]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - MUON/AliMUONTrackHitPattern.cxx
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[u/mrichter/AliRoot.git] / MUON / AliMUONTrackHitPattern.cxx
index 582b7bff0393eabdcfefeee5f249e09463d01179..b6614030785f9c875c58c13b4fcf5d8ffc6caeaa 100644 (file)
 #include "AliMUONVDigitStore.h"
 #include "AliMUONGeometryTransformer.h"
 #include "AliMUONLocalTrigger.h"
-#include "AliMUONLocalTriggerBoard.h"
 #include "AliMUONRecoParam.h"
 #include "AliMUONTrack.h"
 #include "AliMUONTrackExtrap.h"
 #include "AliMUONTrackParam.h"
 #include "AliMUONVTrackStore.h"
 #include "AliMUONVTriggerStore.h"
+#include "AliMUONTriggerTrack.h"
+#include "AliMUONVTriggerTrackStore.h"
+#include "AliMUONTriggerUtilities.h"
+
 #include "AliMpPad.h"
 #include "AliMpSegmentation.h"
 #include "AliMpVSegmentation.h"
 #include "AliMpDEManager.h"
-#include "AliMUONReconstructor.h"
-#include "AliMUONTriggerTrack.h"
-#include "AliMUONVTriggerTrackStore.h"
-
+#include "AliMpArea.h"
 #include "AliMpConstants.h"
 
 #include "AliLog.h"
-#include "AliTracker.h"
 #include "AliESDMuonTrack.h"
+#include "AliCodeTimer.h"
 
 #include <Riostream.h>
-#include <TArrayS.h>
-#include <TClonesArray.h>
+#include <TArrayI.h>
 #include <TMath.h>
 #include <TMatrixD.h>
-#include <TROOT.h>
-#include <TDirectory.h>
-#include <TFile.h>
-#include <TSystem.h>
-#include <TVector2.h>
-
-#include <cassert>
+#include <TVector3.h>
+#include <TArrayF.h>
+#include <TRandom.h>
 
 /// \cond CLASSIMP
 ClassImp(AliMUONTrackHitPattern) // Class implementation in ROOT context
@@ -80,15 +75,17 @@ ClassImp(AliMUONTrackHitPattern) // Class implementation in ROOT context
 //______________________________________________________________________________
 AliMUONTrackHitPattern::AliMUONTrackHitPattern(const AliMUONRecoParam* recoParam,
                                                const AliMUONGeometryTransformer& transformer,
-                                               const AliMUONVDigitStore& digitStore)
+                                               const AliMUONVDigitStore& digitStore,
+                                               const AliMUONTriggerUtilities* triggerUtilities)
 : TObject(),
 fkRecoParam(recoParam),
 fkTransformer(transformer),
 fkDigitStore(digitStore),
-fkMaxDistance(99999.)
+fkTriggerUtilities(triggerUtilities),
+fkMaxDistance(99999.) // obsolete
 {
-    /// Default constructor
-    AliMUONTrackExtrap::SetField();
+  /// Default constructor
+  AliMUONTrackExtrap::SetField();
 }
 
 
@@ -98,14 +95,22 @@ AliMUONTrackHitPattern::~AliMUONTrackHitPattern(void)
   /// Destructor
 }
 
-//_____________________________________________________________________________
-void AliMUONTrackHitPattern::CheckConstants() const
-{
-/// Check consistence of redefined constants 
 
-  assert(fgkNcathodes == AliMpConstants::NofCathodes());    
-  assert(fgkNchambers == AliMpConstants::NofTriggerChambers());    
-  assert(fgkNplanes == AliMpConstants::NofTriggerChambers() * fgkNcathodes);    
+//______________________________________________________________________________
+void 
+AliMUONTrackHitPattern::ApplyMCSCorrections(AliMUONTrackParam& trackParam) const
+{
+  //
+  /// Returns uncertainties on extrapolated position.
+  /// Takes into account Branson plane corrections in the iron wall.
+  //
+  
+  const Float_t kZFilterOut = AliMUONConstants::MuonFilterZEnd();
+  const Float_t kFilterThickness = kZFilterOut-AliMUONConstants::MuonFilterZBeg(); // cm
+  
+  AliMUONTrackExtrap::ExtrapToZCov(&trackParam, kZFilterOut); // Extrap to muon filter end
+  AliMUONTrackExtrap::AddMCSEffect(&trackParam, kFilterThickness, AliMUONConstants::MuonFilterX0()); // Add MCS effects
+  return;
 }
 
 
@@ -124,11 +129,23 @@ void AliMUONTrackHitPattern::ExecuteValidation(const AliMUONVTrackStore& trackSt
   AliMUONTriggerTrack* triggerTrack;
   TIter itTriggerTrack(triggerTrackStore.CreateIterator());
   while ( ( triggerTrack = static_cast<AliMUONTriggerTrack*>(itTriggerTrack() ) ) ){
-    UShort_t pattern = GetHitPattern(triggerTrack);
-    triggerTrack->SetHitsPatternInTrigCh(pattern);
-    AliDebug(1, Form("Hit pattern: hits 0x%x  slat %2i  board %3i  effFlag %i",
-                    pattern & 0xFF, AliESDMuonTrack::GetSlatOrInfo(pattern),
-                    triggerTrack->GetLoTrgNum(), AliESDMuonTrack::GetEffFlag(pattern)));
+    AliMUONTrackParam trackParam;
+    trackParam.SetNonBendingCoor(triggerTrack->GetX11());
+    trackParam.SetBendingCoor(triggerTrack->GetY11());
+    trackParam.SetZ(triggerTrack->GetZ11());
+    trackParam.SetNonBendingSlope(triggerTrack->GetSlopeX());
+    trackParam.SetBendingSlope(triggerTrack->GetSlopeY());
+    trackParam.SetInverseBendingMomentum(1.);
+    UInt_t pattern = GetHitPattern(trackParam, kTRUE);
+    // The pattern is a UInt_t, including the information
+    // on the matched local board,
+    // but for backward compatibility we fill a UShort_t
+    // which do not contain such info.
+    // In the old pattern, we use 15 bits out of 16, so the last one should
+    // be masked or it will be filled with 1 bit with the local board info.
+    triggerTrack->SetHitsPatternInTrigCh((UShort_t)(pattern & 0x7FFF));
+    AliDebug(1, Form("Hit pattern (MTR): hits 0x%x  slat %2i  board %3i  effFlag %i",
+                     pattern & 0xFF, AliESDMuonTrack::GetSlatOrInfo(pattern),triggerTrack->GetLoTrgNum(), AliESDMuonTrack::GetEffFlag(pattern)));
   }
 
   // Match tracker tracks with trigger tracks.
@@ -145,16 +162,328 @@ void AliMUONTrackHitPattern::ExecuteValidation(const AliMUONVTrackStore& trackSt
     AliMUONTrackExtrap::ExtrapToZCov(&trackParam, AliMUONConstants::DefaultChamberZ(kFirstTrigCh)); // extrap to 1st trigger chamber
 
     AliMUONTriggerTrack *matchedTriggerTrack = MatchTriggerTrack(track, trackParam, triggerTrackStore, triggerStore);
+    if ( matchedTriggerTrack ) track->SetHitsPatternInTrigCh(matchedTriggerTrack->GetHitsPatternInTrigCh());
+
+    UInt_t pattern = GetHitPattern(trackParam, kFALSE);
+    track->SetHitsPatternInTrigChTrk(pattern);
+    AliDebug(1, Form("Hit pattern (MTK): hits 0x%x  slat %2i  board %3i  effFlag %i",
+                     pattern & 0xFF, AliESDMuonTrack::GetSlatOrInfo(pattern), AliESDMuonTrack::GetCrossedBoard(pattern), AliESDMuonTrack::GetEffFlag(pattern)));
+  }
+}
 
-    // Copy trigger tracks hit pattern if there is matching,
-    // otherwise calculate the hit pattern directly from tracker track:
-    // the obtained pattern is good for check, but not good for efficiency determination.
-    UShort_t pattern = matchedTriggerTrack ?
-      matchedTriggerTrack->GetHitsPatternInTrigCh() : 
-      GetHitPattern(&trackParam);
 
