1 /**************************************************************************
2 * Copyright(c) 2007-2009, 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 **************************************************************************/
18 #include "AliAODEvent.h"
19 #include "AliAODMCParticle.h"
20 #include "AliVertexingHFUtils.h"
24 ///////////////////////////////////////////////////////////////////
26 // Class with functions useful for different D2H analyses //
27 // - event plane resolution //
28 // - <pt> calculation with side band subtraction //
29 // - tracklet multiplicity calculation //
30 // Origin: F.Prino, Torino, prino@to.infn.it //
32 ///////////////////////////////////////////////////////////////////
34 ClassImp(AliVertexingHFUtils)
36 //______________________________________________________________________
37 AliVertexingHFUtils::AliVertexingHFUtils():TObject(),
40 fMinEtaForTracklets(-1.),
41 fMaxEtaForTracklets(1.)
47 //______________________________________________________________________
48 AliVertexingHFUtils::AliVertexingHFUtils(Int_t k):
52 fMinEtaForTracklets(-1.),
53 fMaxEtaForTracklets(1.)
55 // Standard constructor
59 //______________________________________________________________________
60 Double_t AliVertexingHFUtils::Pol(Double_t x, Int_t k){
61 // compute chi from polynomial approximation
64 c[0]=0.626657; c[1]=0.; c[2]=-0.09694; c[3]=0.02754; c[4]=-0.002283;
67 c[0]=0.; c[1]=0.25; c[2]=-0.011414; c[3]=-0.034726; c[4]=0.006815;
70 return c[0]*x+c[1]*x*x+c[2]*x*x*x+c[3]*x*x*x*x+c[4]*x*x*x*x*x;
73 //______________________________________________________________________
74 Double_t AliVertexingHFUtils:: ResolK1(Double_t x){
75 return TMath::Sqrt(TMath::Pi()/8)*x*TMath::Exp(-x*x/4)*(TMath::BesselI0(x*x/4)+TMath::BesselI1(x*x/4));
79 //______________________________________________________________________
80 Double_t AliVertexingHFUtils::FindChi(Double_t res, Int_t k){
81 // compute chi variable (=v2*sqrt(N)) from external values
96 if(y1*y2>0) return -1;
101 while((x2-x1)>0.0001){
106 ymed=ResolK1(xmed)-res;
111 ymed=Pol(xmed,2)-res;
114 if((y1*ymed)<0) x2=xmed;
115 if((y2*ymed)<0)x1=xmed;
116 if(ymed==0) return xmed;
122 //______________________________________________________________________
123 Double_t AliVertexingHFUtils::GetFullEvResol(Double_t resSub, Int_t k){
124 // computes event plane resolution starting from sub event resolution
125 Double_t chisub=FindChi(resSub,k);
126 Double_t chifull=chisub*TMath::Sqrt(2);
127 if(k==1) return ResolK1(chifull);
128 else if(k==2) return Pol(chifull,2);
130 printf("k should be <=2\n");
135 //______________________________________________________________________
136 Double_t AliVertexingHFUtils::GetFullEvResol(const TH1F* hSubEvCorr, Int_t k){
137 // computes event plane resolution starting from sub event correlation histogram
138 if(!hSubEvCorr) return 1.;
139 Double_t resSub=GetSubEvResol(hSubEvCorr);
140 return GetFullEvResol(resSub,k);
142 //______________________________________________________________________
143 Double_t AliVertexingHFUtils::GetFullEvResolLowLim(const TH1F* hSubEvCorr, Int_t k){
144 // computes low limit event plane resolution starting from sub event correlation histogram
145 if(!hSubEvCorr) return 1.;
146 Double_t resSub=GetSubEvResolLowLim(hSubEvCorr);
147 printf("%f\n",resSub);
148 return GetFullEvResol(resSub,k);
150 //______________________________________________________________________
