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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 | /* $Id$ */ | |
17 | ||
18 | //------------------------------------------------------------------------- | |
19 | // Implementation of the AliKalmanTrack class | |
20 | // that is the base for AliTPCtrack, AliITStrackV2 and AliTRDtrack | |
21 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch | |
22 | //------------------------------------------------------------------------- | |
23 | #include <TGeoManager.h> | |
24 | ||
25 | #include "AliKalmanTrack.h" | |
26 | ||
27 | ClassImp(AliKalmanTrack) | |
28 | ||
29 | //_______________________________________________________________________ | |
30 | AliKalmanTrack::AliKalmanTrack():AliExternalTrackParam(), | |
31 | fFakeRatio(0), | |
32 | fChi2(0), | |
33 | fMass(AliPID::ParticleMass(AliPID::kPion)), | |
34 | fLab(-3141593), | |
35 | fN(0), | |
36 | fStartTimeIntegral(kFALSE), | |
37 | fIntegratedLength(0) | |
38 | { | |
39 | // | |
40 | // Default constructor | |
41 | // | |
42 | ||
43 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; | |
44 | } | |
45 | ||
46 | AliKalmanTrack::AliKalmanTrack(const AliKalmanTrack &t): | |
47 | AliExternalTrackParam(t), | |
48 | fFakeRatio(t.fFakeRatio), | |
49 | fChi2(t.fChi2), | |
50 | fMass(t.fMass), | |
51 | fLab(t.fLab), | |
52 | fN(t.fN), | |
53 | fStartTimeIntegral(t.fStartTimeIntegral), | |
54 | fIntegratedLength(t.fIntegratedLength) | |
55 | { | |
56 | // | |
57 | // Copy constructor | |
58 | // | |
59 | ||
60 | for (Int_t i=0; i<AliPID::kSPECIES; i++) | |
61 | fIntegratedTime[i] = t.fIntegratedTime[i]; | |
62 | } | |
63 | ||
64 | AliKalmanTrack& AliKalmanTrack::operator=(const AliKalmanTrack&o){ | |
65 | if(this!=&o){ | |
66 | AliExternalTrackParam::operator=(o); | |
67 | fLab = o.fLab; | |
68 | fFakeRatio = o.fFakeRatio; | |
69 | fChi2 = o.fChi2; | |
70 | fMass = o.fMass; | |
71 | fN = o.fN; | |
72 | fStartTimeIntegral = o.fStartTimeIntegral; | |
73 | for(Int_t i = 0;i<AliPID::kSPECIES;++i)fIntegratedTime[i] = o.fIntegratedTime[i]; | |
74 | fIntegratedLength = o.fIntegratedLength; | |
75 | } | |
76 | return *this; | |
77 | } | |
78 | ||
79 | //_______________________________________________________________________ | |
80 | void AliKalmanTrack::StartTimeIntegral() | |
81 | { | |
82 | // Sylwester Radomski, GSI | |
83 | // S.Radomski@gsi.de | |
84 | // | |
85 | // Start time integration | |
86 | // To be called at Vertex by ITS tracker | |
87 | // | |
88 | ||
89 | //if (fStartTimeIntegral) | |
90 | // AliWarning("Reseting Recorded Time."); | |
91 | ||
92 | fStartTimeIntegral = kTRUE; | |
93 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; | |
94 | fIntegratedLength = 0; | |
95 | } | |
96 | ||
97 | //_______________________________________________________________________ | |
98 | void AliKalmanTrack:: AddTimeStep(Double_t length) | |
99 | { | |
100 | // | |
101 | // Add step to integrated time | |
102 | // this method should be called by a sublasses at the end | |
103 | // of the PropagateTo function or by a tracker | |
104 | // each time step is made. | |
105 | // | |
106 | // If integration not started function does nothing | |
107 | // | |
108 | // Formula | |
109 | // dt = dl * sqrt(p^2 + m^2) / p | |
110 | // p = pT * (1 + tg^2 (lambda) ) | |
111 | // | |
112 | // pt = 1/external parameter [4] | |
113 | // tg lambda = external parameter [3] | |
114 | // | |
115 | // | |
116 | // Sylwester Radomski, GSI | |
117 | // S.Radomski@gsi.de | |
118 | // | |
119 | ||
120 | static const Double_t kcc = 2.99792458e-2; | |
121 | ||
122 | if (!fStartTimeIntegral) return; | |
123 | ||
124 | fIntegratedLength += length; | |
125 | ||
126 | Double_t xr, param[5]; | |
127 | Double_t pt, tgl; | |
128 | ||
129 | GetExternalParameters(xr, param); | |
130 | pt = 1/param[4] ; | |
131 | tgl = param[3]; | |
132 | ||
133 | Double_t p = TMath::Abs(pt * TMath::Sqrt(1+tgl*tgl)); | |
134 | ||
135 | if (length > 100) return; | |
136 | ||
137 | for (Int_t i=0; i<AliPID::kSPECIES; i++) { | |
138 | ||
139 | Double_t mass = AliPID::ParticleMass(i); | |
140 | Double_t correction = TMath::Sqrt( pt*pt * (1 + tgl*tgl) + mass * mass ) / p; | |
141 | Double_t time = length * correction / kcc; | |
142 | ||
143 | fIntegratedTime[i] += time; | |
144 | } | |
145 | } | |
146 | ||
147 | //_______________________________________________________________________ | |
148 | Double_t AliKalmanTrack::GetIntegratedTime(Int_t pdg) const | |
149 | { | |
150 | // Sylwester Radomski, GSI | |
151 | // S.Radomski@gsi.de | |
152 | // | |
153 | // Return integrated time hypothesis for a given particle | |
154 | // type assumption. | |
155 | // | |
156 | // Input parameter: | |
157 | // pdg - Pdg code of a particle type | |
158 | // | |
159 | ||
160 | ||
161 | if (!fStartTimeIntegral) { | |
162 | AliWarning("Time integration not started"); | |
163 | return 0.; | |
164 | } | |
165 | ||
166 | for (Int_t i=0; i<AliPID::kSPECIES; i++) | |
167 | if (AliPID::ParticleCode(i) == TMath::Abs(pdg)) return fIntegratedTime[i]; | |
168 | ||
169 | AliWarning(Form("Particle type [%d] not found", pdg)); | |
170 | return 0; | |
171 | } | |
172 | ||
173 | void AliKalmanTrack::GetIntegratedTimes(Double_t *times) const { | |
174 | for (Int_t i=0; i<AliPID::kSPECIES; i++) times[i]=fIntegratedTime[i]; | |
175 | } | |
176 | ||
177 | void AliKalmanTrack::SetIntegratedTimes(const Double_t *times) { | |
178 | for (Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i]=times[i]; | |
179 | } | |
180 |