[u/mrichter/AliRoot.git] / PHOS / AliPHOSvFast.cxx

  /**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/* $Id$ */

/* History of cvs commits:
 *
 * $Log$
 * Revision 1.30  2006/09/13 07:31:01  kharlov
 * Effective C++ corrections (T.Pocheptsov)
 *
 * Revision 1.29  2005/05/28 14:19:05  schutz
 * Compilation warnings fixed by T.P.
 *
 */

//_________________________________________________________________________
// Implementation of the PHOS manager class for fast simulations     
// Tracks particles until the reach a grossly designed PHOS module
// Modify the particles property (momentum, energy, type) according to
//  the PHOS response function. The result is called a virtual reconstructed
//  particle.                
//
//*-- Author: Yves Schutz (SUBATECH)

// --- ROOT system ---
 
#include <TGeometry.h>
#include <TParticle.h>
#include "TClonesArray.h" 
#include <TVirtualMC.h>

// --- Standard library ---

// --- AliRoot header files ---
#include "AliPHOSFastRecParticle.h"
#include "AliPHOSGeometry.h"
#include "AliPHOSLoader.h"
#include "AliPHOSvFast.h"
#include "AliRun.h"

ClassImp(AliPHOSvFast)

AliPHOSvFast::AliPHOSvFast() :
  fBigBoxX(0.),
  fBigBoxY(0.),
  fBigBoxZ(0.),
  fFastRecParticles(0),
  fNRecParticles(0),
  fRan(0),
  fResPara1(0.),
  fResPara2(0.),
  fResPara3(0.),
  fPosParaA0(0.),
  fPosParaA1(0.),
  fPosParaB0(0.),
  fPosParaB1(0.),
  fPosParaB2(0.)    
{
  // default ctor : initialize data member
}

//____________________________________________________________________________
AliPHOSvFast::AliPHOSvFast(const char *name, const char *title):
  AliPHOS(name,title),
  fBigBoxX(0.),
  fBigBoxY(0.),
  fBigBoxZ(0.),
  fFastRecParticles(new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100)),
  fNRecParticles(0),
  fRan(0),
  fResPara1(0.030), // GeV
  fResPara2(0.00003),
  fResPara3(0.00001),
  fPosParaA0(2.87),    // mm
  fPosParaA1(-0.0975),
  fPosParaB0(0.257),
  fPosParaB1(0.137),
  fPosParaB2(0.00619)
{
  // ctor
  // create the Loader 
  SetBigBox(0, GetGeometry()->GetOuterBoxSize(0) ) ;
  SetBigBox(1, GetGeometry()->GetOuterBoxSize(3) + GetGeometry()->GetCPVBoxSize(1) ) ; 
  SetBigBox(2, GetGeometry()->GetOuterBoxSize(2) ); 
}

//____________________________________________________________________________
AliPHOSvFast::~AliPHOSvFast()
{
  // dtor
 
  fFastRecParticles->Delete() ; 
  delete fFastRecParticles ;
  fFastRecParticles = 0 ; 

}

//____________________________________________________________________________
void AliPHOSvFast::AddRecParticle(const AliPHOSFastRecParticle & rp)
{  
  // Add a virtually reconstructed particle to the list 

  new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
  fNRecParticles++ ; 
}

//____________________________________________________________________________
void AliPHOSvFast::CreateGeometry()
{
  // Create the geometry for GEANT
  
  AliPHOSvFast *phostmp = (AliPHOSvFast*)gAlice->GetModule("PHOS") ;
  
  if ( phostmp == NULL ) {
    
    fprintf(stderr, "PHOS detector not found!\n") ;
    return ;
    
  }

  // Get pointer to the array containing media indeces
  Int_t *idtmed = fIdtmed->GetArray() - 699 ;
  
  Float_t bigbox[3] ; 
  bigbox[0] =   GetBigBox(0) / 2.0 ;
  bigbox[1] =   GetBigBox(1) / 2.0 ;
  bigbox[2] =   GetBigBox(2) / 2.0 ;
  
  gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
  
  // --- Position  PHOS mdules in ALICE setup ---
  
  Int_t idrotm[99] ;
  Double_t const kRADDEG = 180.0 / TMath::Pi() ;
  
  for( Int_t i = 1; i <= GetGeometry()->GetNModules(); i++ ) {
    
    Float_t angle = GetGeometry()->GetPHOSAngle(i) ;
    AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
 
