RICH/AliRICHv1.cxx

   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
  16
  17 #include "AliRICHv1.h"
  18 #include "AliRICHParam.h"
  19 #include "AliRICHChamber.h"
  20 #include <TParticle.h>
  21 #include <TRandom.h>
  22 #include <TVirtualMC.h>
  23 #include <TPDGCode.h>
  24
  25 #include <AliConst.h>
  26 #include <AliPDG.h>
  27 #include <AliRun.h>
  28 #include <AliMC.h>
  29
  30 ClassImp(AliRICHv1)
  31 //______________________________________________________________________________
  32 void AliRICHv1::StepManager()
  33 {
  34 //Full Step Manager
  35
  36   Int_t          copy;
  37   static Int_t   iCurrentChamber;
  38   static TLorentzVector x4,p4,mipInX4,mipOutX4;
  39   Float_t        pos[3],mom[4],localPos[3],localMom[4];
  40   Float_t        coscerenkov;
  41
  42   TParticle *current = (TParticle*)(*gAlice->GetMCApp()->Particles())[gAlice->GetMCApp()->GetCurrentTrackNumber()];
  43
  44   Float_t cherenkovLoss=0;
  45
  46   if(gMC->TrackPid()==kCerenkov){//C
  47     Float_t ckovEnergy = current->Energy();
  48     if(ckovEnergy > 5.6e-09 && ckovEnergy < 7.8e-09 ){//C+E
  49         if(gMC->IsTrackEntering()){                                     //is track entering?
  50
  51                     if (gMC->VolId("CSI ")==gMC->CurrentVolID(copy)){             //is it in csi?
  52                         gMC->TrackMomentum(p4); mom[0]=p4(0);   mom[1]=p4(1);   mom[2]=p4(2);   mom[3]=p4(3);
  53                         gMC->Gmtod(mom,localMom,2);
  54                         Double_t localTc    = localMom[0]*localMom[0]+localMom[2]*localMom[2];
  55                         Double_t localTheta = TMath::ATan2(TMath::Sqrt(localTc),localMom[1]);
  56                         Double_t cotheta = TMath::Abs(TMath::Cos(localTheta));
  57                         if(gMC->GetRandom()->Rndm() < Fresnel(p4.E()*1e9,cotheta,1))  gMC->StopTrack();
  58
  59                       }//C+E+produced in Freon
  60                   } //track entering?
  61     }//C+E
  62   }//C
  63
  64   if((gMC->TrackPid()==kCerenkov||gMC->TrackPid()==kFeedback)&&gMC->CurrentVolID(copy)==gMC->VolId("CSI ")){//photon in CSI
  65       if(gMC->Edep()>0.){//CF+CSI+DE
  66         gMC->TrackPosition(x4);   pos[0]=x4(0);   pos[1]=x4(1);   pos[2]=x4(2);
  67         gMC->TrackMomentum(p4);   mom[0]=p4(0);   mom[1]=p4(1);   mom[2]=p4(2);   mom[3]=p4(3);
  68         if(IsFresnelLoss()){ gMC->StopTrack(); return;}
  69         gMC->CurrentVolOffID(2,copy);iCurrentChamber=copy;
  70
  71         gMC->Gmtod(pos,localPos,1);     gMC->Gmtod(mom,localMom,2);
  72
  73         cherenkovLoss  += gMC->Edep();
  74
  75         AliRICHhit *mipHit =  (AliRICHhit*) (fHits->UncheckedAt(0));
  76         if(mipHit){
  77           mom[0] = current->Px();   mom[1] = current->Py();   mom[2] = current->Pz();
  78           Float_t mipPx = mipHit->MomX();   Float_t mipPy = mipHit->MomY();   Float_t mipPz = mipHit->MomZ();
  79
  80           Float_t r = mom[0]*mom[0] + mom[1]*mom[1] + mom[2]*mom[2];
  81           Float_t rt = TMath::Sqrt(r);
  82           Float_t mipR = mipPx*mipPx + mipPy*mipPy + mipPz*mipPz;
  83           Float_t mipRt = TMath::Sqrt(mipR);
  84           if((rt*mipRt) > 0)
  85             coscerenkov = (mom[0]*mipPx + mom[1]*mipPy + mom[2]*mipPz)/(rt*mipRt);
  86           else
  87             coscerenkov = 0;
  88         }
  89         AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(),x4.Vect());//HIT for PHOTON in conditions CF+CSI+DE
  90         GenerateFeedbacks(iCurrentChamber,cherenkovLoss);//CF+CSI+DE
  91       }//CF+CSI+DE
  92   }//CF in CSI
  93
  94 //Treat charged particles
  95   static Float_t eloss;
  96   if(gMC->TrackCharge() && gMC->CurrentVolID(copy)==gMC->VolId("GAP ")){//MIP in GAP
  97     gMC->CurrentVolOffID(3,copy); iCurrentChamber=copy;
  98     if(gMC->IsTrackEntering()||gMC->IsNewTrack()) {//MIP in GAP Entering
  99       eloss=0;
 100       gMC->TrackPosition(mipInX4);
 101     }else if(gMC->IsTrackExiting()||gMC->IsTrackStop()||gMC->IsTrackDisappeared()){//MIP in GAP Exiting
 102       eloss+=gMC->Edep();//take into account last step dEdX
 103       gMC->TrackPosition(mipOutX4);
 104       AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(),mipInX4.Vect(),mipOutX4.Vect(),eloss);//HIT for MIP for conditions: MIP in GAP Exiting
 105       GenerateFeedbacks(iCurrentChamber,eloss);//MIP+GAP+Exit
 106     }else//MIP in GAP going inside
 107       eloss   += gMC->Edep();
 108   }//MIP in GAP
 109 }//void AliRICHv1::StepManager()
 110
 111 Bool_t AliRICHv1::IsFresnelLoss()
 112 {
 113   return kFALSE;
 114 }