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():
41 fMuonForwardTracks(0),
45 fXPointOfClosestApproach(9999),
46 fYPointOfClosestApproach(9999),
47 fZPointOfClosestApproach(9999)
50 // default constructor
52 fMuonForwardTracks = new TClonesArray("AliMuonForwardTrack", 2);
53 fMuonForwardTracks -> SetOwner(kTRUE);
57 //====================================================================================================================================================
59 AliMuonForwardTrackPair::AliMuonForwardTrackPair(AliMuonForwardTrack *track0, AliMuonForwardTrack *track1):
61 fMuonForwardTracks(0),
65 fXPointOfClosestApproach(9999),
66 fYPointOfClosestApproach(9999),
67 fZPointOfClosestApproach(9999)
70 fMuonForwardTracks = new TClonesArray("AliMuonForwardTrack", 2);
71 fMuonForwardTracks->SetOwner(kTRUE);
72 new ((*fMuonForwardTracks)[0]) AliMuonForwardTrack(*track0);
73 new ((*fMuonForwardTracks)[1]) AliMuonForwardTrack(*track1);
76 SetPointOfClosestApproach();
80 //====================================================================================================================================================
82 AliMuonForwardTrackPair::AliMuonForwardTrackPair(const AliMuonForwardTrackPair& trackPair):
84 fMuonForwardTracks(NULL),
85 fKinemMC(trackPair.fKinemMC),
86 fKinem(trackPair.fKinem),
87 fIsKinemSet(trackPair.fIsKinemSet),
88 fXPointOfClosestApproach(trackPair.fXPointOfClosestApproach),
89 fYPointOfClosestApproach(trackPair.fYPointOfClosestApproach),
90 fZPointOfClosestApproach(trackPair.fZPointOfClosestApproach)
94 fMuonForwardTracks = new TClonesArray(*(trackPair.fMuonForwardTracks));
95 fMuonForwardTracks -> SetOwner(kTRUE);
99 //====================================================================================================================================================
101 AliMuonForwardTrackPair& AliMuonForwardTrackPair::operator=(const AliMuonForwardTrackPair& trackPair) {
103 // Asignment operator
105 // check assignement to self
106 if (this == &trackPair) return *this;
108 // base class assignement
109 AliMuonForwardTrackPair::operator=(trackPair);
114 fMuonForwardTracks = new TClonesArray(*(trackPair.fMuonForwardTracks));
115 fMuonForwardTracks->SetOwner(kTRUE);
117 fKinemMC = trackPair.fKinemMC;
118 fKinem = trackPair.fKinem;
119 fIsKinemSet = trackPair.fIsKinemSet;
120 fXPointOfClosestApproach = trackPair.fXPointOfClosestApproach;
121 fYPointOfClosestApproach = trackPair.fYPointOfClosestApproach;
122 fZPointOfClosestApproach = trackPair.fZPointOfClosestApproach;
128 //====================================================================================================================================================
130 Double_t AliMuonForwardTrackPair::GetWeightedOffset(Double_t x, Double_t y, Double_t z) {
132 Double_t weightedOffset[2]={0};
134 weightedOffset[0] = GetTrack(0)->GetWeightedOffset(x, y, z);
135 weightedOffset[1] = GetTrack(1)->GetWeightedOffset(x, y, z);
137 Double_t weightedOffsetDimuon = TMath::Sqrt(0.5 * (weightedOffset[0]*weightedOffset[0] + weightedOffset[1]*weightedOffset[1]));
139 return weightedOffsetDimuon;
143 //====================================================================================================================================================
145 Double_t AliMuonForwardTrackPair::GetMassWithoutMFT(Double_t x, Double_t y, Double_t z, Int_t nClusters) {
147 Int_t idCluster[2] = {0};
149 idCluster[0] = GetTrack(0)->GetNMUONClusters() - nClusters;
150 idCluster[1] = GetTrack(1)->GetNMUONClusters() - nClusters;
152 if (idCluster[0]<0) idCluster[0] = 0;
153 if (idCluster[1]<0) idCluster[1] = 0;
155 AliMUONTrackParam *param0 = GetTrack(0)->GetTrackParamAtMUONCluster(idCluster[0]);
156 AliMUONTrackParam *param1 = GetTrack(1)->GetTrackParamAtMUONCluster(idCluster[1]);
158 AliDebug(2, Form("MUON before extrap: 1st muon = (%f, %f, %f) 2nd muon = (%f, %f, %f)",
159 param0->Px(), param0->Py(), param0->Pz(), param1->Px(), param1->Py(), param1->Pz()));
161 AliDebug(2, Form("Extrapolating 1st muon from z = %f to z = %f", param0->GetZ(), z));
162 AliMUONTrackExtrap::ExtrapToVertex(param0, x, y, z, 0., 0.); // this should reproduce what is done in AliMUONESDInterface::MUONToESD(...)