    Float_t r = GetGeometry()->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;

    Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
    Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
    gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
 
  } // for GetNModules

}


//____________________________________________________________________________
void AliPHOSvFast::Init(void)
{
  // Prints out an information message
  
  Int_t i;

  printf("\n");
  for(i=0;i<35;i++) printf("*");
  printf(" FAST PHOS_INIT ");
  for(i=0;i<35;i++) printf("*");
  printf("\n");

  // Here the PHOS initialisation code (if any!)

  for(i=0;i<80;i++) printf("*");
  printf("\n");
  
}

//___________________________________________________________________________
Float_t AliPHOSvFast::GetBigBox(Int_t index) const
{
  // Get the X, Y or Z dimension of the box describing a PHOS module
  
  Float_t rv = 0 ; 

  switch (index) {
  case 0:
    rv = fBigBoxX ; 
    break ; 
  case 1:
     rv = fBigBoxY ; 
    break ; 
  case 2:
     rv = fBigBoxZ ; 
    break ; 
 }
  return rv ; 
}
//___________________________________________________________________________

void AliPHOSvFast::MakeBranch(Option_t* opt)
{  
  // Create new branch in the current reconstructed Root Tree
  AliDetector::MakeBranch(opt);
  const char *cd = strstr(opt,"R");
  
  if (fFastRecParticles && fLoader->TreeR() && cd) {
    MakeBranchInTree(fLoader->TreeR(), GetName(), &fFastRecParticles, fBufferSize, 0);
  }
}
//____________________________________________________________________________

Double_t AliPHOSvFast::MakeEnergy(Double_t energy)
{  
  // Smears the energy according to the energy dependent energy resolution.
  // A gaussian distribution is assumed

  Double_t sigma  = SigmaE(energy) ; 
  return  fRan.Gaus(energy, sigma) ;   
}
//____________________________________________________________________________

TVector3 AliPHOSvFast::MakePosition(Double_t energy, TVector3 pos, Double_t theta, Double_t phi)
{
  // Smears the impact position according to the energy dependent position resolution
  // A gaussian position distribution is assumed

  TVector3 newpos ;
  Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
  Double_t x = fRan.Gaus( pos.X(), sigma ) ;
  sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
  Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
  Double_t y = pos.Y() ; 
  
  newpos.SetX(x) ; 
  newpos.SetY(y) ; 
  newpos.SetZ(z) ; 
	      
  return newpos ; 
}

//____________________________________________________________________________
void AliPHOSvFast::MakeRecParticle(Int_t modid, TVector3 pos, AliPHOSFastRecParticle & rp)
{
  // Modify the primary particle properties according
  //  1. the response function of PHOS
  //  2. the performance of the EMC+PPSD setup
  
  Int_t type = MakeType( rp ) ;
  rp.SetType(type) ;

  
  // get the detected energy

  TLorentzVector momentum ;  
  rp.Momentum(momentum) ; 
  Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ; 
  Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
  Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)  
					 + TMath::Power( rp.GetMass(), 2) ) ;
 
  // get the angle of incidence 
  
  Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ; 
  Double_t incidencephi   = ( 270 + GetGeometry()->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;   

  // get the detected direction
  
  TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ; 
  modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ; 

  // Set the modified 4-momentum of the reconstructed particle

  rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ; 

 }

//____________________________________________________________________________
Int_t AliPHOSvFast::MakeType(AliPHOSFastRecParticle & rp )
{
  // Generate a particle type using the performance of the EMC+PPSD setup

  Int_t rv =   AliPHOSFastRecParticle::kUNDEFINED ;
  Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
  Int_t test ; 
  Float_t ran ; 
  if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) ) 
    test = - 1 ;
  else
    test = rp.GetPdgCode() ; 

