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14 **************************************************************************/
15 /* $Id: AliNeutralMesonSelection.cxx 27413 2008-07-18 13:28:12Z gconesab $ */
17 //_________________________________________________________________________
18 // Class that contains methods to select candidate pairs to neutral meson
19 // 2 main selections, invariant mass around pi0 (also any other mass),
20 // apperture angle to distinguish from combinatorial.
21 //-- Author: Gustavo Conesa (INFN-LNF)
23 // --- ROOT system ---
24 #include <TLorentzVector.h>
28 //---- AliRoot system ----
29 #include "AliNeutralMesonSelection.h"
31 ClassImp(AliNeutralMesonSelection)
34 //____________________________________________________________________________
35 AliNeutralMesonSelection::AliNeutralMesonSelection() :
37 fInvMassMaxCut(0.), fInvMassMinCut(0.),
38 fAngleMaxParam(), fUseAngleCut(0), fKeepNeutralMesonHistos(0),
39 fhAnglePairNoCut(0), fhAnglePairOpeningAngleCut(0),
41 fhInvMassPairNoCut(0), fhInvMassPairOpeningAngleCut(0),
42 fhInvMassPairAllCut(0),
43 fHistoNEBins(0), fHistoEMax(0.), fHistoEMin(0.),
44 fHistoNPtBins(0), fHistoPtMax(0.), fHistoPtMin(0.),
45 fHistoNAngleBins(0), fHistoAngleMax(0.), fHistoAngleMin(0.),
46 fHistoNIMBins(0), fHistoIMMax(0.), fHistoIMMin(0.)
50 //Initialize parameters
52 // kGammaHadron and kGammaJet
53 fAngleMaxParam.Set(4) ;
54 fAngleMaxParam.Reset(0.);
56 //Initialize parameters
60 //____________________________________________________________________________
61 AliNeutralMesonSelection::AliNeutralMesonSelection(const AliNeutralMesonSelection & g) :
63 fInvMassMaxCut(g.fInvMassMaxCut), fInvMassMinCut(g.fInvMassMinCut),
64 fAngleMaxParam(g.fAngleMaxParam),
65 fKeepNeutralMesonHistos(g.fKeepNeutralMesonHistos),
66 fhAnglePairNoCut(g. fhAnglePairNoCut),
67 fhAnglePairOpeningAngleCut(g. fhAnglePairOpeningAngleCut),
68 fhAnglePairAllCut(g. fhAnglePairAllCut),
69 fhInvMassPairNoCut(g.fhInvMassPairNoCut),
70 fhInvMassPairOpeningAngleCut(g.fhInvMassPairOpeningAngleCut),
71 fhInvMassPairAllCut(g.fhInvMassPairAllCut),
72 fHistoNEBins(g.fHistoNEBins), fHistoEMax(g.fHistoEMax), fHistoEMin(g.fHistoEMin),
73 fHistoNPtBins(g.fHistoNPtBins), fHistoPtMax(g.fHistoPtMax), fHistoPtMin(g.fHistoPtMin),
74 fHistoNAngleBins(g.fHistoNAngleBins), fHistoAngleMax(g.fHistoAngleMax), fHistoAngleMin(g.fHistoAngleMin),
75 fHistoNIMBins(g.fHistoNIMBins), fHistoIMMax(g.fHistoIMMax), fHistoIMMin(g.fHistoIMMin)
80 //_________________________________________________________________________
81 AliNeutralMesonSelection & AliNeutralMesonSelection::operator = (const AliNeutralMesonSelection & source)
83 // assignment operator
85 if(this == &source)return *this;
86 ((TObject *)this)->operator=(source);
89 fInvMassMaxCut = source.fInvMassMaxCut ;
90 fInvMassMinCut = source.fInvMassMinCut ;
91 fAngleMaxParam = source.fAngleMaxParam ;
92 fKeepNeutralMesonHistos = source.fKeepNeutralMesonHistos;
94 fhAnglePairNoCut = source. fhAnglePairNoCut ;
95 fhAnglePairOpeningAngleCut = source. fhAnglePairOpeningAngleCut ;
96 fhAnglePairAllCut = source. fhAnglePairAllCut ;
97 fhInvMassPairNoCut = source.fhInvMassPairNoCut ;
98 fhInvMassPairOpeningAngleCut = source.fhInvMassPairOpeningAngleCut ;
99 fhInvMassPairAllCut = source.fhInvMassPairAllCut ;
101 fHistoNEBins = source.fHistoNEBins; fHistoEMax = source.fHistoEMax; fHistoEMin = source.fHistoEMin;
102 fHistoNPtBins = source.fHistoNPtBins; fHistoPtMax = source.fHistoPtMax; fHistoPtMin = source.fHistoPtMin;
103 fHistoNAngleBins = source.fHistoNAngleBins; fHistoAngleMax = source.fHistoAngleMax; fHistoAngleMin = source.fHistoAngleMin;
104 fHistoNIMBins = source.fHistoNIMBins; fHistoIMMax = source.fHistoIMMax; fHistoIMMin = source.fHistoIMMin;
110 //____________________________________________________________________________
111 AliNeutralMesonSelection::~AliNeutralMesonSelection()
115 // if(!fKeepNeutralMesonHistos){
116 // //Histograms initialized and filled but not passed to output container
117 // //delete here, I am not sure this is correct
119 // if(fhAnglePairNoCut) delete fhAnglePairNoCut;
120 // if(fhAnglePairOpeningAngleCut) delete fhAnglePairOpeningAngleCut;
121 // if(fhAnglePairAllCut) delete fhAnglePairAllCut;
122 // if(fhInvMassPairNoCut) delete fhInvMassPairNoCut;
123 // if(fhInvMassPairOpeningAngleCut) delete fhInvMassPairOpeningAngleCut;
124 // if(fhInvMassPairAllCut) delete fhInvMassPairAllCut;
129 //________________________________________________________________________
130 TList * AliNeutralMesonSelection::GetCreateOutputObjects()
132 // Create histograms to be saved in output file and
133 // store them in outputContainer of the analysis class that calls this class.