-    track->SetHitsPatternInTrigCh(pattern);
+//______________________________________________________________________________
+Bool_t AliMUONTrackHitPattern::FindMatchingPads(const AliMUONTrackParam* trackParam,
+                                                TArrayI& matchedDetElemId, TObjArray& pads,
+                                                const AliMUONVDigitStore& digitStore,
+                                                Bool_t isTriggerTrack) const
+{
+  //
+  /// Search for matching digits in trigger chamber
+  //
+  enum {kBending, kNonBending};
+  
+  Double_t minMatchDist[2];
+  Int_t padsInCheckArea[2];
+  
+  AliMUONTrackParam trackParamAtPadZ(*trackParam);
+  
+  Int_t inputDetElemId = matchedDetElemId[0];
+  
+  for(Int_t cath=0; cath<2; cath++){
+    minMatchDist[cath] = 99999.;
+    padsInCheckArea[cath] = 0;
   }
+  
+  Int_t iChamber = AliMpDEManager::GetChamberId(inputDetElemId);  
+  Int_t iSlat = inputDetElemId%100;
+  
+  TIter next(digitStore.CreateTriggerIterator());
+  AliMUONVDigit* mDigit;
+  
+  Double_t xPad = 0., yPad = 0., zPad = 0.;
+  Double_t sigmaX = 0., sigmaY = 0.;
+  
+  Double_t nSigmas = ( isTriggerTrack ) ? GetRecoParam()->GetStripCutForTrigger() : GetRecoParam()->GetSigmaCutForTrigger();
+  Bool_t goodForEff = kTRUE;
+  
+  while ( ( mDigit = static_cast<AliMUONVDigit*>(next()) ) )
+  {
+    Int_t currDetElemId = mDigit->DetElemId();
+    Int_t currCh = AliMpDEManager::GetChamberId(currDetElemId);
+    if ( currCh != iChamber ) continue;
+    Int_t currSlat = currDetElemId%100;
+    Int_t slatDiff = TMath::Abs(currSlat-iSlat);
+    if ( slatDiff>1 && slatDiff<17 ) continue; // Check neighbour slats
+    
+    Int_t cathode = mDigit->Cathode();
+    Int_t ix = mDigit->PadX();
+    Int_t iy = mDigit->PadY();
+    const AliMpVSegmentation* seg = AliMpSegmentation::Instance()
+    ->GetMpSegmentation(currDetElemId,AliMp::GetCathodType(cathode));
+    AliMpPad pad = seg->PadByIndices(ix,iy,kTRUE);
+    
+    // Get local pad coordinates
+    Double_t xPadLocal = pad.GetPositionX();
+    Double_t yPadLocal = pad.GetPositionY();
+    Double_t dpx = pad.GetDimensionX();
+    Double_t dpy = pad.GetDimensionY();
+    Double_t xWidth = 2. * dpx;
+    Double_t yWidth = 2. * dpy;
+    
+    // Get global pad coordinates
+    fkTransformer.Local2Global(currDetElemId, xPadLocal, yPadLocal, 0., xPad, yPad, zPad);
+    
+    // Get track parameters at pad z
+    if ( trackParamAtPadZ.CovariancesExist() ) AliMUONTrackExtrap::LinearExtrapToZCov(&trackParamAtPadZ, zPad);
+    else AliMUONTrackExtrap::LinearExtrapToZ(&trackParamAtPadZ, zPad);
+    
+    Double_t deltaX = TMath::Abs(xPad-trackParamAtPadZ.GetNonBendingCoor()) - dpx;
+    Double_t deltaY = TMath::Abs(yPad-trackParamAtPadZ.GetBendingCoor()) - dpy;
+    
+    
+    // Get sigmas
+    if ( isTriggerTrack ) {
+      Double_t checkWidth = TMath::Min(xWidth, yWidth);
+      Double_t maxCheckArea = GetRecoParam()->GetMaxStripAreaForTrigger() * checkWidth;
+      Double_t sigma = TMath::Max(checkWidth, 2.);
+      sigmaX = sigma; // in cm
+      sigmaY = sigma; // in cm
+      if ( deltaX <= maxCheckArea && deltaY <= maxCheckArea ) {
+        padsInCheckArea[cathode]++;
+        if ( padsInCheckArea[cathode] > 2 ) {
+          goodForEff = kFALSE;
+          AliDebug(2, Form("padsInCheckArea[%i] = %i\n",cathode,padsInCheckArea[cathode]));
+        }
+      }
+    }
+    else {
+      const TMatrixD& kCovParam = trackParamAtPadZ.GetCovariances();
+      sigmaX = TMath::Sqrt(kCovParam(0,0)); // in cm
+      sigmaY = TMath::Sqrt(kCovParam(2,2)); // in cm
+    }
+    
+    AliDebug(2, Form("\nDetElemId %i  Cath %i  Dim = (%.2f,%.2f)  Pad (%i,%i) = (%.2f,%.2f)  Track = (%.2f,%.2f)  Delta (%.2f,%.2f)  Sigma (%.2f,%.2f)  p %g\n",
+                      currDetElemId,cathode,dpx,dpy,ix,iy,xPad,yPad,trackParamAtPadZ.GetNonBendingCoor(),trackParamAtPadZ.GetBendingCoor(),deltaX,deltaY,sigmaX,sigmaY,trackParamAtPadZ.P()));
+    //if ( deltaX <= maxCheckArea && deltaY <= maxCheckArea ) padsInCheckArea[cathode]++;
+    if ( deltaX > nSigmas * sigmaX || deltaY > nSigmas * sigmaY ) continue;
+    Double_t matchDist = TMath::Max(deltaX, deltaY);
+    if ( matchDist > minMatchDist[cathode] ) continue;
+    if ( pads.At(cathode) ) delete pads.RemoveAt(cathode);
+    pads.AddAt((AliMpPad*)pad.Clone(),cathode);
+    minMatchDist[cathode] = matchDist;
+    matchedDetElemId[cathode] = currDetElemId; // Set the input detection element id to the matched one
+  } // loop on digits
+  
+//  // If track matches many pads, it is not good for effciency determination.
+//  // However we still want to calculate the hit pattern.
+//  for ( Int_t cath=0; cath<2; cath++ ){
+//    if ( padsInCheckArea[cath] > 2 ) {
+//      AliDebug(2, Form("padsInCheckArea[%i] = %i\n",cath,padsInCheckArea[cath]));
+//      return kFALSE;
+//    }
+//  }
+  
+  return goodForEff;
+}
+
+
+//_____________________________________________________________________________
+UInt_t AliMUONTrackHitPattern::GetHitPattern(const AliMUONTrackParam& trackParam, Bool_t isTriggerTrack) const
+{
+  //
+  /// Searches for matching digits around the track.
+  //
+  
+  AliCodeTimerAuto("",0);
+  
+  TArrayI digitPerTrack(2);
+  digitPerTrack.Reset();
+  
+  UInt_t pattern = 0;
+  
+  TObjArray trackParamList, matchedPads(2), maskedPads(2), padsFromPos(4), validPads(2);
+  trackParamList.SetOwner(); matchedPads.SetOwner(); maskedPads.SetOwner(); padsFromPos.SetOwner();
+  
+  Int_t firstSlat = -1, firstBoard = -1;
+  AliESDMuonTrack::EAliTriggerChPatternFlag goodForEff = AliESDMuonTrack::kBoardEff;
+  TArrayI matchedDetElemId(2), maskedDetElemId(2), detElemIdFromTrack(2), validDetElemId(2);
+  
+  for(Int_t ich=0; ich<AliMUONConstants::NTriggerCh(); ich++) { // chamber loop
+    
+    trackParamList.Delete(); matchedPads.Delete(); maskedPads.Delete(); padsFromPos.Delete(); validPads.Clear();
+    
+    Int_t nFound = GetTrackParamAtChamber(trackParam, 11+ich, trackParamList, detElemIdFromTrack, padsFromPos);
+    if ( nFound == 0 ) {
+      // track is rejected since the extrapolated track
+      // does not match a slat (border effects)
+      AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackOutsideGeometry);
+      goodForEff = AliESDMuonTrack::kNoEff;
+      AliDebug(2, "Warning: trigger track outside trigger chamber\n");
+      continue;
+    }
+    
+    // Search for masked pads
+    maskedDetElemId.Reset(detElemIdFromTrack[0]);
+    FindMatchingPads((AliMUONTrackParam*)trackParamList.At(0), maskedDetElemId, maskedPads, *(fkTriggerUtilities->GetMaskedDigits()), isTriggerTrack);
+    if ( maskedPads.GetEntries() > 0 ) {
+      AliESDMuonTrack::AddEffInfo(pattern,AliESDMuonTrack::kTrackMatchesMasks); // pad is masked
+      goodForEff = AliESDMuonTrack::kNoEff;
+      for ( Int_t icath=0; icath<2; icath++ ) {