  Fatal("MakeType", "SHOULD NOT BE USED until values of probabilities are properly set ") ;
   // NB: ALL VALUES SHOULD BE CHECKED !!!!
  switch (test) { 

  case 22:    // it's a photon              // NB: ALL VALUES SHOLD BE CHECKED !!!!
    ran = fRan.Rndm() ; 
    if( ran <= 0.9498 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHAFAST ; 
    else
      rv =  AliPHOSFastRecParticle::kNEUTRALEMFAST ;     
    break ; 

  case 2112:  // it's a neutron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9998 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHASLOW ; 
    else 
      rv = AliPHOSFastRecParticle::kNEUTRALEMSLOW ; 
    break ; 
    
  case -2112: // it's a anti-neutron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9984 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHASLOW ; 
    else 
      rv =  AliPHOSFastRecParticle::kNEUTRALEMSLOW ; 
    break ; 
    
  case 11:    // it's a electron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kCHARGEDEMFAST ; 
    else 
      rv =  AliPHOSFastRecParticle::kCHARGEDHAFAST ; 
    break; 

  case -11:   // it's a positon
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kCHARGEDEMFAST ; 
    else 
      rv =  AliPHOSFastRecParticle::kCHARGEDHAFAST ; 
    break; 

  case -1:    // it's a charged
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kCHARGEDHAFAST ; 
    else 
      rv =  AliPHOSFastRecParticle::kNEUTRALHAFAST ; 

    break ; 
  }
    
  
  return rv ;
}

//___________________________________________________________________________
void AliPHOSvFast::ResetPoints()
{
  // This overloads the method in AliDetector
  
  ResetFastRecParticles() ; 
}

//___________________________________________________________________________
void AliPHOSvFast::ResetFastRecParticles()
{
  // Resets the list of virtual reconstructed particles
 
  if (fFastRecParticles) 
    fFastRecParticles->Clear() ;
  fNRecParticles = 0 ; 
}

//___________________________________________________________________________
void AliPHOSvFast::SetBigBox(Int_t index, Float_t value)
{
  // Set the size of the Box describing a PHOS module
  
  switch (index) {
  case 0:
    fBigBoxX = value ; 
    break ; 
  case 1:
    fBigBoxY = value ; 
    break ; 
  case 2:
    fBigBoxZ = value ; 
    break ; 
 }

}

//____________________________________________________________________________
Double_t AliPHOSvFast::SigmaE(Double_t energy)
{
  // Calculates the energy dependent energy resolution
  
  Double_t rv = -1 ; 
  
  rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2) 
	       + TMath::Power(fResPara2/TMath::Sqrt(energy), 2) 
	       + TMath::Power(fResPara3, 2) ) ;  

  return rv * energy ; 
}

//____________________________________________________________________________
Double_t AliPHOSvFast::SigmaP(Double_t energy, Double_t incidence)
{
  // Calculates the energy dependent position resolution 

  Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ; 
  Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ; 

  return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1   ; // in cm  
}

//____________________________________________________________________________
void AliPHOSvFast::StepManager(void)
{
  // Only verifies if the particle reaches PHOS and stops the tracking 

  TLorentzVector lv ; 
  gMC->TrackPosition(lv) ;
  TVector3 pos = lv.Vect() ; 
  Int_t modid  ; 
  gMC->CurrentVolID(modid);
  
  Float_t energy = gMC->Etot() ; //Total energy of current track

  //Calculating mass of current particle
  TDatabasePDG * pdg = TDatabasePDG::Instance() ;
  TParticlePDG * partPDG = pdg->GetParticle(gMC->TrackPid()) ;
  Float_t mass = partPDG->Mass() ;

  if(energy > mass){
    pos.SetMag(TMath::Sqrt(energy*energy-mass*mass)) ;
    TLorentzVector pTrack(pos, energy) ;  

    TParticle * part = new TParticle(gMC->TrackPid(), 0,-1,-1,-1,-1, pTrack, lv)  ;
        
    AliPHOSFastRecParticle rp(*part) ;

    // Adds the response of PHOS to the particle
    MakeRecParticle(modid, pos, rp) ;
    
    // add the `track' particle to the FastRecParticles list
  
    AddRecParticle(rp) ;

    part->Delete() ;
  }
  // stop the track as soon PHOS is reached
  
  gMC->StopTrack() ; 