163 AliDebug(2, Form("Extrapolating 2nd muon from z = %f to z = %f", param1->GetZ(), z));
164 AliMUONTrackExtrap::ExtrapToVertex(param1, x, y, z, 0., 0.); // this should reproduce what is done in AliMUONESDInterface::MUONToESD(...)
166 AliDebug(2, Form("MUON after extrap: 1st muon = (%f, %f, %f) 2nd muon = (%f, %f, %f)",
167 param0->Px(), param0->Py(), param0->Pz(), param1->Px(), param1->Py(), param1->Pz()));
169 Double_t momentum[2] = {0};
171 momentum[0] = param0->P();
172 momentum[1] = param1->P();
174 Double_t mMu = TDatabasePDG::Instance()->GetParticle("mu-")->Mass();
178 dimu.SetE(TMath::Sqrt(mMu*mMu + momentum[0]*momentum[0]) + TMath::Sqrt(mMu*mMu + momentum[1]*momentum[1]));
180 dimu.SetPx(param0->Px() + param1->Px());
181 dimu.SetPy(param0->Py() + param1->Py());
182 dimu.SetPz(param0->Pz() + param1->Pz());
188 //====================================================================================================================================================
190 void AliMuonForwardTrackPair::SetKinemMC() {
192 if ( !(GetTrack(0)->GetMCTrackRef()) || !(GetTrack(1)->GetMCTrackRef()) ) return;
194 AliDebug(2, Form("MC: 1st muon = (%f, %f, %f) 2nd muon = (%f, %f, %f)",
195 GetTrack(0)->GetMCTrackRef()->Px(), GetTrack(0)->GetMCTrackRef()->Py(), GetTrack(0)->GetMCTrackRef()->Pz(),
196 GetTrack(1)->GetMCTrackRef()->Px(), GetTrack(1)->GetMCTrackRef()->Py(), GetTrack(1)->GetMCTrackRef()->Pz()));
198 fKinemMC.SetE(GetTrack(0)->GetMCTrackRef()->Energy() + GetTrack(1)->GetMCTrackRef()->Energy());
200 fKinemMC.SetPx(GetTrack(0)->GetMCTrackRef()->Px() + GetTrack(1)->GetMCTrackRef()->Px());
201 fKinemMC.SetPy(GetTrack(0)->GetMCTrackRef()->Py() + GetTrack(1)->GetMCTrackRef()->Py());
202 fKinemMC.SetPz(GetTrack(0)->GetMCTrackRef()->Pz() + GetTrack(1)->GetMCTrackRef()->Pz());
206 //====================================================================================================================================================
208 void AliMuonForwardTrackPair::SetKinem(Double_t z, Int_t nClusters) {
210 // if (!fMuonForwardTracks) return kFALSE;
211 // if (!fMuonForwardTracks->At(0) || !fMuonForwardTracks->At(1)) return kFALSE;
213 Int_t idCluster[2] = {0};
215 idCluster[0] = GetTrack(0)->GetNMFTClusters() - nClusters;
216 idCluster[1] = GetTrack(1)->GetNMFTClusters() - nClusters;
218 if (idCluster[0]<0) idCluster[0] = 0;
219 if (idCluster[1]<0) idCluster[1] = 0;
221 Double_t momentum[2] = {0};
223 AliMUONTrackParam *param0 = GetTrack(0)->GetTrackParamAtMFTCluster(idCluster[0]);
224 AliMUONTrackParam *param1 = GetTrack(1)->GetTrackParamAtMFTCluster(idCluster[1]);
226 AliDebug(2, Form("MFT before extrap: 1st muon = (%f, %f, %f) 2nd muon = (%f, %f, %f)",
227 param0->Px(), param0->Py(), param0->Pz(), param1->Px(), param1->Py(), param1->Pz()));
229 if (TMath::Abs(z)<1e6) {
230 AliDebug(2, Form("Extrapolating 1st muon from z = %f to z = %f", param0->GetZ(), z));
231 AliMUONTrackExtrap::ExtrapToZCov(param0, z);
232 AliDebug(2, Form("Extrapolating 2nd muon from z = %f to z = %f", param1->GetZ(), z));
233 AliMUONTrackExtrap::ExtrapToZCov(param1, z);
236 AliDebug(2, Form("MFT after extrap: 1st muon = (%f, %f, %f) 2nd muon = (%f, %f, %f)",
237 param0->Px(), param0->Py(), param0->Pz(), param1->Px(), param1->Py(), param1->Pz()));
239 momentum[0] = (param0->P());
240 momentum[1] = (param1->P());
242 Double_t mMu = TDatabasePDG::Instance()->GetParticle("mu-")->Mass();
244 fKinem.SetE(TMath::Sqrt(mMu*mMu + momentum[0]*momentum[0]) + TMath::Sqrt(mMu*mMu + momentum[1]*momentum[1]));
245 fKinem.SetPx(param0->Px() + param1->Px());
246 fKinem.SetPy(param0->Py() + param1->Py());
247 fKinem.SetPz(param0->Pz() + param1->Pz());
253 //====================================================================================================================================================
