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 **************************************************************************/
19 //-----------------------------------------------------------------------------
20 /// \class AliMUONTrackHitPattern
22 /// This class propagates tracks to trigger chambers
23 /// searching for fired strips.
25 /// To each track, a hit pattern for trigger chambers is set.
26 /// The hit pattern is a UShort_t with 8 bits used:
30 /// ----------- ------------
31 /// chamber: 11 12 13 14 | 11 12 13 14
32 /// cathode: bending | non-bending
34 /// The main method is:
37 /// \author Diego Stocco
38 //-----------------------------------------------------------------------------
41 #include "AliMUONTrackHitPattern.h"
43 #include "AliMUONConstants.h"
44 #include "AliMUONVDigit.h"
45 #include "AliMUONDigitMaker.h"
46 #include "AliMUONDigitStoreV1.h"
47 #include "AliMUONGeometryTransformer.h"
48 #include "AliMUONLocalTrigger.h"
49 #include "AliMUONLocalTriggerBoard.h"
50 #include "AliMUONTrack.h"
51 #include "AliMUONTrackExtrap.h"
52 #include "AliMUONTrackParam.h"
53 #include "AliMUONVTrackStore.h"
54 #include "AliMUONVTriggerStore.h"
56 #include "AliMpSegmentation.h"
57 #include "AliMpVSegmentation.h"
58 #include "AliMpDEManager.h"
59 #include "AliMUONReconstructor.h"
60 #include "AliMUONRecoParam.h"
64 #include "AliTracker.h"
66 #include <Riostream.h>
68 #include <TClonesArray.h>
73 ClassImp(AliMUONTrackHitPattern) // Class implementation in ROOT context
77 //______________________________________________________________________________
78 AliMUONTrackHitPattern::AliMUONTrackHitPattern(const AliMUONGeometryTransformer& transformer,
79 const AliMUONDigitMaker& digitMaker)
81 fTransformer(transformer),
82 fDigitMaker(digitMaker)
84 /// Default constructor
87 const AliMagF* kField = AliTracker::GetFieldMap();
88 if (!kField) AliFatal("No field available");
89 AliMUONTrackExtrap::SetField(kField);
93 //______________________________________________________________________________
94 AliMUONTrackHitPattern::~AliMUONTrackHitPattern(void)
100 //______________________________________________________________________________
101 void AliMUONTrackHitPattern::GetHitPattern(AliMUONVTrackStore& trackStore,
102 const AliMUONVTriggerStore& triggerStore) const
106 /// Loops on reco tracks, extrapolates them to trigger chambers
107 /// and searches for matching digits
110 const Int_t kMask[2][4]= {{0x80, 0x40, 0x20, 0x10},
111 {0x08, 0x04, 0x02, 0x01}};
116 AliMUONDigitStoreV1 digitStore;
118 TriggerDigits(triggerStore,digitStore);
120 AliMUONTrack* muonTrack;
121 TIter next(trackStore.CreateIterator());
123 const Int_t kNTrackingCh = AliMUONConstants::NTrackingCh();
125 while ( ( muonTrack = static_cast<AliMUONTrack*>(next()) ) )
128 AliMUONTrackParam trackParam(*((AliMUONTrackParam*) (muonTrack->GetTrackParamAtCluster()->Last())));
130 ApplyMCSCorrections(trackParam);
132 for(Int_t ch=0; ch<4; ++ch)
134 Int_t iChamber = kNTrackingCh+ch;
135 AliMUONTrackExtrap::ExtrapToZCov(&trackParam, AliMUONConstants::DefaultChamberZ(iChamber));
136 FindPadMatchingTrack(digitStore, trackParam, isMatch, iChamber);
137 for(Int_t cath=0; cath<2; ++cath)
139 if(isMatch[cath]) pattern |= kMask[cath][ch];
142 muonTrack->SetHitsPatternInTrigCh(pattern);
147 //______________________________________________________________________________
149 AliMUONTrackHitPattern::FindPadMatchingTrack(AliMUONVDigitStore& digitStore,
150 const AliMUONTrackParam& trackParam,
151 Bool_t isMatch[2], Int_t iChamber) const
154 /// Given track position, searches for matching digits.
