GeV/c] default value
106 fUpperMomBound=2. ; // [GeV/c] default value
107 fTimeResolution = 1.2e-10; // 120 ps by default
108 fHeadersFile = headerFile ;
111 TFile * file = (TFile*) gROOT->GetFile(fHeadersFile.Data() ) ;
113 //File was not opened yet
115 if(fHeadersFile.Contains("rfio"))
116 file = TFile::Open(fHeadersFile,"update") ;
118 file = new TFile(fHeadersFile.Data(),"update") ;
119 gAlice = (AliRun *) file->Get("gAlice") ;
122 // add Task to //root/Tasks folder
123 TTask * roottasks = (TTask*)gROOT->GetRootFolder()->FindObject("Tasks") ;
124 roottasks->Add(this) ;
127 //____________________________________________________________________________
128 AliTOFT0::~AliTOFT0()
133 //____________________________________________________________________________
134 void AliTOFT0::Exec(Option_t *option)
137 // calculate T0 distribution for all events using chisquare
140 Int_t nmisidentified=0;
141 Int_t nmisidentified0=0;
142 Int_t nmisidentified1=0;
143 Int_t nmisidentified2=0;
144 Int_t nmisidentified3=0;
145 Int_t nmisidentified4=0;
146 Int_t nmisidentified5=0;
147 Int_t nmisidentified6=0;
148 Int_t nmisidentified7=0;
149 Int_t nmisidentified8=0;
150 Int_t nmisidentified9=0;
155 Float_t timeresolutioninns=fTimeResolution*(1.e+9); // convert in [ns]
156 const Int_t kUPDATE = 5; // for visual option
162 if(strstr(option,"visual")){
163 // Create a new canvas.
164 //c1 = new TCanvas("c1","Dynamic Visual Filling of time zero histo",10,10,500,500);
165 c1 = new TCanvas("c1","Dynamic Visual Filling of time zero histo",10,10,370,370);
166 c1->SetFillColor(35);
167 c1->GetFrame()->SetFillColor(21);
168 c1->GetFrame()->SetBorderSize(6);
169 c1->GetFrame()->SetBorderMode(-1);
171 //c2 = new TCanvas("c2","Dynamic Visual Filling of chisquare histo",550,10,500,500);
172 c2 = new TCanvas("c2","Dynamic Visual Filling of chisquare histo",380,10,370,370);
173 c2->SetFillColor(35);
174 c2->GetFrame()->SetFillColor(21);
175 c2->GetFrame()->SetBorderSize(6);
176 c2->GetFrame()->SetBorderMode(-1);
178 //c3 = new TCanvas("c3","Dynamic Visual Filling of confidence level histo",280,550,500,500);
179 c3 = new TCanvas("c3","Dynamic Visual Filling of confidence level histo",760,10,370,370);
180 c3->SetFillColor(35);
181 c3->GetFrame()->SetFillColor(21);
182 c3->GetFrame()->SetBorderSize(6);
183 c3->GetFrame()->SetBorderMode(-1);
186 if(strstr(option,"tim") || strstr(option,"all"))
187 gBenchmark->Start("TOFT0");
189 TH1F *htzerobest= new TH1F("htzerobest","T0 for best assignment",200,-1.,1.);
190 TH1F* hchibest = new TH1F("hchibest","ChiSquare Min Distribution",80,0.,40.);
191 TH1F* hchibestconflevel = new TH1F("hchibestconflevel","ChiSquare Min Confidence Level",10,0.,1.);
193 // setting histo colors
194 if(strstr(option,"visual")){
195 htzerobest->SetFillColor(48);
196 hchibest->SetFillColor(50);
197 hchibestconflevel->SetFillColor(52);
200 Int_t assparticle[10]={3,3,3,3,3,3,3,3,3,3};
201 Int_t truparticle[10]={3,3,3,3,3,3,3,3,3,3};
203 Float_t timeofflight[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
204 Float_t momentum[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
205 Float_t timezero[10];
206 Float_t weightedtimezero[10];