135 TList * outputContainer = new TList() ;
136 outputContainer->SetName("MesonDecayHistos") ;
137 if(fKeepNeutralMesonHistos){
139 outputContainer->SetOwner(kFALSE);
141 fhAnglePairNoCut = new TH2F
143 "Angle between all #gamma pair vs E_{#pi^{0}}",fHistoNEBins,fHistoEMin,fHistoEMax,fHistoNAngleBins,fHistoAngleMin,fHistoAngleMax);
144 fhAnglePairNoCut->SetYTitle("Angle (rad)");
145 fhAnglePairNoCut->SetXTitle("E_{ #pi^{0}} (GeV)");
147 fhAnglePairOpeningAngleCut = new TH2F
148 ("AnglePairOpeningAngleCut",
149 "Angle between all #gamma pair (opening angle + azimuth cut) vs E_{#pi^{0}}"
150 ,fHistoNEBins,fHistoEMin,fHistoEMax,fHistoNAngleBins,fHistoAngleMin,fHistoAngleMax);
151 fhAnglePairOpeningAngleCut->SetYTitle("Angle (rad)");
152 fhAnglePairOpeningAngleCut->SetXTitle("E_{ #pi^{0}} (GeV)");
154 fhAnglePairAllCut = new TH2F
156 "Angle between all #gamma pair (opening angle + inv mass cut+azimuth) vs E_{#pi^{0}}"
157 ,fHistoNEBins,fHistoEMin,fHistoEMax,fHistoNAngleBins,fHistoAngleMin,fHistoAngleMax);
158 fhAnglePairAllCut->SetYTitle("Angle (rad)");
159 fhAnglePairAllCut->SetXTitle("E_{ #pi^{0}} (GeV)");
162 fhInvMassPairNoCut = new TH2F
163 ("InvMassPairNoCut","Invariant Mass of all #gamma pair vs E_{#pi^{0}}",
164 fHistoNPtBins,fHistoPtMin,fHistoPtMax,fHistoNIMBins,fHistoIMMin,fHistoIMMax);
165 fhInvMassPairNoCut->SetYTitle("Invariant Mass (GeV/c^{2})");
166 fhInvMassPairNoCut->SetXTitle("E_{ #pi^{0}} (GeV)");
168 fhInvMassPairOpeningAngleCut = new TH2F
169 ("InvMassPairOpeningAngleCut",
170 "Invariant Mass of #gamma pair (angle cut) vs E_{#pi^{0}}",
171 fHistoNPtBins,fHistoPtMin,fHistoPtMax,fHistoNIMBins,fHistoIMMin,fHistoIMMax);
172 fhInvMassPairOpeningAngleCut->SetYTitle("Invariant Mass (GeV/c^{2})");
173 fhInvMassPairOpeningAngleCut->SetXTitle(" E_{#pi^{0}}(GeV)");
175 fhInvMassPairAllCut = new TH2F
176 ("InvMassPairAllCut",
177 "Invariant Mass of #gamma pair (opening angle+invmass cut) vs E_{#pi^{0}}",
178 fHistoNPtBins,fHistoPtMin,fHistoPtMax,fHistoNIMBins,fHistoIMMin,fHistoIMMax);
179 fhInvMassPairAllCut->SetYTitle("Invariant Mass (GeV/c^{2})");
180 fhInvMassPairAllCut->SetXTitle("E_{#pi^{0}}(GeV)");
182 outputContainer->Add(fhAnglePairNoCut) ;
183 outputContainer->Add(fhAnglePairOpeningAngleCut) ;
184 outputContainer->Add(fhAnglePairAllCut) ;
186 outputContainer->Add(fhInvMassPairNoCut) ;
187 outputContainer->Add(fhInvMassPairOpeningAngleCut) ;
188 outputContainer->Add(fhInvMassPairAllCut) ;
190 return outputContainer;
193 //____________________________________________________________________________
194 void AliNeutralMesonSelection::InitParameters()
197 //Initialize the parameters of the analysis.
