Removing obsolete code which affected the event numbering scheme
[u/mrichter/AliRoot.git] / TRD / AliTRDpidESD.cxx
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b0f03c34 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
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 **************************************************************************/
15
16//-----------------------------------------------------------------
17// Implementation of the TRD PID class
bd50219c 18// Assigns the electron and pion liklihoods for each ESD track.
bd50219c 19// The function MakePID(AliESD *event) calculates the probability
20// of having dedx and the probability of having timbin at a given
21// momentum (mom) and particle type k (0 for e) and (2 for pi)
22// from the precalculated timbin distributions.
23// Prashant Shukla <shukla@pi0.physi.uni-heidelberg.de>
b0f03c34 24//-----------------------------------------------------------------
25
26#include "AliTRDpidESD.h"
27#include "AliESD.h"
28#include "AliESDtrack.h"
cc7cef99 29#include "AliTRDcalibDB.h"
7754cd1f 30#include "Cal/AliTRDCalPIDLQ.h"
b0f03c34 31
32ClassImp(AliTRDpidESD)
33
34//_________________________________________________________________________
35AliTRDpidESD::AliTRDpidESD(Double_t *param)
36{
37 //
38 // The main constructor
39 //
40 fMIP=param[0]; // MIP signal
41 fRes=param[1]; // relative resolution
42 fRange=param[2]; // PID "range" (in sigmas)
43}
44
eab5961e 45Double_t AliTRDpidESD::Bethe(Double_t bg)
46{
b0f03c34 47 //
eab5961e 48 // Parametrization of the Bethe-Bloch-curve
49 // The parametrization is the same as for the TPC and is taken from Lehrhaus.
b0f03c34 50 //
eab5961e 51
52 // This parameters have been adjusted to averaged values from GEANT
53 const Double_t kP1 = 7.17960e-02;
54 const Double_t kP2 = 8.54196;
55 const Double_t kP3 = 1.38065e-06;
56 const Double_t kP4 = 5.30972;
57 const Double_t kP5 = 2.83798;
58
59 // This parameters have been adjusted to Xe-data found in:
60 // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253
61 //const Double_t kP1 = 0.76176E-1;
62 //const Double_t kP2 = 10.632;
63 //const Double_t kP3 = 3.17983E-6;
64 //const Double_t kP4 = 1.8631;
65 //const Double_t kP5 = 1.9479;
66
67 // Lower cutoff of the Bethe-Bloch-curve to limit step sizes
68 const Double_t kBgMin = 0.8;
69 const Double_t kBBMax = 6.83298;
70 //const Double_t kBgMin = 0.6;
71 //const Double_t kBBMax = 17.2809;
72 //const Double_t kBgMin = 0.4;
73 //const Double_t kBBMax = 82.0;
74
75 if (bg > kBgMin) {
76 Double_t yy = bg / TMath::Sqrt(1. + bg*bg);
77 Double_t aa = TMath::Power(yy,kP4);
78 Double_t bb = TMath::Power((1./bg),kP5);
79 bb = TMath::Log(kP3 + bb);
80 return ((kP2 - aa - bb)*kP1 / aa);
81 }
82 else {
83 return kBBMax;
84 }
85
b0f03c34 86}
87
88//_________________________________________________________________________
89Int_t AliTRDpidESD::MakePID(AliESD *event)
90{
91 //
92 // This function calculates the "detector response" PID probabilities
93 //
cc7cef99 94
95 AliTRDcalibDB* calibration = AliTRDcalibDB::Instance();
96 if (!calibration)
97 return -1;
98
99 // The class AliTRDCalPIDLQ contains precalculated prob dis.
63a700c6 100 const AliTRDCalPIDLQ *pd = calibration->GetPIDLQObject();
1a567dff 101 if (!pd) return -1;
defc9040 102
103 // Example to get mean for particle 2 (pi) and momentum number 4 (2 GeV)
104 // printf("%.2f \n", pd->GetMean(2, 4));
105 // Example of use of Copy Constructor
cc7cef99 106 // AliTRDCalPIDLQ *pd1 = new AliTRDCalPIDLQ(*pd);
bd50219c 107
108 Int_t ntrk=event->GetNumberOfTracks();
109 for (Int_t i=0; i<ntrk; i++) {
110 AliESDtrack *t=event->GetTrack(i);
111 if ((t->GetStatus()&AliESDtrack::kTRDin)==0)
1642e650 112 if ((t->GetStatus()&AliESDtrack::kTRDout)==0)
113 if ((t->GetStatus()&AliESDtrack::kTRDrefit)==0) continue;
114 if(t->GetTRDsignal()==0) continue;
bd50219c 115 // Int_t ns=AliESDtrack::kSPECIES;
116 Int_t ns=AliPID::kSPECIES;
117 Double_t p[10];
118 Double_t mom=t->GetP();
eee41b89 119 Double_t probTotal=0.0;
bd50219c 120 for (Int_t j=0; j<ns; j++) {
121 p[j]=1.;
122 for (Int_t ilayer=0; ilayer <6; ilayer++) {
6d45eaef 123 Double_t dedx=t->GetTRDsignals(ilayer,1);
bd50219c 124 Int_t timbin=t->GetTRDTimBin(ilayer);
eee41b89 125 p[j]*= pd->GetProbability(j,mom,dedx);
126 p[j]*= pd->GetProbabilityT(j,mom,timbin);
127 p[j]*= 100;
bd50219c 128 } // loop over layers
eee41b89 129 probTotal+=p[j];
bd50219c 130 } //loop over particle species
5f8ccb35 131 // printf(" %f %d %f %f %f \n", mom, timbin, p[0], p[1], p[2]);
b0f03c34 132 for (Int_t j=0; j<ns; j++) {
eee41b89 133 if(probTotal) p[j]/= probTotal;
134 else p[j]=1.0;
5f8ccb35 135 // p[j]=1.;
eee41b89 136 } //loop over particle species
b0f03c34 137 t->SetTRDpid(p);
eee41b89 138 } //loop over tracks
b0f03c34 139 return 0;
140}