+        AliMpPad* currPad = (AliMpPad*)maskedPads.UncheckedAt(icath);
+        if ( ! currPad ) continue;
+        AliDebug(2,Form("DetElemId %i  cath %i  board %i  strip %i is masked: effFlag 0", matchedDetElemId[icath], icath, currPad->GetLocalBoardId(0), currPad->GetLocalBoardChannel(0)));
+      }
+      //      continue;
+      // We want to calculate the hit pattern in any case, so we do not "continue"
+      // However we set the flag in such a way not to use the track for efficiency calculations
+    }
+    
+    // If no masked pads matched, search for active pads
+    matchedDetElemId.Reset(detElemIdFromTrack[0]);
+    if ( ! FindMatchingPads((AliMUONTrackParam*)trackParamList.At(0), matchedDetElemId, matchedPads, fkDigitStore, isTriggerTrack) ) {
+      // if ! FindPadMatchingTrig => too many digits matching pad =>
+      //                          => Event not clear => Do not use for efficiency calculation
+      AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackMatchesManyPads);
+      goodForEff = AliESDMuonTrack::kNoEff;
+      AliDebug(2, Form("Warning: track in %i matches many pads. Rejected!\n", matchedDetElemId[0]));
+    }
+    
+    Int_t nMatched = 0;
+    
+    Int_t mostProbDEmatched = detElemIdFromTrack[0];
+    for ( Int_t icath=0; icath<2; icath++ ) {
+      if ( matchedPads.UncheckedAt(icath) ) {
+        nMatched++;
+        // Fill pattern anyway
+        AliESDMuonTrack::SetFiredChamber(pattern, icath, ich);
+        digitPerTrack[icath]++;
+        mostProbDEmatched = matchedDetElemId[icath];
+      }
+    }
+    Int_t mostProbDEindex = 0;
+    for ( Int_t ifound=0; ifound<nFound; ifound++ ) {
+      if ( detElemIdFromTrack[ifound] == mostProbDEmatched ) {
+        mostProbDEindex = ifound;
+        break;
+      }
+    }
+    
+    if ( goodForEff == AliESDMuonTrack::kNoEff ) continue;
+    
+    for ( Int_t icath=0; icath<2; icath++ ) {
+      if ( matchedPads.UncheckedAt(icath) ) {
+        validPads.AddAt(matchedPads.UncheckedAt(icath),icath);
+        validDetElemId[icath] = matchedDetElemId[icath];
+      }
+      else {
+        validPads.AddAt(padsFromPos.UncheckedAt(2*mostProbDEindex + icath),icath);
+        validDetElemId[icath] = detElemIdFromTrack[mostProbDEindex];
+      }
+    }
+        
+    Int_t currSlat = mostProbDEmatched%100;
+    if ( firstSlat < 0 ) firstSlat = currSlat;
+    
+    if ( currSlat != firstSlat || validDetElemId[0] != validDetElemId[1] ) {
+      goodForEff = AliESDMuonTrack::kChEff;
+      firstSlat = AliESDMuonTrack::kCrossDifferentSlats;
+    }
+    
+    if ( firstBoard < 0 ) firstBoard = ((AliMpPad*)validPads.UncheckedAt(0))->GetLocalBoardId(0);
+    
+    for ( Int_t icath=0; icath<2; icath++ ){      
+      
+      if ( goodForEff == AliESDMuonTrack::kBoardEff) {
+        Bool_t atLeastOneLoc = kFALSE;
+        AliMpPad* currPad = (AliMpPad*)validPads.UncheckedAt(icath);
+        for ( Int_t iloc=0; iloc<currPad->GetNofLocations(); iloc++) {
+          if ( currPad->GetLocalBoardId(iloc) == firstBoard ) {
+            atLeastOneLoc = kTRUE;
+            break;
+          }
+        } // loop on locations
+        if ( ! atLeastOneLoc ) goodForEff = AliESDMuonTrack::kSlatEff;
+      }
+    } // loop on cathodes
+    //    } // if track good for efficiency
+  } // end chamber loop
+  
+  if ( goodForEff == AliESDMuonTrack::kNoEff ) return pattern;
+  
+  for(Int_t cath=0; cath<2; cath++){
+    if(digitPerTrack[cath]<3) {
+      // track is rejected since the number of associated
+      // digits found is less than 3.
+      AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackMatchesFewPads);
+      goodForEff = AliESDMuonTrack::kNoEff;
+      AliDebug(2, Form("Warning: found %i digits for trigger track cathode %i.\nRejecting event\n", digitPerTrack[cath],cath));
+    }
+  } // loop on cathodes 
+  
+  if ( goodForEff == AliESDMuonTrack::kNoEff ) return pattern;
+  
+  AliESDMuonTrack::AddEffInfo(pattern, firstSlat, firstBoard, goodForEff);
+  return pattern;
+}
+
+
+
+//_____________________________________________________________________________
+Int_t AliMUONTrackHitPattern::GetTrackParamAtChamber(const AliMUONTrackParam& inputTrackParam, Int_t chamber,
+                                                     TObjArray& trackParamList, TArrayI& foundDetElemId,
+                                                     TObjArray& padsFromPos) const
+{
+  //
+  /// Return the extrapolated the track parameter at the given chamber
+  /// and returns the matching DetElemId
+  /// CAVEAT: at the border the result is not univoque
+  //
+  
+  Int_t nFound = 0;
+  foundDetElemId[0] = foundDetElemId[1] = 0;
+  AliMUONTrackParam trackParamCopy(inputTrackParam);
+  TVector3 globalPoint1(trackParamCopy.GetNonBendingCoor(), trackParamCopy.GetBendingCoor(), trackParamCopy.GetZ());
+  AliMUONTrackExtrap::LinearExtrapToZ(&trackParamCopy, trackParamCopy.GetZ() + 20.);
+  TVector3 globalPoint2(trackParamCopy.GetNonBendingCoor(), trackParamCopy.GetBendingCoor(), trackParamCopy.GetZ());
+  TVector3 localCoor;
+  
+  //  AliMpArea pointArea(x, y, 2.*AliMpConstants::LengthTolerance(), 2.*AliMpConstants::LengthTolerance());
+  AliMpDEIterator it;
+  Double_t xGlobal, yGlobal, zGlobal;
+  for ( it.First(chamber-1); ! it.IsDone(); it.Next() ){
+    Int_t detElemId = it.CurrentDEId();
+    PosInDetElemIdLocal(localCoor, globalPoint1, globalPoint2, detElemId);
+    fkTransformer.Local2Global(detElemId, localCoor.X(), localCoor.Y(), localCoor.Z(), xGlobal, yGlobal, zGlobal);
+    AliMpArea pointArea(xGlobal, yGlobal, 2.*AliMpConstants::LengthTolerance(), 2.*AliMpConstants::LengthTolerance());
+    AliMpArea* deArea = fkTransformer.GetDEArea(detElemId);
+    if ( deArea->Contains(pointArea) ) {
+      // Check if track matches valid pads
+      // (this is not trivial for cut RPC)
+      Int_t validPads = 0;
+      for ( Int_t icath=0; icath<2; icath++ ) {
+        const AliMpVSegmentation* seg = 
+        AliMpSegmentation::Instance()
+        ->GetMpSegmentation(detElemId,AliMp::GetCathodType(icath));
+        AliMpPad pad = seg->PadByPosition(localCoor.X(),localCoor.Y(),kFALSE);
+        if ( pad.IsValid() ) {
+          padsFromPos.AddAt(pad.Clone(), 2*nFound + icath);
+          validPads++;
+        }
+      }
+      if ( validPads < 2 ) continue;
+      AliMUONTrackParam* extrapTrackParam = new AliMUONTrackParam(inputTrackParam);
+      if ( extrapTrackParam->CovariancesExist() ) AliMUONTrackExtrap::LinearExtrapToZCov(extrapTrackParam, zGlobal);
+      else AliMUONTrackExtrap::LinearExtrapToZ(extrapTrackParam, zGlobal);
+      trackParamList.AddAt(extrapTrackParam,nFound);
+      foundDetElemId[nFound] = detElemId;
+      nFound++;
+      if ( nFound == 2 ) break;
+    }
+    else if ( nFound > 0 ) break;
+  } // loop on detElemId
+  
+  return nFound;
 }
 
