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16 // Author: Dariusz Miskowiec <mailto:d.miskowiec@gsi.de> 2005
18 //=============================================================================
19 // two-particle correlation analyzer
20 // Loop over pairs and fill pair histograms. The first particle is always
21 // taken from ev0 and the second from ev1 so for ev0=ev1 one is getting true
22 // pairs, otherwise mixed ones.
23 //=============================================================================
28 #include "AliUnicorEvent.h"
29 #include "AliUnicorHN.h"
30 #include "AliUnicorAnalCorrel.h"
32 ClassImp(AliUnicorAnalCorrel)
34 //=============================================================================
35 AliUnicorAnalCorrel::AliUnicorAnalCorrel(const char *nam, Double_t emi, Double_t ema,
36 Int_t pid0, Int_t pid1, AnalysisFrame frame):
37 AliUnicorAnal(nam), fPid0(pid0), fPid1(pid1), fMass0(0), fMass1(0), fZ0(0), fZ1(0),
38 fFrame(frame), fPa() {
40 // emi and ema define the rapidity range for histogram
42 TParticlePDG *part0 = AliUnicorAnal::fgPDG.GetParticle(fPid0);
43 TParticlePDG *part1 = AliUnicorAnal::fgPDG.GetParticle(fPid1);
44 fMass0 = part0? part0->Mass() : 0;
45 fMass1 = part1? part1->Mass() : 0;
46 fZ0 = part0? part0->Charge()/3.0 : 0;
47 fZ1 = part1? part1->Charge()/3.0 : 0;
48 double pi = TMath::Pi();
50 // correlation function
52 int nce = 6; double cebins[]={0,0.05,0.1,0.2,0.4,0.6,1.0}; // centrality bins
54 //int npt = 7; double ptbins[]={0,0.1,0.2,0.3,0.4,0.5,0.7,1.0};
55 //int npt = 6; double ptbins[]={0,0.1,0.25,0.35,0.55,1.0,2.0}; // like Adam, except last bin split
56 //int npt = 7; double ptbins[]={0,0.1,0.25,0.40,0.55,0.7,1.0,2.0}; // like Adam in Mar-2010, + first+last
57 int npt = 10; double ptbins[]={0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,1.0,2.0}; // for Pb
59 double qbins[200] = {0};
60 // for (int i=0;i<60;i++) qbins[i]=i*0.005;
61 // for (int i=0;i<45;i++) qbins[20+i]=0.1+i*0.02;
62 // for (int i=0;i<30;i++) qbins[i]=i*0.010;
63 for (int i=0;i<60;i++) qbins[i]=i*0.005;
64 for (int i=0;i<35;i++) qbins[60+i]=0.3+i*0.02;
65 for (int i=0;i<20;i++) qbins[95+i]=1.0+i*0.05;
66 for (int i=0;i<11;i++) qbins[115+i]=2.0+i*0.20;
69 ax[0] = new TAxis(4,-0.5,3.5);ax[0]->SetTitle("trumixrot");
70 // ax[1] = new TAxis(5,0,1.0); ax[1]->SetTitle("centrality");
71 ax[1] = new TAxis(nce,cebins);ax[1]->SetTitle("centrality");
72 ax[2] = new TAxis(3,emi,ema); ax[2]->SetTitle("y"); // pair y
73 // ax[3] = new TAxis(8,-pi,pi); ax[3]->SetTitle("phi"); // wrt event plane
74 ax[3] = new TAxis(1,-pi,pi); ax[3]->SetTitle("phi"); // wrt event plane
75 ax[4] = new TAxis(npt,ptbins);ax[4]->SetTitle("kt (GeV/c)"); // pair pt/2
76 ax[5] = new TAxis(8,0,pi); ax[5]->SetTitle("q-theta");
77 ax[6] = new TAxis(16,-pi,pi); ax[6]->SetTitle("q-phi");
78 ax[7] = new TAxis(125,qbins); ax[7]->SetTitle("q (GeV/c)");
79 // ax[7] = new TAxis(700,0,3.5); ax[7]->SetTitle("q (GeV/c)");
80 AliUnicorHN *pair = new AliUnicorHN("pair",8,ax);
83 // correlation function bin monitor (needed to get <kt> etc.)
86 //bx[0] = new TAxis(*(pair->GetAxis(1))); // wait until root bug (516-00..527-06) fixed. For now, do:
87 bx[0] = new TAxis(ax[1]->GetNbins(), ax[1]->GetXmin(), ax[1]->GetXmax()); bx[0]->SetTitle("centrality");
88 bx[1] = new TAxis(10*ax[2]->GetNbins(),emi,ema); bx[1]->SetTitle("y"); // pair y
89 bx[2] = new TAxis(100,0,2); bx[2]->SetTitle("kt (GeV/c)"); // pair pt/2
90 AliUnicorHN *bimo = new AliUnicorHN("bimo",3,bx);
91 for (int i=0; i<8; i++) delete ax[i];
92 for (int i=0; i<3; i++) delete bx[i];
95 // two-track resolution monitoring histogram
97 ax[0] = new TAxis(3,-0.5,2.5); ax[0]->SetTitle("trumixrot");
98 ax[1] = new TAxis(2,-0.5,1.5); ax[1]->SetTitle("cut applied");
99 ax[2] = new TAxis(npt,ptbins); ax[2]->SetTitle("(pair pt)/2 (GeV)");
100 ax[3] = new TAxis(80,-0.08,0.08); ax[3]->SetTitle("dtheta");
101 ax[4] = new TAxis(80,-0.20,0.20); ax[4]->SetTitle("dphi");
102 AliUnicorHN *twot = new AliUnicorHN("twot",5,ax);
103 for (int i=0; i<5; i++) delete ax[i];
107 printf("%s object named %s created\n",ClassName(),GetName());
109 //=============================================================================
110 void AliUnicorAnalCorrel::Process(Int_t tmr, const AliUnicorEvent * const ev0, const AliUnicorEvent * const ev1, Double_t phirot)
112 // process pairs from one or two (if mixing) events
113 // tmr tells which histogram (bins) to fill: tru,mix,rot
115 // Could be possibly accelerated by checking the "good particle" only once
116 // and caching the result. (Maybe the optimizer does it already.)
