PWGCF/FEMTOSCOPY/AliFemto/AliFemtoModelGausLCMSFreezeOutGenerator.cxx

   1 ////////////////////////////////////////////////////////////////////////////////
   2 ///                                                                          ///
   3 /// AliFemtoModelGausLCMSFreezeOutGenerator - freeze-out                     ///
   4 /// coordinates generator, generating a 3D gaussian ellipsoid in LCMS        ///
   5 /// Authors: Adam Kisiel kisiel@mps.ohio-state.edu                           ///
   6 ///                                                                          ///
   7 ////////////////////////////////////////////////////////////////////////////////
   8 #ifdef __ROOT__
   9   ClassImp(AliFemtoModelGausLCMSFreezeOutGenerator, 1)
  10 #endif
  11
  12 #include "math.h"
  13 #include "AliFemtoModelGausLCMSFreezeOutGenerator.h"
  14 #include "AliFemtoModelHiddenInfo.h"
  15 #include "AliFemtoLorentzVector.h"
  16 #include <TMath.h>
  17
  18 //_______________________
  19 AliFemtoModelGausLCMSFreezeOutGenerator::AliFemtoModelGausLCMSFreezeOutGenerator() :
  20   fSizeOut(0), fSizeSide(0), fSizeLong(0)
  21 {
  22   // Default constructor
  23   fRandom = new TRandom2();
  24 }
  25
  26 //_______________________
  27 AliFemtoModelGausLCMSFreezeOutGenerator::AliFemtoModelGausLCMSFreezeOutGenerator(const AliFemtoModelGausLCMSFreezeOutGenerator &aModel):
  28   AliFemtoModelFreezeOutGenerator(aModel),
  29   fSizeOut(0), fSizeSide(0), fSizeLong(0)
  30 {
  31   // Copy constructor
  32   fRandom = new TRandom2();
  33   SetSizeOut(aModel.GetSizeOut());
  34   SetSizeSide(aModel.GetSizeSide());
  35   SetSizeLong(aModel.GetSizeLong());
  36 }
  37 //_______________________
  38 AliFemtoModelGausLCMSFreezeOutGenerator::~AliFemtoModelGausLCMSFreezeOutGenerator()
  39 {
  40   if (fRandom) delete fRandom;
  41 }
  42 //_______________________
  43 AliFemtoModelGausLCMSFreezeOutGenerator& AliFemtoModelGausLCMSFreezeOutGenerator::operator=(const AliFemtoModelGausLCMSFreezeOutGenerator &aModel)
  44 {
  45   if (this != &aModel) {
  46     fRandom = new TRandom2();
  47     SetSizeOut(aModel.GetSizeOut());
  48     SetSizeSide(aModel.GetSizeSide());
  49     SetSizeLong(aModel.GetSizeLong());
  50   }
  51
  52   return *this;
  53 }
  54 //_______________________
  55 void AliFemtoModelGausLCMSFreezeOutGenerator::GenerateFreezeOut(AliFemtoPair *aPair)
  56 {
  57   // Generate two particle emission points with respect
  58   // to their pair momentum
  59   // The source is the 3D Gaussian ellipsoid in the LCMS frame
  60   //AliFemtoModelHiddenInfo *inf1 = (AliFemtoModelHiddenInfo *) aPair->Track1()->HiddenInfo();
  61   //AliFemtoModelHiddenInfo *inf2 = (AliFemtoModelHiddenInfo *) aPair->Track2()->HiddenInfo();
  62   AliFemtoTrack *inf1 = (AliFemtoTrack *) aPair->Track1()->Track();
  63   AliFemtoTrack *inf2 = (AliFemtoTrack *) aPair->Track2()->Track();
  64
  65   if ((!inf1) || (!inf2)) { cout << "Hidden info not created! "  << endl; exit(kFALSE); }