 
@@ -288,28 +617,48 @@ AliMUONTrackHitPattern::MatchTriggerTrack(AliMUONTrack* track,
 }
 
 
+//_____________________________________________________________________________
+Bool_t AliMUONTrackHitPattern::PosInDetElemIdLocal(TVector3& localCoor, const TVector3& globalPoint1,
+                                                   const TVector3& globalPoint2, Int_t detElemId) const
+{
+  /// Given two points belonging to a line (global coordinates)
+  /// it returns the intersection point with the detElemId (local coordinates)
+  
+  Double_t xloc, yloc, zloc;
+  fkTransformer.Global2Local(detElemId, globalPoint1.X(), globalPoint1.Y(), globalPoint1.Z(), xloc, yloc, zloc);
+  TVector3 localPoint1(xloc, yloc, zloc);
+  fkTransformer.Global2Local(detElemId, globalPoint2.X(), globalPoint2.Y(), globalPoint2.Z(), xloc, yloc, zloc);
+  TVector3 localPoint2(xloc, yloc, zloc);
+  localCoor = localPoint1 - ( localPoint1.Z() / ( localPoint2.Z() - localPoint1.Z() ) ) * ( localPoint2 - localPoint1 );
+  
+  return kTRUE;
+}
+
+
+// THE FOLLOWING METHODS ARE OBSOLETE
+
 //______________________________________________________________________________
-UShort_t AliMUONTrackHitPattern::GetHitPattern(AliMUONTriggerTrack* matchedTriggerTrack) const
+UInt_t AliMUONTrackHitPattern::GetHitPattern(const AliMUONTriggerTrack* matchedTriggerTrack) const
 {
   //
   /// Get hit pattern on trigger chambers for the current trigger track
   //
-  UShort_t pattern = 0;
+  UInt_t pattern = 0;
   PerformTrigTrackMatch(pattern, matchedTriggerTrack);
   return pattern;
 }
 
 
 //______________________________________________________________________________
-UShort_t AliMUONTrackHitPattern::GetHitPattern(AliMUONTrackParam* trackParam) const
+UInt_t AliMUONTrackHitPattern::GetHitPattern(AliMUONTrackParam* trackParam) const
 {
   //
   /// Get hit pattern on trigger chambers for the current tracker track
   //
-  UShort_t pattern = 0;
+  UInt_t pattern = 0;
   Bool_t isMatch[2];
   const Int_t kNTrackingCh = AliMUONConstants::NTrackingCh();
-
+  
   for(Int_t ch=0; ch<4; ++ch)
   {
     Int_t iChamber = kNTrackingCh+ch;
@@ -320,31 +669,14 @@ UShort_t AliMUONTrackHitPattern::GetHitPattern(AliMUONTrackParam* trackParam) co
       if(isMatch[cath]) AliESDMuonTrack::SetFiredChamber(pattern, cath, ch);
     }
   }
-
+  
   // pattern obtained by propagation of tracker track
   // when it does not match the trigger.
   AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackerTrackPattern);
-
+  
   return pattern;
 }
 
-//______________________________________________________________________________
-void 
-AliMUONTrackHitPattern::ApplyMCSCorrections(AliMUONTrackParam& trackParam) const
-{
-  //
-  /// Returns uncertainties on extrapolated position.
-  /// Takes into account Branson plane corrections in the iron wall.
-  //
-
-  const Float_t kZFilterOut = AliMUONConstants::MuonFilterZEnd();
-  const Float_t kFilterThickness = kZFilterOut-AliMUONConstants::MuonFilterZBeg(); // cm
-
-  AliMUONTrackExtrap::ExtrapToZCov(&trackParam, kZFilterOut); // Extrap to muon filter end
-  AliMUONTrackExtrap::AddMCSEffect(&trackParam, kFilterThickness, AliMUONConstants::MuonFilterX0()); // Add MCS effects
-  return;
-}
-
 
 //______________________________________________________________________________
 void 
@@ -431,393 +763,406 @@ AliMUONTrackHitPattern::MinDistanceFromPad(Float_t xPad, Float_t yPad, Float_t z
 
 
 //_____________________________________________________________________________
-Int_t AliMUONTrackHitPattern::FindPadMatchingTrig(Int_t &detElemId,
-                                                 Float_t coor[2], Bool_t isMatch[2],
-                                                 TArrayI nboard[2], TArrayF &zRealMatch, Float_t y11) const
+Bool_t AliMUONTrackHitPattern::FindPadMatchingTrig(const TVector3& vec11, const TVector3& vec21,
+                                                  Int_t matchedDetElemId[2], TObjArray& pads) const
 {
-    //
-    /// Check slat and board number of digit matching trigger track
-    //
-
-    enum {kBending, kNonBending};
-
-    Float_t minMatchDist[fgkNcathodes];
-    Int_t padsInCheckArea[fgkNcathodes];
-
-    for(Int_t cath=0; cath<fgkNcathodes; cath++){
-       isMatch[cath] = kFALSE;
-       minMatchDist[cath] = fkMaxDistance/10.;
-       padsInCheckArea[cath] = 0;
-    }
+  //
+  /// Check slat and board number of digit matching trigger track
+  //
+  
+  enum {kBending, kNonBending};
+  
+  Float_t minMatchDist[2];
+  Int_t padsInCheckArea[2];
+  
+  Int_t inputDetElemId = matchedDetElemId[0];
+  
+  for(Int_t cath=0; cath<2; cath++){
+    minMatchDist[cath] = fkMaxDistance/10.;
+    padsInCheckArea[cath] = 0;
+  }
+  
+  Int_t iChamber = AliMpDEManager::GetChamberId(inputDetElemId);  
+  Int_t iSlat = inputDetElemId%100;
+  
+  TIter next(fkDigitStore.CreateTriggerIterator());
+  AliMUONVDigit* mDigit;
+  TVector3 localExtrap;
+  
+  Int_t previousDetElemId = -1;
+  
+  while ( ( mDigit = static_cast<AliMUONVDigit*>(next()) ) )
+  {
+    Int_t currDetElemId = mDigit->DetElemId();
+    Int_t currCh = AliMpDEManager::GetChamberId(currDetElemId);
+    if ( currCh != iChamber ) continue;
+    Int_t currSlat = currDetElemId%100;
+    Int_t slatDiff = TMath::Abs(currSlat-iSlat);
+    if ( slatDiff>1 && slatDiff<17 ) continue; // Check neighbour slats
+    Int_t cathode = mDigit->Cathode();
+    Int_t ix = mDigit->PadX();
+    Int_t iy = mDigit->PadY();
+    const AliMpVSegmentation* seg = AliMpSegmentation::Instance()
+    ->GetMpSegmentation(currDetElemId,AliMp::GetCathodType(cathode));
     
-    Int_t iChamber = AliMpDEManager::GetChamberId(detElemId);  
-    if ( iChamber < 0 ) {
-      AliErrorStream() << "Cannot get chamberId from detElemId=" << detElemId << endl;
-      return -1;
-    }  
-
-    Int_t ch = iChamber-10;
-    Float_t oldDeltaZ = AliMUONConstants::DefaultChamberZ(iChamber) - AliMUONConstants::DefaultChamberZ(10);
-    Float_t y = coor[1];
-    Int_t iSlat = detElemId%100;
-    Int_t trigDigitBendPlane = -1;
-    Int_t foundDetElemId = detElemId;
-    Float_t foundZmatch=999.;
-    Float_t yCoorAtPadZ=999.;
-
-    TIter next(fkDigitStore.CreateTriggerIterator());
-    AliMUONVDigit* mDigit;
-    Int_t idigit=0;
+    AliMpPad pad = seg->PadByIndices(ix,iy,kTRUE);
     