}
Commit	Line	Data
88cb7938	1	/**************************************************************************
3decf5cb	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
b2a60966	16	/* $Id$ */
b2a60966	17
702ab87e	18	/* History of cvs commits:
	19	*
	20	* $Log$
e939a978	21	* Revision 1.30 2006/09/13 07:31:01 kharlov
	22	* Effective C++ corrections (T.Pocheptsov)
	23	*
43fbaae1	24	* Revision 1.29 2005/05/28 14:19:05 schutz
	25	* Compilation warnings fixed by T.P.
	26	*
702ab87e	27	*/
702ab87e	28
3decf5cb	29	//_________________________________________________________________________
b2a60966	30	// Implementation of the PHOS manager class for fast simulations
	31	// Tracks particles until the reach a grossly designed PHOS module
	32	// Modify the particles property (momentum, energy, type) according to
	33	// the PHOS response function. The result is called a virtual reconstructed
	34	// particle.
	35	//
	36	//*-- Author: Yves Schutz (SUBATECH)
3decf5cb	37
3decf5cb	38	// --- ROOT system ---
3a4295ee	39
88cb7938	40	#include <TGeometry.h>
88cb7938	41	#include <TParticle.h>
e957fea8	42	#include "TClonesArray.h"
88cb7938	43	#include <TVirtualMC.h>
3decf5cb	44
	45	// --- Standard library ---
	46
3decf5cb	47	// --- AliRoot header files ---
3a4295ee	48	#include "AliPHOSFastRecParticle.h"
88cb7938	49	#include "AliPHOSGeometry.h"
88cb7938	50	#include "AliPHOSLoader.h"
3decf5cb	51	#include "AliPHOSvFast.h"
3decf5cb	52	#include "AliRun.h"
3decf5cb	53
	54	ClassImp(AliPHOSvFast)
	55
43fbaae1	56	AliPHOSvFast::AliPHOSvFast() :
	57	fBigBoxX(0.),
	58	fBigBoxY(0.),
	59	fBigBoxZ(0.),
	60	fFastRecParticles(0),
	61	fNRecParticles(0),
	62	fRan(0),
	63	fResPara1(0.),
	64	fResPara2(0.),
	65	fResPara3(0.),
	66	fPosParaA0(0.),
	67	fPosParaA1(0.),
	68	fPosParaB0(0.),
	69	fPosParaB1(0.),
	70	fPosParaB2(0.)
3decf5cb	71	{
3a4295ee	72	// default ctor : initialize data member
3decf5cb	73	}
	74
	75	//____________________________________________________________________________
	76	AliPHOSvFast::AliPHOSvFast(const char name, const char title):
43fbaae1	77	AliPHOS(name,title),
	78	fBigBoxX(0.),
	79	fBigBoxY(0.),
	80	fBigBoxZ(0.),
	81	fFastRecParticles(new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100)),
	82	fNRecParticles(0),
	83	fRan(0),
	84	fResPara1(0.030), // GeV
	85	fResPara2(0.00003),
	86	fResPara3(0.00001),
	87	fPosParaA0(2.87), // mm
	88	fPosParaA1(-0.0975),
	89	fPosParaB0(0.257),
	90	fPosParaB1(0.137),
	91	fPosParaB2(0.00619)
3decf5cb	92	{
b2a60966	93	// ctor
88cb7938	94	// create the Loader
7a9d98f9	95	SetBigBox(0, GetGeometry()->GetOuterBoxSize(0) ) ;
	96	SetBigBox(1, GetGeometry()->GetOuterBoxSize(3) + GetGeometry()->GetCPVBoxSize(1) ) ;
	97	SetBigBox(2, GetGeometry()->GetOuterBoxSize(2) );
3decf5cb	98	}
	99
	100	//____________________________________________________________________________
	101	AliPHOSvFast::~AliPHOSvFast()
	102	{
b2a60966	103	// dtor
3decf5cb	104
a73f33f0	105	fFastRecParticles->Delete() ;
	106	delete fFastRecParticles ;
	107	fFastRecParticles = 0 ;
3decf5cb	108
	109	}
	110
	111	//____________________________________________________________________________
a73f33f0	112	void AliPHOSvFast::AddRecParticle(const AliPHOSFastRecParticle & rp)
a73f33f0	113	{
b2a60966	114	// Add a virtually reconstructed particle to the list
b2a60966	115
f96d3dc7	116	new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
f96d3dc7	117	fNRecParticles++ ;
3decf5cb	118	}
3decf5cb	119
3decf5cb	120	//____________________________________________________________________________
	121	void AliPHOSvFast::CreateGeometry()
	122	{
b2a60966	123	// Create the geometry for GEANT
b2a60966	124
3decf5cb	125	AliPHOSvFast phostmp = (AliPHOSvFast)gAlice->GetModule("PHOS") ;