  66
  67   Double_t tPx = inf1->GetTrueMomentum()->x() + inf2->GetTrueMomentum()->x();
  68   Double_t tPy = inf1->GetTrueMomentum()->y() + inf2->GetTrueMomentum()->y();
  69   Double_t tPz = inf1->GetTrueMomentum()->z() + inf2->GetTrueMomentum()->z();
  70   Double_t tM1 = inf1->GetMass();
  71   Double_t tM2 = inf2->GetMass();
  72   Double_t tE1 = sqrt(tM1*tM1 + inf1->GetTrueMomentum()->Mag2());
  73   Double_t tE2 = sqrt(tM2*tM2 + inf2->GetTrueMomentum()->Mag2());
  74   Double_t tEs = tE1 + tE2;
  75
  76   Double_t tPt = sqrt(tPx*tPx + tPy*tPy);
  77
  78   Double_t tRout = fRandom->Gaus(0.0, fSizeOut);
  79   Double_t tRside = fRandom->Gaus(0.0, fSizeSide);
  80   Double_t tRlong = fRandom->Gaus(0.0, fSizeLong);
  81
  82   Double_t tXout = (tPx * tRout + tPy * tRside)/tPt;
  83   Double_t tXside = (tPy * tRout - tPx * tRside)/tPt;
  84
  85   Double_t tBetaz = tPz/tEs;
  86   Double_t tGammaz = 1.0/TMath::Sqrt(1-tBetaz*tBetaz);
  87
  88   Double_t tXlong = tGammaz * (tRlong + tBetaz * 0);
  89   Double_t tXtime = tGammaz * (0 + tBetaz * tRlong);
  90
  91   if (!(inf1->GetEmissionPoint())) {
  92     AliFemtoLorentzVector *tPos = new AliFemtoLorentzVector(0,0,0,0);
  93     inf1->SetEmissionPoint(tPos);
  94     delete tPos;
  95   }
  96   else
  97     inf1->SetEmissionPoint(0,0,0,0);
  98   if (!(inf2->GetEmissionPoint())) {
  99     AliFemtoLorentzVector *tPos = new AliFemtoLorentzVector(tXout,tXside,tXlong,tXtime);
 100     inf2->SetEmissionPoint(tPos);
 101     delete tPos;
 102   }
 103   else
 104     inf2->SetEmissionPoint(tXout, tXside, tXlong, tXtime);
 105 }
 106
 107 //_______________________
 108 void AliFemtoModelGausLCMSFreezeOutGenerator::SetSizeOut(Double_t aSizeOut)
 109 {
 110   fSizeOut = aSizeOut;
 111 }
 112 //_______________________
 113 void AliFemtoModelGausLCMSFreezeOutGenerator::SetSizeSide(Double_t aSizeSide)
 114 {
 115   fSizeSide = aSizeSide;
 116 }
 117 //_______________________
 118 void AliFemtoModelGausLCMSFreezeOutGenerator::SetSizeLong(Double_t aSizeLong)
 119 {
 120   fSizeLong = aSizeLong;
 121 }
 122
 123 //_______________________
 124 Double_t AliFemtoModelGausLCMSFreezeOutGenerator::GetSizeOut() const
 125 {
 126   return fSizeOut;
 127 }
 128 //_______________________
 129 Double_t AliFemtoModelGausLCMSFreezeOutGenerator::GetSizeSide() const
 130 {
 131   return fSizeSide;
 132 }
 133 //_______________________
 134 Double_t AliFemtoModelGausLCMSFreezeOutGenerator::GetSizeLong() const
 135 {
 136   return fSizeLong;
 137 }
 138 //_______________________
 139 AliFemtoModelFreezeOutGenerator* AliFemtoModelGausLCMSFreezeOutGenerator::Clone() const
 140 {
 141   return GetGenerator();
 142 }
 143 //_______________________
 144 AliFemtoModelFreezeOutGenerator* AliFemtoModelGausLCMSFreezeOutGenerator::GetGenerator() const
 145 {
 146   AliFemtoModelFreezeOutGenerator* tModel = new AliFemtoModelGausLCMSFreezeOutGenerator(*this); return tModel;
 147 }