-    while ( ( mDigit = static_cast<AliMUONVDigit*>(next()) ) )
-    {
-       idigit++;
-       Int_t currDetElemId = mDigit->DetElemId();
-       Int_t currCh = AliMpDEManager::GetChamberId(currDetElemId);
-       if(currCh!=iChamber) continue;
-       Int_t currSlat = currDetElemId%100;
-       Int_t slatDiff = TMath::Abs(currSlat-iSlat);
-       if(slatDiff>1 && slatDiff<17) continue; // Check neighbour slats
-       Int_t cathode = mDigit->Cathode();
-       Int_t ix = mDigit->PadX();
-       Int_t iy = mDigit->PadY();
-       Float_t xpad, ypad, zpad;
-       const AliMpVSegmentation* seg = AliMpSegmentation::Instance()
-           ->GetMpSegmentation(currDetElemId,AliMp::GetCathodType(cathode));
-
-       AliMpPad pad = seg->PadByIndices(ix,iy,kTRUE);
-       Float_t xlocal1 = pad.GetPositionX();
-       Float_t ylocal1 = pad.GetPositionY();
-       Float_t dpx = pad.GetDimensionX();
-       Float_t dpy = pad.GetDimensionY();
-
-       fkTransformer.Local2Global(currDetElemId, xlocal1, ylocal1, 0, xpad, ypad, zpad);
-       AliDebug(2, Form("\nDetElemId = %i  Cathode = %i  Pad = (%i,%i) = (%.2f,%.2f)  Dim = (%.2f,%.2f)  Track = (%.2f,%.2f)\n",currDetElemId,cathode,ix,iy,xpad,ypad,dpx,dpy,coor[0],coor[1]));
-       // searching track intersection with chambers (second approximation)
-       if(ch%2==1){
-           //if(iChamber%2==1){
-           Float_t deltaZ = zpad - zRealMatch[0];
-           y = (coor[1]-y11)*deltaZ/oldDeltaZ + y11;
-           if(TMath::Abs(y-coor[1])>0.1) AliDebug(3, Form("oldDeltaZ = %7.2f   newDeltaZ = %7.2f\toldY = %7.2f   new y = %7.2f\n",oldDeltaZ,deltaZ,coor[1],y));
-       }
-       Float_t matchDist = PadMatchTrack(xpad, ypad, dpx, dpy, coor[0], y);
-       if(matchDist<fkMaxDistance/2.) padsInCheckArea[cathode]++;
-       if(matchDist>minMatchDist[cathode])continue;
-       isMatch[cathode] = kTRUE;
-       minMatchDist[cathode] = matchDist;
-       foundDetElemId = currDetElemId;
-       foundZmatch=zpad;
-       yCoorAtPadZ=y;
-       if(cathode==kBending) trigDigitBendPlane = idigit;
-       for (Int_t loc=0; loc<pad.GetNofLocations(); loc++){
-           nboard[cathode][loc] = pad.GetLocalBoardId(loc);
-       }
-       for(Int_t loc=pad.GetNofLocations(); loc<fgkNlocations; loc++){
-           nboard[cathode][loc]=-1;
-       }
+    if ( currDetElemId != previousDetElemId ) {
+      PosInDetElemIdLocal(localExtrap, vec11, vec21, currDetElemId);
+      previousDetElemId = currDetElemId;
     }
-
-    if(isMatch[kBending] || isMatch[kNonBending]){
-       detElemId = foundDetElemId;
-       zRealMatch[ch] = foundZmatch;
-       coor[1] = yCoorAtPadZ;
-    }
-
-    // If track matches many pads, it is not good for effciency determination.
-    // However we still want to calculate the hit pattern.
-    for(Int_t cath=0; cath<fgkNcathodes; cath++){
-      if(padsInCheckArea[cath]>2) {
-       AliDebug(1, Form("padsInCheckArea[%i] = %i\n",cath,padsInCheckArea[cath]));
-       return -500;
-      }
+    
+    AliDebug(11, Form("\nDetElemId = %i  Cathode = %i  Pad = (%i,%i) = (%.2f,%.2f)  Dim = (%.2f,%.2f)  Track = (%.2f,%.2f)\n",
+                     currDetElemId,cathode,ix,iy,pad.GetPositionX(),pad.GetPositionY(),pad.GetDimensionX(),pad.GetDimensionY(),localExtrap.X(),localExtrap.Y()));
+    Float_t matchDist = PadMatchTrack(pad, localExtrap);
+    if ( matchDist < fkMaxDistance/2. ) padsInCheckArea[cathode]++;
+    if ( matchDist > minMatchDist[cathode] ) continue;
+    if ( pads.At(cathode) ) delete pads.RemoveAt(cathode);
+    pads.AddAt((AliMpPad*)pad.Clone(),cathode);
+    minMatchDist[cathode] = matchDist;
+    matchedDetElemId[cathode] = currDetElemId; // Set the input detection element id to the matched one
+  } // loop on digits
+  
+  // If track matches many pads, it is not good for effciency determination.
+  // However we still want to calculate the hit pattern.
+  for ( Int_t cath=0; cath<2; cath++ ){
+    if ( padsInCheckArea[cath] > 2 ) {
+      AliDebug(10, Form("padsInCheckArea[%i] = %i\n",cath,padsInCheckArea[cath]));
+      return kFALSE;
     }
-
-    return trigDigitBendPlane;
+  }
+  
+  return kTRUE;
 }
 
 //_____________________________________________________________________________
-Float_t AliMUONTrackHitPattern::PadMatchTrack(Float_t xPad, Float_t yPad,
-                                               Float_t dpx, Float_t dpy, 
-                                               Float_t xTrackAtPad, Float_t yTrackAtPad) const
+Float_t AliMUONTrackHitPattern::PadMatchTrack(const AliMpPad& pad, const TVector3& trackPosAtPad) const
 {
-    //
-    /// Decides if the digit belongs to the trigger track.
-    //
+  //
+  /// Decides if the digit belongs to the trigger track.
+  //
+  
+  Float_t xPad = pad.GetPositionX();
+  Float_t yPad = pad.GetPositionY();
+  Float_t dpx = pad.GetDimensionX();
+  Float_t dpy = pad.GetDimensionY();  
+  
 
   Float_t maxDist = GetRecoParam()->GetStripCutForTrigger() * 2. * TMath::Min(dpx,dpy); // cm
-  if(maxDist<2.) maxDist = 2.;
+  if ( maxDist<2. ) maxDist = 2.;
   Float_t maxDistCheckArea = GetRecoParam()->GetMaxStripAreaForTrigger() * 2. *  TMath::Min(dpx,dpy); // cm
 
-    Float_t matchDist = fkMaxDistance;
+  Float_t matchDist = fkMaxDistance;
 
-    Float_t deltaX = TMath::Abs(xPad-xTrackAtPad)-dpx;
-    Float_t deltaY = TMath::Abs(yPad-yTrackAtPad)-dpy;
-    Float_t maxDistX = maxDist;
-    Float_t maxDistY = maxDist;
+  Float_t deltaX = TMath::Abs(xPad-trackPosAtPad.X())-dpx;
+  Float_t deltaY = TMath::Abs(yPad-trackPosAtPad.Y())-dpy;
+  Float_t maxDistX = maxDist;
+  Float_t maxDistY = maxDist;
 
-    if(deltaX<=maxDistX && deltaY<=maxDistY) matchDist = TMath::Max(deltaX, deltaY);
-    else if(deltaX<=maxDistCheckArea && deltaY<=maxDistCheckArea) matchDist = fkMaxDistance/5.;
-    return matchDist;
+  if(deltaX<=maxDistX && deltaY<=maxDistY) matchDist = TMath::Max(deltaX, deltaY);
+  else if(deltaX<=maxDistCheckArea && deltaY<=maxDistCheckArea) matchDist = fkMaxDistance/5.;
+  return matchDist;
 }
 
