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 //====================================================================================================================================================
18 // Description of an ALICE muon forward track pair, i.e. a pair of AliMuonForwardTrack objects
20 // Contact author: antonio.uras@cern.ch
22 //====================================================================================================================================================
25 #include "AliMUONTrackParam.h"
26 #include "TParticle.h"
27 #include "AliMuonForwardTrack.h"
28 #include "AliMUONTrackExtrap.h"
29 #include "TClonesArray.h"
30 #include "TDatabasePDG.h"
31 #include "TLorentzVector.h"
33 #include "AliMuonForwardTrackPair.h"
35 ClassImp(AliMuonForwardTrackPair)
37 //====================================================================================================================================================
39 AliMuonForwardTrackPair::AliMuonForwardTrackPair():
44 // default constructor
46 fMuonForwardTracks = new TClonesArray("AliMuonForwardTrack", 2);
50 //====================================================================================================================================================
52 AliMuonForwardTrackPair::AliMuonForwardTrackPair(AliMuonForwardTrack *track0, AliMuonForwardTrack *track1):
57 fMuonForwardTracks = new TClonesArray("AliMuonForwardTrack", 2);
59 new ((*fMuonForwardTracks)[0]) AliMuonForwardTrack(*track0);
60 new ((*fMuonForwardTracks)[1]) AliMuonForwardTrack(*track1);
64 //====================================================================================================================================================
66 AliMuonForwardTrackPair::AliMuonForwardTrackPair(const AliMuonForwardTrackPair& trackPair):
68 fMuonForwardTracks(trackPair.fMuonForwardTracks)
75 //====================================================================================================================================================
77 AliMuonForwardTrackPair& AliMuonForwardTrackPair::operator=(const AliMuonForwardTrackPair& trackPair) {
81 // check assignement to self
82 if (this == &trackPair) return *this;
84 // base class assignement
85 AliMuonForwardTrackPair::operator=(trackPair);
90 fMuonForwardTracks = trackPair.fMuonForwardTracks;
96 //====================================================================================================================================================
98 void AliMuonForwardTrackPair::SetTrack(Int_t iTrack, AliMuonForwardTrack *track) {
100 if (iTrack==0 || iTrack==1) {
101 new ((*fMuonForwardTracks)[iTrack]) AliMuonForwardTrack(*track);
106 //====================================================================================================================================================
108 Double_t AliMuonForwardTrackPair::GetWeightedOffset(Double_t x, Double_t y, Double_t z) {
110 Double_t weightedOffset[2]={0};
112 weightedOffset[0] = ((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetWeightedOffset(x, y, z);
113 weightedOffset[1] = ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetWeightedOffset(x, y, z);
115 Double_t weightedOffsetDimuon = TMath::Sqrt(0.5 * (weightedOffset[0]*weightedOffset[0] + weightedOffset[1]*weightedOffset[1]));
117 return weightedOffsetDimuon;
121 //====================================================================================================================================================
123 Double_t AliMuonForwardTrackPair::GetMass(Double_t z, Int_t nClusters) {
125 Int_t idCluster[2] = {0};
127 idCluster[0] = ((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetNMFTClusters() - nClusters;
128 idCluster[1] = ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetNMFTClusters() - nClusters;
130 if (idCluster[0]<0) idCluster[0] = 0;
131 if (idCluster[1]<0) idCluster[1] = 0;
133 Double_t momentum[2] = {0};
135 AliMUONTrackParam *param0 = ((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetTrackParamAtMFTCluster(idCluster[0]);
136 AliMUONTrackParam *param1 = ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetTrackParamAtMFTCluster(idCluster[1]);
138 if (TMath::Abs(z)<1e6) {
139 AliMUONTrackExtrap::ExtrapToZCov(param0, z);
140 AliMUONTrackExtrap::ExtrapToZCov(param1, z);
143 momentum[0] = (param0->P());
144 momentum[1] = (param1->P());
146 Double_t mMu = TDatabasePDG::Instance()->GetParticle("mu-")->Mass();
150 dimu.SetE(TMath::Sqrt(mMu*mMu + momentum[0]*momentum[0]) + TMath::Sqrt(mMu*mMu + momentum[1]*momentum[1]));
152 dimu.SetPx(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetTrackParamAtMFTCluster(idCluster[0])->Px()+
153 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetTrackParamAtMFTCluster(idCluster[1])->Px());
155 dimu.SetPy(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetTrackParamAtMFTCluster(idCluster[0])->Py()+
156 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetTrackParamAtMFTCluster(idCluster[1])->Py());
158 dimu.SetPz(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetTrackParamAtMFTCluster(idCluster[0])->Pz()+
159 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetTrackParamAtMFTCluster(idCluster[1])->Pz());
165 //====================================================================================================================================================
167 Double_t AliMuonForwardTrackPair::GetMassWithoutMFT(Double_t x, Double_t y, Double_t z, Int_t nClusters) {
169 Int_t idCluster[2] = {0};
171 idCluster[0] = ((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetNMUONClusters() - nClusters;
172 idCluster[1] = ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetNMUONClusters() - nClusters;
174 if (idCluster[0]<0) idCluster[0] = 0;
175 if (idCluster[1]<0) idCluster[1] = 0;
177 AliMUONTrackParam *param0 = ((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetTrackParamAtMUONCluster(idCluster[0]);
178 AliMUONTrackParam *param1 = ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetTrackParamAtMUONCluster(idCluster[1]);
180 AliMUONTrackExtrap::ExtrapToVertex(param0, x, y, z, 0., 0.); // this should reproduce what is done in AliMUONESDInterface::MUONToESD(...)
181 AliMUONTrackExtrap::ExtrapToVertex(param1, x, y, z, 0., 0.); // this should reproduce what is done in AliMUONESDInterface::MUONToESD(...)
183 Double_t momentum[2] = {0};
185 momentum[0] = param0->P();
186 momentum[1] = param1->P();
188 Double_t mMu = TDatabasePDG::Instance()->GetParticle("mu-")->Mass();
192 dimu.SetE(TMath::Sqrt(mMu*mMu + momentum[0]*momentum[0]) + TMath::Sqrt(mMu*mMu + momentum[1]*momentum[1]));
194 dimu.SetPx(param0->Px() + param1->Px());
195 dimu.SetPy(param0->Py() + param1->Py());
196 dimu.SetPz(param0->Pz() + param1->Pz());
202 //====================================================================================================================================================
204 Double_t AliMuonForwardTrackPair::GetMassMC() {
208 dimu.SetE(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetMCTrackRef()->Energy() +
209 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetMCTrackRef()->Energy());
211 dimu.SetPx(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetMCTrackRef()->Px() +
212 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetMCTrackRef()->Px());
214 dimu.SetPy(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetMCTrackRef()->Py() +
215 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetMCTrackRef()->Py());
217 dimu.SetPz(((AliMuonForwardTrack*) fMuonForwardTracks->At(0))->GetMCTrackRef()->Pz() +
218 ((AliMuonForwardTrack*) fMuonForwardTracks->At(1))->GetMCTrackRef()->Pz());
224 //====================================================================================================================================================