207 Float_t beta[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
208 Float_t sqMomError[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
209 Float_t sqTrackError[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
210 Float_t massarray[3]={0.13957,0.493677,0.9382723};
211 Float_t dummychisquare=0.;
212 Float_t chisquare=999.;
213 Float_t tracktoflen[10]={0.,0.,0.,0.,0.,0.,0.,0.,0.,0.};
215 AliTOF *TOF = (AliTOF *) gAlice->GetDetector ("TOF");
218 Error("AliTOFT0","TOF not found");
222 if(strstr(option,"all")){
223 cout << "Selecting primary tracks with momentum between " << fLowerMomBound << " GeV/c and " << fUpperMomBound << " GeV/c" << endl;
224 cout << "Memorandum: 0 means PION | 1 means KAON | 2 means PROTON" << endl;
227 if (fNevents == 0) fNevents = (Int_t) gAlice->TreeE()->GetEntries();
229 for (Int_t ievent = 0; ievent < fNevents; ievent++) {
230 gAlice->GetEvent(ievent);
231 TTree *TH = gAlice->TreeH ();
236 TClonesArray* TOFhits = TOF->Hits();
240 // Start loop on primary tracks in the hits containers
242 Int_t ntracks = static_cast<Int_t>(TH->GetEntries());
243 for (Int_t track = 0; track < ntracks; track++)
245 if(nset>=5) break; // check on the number of set analyzed
249 particle = gAlice->Particle(track);
250 Int_t nhits = TOFhits->GetEntriesFast();
252 for (Int_t hit = 0; hit < nhits; hit++)
254 tofHit = (AliTOFhitT0 *) TOFhits->UncheckedAt(hit);
255 ipart = tofHit->GetTrack();
256 // check to discard the case when the same particle is selected more than one
259 if (ipart != ipartold){
261 particle = (TParticle*)gAlice->Particle(ipart);
263 Float_t idealtime=tofHit->GetTof();
264 // Float_t time=idealtime;
265 Float_t time = gRandom->Gaus(idealtime, fTimeResolution);
266 Float_t toflen=tofHit->GetLen();
267 toflen=toflen/100.; // toflen given in m
268 Int_t pdg = particle->GetPdgCode();
269 Int_t abspdg =TMath::Abs(pdg);
270 Float_t idealmom = particle->P();
271 Float_t momres=idealmom*0.025; // 2.5% res token into account for all momenta
272 Float_t mom =gRandom->Gaus(idealmom,momres);
274 Bool_t isgoodpart=(abspdg==211 || abspdg==2212 || abspdg==321);
276 time*=1.E+9; // tof given in nanoseconds
277 if (particle->GetFirstMother() < 0 && isgoodpart && mom<=fUpperMomBound && mom>=fLowerMomBound){
281 Int_t index=selected-1;
282 timeofflight[index]=time;
283 tracktoflen[index]=toflen;
285 // cout << timeofflight[index] << " " << tracktoflen[index] << " " << momentum[index] << endl;
288 truparticle[index]=0;
291 truparticle[index]=1;
294 truparticle[index]=2;
301 if(istop==10){ // start analysis on current set
306 //cout << "starting t0 calculation for current set" << endl;
307 for (Int_t i1=0; i1<3;i1++) {
308 for (Int_t i2=0; i2<3;i2++) {
309 for (Int_t i3=0; i3<3;i3++) {
310 for (Int_t i4=0; i4<3;i4++) {
311 for (Int_t i5=0; i5<3;i5++) {
312 for (Int_t i6=0; i6<3;i6++) {
313 for (Int_t i7=0; i7<3;i7++) {
314 for (Int_t i8=0; i8<3;i8++) {
315 for (Int_t i9=0; i9<3;i9++) {
316 for (Int_t i10=0; i10<3;i10++) {
318 beta[0]=momentum[0]/sqrt(massarray[i1]*massarray[i1]+momentum[0]*momentum[0]);
319 beta[1]=momentum[1]/sqrt(massarray[i2]*massarray[i2]+momentum[1]*momentum[1]);