 
 //_____________________________________________________________________________
 Int_t AliMUONTrackHitPattern::DetElemIdFromPos(Float_t x, Float_t y, 
-                                                Int_t chamber, Int_t cathode) const
+                                               Int_t chamber, Int_t foundDetElemId[2]) const
 {
-    //
-    /// Given the (x,y) position in the chamber,
-    /// it returns the corresponding slat
-    //
-
-    Int_t resultingDetElemId = -1;
-    AliMpDEIterator it;
-    Float_t minDist = 999.;
-    for ( it.First(chamber-1); ! it.IsDone(); it.Next() ){
-       Int_t detElemId = it.CurrentDEId();
-       Int_t ich = detElemId/100-10;
-       Float_t tolerance=0.2*((Float_t)ich);
-       Float_t currDist=9999.;
-
-       const AliMpVSegmentation* seg = 
-           AliMpSegmentation::Instance()
-           ->GetMpSegmentation(detElemId,AliMp::GetCathodType(cathode));
-       if (!seg) continue;
-
-       Float_t deltax = seg->GetDimensionX();
-       Float_t deltay = seg->GetDimensionY();
-       Float_t xlocal1 =  -deltax;
-       Float_t ylocal1 =  -deltay;
-       Float_t xlocal2 =  +deltax;
-       Float_t ylocal2 =  +deltay;
-       Float_t xg01, yg01, zg1, xg02, yg02, zg2;
-       fkTransformer.Local2Global(detElemId, xlocal1, ylocal1, 0, xg01, yg01, zg1);
-       fkTransformer.Local2Global(detElemId, xlocal2, ylocal2, 0, xg02, yg02, zg2);
-
-       Float_t xg1 = xg01, xg2 = xg02, yg1 = yg01, yg2 = yg02;
-
-       if(xg01>xg02){
-           xg1 = xg02;
-           xg2 = xg01;
-       }
-       if(yg01>yg02){
-           yg1 = yg02;
-           yg2 = yg01;
-       }
-
-       if(x>=xg1-tolerance && x<=xg2+tolerance && y>=yg1-tolerance && y<=yg2+tolerance){ // takes into account errors in extrapolation
-           if(y<yg1) currDist = yg1-y;
-           else if(y>yg2) currDist = y-yg2;
-           if(currDist<minDist) {
-               resultingDetElemId = detElemId;
-               minDist=currDist;
-               continue;
-           }
-           resultingDetElemId = detElemId;
-           break;
-       }
-    } // loop on detElemId
-    return resultingDetElemId;
+  //
+  /// Given the (x,y) position in the chamber,
+  /// it returns the corresponding slats
+  /// Caveat: at the border the result is not univoque
+  //
+  
+  Int_t nFound = 0;
+  
+  foundDetElemId[0] = foundDetElemId[1] = 0;
+  AliMpArea pointArea(x, y, 2.*AliMpConstants::LengthTolerance(), 2.*AliMpConstants::LengthTolerance());
+  AliMpDEIterator it;
+  for ( it.First(chamber-1); ! it.IsDone(); it.Next() ){
+    Int_t detElemId = it.CurrentDEId();
+    AliMpArea* deArea = fkTransformer.GetDEArea(detElemId);
+    
+    if ( deArea->Contains(pointArea) ) {
+      foundDetElemId[nFound++] = detElemId;
+      if ( nFound == 2 ) break;
+    }
+    else if ( nFound > 0 ) break;
+  } // loop on detElemId
+  
+  return nFound;
 }
 
 
+
 //_____________________________________________________________________________
-void AliMUONTrackHitPattern::LocalBoardFromPos(Float_t x, Float_t y,
-                                                Int_t detElemId, Int_t cathode,
-                                                Int_t localBoard[4]) const
+Bool_t AliMUONTrackHitPattern::PadsFromPos(const TVector3& vec11, const TVector3& vec21,
+                                           Int_t detElemId, TObjArray& pads) const
 {
-    //
-    /// Given the (x,y) position in the chamber,
-    /// it returns the corresponding local board
-    //
-
-    for(Int_t loc=0; loc<fgkNlocations; loc++){
-       localBoard[loc]=-1;
-    }
-    Float_t xg, yg, zg;
-    fkTransformer.Local2Global(detElemId, 0., 0., 0., xg, yg, zg);
-    Float_t z = zg - (y-yg)*TMath::Tan(TMath::DegToRad()*AliMUONConstants::St345Inclination());
-    Float_t xl, yl, zl;
-    fkTransformer.Global2Local(detElemId, x, y, z, xl, yl, zl);
+  //
+  /// Given the (x,y) position in the chamber,
+  /// it returns the corresponding local board
+  //
+  
+  pads.Delete();
+  
+  TVector3 localCoor;
+  PosInDetElemIdLocal(localCoor, vec11, vec21, detElemId);
+  for ( Int_t icath=0; icath<2; icath++ ) {
     const AliMpVSegmentation* seg = 
-       AliMpSegmentation::Instance()
-          ->GetMpSegmentation(detElemId,AliMp::GetCathodType(cathode));
-    if ( ! seg ) return;
-    AliMpPad pad = seg->PadByPosition(xl,yl,kFALSE);
-    if ( ! pad.IsValid() ){
-      AliWarning(Form("Pad not found! DetElemId %i  position global (%f, %f, %f)  local (%f, %f, %f)\n", detElemId, x, y, z, xl, yl, zl));
-      return;
+    AliMpSegmentation::Instance()
+    ->GetMpSegmentation(detElemId,AliMp::GetCathodType(icath));
+    AliMpPad pad = seg->PadByPosition(localCoor.X(),localCoor.Y(),kFALSE);
+    if ( pad.IsValid() ) {
+      pads.AddAt(pad.Clone(), icath);
     }
+  }
+  
+  return pads.GetEntries();
+}
+
+
+//_____________________________________________________________________________
+Bool_t AliMUONTrackHitPattern::IsCloseToAccEdge(TObjArray& pads, Int_t detElemId, Float_t coor[2]) const
+{
+  AliMpArea* deArea = fkTransformer.GetDEArea(detElemId);
+  Float_t dpx = ((AliMpPad*)pads.At(1))->GetDimensionX();
+  Float_t dpy = ((AliMpPad*)pads.At(0))->GetDimensionY();
+  Float_t resolution[2] = { static_cast<Float_t>(0.75*dpx), static_cast<Float_t>(0.75*dpy) };
+  Float_t sign[3] = {0., 1., -1.};
+  for ( Int_t ineighx=0; ineighx<3; ineighx++ ) {
+    for ( Int_t ineighy=0; ineighy<3; ineighy++ ) {
+      AliMpArea pointArea(coor[0]+sign[ineighx]*resolution[0],
+                          coor[1]+sign[ineighy]*resolution[1],
+                          2.*AliMpConstants::LengthTolerance(),
+                          2.*AliMpConstants::LengthTolerance());
+      if ( ! deArea->Contains(pointArea) ) return kTRUE;
+    } // loop on y neighbours
+  } // loop on x neighbours
+  return kFALSE;
+}
 
-    AliDebug(2, Form("\nWould match: DetElemId = %i  Pad = (%i,%i) = (%.2f,%.2f,%.2f)   Board %3i\n",detElemId,pad.GetIx(),pad.GetIy(),xl,yl,zl,pad.GetLocalBoardId(0)));
 
-    for (Int_t loc=0; loc<pad.GetNofLocations(); loc++){
-      localBoard[loc] = pad.GetLocalBoardId(loc);
+//_____________________________________________________________________________
+Bool_t AliMUONTrackHitPattern::IsMasked(const AliMpPad& pad, Int_t detElemId, Int_t cathode, const TVector3& vec11, const TVector3& vec21) const
+{
+  //
+  /// Check if pad or its neighbours are masked
+  //
+  
+  Int_t nMasked = 0;
+  
+  if ( fkTriggerUtilities->IsMasked(pad, detElemId, cathode) ) ++nMasked;
+  
+  // Check closest neighbour
+  
+  TVector3 localCoor;
+  PosInDetElemIdLocal(localCoor, vec11, vec21, detElemId);
+  
+  Float_t padPos[2] = { static_cast<Float_t>(pad.GetPositionX()), static_cast<Float_t>(pad.GetPositionY())};
+  Float_t padDim[2] = { static_cast<Float_t>(pad.GetDimensionX()), static_cast<Float_t>(pad.GetDimensionY())};
+  Float_t inpactPos[2] = { static_cast<Float_t>(localCoor.X()), static_cast<Float_t>(localCoor.Y())};
+  Float_t sign[2] = {-1., 1.};
+  Int_t icoor = 1-cathode;
+  Int_t addSlatSign[3] = {0,1,-1};
+  Int_t inputCh = AliMpDEManager::GetChamberId(detElemId)+1;
+  Int_t inputSlat = detElemId%100;
+  
+  Float_t newPos[2];
+  for ( Int_t ineigh=0; ineigh<2; ineigh++ ) {
+    newPos[1-icoor] = inpactPos[1-icoor];
+    newPos[icoor] = inpactPos[icoor] + 1.05 * sign[ineigh] * padDim[icoor];
+    if ( TMath::Abs(newPos[icoor] - padPos[icoor]) < padDim[icoor] ) continue;
+    const AliMpVSegmentation* seg = 
+      AliMpSegmentation::Instance()->GetMpSegmentation(detElemId,AliMp::GetCathodType(cathode));
+    AliMpPad neighPad = seg->PadByPosition(newPos[0],newPos[1],kFALSE);
+    if ( neighPad.IsValid() ) {
+      if ( fkTriggerUtilities->IsMasked(neighPad, detElemId, cathode) ) ++nMasked;
     }
+    else {
+      TVector3 deltaVec(newPos[0]-inpactPos[0],newPos[1]-inpactPos[1],0.);
+      TVector3 transVec11 = vec11+deltaVec;
+      TVector3 transVec21 = vec21+deltaVec;
+      TObjArray padsFromPos;
+      padsFromPos.SetOwner();
+      for ( Int_t iAddSlat=0; iAddSlat<2; iAddSlat++ ) {
+        Int_t currSlat = (inputSlat + addSlatSign[iAddSlat])%18;
+        Int_t currDetElemId = 100 * inputCh + currSlat;
+        PadsFromPos(transVec11,transVec21,currDetElemId,padsFromPos);
+        AliMpPad* currPad = (AliMpPad*)padsFromPos.UncheckedAt(cathode);
+        Bool_t isMasked = ( currPad ) ? fkTriggerUtilities->IsMasked(*currPad, currDetElemId, cathode) : kFALSE;
+        padsFromPos.Delete();
+        if ( isMasked ) ++nMasked;
+      }
+    } // loop on slats
+  } // loop on neigbours
+  
+  Double_t maskedProb = ((Double_t)nMasked)/3.;
+  if ( gRandom->Rndm() < maskedProb ) return kTRUE;
+  
+  return kFALSE;
 }
 
