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87594435 | 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 | ||
acd84897 | 16 | /* $Id$ */ |
fb17acd4 | 17 | |
87594435 | 18 | //------------------------------------------------------------------------- |
19 | // Implementation of the AliKalmanTrack class | |
066782e8 | 20 | // that is the base for AliTPCtrack, AliITStrackV2 and AliTRDtrack |
87594435 | 21 | // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch |
22 | //------------------------------------------------------------------------- | |
6c94f330 | 23 | #include <TGeoManager.h> |
39d4ae58 | 24 | |
87594435 | 25 | #include "AliKalmanTrack.h" |
87594435 | 26 | |
27 | ClassImp(AliKalmanTrack) | |
28 | ||
e2afb3b6 | 29 | //_______________________________________________________________________ |
6c94f330 | 30 | AliKalmanTrack::AliKalmanTrack():AliExternalTrackParam(), |
e2afb3b6 | 31 | fLab(-3141593), |
68b8060b | 32 | fFakeRatio(0), |
e2afb3b6 | 33 | fChi2(0), |
304864ab | 34 | fMass(AliPID::ParticleMass(AliPID::kPion)), |
90e48c0c | 35 | fN(0), |
36 | fStartTimeIntegral(kFALSE), | |
37 | fIntegratedLength(0) | |
e2afb3b6 | 38 | { |
116cbefd | 39 | // |
40 | // Default constructor | |
41 | // | |
c84a5e9e | 42 | |
7d0f8548 | 43 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; |
e2afb3b6 | 44 | } |
45 | ||
46 | //_______________________________________________________________________ | |
47 | AliKalmanTrack::AliKalmanTrack(const AliKalmanTrack &t): | |
6c94f330 | 48 | AliExternalTrackParam(t), |
e2afb3b6 | 49 | fLab(t.fLab), |
babd135a | 50 | fFakeRatio(t.fFakeRatio), |
e2afb3b6 | 51 | fChi2(t.fChi2), |
52 | fMass(t.fMass), | |
90e48c0c | 53 | fN(t.fN), |
54 | fStartTimeIntegral(t.fStartTimeIntegral), | |
55 | fIntegratedLength(t.fIntegratedLength) | |
e2afb3b6 | 56 | { |
116cbefd | 57 | // |
58 | // Copy constructor | |
59 | // | |
74f9526e | 60 | |
c84a5e9e | 61 | for (Int_t i=0; i<AliPID::kSPECIES; i++) |
62 | fIntegratedTime[i] = t.fIntegratedTime[i]; | |
74f9526e | 63 | } |
c5507f6d | 64 | |
74f9526e | 65 | //_______________________________________________________________________ |
66 | void AliKalmanTrack::StartTimeIntegral() | |
67 | { | |
49a7a79a | 68 | // Sylwester Radomski, GSI |
69 | // S.Radomski@gsi.de | |
74f9526e | 70 | // |
71 | // Start time integration | |
72 | // To be called at Vertex by ITS tracker | |
73 | // | |
74 | ||
75 | //if (fStartTimeIntegral) | |
f37d970d | 76 | // AliWarning("Reseting Recorded Time."); |
74f9526e | 77 | |
78 | fStartTimeIntegral = kTRUE; | |
304864ab | 79 | for(Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i] = 0; |
74f9526e | 80 | fIntegratedLength = 0; |
81 | } | |
7d0f8548 | 82 | |
74f9526e | 83 | //_______________________________________________________________________ |
84 | void AliKalmanTrack:: AddTimeStep(Double_t length) | |
85 | { | |
86 | // | |
87 | // Add step to integrated time | |
88 | // this method should be called by a sublasses at the end | |
89 | // of the PropagateTo function or by a tracker | |
90 | // each time step is made. | |
91 | // | |
92 | // If integration not started function does nothing | |
93 | // | |
94 | // Formula | |
95 | // dt = dl * sqrt(p^2 + m^2) / p | |
96 | // p = pT * (1 + tg^2 (lambda) ) | |
97 | // | |
98 | // pt = 1/external parameter [4] | |
99 | // tg lambda = external parameter [3] | |
100 | // | |
101 | // | |
102 | // Sylwester Radomski, GSI | |
103 | // S.Radomski@gsi.de | |
104 | // | |
105 | ||
5d8718b8 | 106 | static const Double_t kcc = 2.99792458e-2; |
74f9526e | 107 | |
108 | if (!fStartTimeIntegral) return; | |
109 | ||
110 | fIntegratedLength += length; | |
111 | ||
74f9526e | 112 | Double_t xr, param[5]; |
113 | Double_t pt, tgl; | |
114 | ||
115 | GetExternalParameters(xr, param); | |
116 | pt = 1/param[4] ; | |
117 | tgl = param[3]; | |
118 | ||
119 | Double_t p = TMath::Abs(pt * TMath::Sqrt(1+tgl*tgl)); | |
120 | ||
121 | if (length > 100) return; | |
122 | ||
304864ab | 123 | for (Int_t i=0; i<AliPID::kSPECIES; i++) { |
74f9526e | 124 | |
304864ab | 125 | Double_t mass = AliPID::ParticleMass(i); |
74f9526e | 126 | Double_t correction = TMath::Sqrt( pt*pt * (1 + tgl*tgl) + mass * mass ) / p; |
5d8718b8 | 127 | Double_t time = length * correction / kcc; |
74f9526e | 128 | |
74f9526e | 129 | fIntegratedTime[i] += time; |
130 | } | |
e2afb3b6 | 131 | } |
132 | ||
74f9526e | 133 | //_______________________________________________________________________ |
74f9526e | 134 | Double_t AliKalmanTrack::GetIntegratedTime(Int_t pdg) const |
135 | { | |
49a7a79a | 136 | // Sylwester Radomski, GSI |
137 | // S.Radomski@gsi.de | |
74f9526e | 138 | // |
139 | // Return integrated time hypothesis for a given particle | |
140 | // type assumption. | |
141 | // | |
142 | // Input parameter: | |
143 | // pdg - Pdg code of a particle type | |
144 | // | |
145 | ||
146 | ||
147 | if (!fStartTimeIntegral) { | |
f37d970d | 148 | AliWarning("Time integration not started"); |
74f9526e | 149 | return 0.; |
150 | } | |
151 | ||
304864ab | 152 | for (Int_t i=0; i<AliPID::kSPECIES; i++) |
153 | if (AliPID::ParticleCode(i) == TMath::Abs(pdg)) return fIntegratedTime[i]; | |
74f9526e | 154 | |
f37d970d | 155 | AliWarning(Form("Particle type [%d] not found", pdg)); |
74f9526e | 156 | return 0; |
157 | } | |
ae982df3 | 158 | |
159 | void AliKalmanTrack::GetIntegratedTimes(Double_t *times) const { | |
304864ab | 160 | for (Int_t i=0; i<AliPID::kSPECIES; i++) times[i]=fIntegratedTime[i]; |
ae982df3 | 161 | } |
162 | ||
163 | void AliKalmanTrack::SetIntegratedTimes(const Double_t *times) { | |
304864ab | 164 | for (Int_t i=0; i<AliPID::kSPECIES; i++) fIntegratedTime[i]=times[i]; |
ae982df3 | 165 | } |
166 |