320 beta[2]=momentum[2]/sqrt(massarray[i3]*massarray[i3]+momentum[2]*momentum[2]);
321 beta[3]=momentum[3]/sqrt(massarray[i4]*massarray[i4]+momentum[3]*momentum[3]);
322 beta[4]=momentum[4]/sqrt(massarray[i5]*massarray[i5]+momentum[4]*momentum[4]);
323 beta[5]=momentum[5]/sqrt(massarray[i6]*massarray[i6]+momentum[5]*momentum[5]);
324 beta[6]=momentum[6]/sqrt(massarray[i7]*massarray[i7]+momentum[6]*momentum[6]);
325 beta[7]=momentum[7]/sqrt(massarray[i8]*massarray[i8]+momentum[7]*momentum[7]);
326 beta[8]=momentum[8]/sqrt(massarray[i9]*massarray[i9]+momentum[8]*momentum[8]);
327 beta[9]=momentum[9]/sqrt(massarray[i10]*massarray[i10]+momentum[9]*momentum[9]);
330 Float_t meantzero=0.;
331 Float_t sumAllweights=0.;
332 for (Int_t itz=0; itz<10;itz++) {
333 sqMomError[itz]=((1.-beta[itz]*beta[itz])*0.025)*((1.-beta[itz]*beta[itz])*0.025)*(tracktoflen[itz]/(0.299792*beta[itz]))*(tracktoflen[itz]/(0.299792*beta[itz])); // this gives the square of the momentum error in nanoseconds
334 sqTrackError[itz]=(timeresolutioninns*timeresolutioninns+sqMomError[itz]); // total error for the current track
335 sumAllweights+=1./sqTrackError[itz];
336 // redefining beta, it is useful in order to calculate t zero
338 timezero[itz]=(tracktoflen[itz]/beta[itz])-timeofflight[itz];
339 weightedtimezero[itz]=((tracktoflen[itz]/beta[itz])-timeofflight[itz])/sqTrackError[itz];// weighted time zero for current track
340 meantzero+=weightedtimezero[itz];
341 } // end loop for (Int_t itz=0; itz<10;itz++)
342 meantzero=meantzero/sumAllweights; // it is given in [ns]
345 // calculate the chisquare for the current assignment
346 for (Int_t icsq=0; icsq<10;icsq++) {
347 dummychisquare+=(timezero[icsq]-meantzero)*(timezero[icsq]-meantzero)/sqTrackError[icsq];
348 } // end loop for (Int_t icsq=0; icsq<10;icsq++)
350 if(dummychisquare<=chisquare){
361 chisquare=dummychisquare;
363 } // close if(dummychisquare<=chisquare)
376 if(truparticle[0]==assparticle[0] && truparticle[1]==assparticle[1] && truparticle[2]==assparticle[2] && truparticle[3]==assparticle[3] && truparticle[4]==assparticle[4]&& truparticle[5]==assparticle[5] && truparticle[6]==assparticle[6] && truparticle[7]==assparticle[7] && truparticle[8]==assparticle[8] && truparticle[9]==assparticle[9]) ngood+=1;
377 if(truparticle[0]!=assparticle[0]) nmisidentified0+=1;
378 if(truparticle[1]!=assparticle[1]) nmisidentified1+=1;
379 if(truparticle[2]!=assparticle[2]) nmisidentified2+=1;
380 if(truparticle[3]!=assparticle[3]) nmisidentified3+=1;
381 if(truparticle[4]!=assparticle[4]) nmisidentified4+=1;
382 if(truparticle[5]!=assparticle[5]) nmisidentified5+=1;
383 if(truparticle[6]!=assparticle[6]) nmisidentified6+=1;
384 if(truparticle[7]!=assparticle[7]) nmisidentified7+=1;
385 if(truparticle[8]!=assparticle[8]) nmisidentified8+=1;
386 if(truparticle[9]!=assparticle[9]) nmisidentified9+=1;
388 htzerobest->Fill(t0best);
389 hchibest->Fill(chisquare);
390 Double_t dblechisquare=(Double_t)chisquare;
391 Float_t confLevel=(Float_t)TMath::Prob(dblechisquare,9); // ndf 10-1=9
392 hchibestconflevel->Fill(confLevel);
394 if(strstr(option,"all")){