 
 //_____________________________________________________________________________
-Bool_t AliMUONTrackHitPattern::PerformTrigTrackMatch(UShort_t &pattern,
+Bool_t AliMUONTrackHitPattern::PerformTrigTrackMatch(UInt_t &pattern,
                                                     const AliMUONTriggerTrack* matchedTrigTrack) const
 {
   //
   /// It searches for matching digits around the trigger track.
   //
+  
+  AliCodeTimerAuto("",0);
 
   enum {kBending, kNonBending};
 
-  Int_t chOrder[fgkNchambers] = {0,2,1,3};
-
-  TArrayF zRealMatch(fgkNchambers);
-
-  Bool_t isMatch[fgkNcathodes];
-  for(Int_t cath=0; cath<fgkNcathodes; cath++){
-    isMatch[cath] = kFALSE;
-  }
-
-  TArrayF zMeanChamber(fgkNchambers);
+  TArrayF zMeanChamber(AliMUONConstants::NTriggerCh());
   zMeanChamber[0] = matchedTrigTrack->GetZ11();
   zMeanChamber[1] = matchedTrigTrack->GetZ11() + AliMUONConstants::DefaultChamberZ(11) - AliMUONConstants::DefaultChamberZ(10);
   zMeanChamber[2] = matchedTrigTrack->GetZ21();
   zMeanChamber[3] = matchedTrigTrack->GetZ21() + AliMUONConstants::DefaultChamberZ(13) - AliMUONConstants::DefaultChamberZ(12);
 
-  TArrayI digitPerTrack(fgkNcathodes);
-
-  Float_t trackIntersectCh[fgkNchambers][fgkNcathodes];
-
-  TArrayI triggeredDigits;
-  triggeredDigits.Set(fgkNchambers);
-  triggeredDigits.Reset(-1);
-
-  TArrayI trigScheme[fgkNcathodes];
-  TArrayI slatThatTriggered[fgkNcathodes];
-  for(Int_t cath=0; cath<fgkNcathodes; cath++){
-    trigScheme[cath].Set(fgkNchambers);
-    slatThatTriggered[cath].Set(fgkNchambers);
-  }
-
-  Int_t boardThatTriggered[fgkNchambers][fgkNcathodes][fgkNlocations];
-  TArrayI nboard[fgkNcathodes];
-  for(Int_t cath=0; cath<fgkNcathodes; cath++){
-    nboard[cath].Set(fgkNlocations);
-  }
-  Int_t ineffBoard[fgkNlocations];
-  for(Int_t loc=0; loc<fgkNlocations; loc++){
-    ineffBoard[loc] = -1;
-  }
-
+  TArrayI digitPerTrack(2);
   digitPerTrack.Reset();
-  for(Int_t ch=0; ch<fgkNchambers; ch++){
-    zRealMatch[ch] = zMeanChamber[ch];
-    for(Int_t cath=0; cath<fgkNcathodes; cath++){
-      for(Int_t loc=0; loc<fgkNlocations; loc++){
-       boardThatTriggered[ch][cath][loc]=-1;
-      }
-    }
-  }
-
-  for(Int_t cath=0; cath<fgkNcathodes; cath++){
-    slatThatTriggered[cath].Reset(-1);
-    trigScheme[cath].Reset();
-  }
 
-  Bool_t isClearEvent = kTRUE;
+  Float_t trackIntersectCh[2];
 