b2a60966	126
3decf5cb	127	if ( phostmp == NULL ) {
	128
	129	fprintf(stderr, "PHOS detector not found!\n") ;
	130	return ;
	131
	132	}
	133
	134	// Get pointer to the array containing media indeces
	135	Int_t *idtmed = fIdtmed->GetArray() - 699 ;
	136
	137	Float_t bigbox[3] ;
	138	bigbox[0] = GetBigBox(0) / 2.0 ;
	139	bigbox[1] = GetBigBox(1) / 2.0 ;
	140	bigbox[2] = GetBigBox(2) / 2.0 ;
	141
	142	gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
	143
	144	// --- Position PHOS mdules in ALICE setup ---
	145
	146	Int_t idrotm[99] ;
a8c47ab6	147	Double_t const kRADDEG = 180.0 / TMath::Pi() ;
3decf5cb	148
fa7cce36	149	for( Int_t i = 1; i <= GetGeometry()->GetNModules(); i++ ) {
3decf5cb	150
fa7cce36	151	Float_t angle = GetGeometry()->GetPHOSAngle(i) ;
3decf5cb	152	AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
3decf5cb	153
fa7cce36	154	Float_t r = GetGeometry()->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
3decf5cb	155
	156	Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
	157	Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
3decf5cb	158	gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
	159
	160	} // for GetNModules
	161
	162	}
	163
	164
	165	//____________________________________________________________________________
	166	void AliPHOSvFast::Init(void)
	167	{
b2a60966	168	// Prints out an information message
b2a60966	169
3decf5cb	170	Int_t i;
	171
	172	printf("\n");
	173	for(i=0;i<35;i++) printf("*");
	174	printf(" FAST PHOS_INIT ");
	175	for(i=0;i<35;i++) printf("*");
	176	printf("\n");
	177
	178	// Here the PHOS initialisation code (if any!)
	179
	180	for(i=0;i<80;i++) printf("*");
	181	printf("\n");
	182
	183	}
	184
	185	//___________________________________________________________________________
3a4295ee	186	Float_t AliPHOSvFast::GetBigBox(Int_t index) const
3decf5cb	187	{
b2a60966	188	// Get the X, Y or Z dimension of the box describing a PHOS module
b2a60966	189
3decf5cb	190	Float_t rv = 0 ;
	191
	192	switch (index) {
	193	case 0:
	194	rv = fBigBoxX ;
	195	break ;
	196	case 1:
	197	rv = fBigBoxY ;
	198	break ;
	199	case 2:
	200	rv = fBigBoxZ ;
	201	break ;
	202	}
	203	return rv ;
	204	}
3decf5cb	205	//___________________________________________________________________________
88cb7938	206
88cb7938	207	void AliPHOSvFast::MakeBranch(Option_t* opt)
3decf5cb	208	{
b2a60966	209	// Create new branch in the current reconstructed Root Tree
88cb7938	210	AliDetector::MakeBranch(opt);
3a4295ee	211	const char *cd = strstr(opt,"R");
3decf5cb	212
88cb7938	213	if (fFastRecParticles && fLoader->TreeR() && cd) {
88cb7938	214	MakeBranchInTree(fLoader->TreeR(), GetName(), &fFastRecParticles, fBufferSize, 0);
3decf5cb	215	}
3decf5cb	216	}
a73f33f0	217	//____________________________________________________________________________
88cb7938	218
fc7e2f43	219	Double_t AliPHOSvFast::MakeEnergy(Double_t energy)
a73f33f0	220	{
b2a60966	221	// Smears the energy according to the energy dependent energy resolution.
	222	// A gaussian distribution is assumed
	223
b1aa729d	224	Double_t sigma = SigmaE(energy) ;
b1aa729d	225	return fRan.Gaus(energy, sigma) ;
a73f33f0	226	}
a73f33f0	227	//____________________________________________________________________________
88cb7938	228
fc7e2f43	229	TVector3 AliPHOSvFast::MakePosition(Double_t energy, TVector3 pos, Double_t theta, Double_t phi)
a73f33f0	230	{
b2a60966	231	// Smears the impact position according to the energy dependent position resolution
	232	// A gaussian position distribution is assumed
	233
b1aa729d	234	TVector3 newpos ;
	235	Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
	236	Double_t x = fRan.Gaus( pos.X(), sigma ) ;