395 cout << "True Assignment " << truparticle[0] << truparticle[1] << truparticle[2] << truparticle[3] << truparticle[4] << truparticle[5] << truparticle[6] << truparticle[7] << truparticle[8] << truparticle[9] <<endl;
396 cout << "Best Assignment " << assparticle[0] << assparticle[1] << assparticle[2] << assparticle[3] << assparticle[4] << assparticle[5] << assparticle[6] << assparticle[7] << assparticle[8] << assparticle[9] << endl;
397 cout << "Minimum ChiSquare for current set " << chisquare << endl;
398 cout << "Confidence Level (Minimum ChiSquare) " << confLevel << endl;
400 if (strstr(option,"visual") && itimes && (itimes%kUPDATE) == 0) {
401 if (itimes == kUPDATE){
407 hchibestconflevel->Draw();
415 if (gSystem->ProcessEvents())
421 } // end for the current set. close if(istop==5)
422 } // end condition on ipartold
423 } // end loop on hits for the current track
425 } // end loop on ntracks
428 if(strstr(option,"all")){
429 nmisidentified=(nmisidentified0+nmisidentified1+nmisidentified2+nmisidentified3+nmisidentified4+nmisidentified5+nmisidentified6+nmisidentified7+nmisidentified8+nmisidentified9);
430 cout << "total number of tracks token into account " << 10*5*fNevents << endl;
431 Float_t badPercentage=100.*(Float_t)nmisidentified/(10*5*fNevents);
432 cout << "total misidentified " << nmisidentified << "("<< badPercentage << "%)" <<endl;
433 cout << "Total Number of set token into account " << 5*fNevents << endl;
434 Float_t goodSetPercentage=100.*(Float_t)ngood/(5*fNevents);
435 cout << "Number of set with no misidentified tracks " << ngood << "("<< goodSetPercentage << "%)" <<endl;
438 // free used memory for canvas
443 // generating output filename only if not previously specified using SetTZeroFile
444 char outFileName[70];
445 strcpy(outFileName,"ht010tr120ps"); // global time resolution has to be converted from Int_t to char
446 // in order to have in the output filename this parameter
447 strcat(outFileName,fHeadersFile);
449 if(fT0File.IsNull()) fT0File=outFileName;
451 TFile* houtfile = new TFile(fT0File,"recreate");
453 htzerobest->Write(0,TObject::kOverwrite);
454 hchibest->Write(0,TObject::kOverwrite);
455 hchibestconflevel->Write(0,TObject::kOverwrite);
459 if(strstr(option,"tim") || strstr(option,"all")){
460 gBenchmark->Stop("TOFT0");
461 cout << "AliTOFT0:" << endl ;
462 cout << " took " << gBenchmark->GetCpuTime("TOFT0") << " seconds in order to calculate T0 "
463 << gBenchmark->GetCpuTime("TOFT0")/fNevents << " seconds per event " << endl ;
468 //__________________________________________________________________
469 void AliTOFT0::SetTZeroFile(char * file ){
470 cout << "Destination file : " << file << endl ;
473 //__________________________________________________________________
474 void AliTOFT0::Print(Option_t* option)const
476 cout << "------------------- "<< GetName() << " -------------" << endl ;
477 if(!fT0File.IsNull())
478 cout << " Writing T0 Distribution to file " << (char*) fT0File.Data() << endl ;
481 //__________________________________________________________________
482 Bool_t AliTOFT0::operator==( AliTOFT0 const &tzero )const
487 if( (fTimeResolution==tzero.fTimeResolution)&&(fLowerMomBound==tzero.fLowerMomBound)&&(fUpperMomBound==tzero.fUpperMomBound))