-  Float_t y11 = matchedTrigTrack->GetY11();// y position (info from bending plane)
   Float_t slopeX = matchedTrigTrack->GetSlopeX();
   Float_t slopeY = matchedTrigTrack->GetSlopeY();
-
-  for(Int_t ch=0; ch<fgkNchambers; ch++) { // chamber loop
-    Int_t currCh = chOrder[ch];
-    AliDebug(3, Form("zMeanChamber[%i] = %.2f\tzRealMatch[0] = %.2f\n",currCh,zMeanChamber[currCh],zRealMatch[0]));
-
+  
+  Float_t z11 = matchedTrigTrack->GetZ11();
+  Float_t x11 = slopeX * z11;
+  Float_t y11 = matchedTrigTrack->GetY11();
+  Float_t z21 =  matchedTrigTrack->GetZ21();
+  Float_t x21 = slopeX * z21;
+  Float_t y21 = y11 + slopeY * (z21-z11);
+  TVector3 vec11(x11, y11, z11), vec21(x21, y21, z21);
+  
+  Int_t firstSlat = -1, firstBoard = -1;
+  AliESDMuonTrack::EAliTriggerChPatternFlag goodForEff = AliESDMuonTrack::kBoardEff;
+  TObjArray matchedPads(2), padsFromPos(2), validPads(2);
+  matchedPads.SetOwner(); padsFromPos.SetOwner();
+  Int_t matchedDetElemId[2], detElemIdFromTrack[2];
+  
+  for(Int_t ich=0; ich<AliMUONConstants::NTriggerCh(); ich++) { // chamber loop
+    
     // searching track intersection with chambers (first approximation)
-    Float_t deltaZ = zMeanChamber[currCh] - zMeanChamber[0];
-    trackIntersectCh[currCh][0] = zMeanChamber[currCh] * slopeX;
-    trackIntersectCh[currCh][1] = y11 + deltaZ * slopeY;
-    Int_t detElemIdFromTrack = DetElemIdFromPos(trackIntersectCh[currCh][0], trackIntersectCh[currCh][1], 11+currCh, 0);
-    if(detElemIdFromTrack<0) {
-      AliDebug(1, "Warning: trigger track outside trigger chamber\n");
-      isClearEvent = kFALSE;
-
+    Float_t deltaZ = zMeanChamber[ich] - zMeanChamber[0];
+    trackIntersectCh[0] = zMeanChamber[ich] * slopeX;
+    trackIntersectCh[1] = y11 + deltaZ * slopeY;
+    Int_t nFound = DetElemIdFromPos(trackIntersectCh[0], trackIntersectCh[1], 11+ich, detElemIdFromTrack);
+    if ( nFound == 0 ) {
       // track is rejected since the extrapolated track
       // does not match a slat (border effects)
       AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackOutsideGeometry);
+      goodForEff = AliESDMuonTrack::kNoEff;
+      AliDebug(10, "Warning: trigger track outside trigger chamber\n");
       continue;
     }
-               
-    triggeredDigits[currCh] = FindPadMatchingTrig(detElemIdFromTrack, trackIntersectCh[currCh], isMatch, nboard, zRealMatch, y11);
-
-    // if FindPadMatchingTrig = -500 => too many digits matching pad =>
-    //                               => Event not clear => Do not use for efficiency calculation
-    if(triggeredDigits[currCh]<-100){
-      isClearEvent = kFALSE;
-      // track is rejected since it matches many pads
+    
+    matchedDetElemId[0] = matchedDetElemId[1] = detElemIdFromTrack[0];
+    
+    if ( ! FindPadMatchingTrig(vec11, vec21, matchedDetElemId, matchedPads) ) {
+      // if ! FindPadMatchingTrig => too many digits matching pad =>
+      //                          => Event not clear => Do not use for efficiency calculation
       AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackMatchesManyPads);
-      AliDebug(1, Form("Warning: track = %p (%i) matches many pads. Rejected!\n",(void *)matchedTrigTrack, detElemIdFromTrack));
+      goodForEff = AliESDMuonTrack::kNoEff;
+      AliDebug(10, Form("Warning: track = %p (%i) matches many pads. Rejected!\n",(void *)matchedTrigTrack, matchedDetElemId[0]));
     }
-
-    for(Int_t cath=0; cath<fgkNcathodes; cath++){
-      if(!isMatch[cath]) continue;
-      AliESDMuonTrack::SetFiredChamber(pattern, cath, currCh);
-      digitPerTrack[cath]++;
-      trigScheme[cath][currCh]++;
-      slatThatTriggered[cath][currCh] = detElemIdFromTrack;
-      for(Int_t loc=0; loc<fgkNlocations; loc++){
-       boardThatTriggered[currCh][cath][loc] = nboard[cath][loc];
+    
+    Int_t nMatched = 0;
+
+    Int_t mostProbDEmatched = detElemIdFromTrack[0];
+    for ( Int_t icath=0; icath<2; icath++ ) {
+      if ( matchedPads.UncheckedAt(icath) ) {
+        nMatched++;
+        // Fill pattern anyway
+        AliESDMuonTrack::SetFiredChamber(pattern, icath, ich);
+        digitPerTrack[icath]++;
+        mostProbDEmatched = matchedDetElemId[icath];
+      }
+    }
+    Int_t mostProbDEfromTrack = detElemIdFromTrack[0];
+    for ( Int_t ifound=0; ifound<nFound; ifound++ ) {
+      if ( detElemIdFromTrack[ifound] == mostProbDEmatched ) {
+        mostProbDEfromTrack = mostProbDEmatched;
+        break;
       }
     }
+    
+    if ( goodForEff == AliESDMuonTrack::kNoEff ) continue;
+
+    if ( nMatched < 2 ) PadsFromPos(vec11, vec21, mostProbDEfromTrack, padsFromPos);
+
+    for ( Int_t cath=0; cath<2; cath++ ) {
+      if ( matchedPads.UncheckedAt(cath) ) validPads.AddAt(matchedPads.UncheckedAt(cath),cath);
+      else if ( padsFromPos.UncheckedAt(cath) ) {
+        AliMpPad* currPad = (AliMpPad*)padsFromPos.UncheckedAt(cath);
+        validPads.AddAt(currPad,cath);
+        if ( IsMasked(*currPad, mostProbDEfromTrack, cath, vec11, vec21) ) {
+          // Check if strip was masked (if inefficient strip is found)
+          AliESDMuonTrack::AddEffInfo(pattern,AliESDMuonTrack::kTrackMatchesMasks); // pad is masked
+          AliDebug(10,Form("DetElemId %i  cath %i  board %i  strip %i is masked: effFlag 0", mostProbDEfromTrack, cath, currPad->GetLocalBoardId(0), currPad->GetLocalBoardChannel(0)));
+          goodForEff = AliESDMuonTrack::kNoEff;
+        }
+      }
+      else goodForEff = AliESDMuonTrack::kNoEff;
+    } // loop on cathodes
+        
+    if ( goodForEff != AliESDMuonTrack::kNoEff ) {
+      
+      if ( nMatched == 0 && IsCloseToAccEdge(padsFromPos, mostProbDEfromTrack, trackIntersectCh) ) {
+        // Non of cathodes is fired.
+        // If we are close to the edge of the RPC
+        // it could be a problem of acceptance 
+        AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackOutsideGeometry);
+        goodForEff = AliESDMuonTrack::kNoEff;
+        AliDebug(10, "Warning: trigger track at the edge of the chamber\n");
+      }
+      
+      Int_t currSlat = mostProbDEmatched%100;
+      if ( firstSlat < 0 ) firstSlat = currSlat;
+      else if ( currSlat != firstSlat ) {
+        goodForEff = AliESDMuonTrack::kChEff;
+        firstSlat = AliESDMuonTrack::kCrossDifferentSlats;
+      }
+    
+      if ( firstBoard < 0 ) firstBoard = ((AliMpPad*)validPads[kBending])->GetLocalBoardId(0);
+        
+      for ( Int_t cath=0; cath<2; cath++ ){      
+      
+        if ( goodForEff == AliESDMuonTrack::kBoardEff) {
+          Bool_t atLeastOneLoc = kFALSE;
+          AliMpPad* currPad = (AliMpPad*)validPads.UncheckedAt(cath);
+          for ( Int_t iloc=0; iloc<currPad->GetNofLocations(); iloc++) {
+            if ( currPad->GetLocalBoardId(iloc) == firstBoard ) {
+              atLeastOneLoc = kTRUE;
+              break;
+            }
+          } // loop on locations
+          if ( ! atLeastOneLoc ) goodForEff = AliESDMuonTrack::kSlatEff;
+        }
+      } // loop on cathodes
+    } // if track good for efficiency
+    matchedPads.Delete();
+    padsFromPos.Delete();
   } // end chamber loop
+  
+  if ( goodForEff == AliESDMuonTrack::kNoEff ) return kFALSE;
 
-  for(Int_t cath=0; cath<fgkNcathodes; cath++){
+  for(Int_t cath=0; cath<2; cath++){
     if(digitPerTrack[cath]<3) {
-      isClearEvent = kFALSE;
       // track is rejected since the number of associated
       // digits found is less than 3.
       AliESDMuonTrack::AddEffInfo(pattern, AliESDMuonTrack::kTrackMatchesFewPads);
-      AliDebug(1, Form("Warning: found %i digits for trigger track cathode %i.\nRejecting event\n", digitPerTrack[cath],cath));
+      goodForEff = AliESDMuonTrack::kNoEff;
+      AliDebug(10, Form("Warning: found %i digits for trigger track cathode %i.\nRejecting event\n", digitPerTrack[cath],cath));
     }
-  }
-
-  if(!isClearEvent) return kFALSE;
+  } // loop on cathodes 
 
-  AliESDMuonTrack::EAliTriggerChPatternFlag goodForEff = AliESDMuonTrack::kBoardEff;
-
-  Int_t ineffSlat = -1;
-  Int_t ineffDetElId = -1;
-  Int_t firstSlat = slatThatTriggered[kBending][0]%100;
-  if(firstSlat<0) firstSlat = slatThatTriggered[kBending][1]%100;
-  Int_t firstBoard = boardThatTriggered[0][kBending][0];
-  if(firstBoard<0) firstBoard = boardThatTriggered[1][kBending][0];
-  for(Int_t ch=0; ch<fgkNchambers; ch++){
-    Bool_t isCurrChIneff = kFALSE;
-    Int_t currSlat = slatThatTriggered[kBending][ch]%100;
-    if(currSlat<0){
-      ineffDetElId = DetElemIdFromPos(trackIntersectCh[ch][0], trackIntersectCh[ch][1], 11+ch, kBending);
-      currSlat = ineffDetElId%100;
-      ineffSlat = currSlat;
-      isCurrChIneff = kTRUE;
-    }
-    if(currSlat!=firstSlat) {
-      AliESDMuonTrack::AddEffInfo(pattern,
-                                 AliESDMuonTrack::kCrossDifferentSlats,
-                                 AliESDMuonTrack::kChEff); // track crosses different slats
-      return kTRUE;
-    }
-    Bool_t atLeastOneLoc=kFALSE;
-    if(isCurrChIneff) LocalBoardFromPos(trackIntersectCh[ch][0], trackIntersectCh[ch][1], ineffDetElId, kBending, ineffBoard);
-    for(Int_t loc=0; loc<fgkNlocations; loc++){
-      Int_t currBoard = boardThatTriggered[ch][kBending][loc];
-      if(isCurrChIneff) currBoard = ineffBoard[loc];
-      if(currBoard==firstBoard){
-       atLeastOneLoc=kTRUE;
-       break;
-      }
-    }
-    if(!atLeastOneLoc) goodForEff = AliESDMuonTrack::kSlatEff;
-  } // end chamber loop
+  if ( goodForEff == AliESDMuonTrack::kNoEff ) return kFALSE;
   
-  AliESDMuonTrack::AddEffInfo(pattern, firstSlat, goodForEff);
+  AliESDMuonTrack::AddEffInfo(pattern, firstSlat, firstBoard, goodForEff);
   return kTRUE;
 }