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 // Jet kinematics reader
18 // MC reader for jet analysis
19 // Author: Andreas Morsch (andreas.morsch@cern.ch)
20 //-------------------------------------------------------------------------
23 #include <TClonesArray.h>
25 #include <TParticle.h>
26 #include <TParticlePDG.h>
27 #include <TLorentzVector.h>
29 #include <TDatabasePDG.h>
32 #include "AliAODJet.h"
34 #include "AliJetKineReaderHeader.h"
35 #include "AliJetKineReader.h"
36 #include "AliMCEventHandler.h"
37 #include "AliMCEvent.h"
39 #include "AliHeader.h"
40 #include "AliGenPythiaEventHeader.h"
43 ClassImp(AliJetKineReader)
45 AliJetKineReader::AliJetKineReader():
51 // Default constructor
54 //____________________________________________________________________________
56 AliJetKineReader::~AliJetKineReader()
65 //____________________________________________________________________________
67 void AliJetKineReader::OpenInputFiles()
69 // Opens the input file using the run loader
73 //____________________________________________________________________________
75 Bool_t AliJetKineReader::FillMomentumArray()
77 // Fill momentum array for event
80 // temporary storage of signal and cut flags
81 Int_t* sflag = new Int_t[50000];
82 Int_t* cflag = new Int_t[50000];
86 AliStack* stack = fMCEvent->Stack();
87 // Number of primaries
88 Int_t nt = stack->GetNprimary();
90 // Get cuts set by user and header
91 Double_t ptMin = ((AliJetKineReaderHeader*) fReaderHeader)->GetPtCut();
92 Float_t etaMin = fReaderHeader->GetFiducialEtaMin();
93 Float_t etaMax = fReaderHeader->GetFiducialEtaMax();
94 fAliHeader = fMCEvent->Header();
98 // Loop over particles
99 for (Int_t it = 0; it < nt; it++) {
100 TParticle *part = stack->Particle(it);
101 Int_t status = part->GetStatusCode();
102 Int_t pdg = TMath::Abs(part->GetPdgCode());
103 Float_t pt = part->Pt();
105 // Skip non-final state particles, neutrinos
106 // and particles with pt < pt_min
108 || (pdg == 12 || pdg == 14 || pdg == 16)) continue;
110 Float_t p = part->P();
112 Float_t eta = part->Eta();
113 Float_t phi = part->Phi();
116 if (((AliJetKineReaderHeader*)fReaderHeader)->ChargedOnly()) {
117 // Charged particles only
119 TDatabasePDG::Instance()->GetParticle(pdg)->Charge();
120 if (charge == 0) continue;
121 } // End charged only
124 // Fast simulation of TPC if requested
125 if (((AliJetKineReaderHeader*)fReaderHeader)->FastSimTPC()) {
126 // Charged particles only
128 TDatabasePDG::Instance()->GetParticle(pdg)->Charge();
129 if (charge == 0) continue;
130 // Simulate efficiency
131 if (!Efficiency(p0, eta, phi)) continue;
132 // Simulate resolution
133 p = SmearMomentum(4, p0);
136 // Fast simulation of EMCAL if requested
137 if (((AliJetKineReaderHeader*)fReaderHeader)->FastSimEMCAL()) {
139 TDatabasePDG::Instance()->GetParticle(pdg)->Charge();
140 // Charged particles only
142 // Simulate efficiency
143 if (!Efficiency(p0, eta, phi)) continue;
144 // Simulate resolution
145 p = SmearMomentum(4, p0);
146 } // end "if" charged particles
147 // Neutral particles (exclude K0L, n, nbar)
148 if (pdg == kNeutron || pdg == kK0Long) continue;
151 // Fill momentum array
153 Float_t px = r * part->Px();
154 Float_t py = r * part->Py();
155 Float_t pz = r * part->Pz();
156 TParticlePDG *pPDG = part->GetPDG();
159 // this is very rare...
160 // Is avoided by AliPDG::AddParticlesToPdgDataBase();
161 // but this should be called only once... (how in proof?)
162 // Calucluate mass with unsmeared momentum values
163 m = part->Energy()*part->Energy() -
164 (px * px + py * py + pz * pz)/r/r;
165 if(m>0)m = TMath::Sqrt(m);
167 AliInfo(Form("Unknown Particle using %d calculated mass m = %3.3f",part->GetPdgCode(),m));
173 Float_t e = TMath::Sqrt(px * px + py * py + pz * pz + m * m);
174 p4 = TLorentzVector(px, py, pz, e);
175 if ( (p4.Eta()>etaMax) || (p4.Eta()<etaMin)) continue;
176 new ((*fMomentumArray)[goodTrack]) TLorentzVector(p4);
178 // all tracks are signal ... ?
181 if (pt > ptMin) cflag[goodTrack] = 1; // track surviving pt cut
185 // set the signal flags
186 fSignalFlag.Set(goodTrack, sflag);
187 fCutFlag.Set(goodTrack, cflag);
188 AliInfo(Form(" Number of good tracks %d \n", goodTrack));
197 Float_t AliJetKineReader::SmearMomentum(Int_t ind, Float_t p)
199 // The relative momentum error, i.e.
200 // (delta p)/p = sqrt (a**2 + (b*p)**2) * 10**-2,
201 // where typically a = 0.75 and b = 0.16 - 0.24 depending on multiplicity
202 // (the lower value is for dn/d(eta) about 2000, and the higher one for 8000)
204 // If we include information from TRD, b will be a factor 2/3 smaller.
206 // ind = 1: high multiplicity
207 // ind = 2: low multiplicity
208 // ind = 3: high multiplicity + TRD
209 // ind = 4: low multiplicity + TRD
215 if (ind == 1) b = 0.12;
216 if (ind == 2) b = 0.08;
217 if (ind == 3) b = 0.12;
218 if (ind == 4) b = 0.08;
220 Float_t sigma = p * TMath::Sqrt(a * a + b * b * p * p)*0.01;
221 pSmeared = p + gRandom->Gaus(0., sigma);
226 Bool_t AliJetKineReader::Efficiency(Float_t p, Float_t /*eta*/, Float_t phi)
228 // Fast simulation of geometrical acceptance and tracking efficiency
232 if (p < 0.5) eff -= (0.5-p)*0.2/0.3;
235 phi *= 180. / TMath::Pi();
236 // Sector number 0 - 17
237 Int_t isec = Int_t(phi / 20.);
239 Float_t phi0 = isec * 20. + 10.;
240 Float_t phir = TMath::Abs(phi-phi0);
241 // 2 deg of dead space
242 if (phir > 9.) eff = 0.;
245 if (gRandom->Rndm() > eff) {
253 TClonesArray* AliJetKineReader::GetGeneratedJets()
256 // Get generated jets from mc header
259 fGenJets = new TClonesArray("AliAODJets", 100);
265 AliHeader* alih = GetAliHeader();
266 if (alih == 0) return 0;
267 AliGenEventHeader * genh = alih->GenEventHeader();
268 if (genh == 0) return 0;
270 Int_t nj =((AliGenPythiaEventHeader*)genh)->NTriggerJets();
271 for (Int_t i = 0; i < nj; i++) {
273 ((AliGenPythiaEventHeader*)genh)->TriggerJet(i,p);
274 new ((*fGenJets)[i]) AliAODJet(p[0], p[1], p[2], p[3]);
280 void AliJetKineReader::SetInputEvent(const TObject* /*esd*/, const TObject* /*aod*/, const TObject* mc)
282 // Connect the input event
283 fMCEvent = (AliMCEvent*) mc;