Merge branch '21.0-FastCaloSim-dev' into '21.0'

21.0-FastCaloSim: Changed coordinates used for shower shapes simulation

See merge request atlas/athena!16320

(cherry picked from commit 02984203bb2d4b6d6178d4f99eee550273ffdc37)

b43eade7 Added HepPDT to CMakeLists
d78c75e0 Implemented sign flips for negative particle charge and eta
3686c1bc Changing to new coordinates used for shower shape parameterization in FCal
7f9bb2fa Added comments to the code to explain changes in signs in shower shape coordinates

Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent/CMakeLists.txt

@@ -18,6 +18,7 @@ atlas_depends_on_subdirs(
 
 # External dependencies:
 find_package( CLHEP )
+find_package( HepPDT )
 find_package( ROOT COMPONENTS Core Tree MathCore Hist RIO Matrix Physics )
 
 # Remove the --as-needed linker flags:
@@ -70,14 +71,15 @@ atlas_add_root_dictionary( ISF_FastCaloSimEvent _dictSource
                            ISF_FastCaloSimEvent/TFCSExtrapolationState.h 
                            ISF_FastCaloSimEvent/TFCSSimulationState.h 
                            ISF_FastCaloSimEvent/TFCSTruthState.h 
-                           ISF_FastCaloSimEvent/LinkDef.h )
+                           ISF_FastCaloSimEvent/LinkDef.h 
+			   EXTERNAL_PACKAGES HepPDT)
 
 atlas_add_library( ISF_FastCaloSimEvent
    ISF_FastCaloSimEvent/*.h ${_dictSource} src/*.cxx
    PUBLIC_HEADERS ISF_FastCaloSimEvent
-   INCLUDE_DIRS ${CLHEP_INCLUDE_DIRS} ${ROOT_INCLUDE_DIRS}
+   INCLUDE_DIRS ${CLHEP_INCLUDE_DIRS} ${HEPPDT_INCLUDE_DIRS} ${ROOT_INCLUDE_DIRS}
    DEFINITIONS ${CLHEP_DEFINITIONS}
-   LINK_LIBRARIES ${CLHEP_LIBRARIES} ${ROOT_LIBRARIES} AthContainers SGTools
+   LINK_LIBRARIES ${CLHEP_LIBRARIES} ${HEPPDT_LIBRARIES} ${ROOT_LIBRARIES} AthContainers SGTools
    CaloGeoHelpers TileSimEvent
    PRIVATE_LINK_LIBRARIES GaudiKernel )
 

Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent/ISF_FastCaloSimEvent/TFCSHistoLateralShapeParametrization.h

@@ -7,6 +7,7 @@
 
 #include "ISF_FastCaloSimEvent/TFCSLateralShapeParametrizationHitBase.h"
 #include "ISF_FastCaloSimEvent/TFCS2DFunctionHistogram.h"
+#include "ISF_FastCaloSimEvent/TFCSTruthState.h"
 
 class TH2;
 

Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent/ISF_FastCaloSimEvent/TFCSHistoLateralShapeParametrizationFCal.h

@@ -7,6 +7,7 @@
 
 #include "ISF_FastCaloSimEvent/TFCSHistoLateralShapeParametrization.h"
 #include "ISF_FastCaloSimEvent/TFCS2DFunctionHistogram.h"
+#include "ISF_FastCaloSimEvent/TFCSTruthState.h"
 
 class TH2;
 

Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent/src/TFCSHistoLateralShapeParametrization.cxx

@@ -14,6 +14,8 @@
 #include "TMath.h"
 #include "TH2.h"
 
+#include "HepPDT/ParticleData.hh"
+#include "HepPDT/ParticleDataTable.hh"
 
 //=============================================
 //======= TFCSHistoLateralShapeParametrization =========
@@ -43,11 +45,14 @@ void TFCSHistoLateralShapeParametrization::set_number_of_hits(float nhits)
   m_nhits=nhits;
 }
 
-FCSReturnCode TFCSHistoLateralShapeParametrization::simulate_hit(Hit &hit, TFCSSimulationState &simulstate, const TFCSTruthState* /*truth*/, const TFCSExtrapolationState* extrapol)
+FCSReturnCode TFCSHistoLateralShapeParametrization::simulate_hit(Hit &hit, TFCSSimulationState &simulstate, const TFCSTruthState* truth, const TFCSExtrapolationState* extrapol)
 {
   if (!simulstate.randomEngine()) {
     return FCSFatal;
   }
+  
+  const int     pdgId    = truth->pdgid();
+  const double  charge   = HepPDT::ParticleID(pdgId).charge();
 
   const int cs=calosample();
   const double center_eta=0.5*( extrapol->eta(cs, CaloSubPos::SUBPOS_ENT) + extrapol->eta(cs, CaloSubPos::SUBPOS_EXT) );
@@ -84,8 +89,14 @@ FCSReturnCode TFCSHistoLateralShapeParametrization::simulate_hit(Hit &hit, TFCSS
     return FCSFatal;
   }
   