151 Double_t AliVertexingHFUtils::GetFullEvResolHighLim(const TH1F* hSubEvCorr, Int_t k){
152 // computes high limit event plane resolution starting from sub event correlation histogram
153 if(!hSubEvCorr) return 1.;
154 Double_t resSub=GetSubEvResolHighLim(hSubEvCorr);
155 printf("%f\n",resSub);
156 return GetFullEvResol(resSub,k);
158 //______________________________________________________________________
159 Int_t AliVertexingHFUtils::GetNumberOfTrackletsInEtaRange(AliAODEvent* ev, Double_t mineta, Double_t maxeta){
160 // counts tracklets in given eta range
161 AliAODTracklets* tracklets=ev->GetTracklets();
162 Int_t nTr=tracklets->GetNumberOfTracklets();
164 for(Int_t iTr=0; iTr<nTr; iTr++){
165 Double_t theta=tracklets->GetTheta(iTr);
166 Double_t eta=-TMath::Log(TMath::Tan(theta/2.));
167 if(eta>mineta && eta<maxeta) count++;
171 //______________________________________________________________________
172 Int_t AliVertexingHFUtils::GetGeneratedMultiplicityInEtaRange(TClonesArray* arrayMC, Double_t mineta, Double_t maxeta){
173 // counts generated particles in fgiven eta range
176 for(Int_t i=0;i<arrayMC->GetEntriesFast();i++){
177 AliAODMCParticle *part=(AliAODMCParticle*)arrayMC->UncheckedAt(i);
178 Int_t charge = part->Charge();
179 Double_t eta = part->Eta();
180 if(charge!=0 && eta>mineta && eta<maxeta) nChargedMC++;
184 //______________________________________________________________________
185 Int_t AliVertexingHFUtils::GetGeneratedPrimariesInEtaRange(TClonesArray* arrayMC, Double_t mineta, Double_t maxeta){
186 // counts generated primary particles in given eta range
189 for(Int_t i=0;i<arrayMC->GetEntriesFast();i++){
190 AliAODMCParticle *part=(AliAODMCParticle*)arrayMC->UncheckedAt(i);
191 Int_t charge = part->Charge();
192 Double_t eta = part->Eta();
193 if(charge!=0 && eta>mineta && eta<maxeta){
194 if(part->IsPrimary())nChargedMC++;
199 //______________________________________________________________________
200 Int_t AliVertexingHFUtils::GetGeneratedPhysicalPrimariesInEtaRange(TClonesArray* arrayMC, Double_t mineta, Double_t maxeta){
201 // counts generated primary particles in given eta range
204 for(Int_t i=0;i<arrayMC->GetEntriesFast();i++){
205 AliAODMCParticle *part=(AliAODMCParticle*)arrayMC->UncheckedAt(i);
206 Int_t charge = part->Charge();
207 Double_t eta = part->Eta();
208 if(charge!=0 && eta>mineta && eta<maxeta){
209 if(part->IsPhysicalPrimary())nChargedMC++;
214 //______________________________________________________________________
215 void AliVertexingHFUtils::AveragePt(Float_t& averagePt, Float_t& errorPt,Float_t ptmin,Float_t ptmax, TH2F* hMassD, Float_t massFromFit, Float_t sigmaFromFit, TF1* funcB2, Float_t sigmaRangeForSig,Float_t sigmaRangeForBkg, Int_t rebin){
217 // Compute <pt> from 2D histogram M vs pt
219 //Make 2D histos in the desired pt range
220 Int_t start=hMassD->FindBin(ptmin);
221 Int_t end=hMassD->FindBin(ptmax)-1;
222 const Int_t nx=end-start;
223 TH2F *hMassDpt=new TH2F("hptmass","hptmass",nx,ptmin,ptmax,hMassD->GetNbinsY(),hMassD->GetYaxis()->GetBinLowEdge(1),hMassD->GetYaxis()->GetBinLowEdge(hMassD->GetNbinsY())+hMassD->GetYaxis()->GetBinWidth(hMassD->GetNbinsY()));
224 for(Int_t ix=start;ix<end;ix++){
225 for(Int_t iy=1;iy<=hMassD->GetNbinsY();iy++){
226 hMassDpt->SetBinContent(ix-start+1,iy,hMassD->GetBinContent(ix,iy));
227 hMassDpt->SetBinError(ix-start+1,iy,hMassD->GetBinError(ix,iy));