119 AliUnicorHN *pair = (AliUnicorHN*) fHistos.At(0);
120 AliUnicorHN *bimo = (AliUnicorHN*) fHistos.At(1);
121 AliUnicorHN *twot = (AliUnicorHN*) fHistos.At(2);
123 // mixing-and-rotating-proof centrality and reaction plane angle
124 // (but not rotation-proof for rotation angles much different from 0 and 180)
125 // true and rotated pairs are within the triangle (j<i), mixed - all
126 // thus, proper rotation is either by 180, or by 170 AND 190, etc.
128 double cent = (ev0->Centrality()+ev1->Centrality())/2.0;
129 double q0x=0,q0y=0,q1x=0,q1y=0;
132 double rpphi = atan2(q0y+q1y,q0x+q1x);
136 for (int i=0; i<ev0->NParticles(); i++) {
137 if (!ev0->ParticleGood(i,fPid0)) continue;
138 for (int j=0; j<ev1->NParticles(); j++) {
139 if (ev0==ev1 && j<i && fPid0==fPid1 ) continue;
140 if (ev0==ev1 && j==i) continue; // beware, not even when rotated or non-identical
141 if (!ev1->ParticleGood(j,fPid1)) continue;
142 fPa.Set0(fMass0,ev0->ParticleP(i),ev0->ParticleTheta(i),ev0->ParticlePhi(i));
143 fPa.Set1(fMass1,ev1->ParticleP(j),ev1->ParticleTheta(j),ev1->ParticlePhi(j)+phirot);
144 if (ev0==ev1 && fPid0==fPid1 && ran.Rndm()>=0.5) fPa.Swap();
145 twot->Fill((double) tmr, 0.0, fPa.Pt()/2.0, fPa.DTheta(), fPa.DPhi(),1.0);
146 if (!ev0->PairGood(ev0->ParticleP(i),ev0->ParticleTheta(i),ev0->ParticlePhi(i),fZ0,
147 ev1->ParticleP(j),ev1->ParticleTheta(j),ev1->ParticlePhi(j)+phirot,fZ1)) continue;
148 twot->Fill((double) tmr, 1.0, fPa.Pt()/2.0, fPa.DTheta(), fPa.DPhi(),1.0);
149 fPa.CalcLAB(); // this could be organized better. AliUnicorPair should give k*?
151 double qcm = fPa.QCM(); // momdif in pair cm - argument for Coulomb correction
154 if (fFrame == kPairFrame) fPa.CalcPairCM();
155 if (fFrame == kLCMS) fPa.CalcLcmsCM();
156 if (fPa.QCM()==0) {printf("AliUnicorAnalCorrel: Q=0\n"); return;} // should not be too frequent
157 double phi = TVector2::Phi_mpi_pi(fPa.Phi()-rpphi);
160 static TH2D *coul = 0;
162 TFile::Open("coulomb.root","read");
163 coul = (TH2D*) gFile->Get("co");
164 coul->SetDirectory(gROOT);
167 if (tmr==0 && fPid0==fPid1) {
169 if (qcm>0.999) co = 1;
170 else if (qcm>0.001) co = coul->Interpolate(7,qcm);
171 weigth = 1.0-0.5+0.5*co*(1+exp(-pow(fPa.QCM()*7/0.197,2)));
174 pair->Fill((double) tmr, // 0 for tru, 1 for mix, 2 for rot
176 fPa.Rapidity(), // pair rapidity
177 phi, // pair phi wrt reaction plane
178 fPa.Pt()/2.0, // half of pair pt
179 fPa.QCMTheta(), // polar angle of Q
180 fPa.QCMPhiOut(), // azimuthal angle of Q w.r.t. out
181 fPa.QCM(), // |p2-p1| in c.m.s.
183 if (tmr==0 && fPa.QCM()<0.2) bimo->Fill(cent, fPa.Rapidity(), fPa.Pt()/2.0, weigth);
184 if (tmr==0) pair->Fill((double) 3, // this is for Coulomb correction, maybe not necessary
186 fPa.Rapidity(), // pair rapidity
187 phi, // pair phi wrt reaction plane
188 fPa.Pt()/2.0, // half of pair pt
189 fPa.QCMTheta(), // polar angle of Q
190 fPa.QCMPhiOut(), // azimuthal angle of Q w.r.t. out
191 fPa.QCM(), // |p2-p1| in c.m.s.
192 weigth*qcm); // weigth*Q
196 //=============================================================================