	237	sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
	238	Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
	239	Double_t y = pos.Y() ;
	240
	241	newpos.SetX(x) ;
	242	newpos.SetY(y) ;
	243	newpos.SetZ(z) ;
	244
	245	return newpos ;
	246	}
a73f33f0	247
b1aa729d	248	//____________________________________________________________________________
fc7e2f43	249	void AliPHOSvFast::MakeRecParticle(Int_t modid, TVector3 pos, AliPHOSFastRecParticle & rp)
b1aa729d	250	{
b2a60966	251	// Modify the primary particle properties according
	252	// 1. the response function of PHOS
	253	// 2. the performance of the EMC+PPSD setup
	254
b1aa729d	255	Int_t type = MakeType( rp ) ;
a73f33f0	256	rp.SetType(type) ;
	257
	258
	259	// get the detected energy
	260
	261	TLorentzVector momentum ;
	262	rp.Momentum(momentum) ;
	263	Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ;
	264	Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
b1aa729d	265	Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)
	266	+ TMath::Power( rp.GetMass(), 2) ) ;
	267
	268	// get the angle of incidence
	269
	270	Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ;
fa7cce36	271	Double_t incidencephi = ( 270 + GetGeometry()->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;
b1aa729d	272
	273	// get the detected direction
	274
	275	TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ;
	276	modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ;
	277
	278	// Set the modified 4-momentum of the reconstructed particle
	279
	280	rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ;
	281
a73f33f0	282	}
	283
	284	//____________________________________________________________________________
b1aa729d	285	Int_t AliPHOSvFast::MakeType(AliPHOSFastRecParticle & rp )
a73f33f0	286	{
b2a60966	287	// Generate a particle type using the performance of the EMC+PPSD setup
b2a60966	288
9ec91567	289	Int_t rv = AliPHOSFastRecParticle::kUNDEFINED ;
b1aa729d	290	Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
	291	Int_t test ;
	292	Float_t ran ;
f96d3dc7	293	if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) )
b1aa729d	294	test = - 1 ;
	295	else
	296	test = rp.GetPdgCode() ;
	297
a4765fe4	298	Fatal("MakeType", "SHOULD NOT BE USED until values of probabilities are properly set ") ;
a4765fe4	299	// NB: ALL VALUES SHOULD BE CHECKED !!!!
b1aa729d	300	switch (test) {
b1aa729d	301
3a4295ee	302	case 22: // it's a photon // NB: ALL VALUES SHOLD BE CHECKED !!!!
b1aa729d	303	ran = fRan.Rndm() ;
3a4295ee	304	if( ran <= 0.9498 )
	305	rv = AliPHOSFastRecParticle::kNEUTRALHAFAST ;
	306	else
	307	rv = AliPHOSFastRecParticle::kNEUTRALEMFAST ;
b1aa729d	308	break ;
	309
	310	case 2112: // it's a neutron
	311	ran = fRan.Rndm() ;
	312	if ( ran <= 0.9998 )
3a4295ee	313	rv = AliPHOSFastRecParticle::kNEUTRALHASLOW ;
b1aa729d	314	else
3a4295ee	315	rv = AliPHOSFastRecParticle::kNEUTRALEMSLOW ;
b1aa729d	316	break ;
3a4295ee	317
b1aa729d	318	case -2112: // it's a anti-neutron
	319	ran = fRan.Rndm() ;
	320	if ( ran <= 0.9984 )
3a4295ee	321	rv = AliPHOSFastRecParticle::kNEUTRALHASLOW ;
b1aa729d	322	else
3a4295ee	323	rv = AliPHOSFastRecParticle::kNEUTRALEMSLOW ;
b1aa729d	324	break ;
	325
	326	case 11: // it's a electron
	327	ran = fRan.Rndm() ;
	328	if ( ran <= 0.9996 )
3a4295ee	329	rv = AliPHOSFastRecParticle::kCHARGEDEMFAST ;
b1aa729d	330	else
3a4295ee	331	rv = AliPHOSFastRecParticle::kCHARGEDHAFAST ;
b1aa729d	332	break;
b1aa729d	333
f96d3dc7	334	case -11: // it's a positon
b1aa729d	335	ran = fRan.Rndm() ;
b1aa729d	336	if ( ran <= 0.9996 )
3a4295ee	337	rv = AliPHOSFastRecParticle::kCHARGEDEMFAST ;
b1aa729d	338	else
3a4295ee	339	rv = AliPHOSFastRecParticle::kCHARGEDHAFAST ;