-  const float delta_eta_mm = r * cos(alpha);
-  const float delta_phi_mm = r * sin(alpha);
+  
+  float delta_eta_mm = r * cos(alpha);
+  float delta_phi_mm = r * sin(alpha);
+  
+  // Particles with negative eta are expected to have the same shape as those with positive eta after transformation: delta_eta --> -delta_eta
+  if(center_eta<0.)delta_eta_mm = -delta_eta_mm;
+  // Particle with negative charge are expected to have the same shape as positively charged particles after transformation: delta_phi --> -delta_phi
+  if(charge < 0.)  delta_phi_mm = -delta_phi_mm;
 
   const float dist000    = TMath::Sqrt(center_r * center_r + center_z * center_z);
   const float eta_jakobi = TMath::Abs(2.0 * TMath::Exp(-center_eta) / (1.0 + TMath::Exp(-2 * center_eta)));

Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent/src/TFCSHistoLateralShapeParametrizationFCal.cxx

@@ -11,6 +11,9 @@
 
 #include "TMath.h"
 
+#include "HepPDT/ParticleData.hh"
+#include "HepPDT/ParticleDataTable.hh"
+
 
 //=============================================
 //======= TFCSHistoLateralShapeParametrizationFCal =========
@@ -25,19 +28,19 @@ TFCSHistoLateralShapeParametrizationFCal::~TFCSHistoLateralShapeParametrizationF
 {
 }
 
-FCSReturnCode TFCSHistoLateralShapeParametrizationFCal::simulate_hit(Hit &hit, TFCSSimulationState &simulstate, const TFCSTruthState* /*truth*/, const TFCSExtrapolationState* extrapol)
+FCSReturnCode TFCSHistoLateralShapeParametrizationFCal::simulate_hit(Hit &hit, TFCSSimulationState &simulstate, const TFCSTruthState* truth, const TFCSExtrapolationState* extrapol)
 {
   if (!simulstate.randomEngine()) {
     return FCSFatal;
   }
 
+  const int     pdgId    = truth->pdgid();
+  const double  charge   = HepPDT::ParticleID(pdgId).charge();
+
   const int cs=calosample();
   const double center_phi=0.5*( extrapol->phi(cs, CaloSubPos::SUBPOS_ENT) + extrapol->phi(cs, CaloSubPos::SUBPOS_EXT) );
   const double center_r=0.5*( extrapol->r(cs, CaloSubPos::SUBPOS_ENT) + extrapol->r(cs, CaloSubPos::SUBPOS_EXT) );
   const double center_z=0.5*( extrapol->z(cs, CaloSubPos::SUBPOS_ENT) + extrapol->z(cs, CaloSubPos::SUBPOS_EXT) );
-  
-  const double center_x=center_r*cos(center_phi);
-  const double center_y=center_r*sin(center_phi);
 
   float alpha, r, rnd1, rnd2;
   rnd1 = CLHEP::RandFlat::shoot(simulstate.randomEngine());
@@ -64,10 +67,13 @@ FCSReturnCode TFCSHistoLateralShapeParametrizationFCal::simulate_hit(Hit &hit, T
     return FCSFatal;
   }
   
-  const float delta_x = r * cos(alpha);
-  const float delta_y = r * sin(alpha);
+  const float hit_r = r*cos(alpha) + center_r;
+  float delta_phi = r*sin(alpha)/center_r;
+  // Particle with negative charge are expected to have the same shape as positively charged particles after transformation: delta_phi --> -delta_phi
+  if(charge < 0.) delta_phi = -delta_phi;
+  const float hit_phi= delta_phi + center_phi;
 
-  hit.setXYZE(center_x+delta_x,center_y+delta_y,center_z,hit.E());
+  hit.setXYZE(hit_r*cos(hit_phi),hit_r*sin(hit_phi),center_z,hit.E());
 
   ATH_MSG_DEBUG("HIT: E="<<hit.E()<<" cs="<<cs<<" x="<<hit.x()<<" y="<<hit.y()<<" z="<<hit.z()<<" r=" << r <<" alpha="<<alpha);