255 void AliMuonForwardTrackPair::SetPointOfClosestApproach() {
257 AliMUONTrackParam *param0 = GetTrack(0)->GetTrackParamAtMFTCluster(0);
258 AliMUONTrackParam *param1 = GetTrack(1)->GetTrackParamAtMFTCluster(0);
260 Double_t step = 1.; // in cm
261 Double_t startPoint = 0.;
263 Double_t r[3]={0}, z[3]={startPoint, startPoint+step, startPoint+2*step};
265 for (Int_t i=0; i<3; i++) {
266 AliMUONTrackExtrap::ExtrapToZCov(param0, z[i]);
267 AliMUONTrackExtrap::ExtrapToZCov(param1, z[i]);
268 Double_t dX = param0->GetNonBendingCoor() - param1->GetNonBendingCoor();
269 Double_t dY = param0->GetBendingCoor() - param1->GetBendingCoor();
270 r[i] = TMath::Sqrt(dX*dX + dY*dY);
273 Double_t researchDirection=0.;
275 if (r[0]>r[1] && r[1]>r[2]) researchDirection = +1.; // towards z positive
276 else if (r[0]<r[1] && r[1]<r[2]) researchDirection = -1.; // towards z negative
277 else if (r[0]<r[1] && r[1]>r[2]) {
278 AliError("Point of closest approach cannot be found for dimuon (no minima)");
282 while (TMath::Abs(researchDirection)>0.5) {
283 if (researchDirection>0.) {
286 z[2] = z[1]+researchDirection*step;
291 z[0] = z[1]+researchDirection*step;
293 if (TMath::Abs(z[0])>900.) {
294 AliError("Point of closest approach cannot be found for dimuon (no minima)");
297 for (Int_t i=0; i<3; i++) {
298 AliMUONTrackExtrap::ExtrapToZCov(param0, z[i]);
299 AliMUONTrackExtrap::ExtrapToZCov(param1, z[i]);
300 Double_t dX = param0->GetNonBendingCoor() - param1->GetNonBendingCoor();
301 Double_t dY = param0->GetBendingCoor() - param1->GetBendingCoor();
302 r[i] = TMath::Sqrt(dX*dX + dY*dY);
304 researchDirection=0.;
305 if (r[0]>r[1] && r[1]>r[2]) researchDirection = +1.; // towards z positive
306 else if (r[0]<r[1] && r[1]<r[2]) researchDirection = -1.; // towards z negative
309 AliDebug(2,"Minimum region has been found");
312 while (step>AliMFTConstants::fPrecisionPointOfClosestApproach) {
315 for (Int_t i=0; i<3; i++) {
316 AliMUONTrackExtrap::ExtrapToZCov(param0, z[i]);
317 AliMUONTrackExtrap::ExtrapToZCov(param1, z[i]);
318 Double_t dX = param0->GetNonBendingCoor() - param1->GetNonBendingCoor();
319 Double_t dY = param0->GetBendingCoor() - param1->GetBendingCoor();
320 r[i] = TMath::Sqrt(dX*dX + dY*dY);
322 if (r[0]<r[1]) z[1] = z[0];
323 else if (r[2]<r[1]) z[1] = z[2];
327 fZPointOfClosestApproach = z[1];
328 AliMUONTrackExtrap::ExtrapToZCov(param0, fZPointOfClosestApproach);
329 AliMUONTrackExtrap::ExtrapToZCov(param1, fZPointOfClosestApproach);
330 fXPointOfClosestApproach = 0.5*(param0->GetNonBendingCoor() + param1->GetNonBendingCoor());
331 fYPointOfClosestApproach = 0.5*(param0->GetBendingCoor() + param1->GetBendingCoor());
333 AliDebug(2,Form("Point of Closest Approach: (%f, %f, %f)",fXPointOfClosestApproach,fYPointOfClosestApproach,fZPointOfClosestApproach));
337 //====================================================================================================================================================
339 Bool_t AliMuonForwardTrackPair::IsResonance() {
341 Bool_t result = kFALSE;
343 Int_t labelMC[2] = {0};
344 Int_t codePDG[2] = {0};
346 for (Int_t iTrack=0; iTrack<2; iTrack++) {
347 labelMC[iTrack] = GetTrack(iTrack)->GetParentMCLabel(0);
348 codePDG[iTrack] = GetTrack(iTrack)->GetParentPDGCode(0);
351 AliDebug(1, Form("Muons' mothers: (%d, %d)", labelMC[0], labelMC[1]));
353 if (labelMC[0]==labelMC[1] && codePDG[0]==codePDG[1] && (codePDG[0]== 113 ||
359 codePDG[0]==100443 ||
361 codePDG[0]==100553 ) ) result = kTRUE;
363 if (result) AliDebug(1, Form("Pair is a resonance %d", codePDG[0]));
369 //====================================================================================================================================================