b1aa729d	340	break;
	341
	342	case -1: // it's a charged
	343	ran = fRan.Rndm() ;
	344	if ( ran <= 0.9996 )
3a4295ee	345	rv = AliPHOSFastRecParticle::kCHARGEDHAFAST ;
b1aa729d	346	else
3a4295ee	347	rv = AliPHOSFastRecParticle::kNEUTRALHAFAST ;
b1aa729d	348
	349	break ;
	350	}
	351
	352
a73f33f0	353	return rv ;
	354	}
	355
f96d3dc7	356	//___________________________________________________________________________
	357	void AliPHOSvFast::ResetPoints()
	358	{
b2a60966	359	// This overloads the method in AliDetector
b2a60966	360
f96d3dc7	361	ResetFastRecParticles() ;
	362	}
	363
	364	//___________________________________________________________________________
	365	void AliPHOSvFast::ResetFastRecParticles()
	366	{
b2a60966	367	// Resets the list of virtual reconstructed particles
b2a60966	368
f96d3dc7	369	if (fFastRecParticles)
	370	fFastRecParticles->Clear() ;
	371	fNRecParticles = 0 ;
	372	}
	373
3decf5cb	374	//___________________________________________________________________________
	375	void AliPHOSvFast::SetBigBox(Int_t index, Float_t value)
	376	{
b2a60966	377	// Set the size of the Box describing a PHOS module
b2a60966	378
3decf5cb	379	switch (index) {
	380	case 0:
	381	fBigBoxX = value ;
	382	break ;
	383	case 1:
	384	fBigBoxY = value ;
	385	break ;
	386	case 2:
	387	fBigBoxZ = value ;
	388	break ;
	389	}
	390
	391	}
	392
a73f33f0	393	//____________________________________________________________________________
	394	Double_t AliPHOSvFast::SigmaE(Double_t energy)
	395	{
b2a60966	396	// Calculates the energy dependent energy resolution
b2a60966	397
a73f33f0	398	Double_t rv = -1 ;
	399
	400	rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2)
	401	+ TMath::Power(fResPara2/TMath::Sqrt(energy), 2)
	402	+ TMath::Power(fResPara3, 2) ) ;
	403
	404	return rv * energy ;
	405	}
	406
b1aa729d	407	//____________________________________________________________________________
7a9d98f9	408	Double_t AliPHOSvFast::SigmaP(Double_t energy, Double_t incidence)
b1aa729d	409	{
b2a60966	410	// Calculates the energy dependent position resolution
b2a60966	411
b1aa729d	412	Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ;
	413	Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ;
	414
	415	return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm
	416	}
	417
3decf5cb	418	//____________________________________________________________________________
	419	void AliPHOSvFast::StepManager(void)
	420	{
b2a60966	421	// Only verifies if the particle reaches PHOS and stops the tracking
3a4295ee	422
a73f33f0	423	TLorentzVector lv ;
a73f33f0	424	gMC->TrackPosition(lv) ;
b1aa729d	425	TVector3 pos = lv.Vect() ;
	426	Int_t modid ;
	427	gMC->CurrentVolID(modid);
a73f33f0	428
3a4295ee	429	Float_t energy = gMC->Etot() ; //Total energy of current track
3decf5cb	430
3a4295ee	431	//Calculating mass of current particle
	432	TDatabasePDG * pdg = TDatabasePDG::Instance() ;
	433	TParticlePDG * partPDG = pdg->GetParticle(gMC->TrackPid()) ;
	434	Float_t mass = partPDG->Mass() ;
a73f33f0	435
3a4295ee	436	if(energy > mass){
	437	pos.SetMag(TMath::Sqrt(energyenergy-massmass)) ;
	438	TLorentzVector pTrack(pos, energy) ;
a73f33f0	439
3a4295ee	440	TParticle * part = new TParticle(gMC->TrackPid(), 0,-1,-1,-1,-1, pTrack, lv) ;
	441
	442	AliPHOSFastRecParticle rp(*part) ;
b1aa729d	443
3a4295ee	444	// Adds the response of PHOS to the particle
	445	MakeRecParticle(modid, pos, rp) ;
	446
	447	// add the `track' particle to the FastRecParticles list
b1aa729d	448
3a4295ee	449	AddRecParticle(rp) ;
a73f33f0	450
3a4295ee	451	part->Delete() ;
3a4295ee	452	}
a73f33f0	453	// stop the track as soon PHOS is reached
b1aa729d	454
3decf5cb	455	gMC->StopTrack() ;
	456
	457	}
	458