157 Float_t minMatchDist[2];
159 for(Int_t cath=0; cath<2; ++cath)
161 isMatch[cath]=kFALSE;
162 minMatchDist[cath]=9999.;
165 TIter next(digitStore.CreateIterator());
166 AliMUONVDigit* mDigit;
168 while ( ( mDigit = static_cast<AliMUONVDigit*>(next()) ) )
170 Int_t currDetElemId = mDigit->DetElemId();
171 Int_t currCh = AliMpDEManager::GetChamberId(currDetElemId);
172 if(currCh!=iChamber) continue;
173 Int_t cathode = mDigit->Cathode();
174 Int_t ix = mDigit->PadX();
175 Int_t iy = mDigit->PadY();
176 Float_t xpad, ypad, zpad;
177 const AliMpVSegmentation* seg = AliMpSegmentation::Instance()
178 ->GetMpSegmentation(currDetElemId,AliMp::GetCathodType(cathode));
180 AliMpPad pad = seg->PadByIndices(AliMpIntPair(ix,iy),kTRUE);
181 Float_t xlocal1 = pad.Position().X();
182 Float_t ylocal1 = pad.Position().Y();
183 Float_t dpx = pad.Dimensions().X();
184 Float_t dpy = pad.Dimensions().Y();
185 fTransformer.Local2Global(currDetElemId, xlocal1, ylocal1, 0, xpad, ypad, zpad);
186 Float_t matchDist = MinDistanceFromPad(xpad, ypad, zpad, dpx, dpy, trackParam);
187 if(matchDist>minMatchDist[cathode])continue;
188 isMatch[cathode] = kTRUE;
189 if(isMatch[0] && isMatch[1]) break;
190 minMatchDist[cathode] = matchDist;
195 //______________________________________________________________________________
197 AliMUONTrackHitPattern::MinDistanceFromPad(Float_t xPad, Float_t yPad, Float_t zPad,
198 Float_t dpx, Float_t dpy,
199 const AliMUONTrackParam& trackParam) const
202 /// Decides if the digit belongs to the track.
205 AliMUONTrackParam trackParamAtPadZ(trackParam);
206 AliMUONTrackExtrap::ExtrapToZCov(&trackParamAtPadZ, zPad);
208 Float_t xTrackAtPad = trackParamAtPadZ.GetNonBendingCoor();
209 Float_t yTrackAtPad = trackParamAtPadZ.GetBendingCoor();
211 const Float_t kNSigma = AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTrigger();
213 const TMatrixD& kCovParam = trackParamAtPadZ.GetCovariances();
215 Float_t sigmaX = TMath::Sqrt(kCovParam(0,0));
216 Float_t sigmaY = TMath::Sqrt(kCovParam(2,2));
218 Float_t maxDistX = kNSigma * sigmaX; // in cm
219 Float_t maxDistY = kNSigma * sigmaY; // in cm
221 Float_t deltaX = TMath::Abs(xPad-xTrackAtPad)-dpx;
222 Float_t deltaY = TMath::Abs(yPad-yTrackAtPad)-dpy;
224 Float_t matchDist = 99999.;
225 if(deltaX<=maxDistX && deltaY<=maxDistY) matchDist = TMath::Max(deltaX, deltaY);
231 //______________________________________________________________________________
233 AliMUONTrackHitPattern::ApplyMCSCorrections(AliMUONTrackParam& trackParam) const
236 /// Returns uncertainties on extrapolated position.
237 /// Takes into account Branson plane corrections in the iron wall.
240 const Float_t kZFilterOut = AliMUONConstants::MuonFilterZEnd();
241 const Float_t kFilterThickness = TMath::Abs(kZFilterOut-AliMUONConstants::MuonFilterZBeg()); // cm
243 AliMUONTrackExtrap::ExtrapToZCov(&trackParam, kZFilterOut);
244 AliMUONTrackExtrap::AddMCSEffect(&trackParam, kFilterThickness, AliMUONConstants::MuonFilterX0());
249 //______________________________________________________________________________
251 AliMUONTrackHitPattern::TriggerDigits(const AliMUONVTriggerStore& triggerStore,
252 AliMUONVDigitStore& digitStore) const
255 /// make (S)Digit for trigger
260 AliMUONLocalTrigger* locTrg;
261 TIter next(triggerStore.CreateLocalIterator());
263 while ( ( locTrg = static_cast<AliMUONLocalTrigger*>(next()) ) )
265 if (locTrg->IsNull()) continue;
267 TArrayS xyPattern[2];
268 locTrg->GetXPattern(xyPattern[0]);
269 locTrg->GetYPattern(xyPattern[1]);
271 // do we need this ? (Ch.F.)
272 // for(Int_t cath=0; cath<2; ++cath)
274 // for(Int_t ch=0; ch<4; ++ch)
276 // if(xyPattern[cath][ch]==0) continue;
280 Int_t nBoard = locTrg->LoCircuit();
281 fDigitMaker.TriggerDigits(nBoard, xyPattern, digitStore);