198 fKeepNeutralMesonHistos = kFALSE ;
199 fUseAngleCut = kFALSE;
200 fAngleMaxParam.Set(4) ;
201 fAngleMaxParam.AddAt(0.4,0);//={0.4,-0.25,0.025,-2e-4};
202 fAngleMaxParam.AddAt(-0.25,1) ;
203 fAngleMaxParam.AddAt(0.025,2) ;
204 fAngleMaxParam.AddAt(-2e-4,3) ;
206 fInvMassMaxCut = 0.16 ;
207 fInvMassMinCut = 0.11 ;
209 fM = 0.1349766;//neutralMeson mass, pi0
211 //Histogrammes settings
216 fHistoNPtBins = 100 ;
220 fHistoNAngleBins = 100 ;
221 fHistoAngleMax = 0.2;
222 fHistoAngleMin = 0. ;
224 fHistoNIMBins = 100 ;
229 //__________________________________________________________________________-
230 Bool_t AliNeutralMesonSelection::IsAngleInWindow(const Float_t angle,const Float_t e) const {
231 //Check if the opening angle of the candidate pairs is inside
232 //our selection windowd
234 if (!fUseAngleCut) return kTRUE; //Accept any angle
236 Bool_t result = kFALSE;
237 Double_t max = fAngleMaxParam.At(0)*TMath::Exp(fAngleMaxParam.At(1)*e)
238 +fAngleMaxParam.At(2)+fAngleMaxParam.At(3)*e;
239 Double_t arg = (e*e-2*fM*fM)/(e*e);
240 Double_t min = 100. ;
242 min = TMath::ACos(arg);
244 if((angle<max)&&(angle>=min))
250 //____________________________________________________________________________
251 Bool_t AliNeutralMesonSelection::SelectPair(TLorentzVector gammai, TLorentzVector gammaj)
254 //Search for the neutral pion within selection cuts
255 Bool_t goodpair = kFALSE ;
257 // Double_t pt = (gammai+gammaj).Pt();
258 Double_t phi = (gammai+gammaj).Phi();
261 Double_t invmass = (gammai+gammaj).M();
262 Double_t angle = gammaj.Angle(gammai.Vect());
263 Double_t e = (gammai+gammaj).E();
265 //Fill histograms with no cuts applied.
266 if(fKeepNeutralMesonHistos){
267 fhAnglePairNoCut ->Fill(e,angle);
268 fhInvMassPairNoCut->Fill(e,invmass);
270 //Cut on the aperture of the pair
271 if(IsAngleInWindow(angle,e)){
272 if(fKeepNeutralMesonHistos){
273 fhAnglePairOpeningAngleCut ->Fill(e,angle);
274 fhInvMassPairOpeningAngleCut->Fill(e,invmass);
276 //AliDebug(2,Form("Angle cut: pt %f, phi %f",pt,phi));
278 //Cut on the invariant mass of the pair
279 if((invmass>fInvMassMinCut) && (invmass<fInvMassMaxCut)){
280 if(fKeepNeutralMesonHistos){
281 fhInvMassPairAllCut ->Fill(e,invmass);
282 fhAnglePairAllCut ->Fill(e,angle);
285 //AliDebug(2,Form("IM cut: pt %f, phi %f",pt,phi));
286 }//(invmass>0.125) && (invmass<0.145)
293 //__________________________________________________________________
294 void AliNeutralMesonSelection::Print(const Option_t * opt) const
297 //Print some relevant parameters set for the analysis
301 printf("**** Print %s %s ****\n", GetName(), GetTitle() ) ;
303 printf("mass : %f \n", fM );
304 printf("Invariant mass limits : %f < m < %f \n", fInvMassMinCut , fInvMassMinCut );
305 printf("Angle selection param: \n");
306 printf("p0 : %f\n", fAngleMaxParam.At(0));
307 printf("p1 : %f\n", fAngleMaxParam.At(1));
308 printf("p2 : %f\n", fAngleMaxParam.At(2));
309 printf("p3 : %f\n", fAngleMaxParam.At(3));
311 printf("Keep Neutral Meson Histos = %d\n",fKeepNeutralMesonHistos);
313 if(fKeepNeutralMesonHistos){
314 printf("Histograms: %3.1f < E < %3.1f, Nbin = %d\n", fHistoEMin, fHistoEMax, fHistoNEBins);
315 printf("Histograms: %3.1f < pT < %3.1f, Nbin = %d\n", fHistoPtMin, fHistoPtMax, fHistoNPtBins);
316 printf("Histograms: %3.1f < angle < %3.1f, Nbin = %d\n", fHistoAngleMin, fHistoAngleMax, fHistoNAngleBins);
317 printf("Histograms: %3.1f < IM < %3.1f, Nbin = %d\n", fHistoIMMin, fHistoIMMax, fHistoNIMBins);