231 Double_t minMassSig=massFromFit-sigmaRangeForSig*sigmaFromFit;
232 Double_t maxMassSig=massFromFit+sigmaRangeForSig*sigmaFromFit;
233 Int_t minBinSig=hMassD->GetYaxis()->FindBin(minMassSig);
234 Int_t maxBinSig=hMassD->GetYaxis()->FindBin(maxMassSig);
235 Double_t minMassSigBin=hMassD->GetYaxis()->GetBinLowEdge(minBinSig);
236 Double_t maxMassSigBin=hMassD->GetYaxis()->GetBinLowEdge(maxBinSig)+hMassD->GetYaxis()->GetBinWidth(maxBinSig);
237 // printf("Signal Fit Limits = %f %f\n",minMassSigBin,maxMassSigBin);
239 Double_t maxMassBkgLow=massFromFit-sigmaRangeForBkg*sigmaFromFit;
240 Int_t minBinBkgLow=2;
241 Int_t maxBinBkgLow=hMassD->GetYaxis()->FindBin(maxMassBkgLow);
242 Double_t minMassBkgLowBin=hMassD->GetYaxis()->GetBinLowEdge(minBinBkgLow);
243 Double_t maxMassBkgLowBin=hMassD->GetYaxis()->GetBinLowEdge(maxBinBkgLow)+hMassD->GetYaxis()->GetBinWidth(maxBinBkgLow);
244 Double_t minMassBkgHi=massFromFit+sigmaRangeForBkg*sigmaFromFit;
245 Int_t minBinBkgHi=hMassD->GetYaxis()->FindBin(minMassBkgHi);
246 Int_t maxBinBkgHi=hMassD->GetNbinsY()-1;
247 Double_t minMassBkgHiBin=hMassD->GetYaxis()->GetBinLowEdge(minBinBkgHi);
248 Double_t maxMassBkgHiBin=hMassD->GetYaxis()->GetBinLowEdge(maxBinBkgHi)+hMassD->GetYaxis()->GetBinWidth(maxBinBkgHi);
249 // printf("BKG Fit Limits = %f %f && %f %f\n",minMassBkgLowBin,maxMassBkgLowBin,minMassBkgHiBin,maxMassBkgHiBin);
251 Double_t bkgSig=funcB2->Integral(minMassSigBin,maxMassSigBin);
252 Double_t bkgLow=funcB2->Integral(minMassBkgLowBin,maxMassBkgLowBin);
253 Double_t bkgHi=funcB2->Integral(minMassBkgHiBin,maxMassBkgHiBin);
254 // printf("Background integrals = %f %f %f\n",bkgLow,bkgSig,bkgHi);
256 TH1F* hMptBkgLo=(TH1F*)hMassDpt->ProjectionX("hPtBkgLoBin",minBinBkgLow,maxBinBkgLow);
257 TH1F* hMptBkgHi=(TH1F*)hMassDpt->ProjectionX("hPtBkgHiBin",minBinBkgHi,maxBinBkgHi);
258 TH1F* hMptSigReg=(TH1F*)hMassDpt->ProjectionX("hCPtBkgSigBin",minBinSig,maxBinSig);
260 hMptBkgLo->Rebin(rebin);
261 hMptBkgHi->Rebin(rebin);
262 hMptSigReg->Rebin(rebin);
266 TH1F* hMptBkgLoScal=(TH1F*)hMptBkgLo->Clone("hPtBkgLoScalBin");
267 hMptBkgLoScal->Scale(bkgSig/bkgLow);
268 TH1F* hMptBkgHiScal=(TH1F*)hMptBkgHi->Clone("hPtBkgHiScalBin");
269 hMptBkgHiScal->Scale(bkgSig/bkgHi);
271 TH1F* hMptBkgAver=0x0;
272 hMptBkgAver=(TH1F*)hMptBkgLoScal->Clone("hPtBkgAverBin");
273 hMptBkgAver->Add(hMptBkgHiScal);
274 hMptBkgAver->Scale(0.5);
275 TH1F* hMptSig=(TH1F*)hMptSigReg->Clone("hCPtSigBin");
276 hMptSig->Add(hMptBkgAver,-1.);
278 averagePt = hMptSig->GetMean();
279 errorPt = hMptSig->GetMeanError();
284 delete hMptBkgLoScal;
285 delete hMptBkgHiScal;
291 //____________________________________________________________________________
292 Double_t AliVertexingHFUtils::GetCorrectedNtracklets(TProfile* estimatorAvg, Double_t uncorrectedNacc, Double_t vtxZ, Double_t refMult) {
294 // Correct the number of accepted tracklets based on a TProfile Hist
298 if(TMath::Abs(vtxZ)>10.0){
299 printf("ERROR: Z vertex out of range for correction of multiplicity\n");
300 return uncorrectedNacc;
304 printf("ERROR: Missing TProfile for correction of multiplicity\n");
305 return uncorrectedNacc;
308 Double_t localAvg = estimatorAvg->GetBinContent(estimatorAvg->FindBin(vtxZ));
310 Double_t deltaM = uncorrectedNacc*(refMult/localAvg - 1);
312 Double_t correctedNacc = uncorrectedNacc + (deltaM>0 ? 1 : -1) * gRandom->Poisson(TMath::Abs(deltaM));
314 return correctedNacc;