[u/mrichter/AliRoot.git] / PHOS / AliPHOSv4.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.                  *
 **************************************************************************/

/* $Id$ */

//_________________________________________________________________________
// 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 "TBRIK.h"
#include "TNode.h"
#include "TParticle.h"
#include "TTree.h"
#include "TGeometry.h"

// --- Standard library ---

#include <stdio.h>

// --- AliRoot header files ---

#include "AliPHOSv4.h"
#include "AliRun.h"
#include "AliConst.h"
#include "AliMC.h"

ClassImp(AliPHOSv4)

//____________________________________________________________________________
AliPHOSv4::AliPHOSv4(const char *name, const char *title):
  AliPHOS(name,title)
{
  // ctor

  // gets an instance of the geometry parameters class  
  if (strcmp(GetTitle(),"") != 0 ) 
    fGeom =  AliPHOSGeometry::GetInstance(GetTitle(), "") ; 
     
    
    SetBigBox(0, fGeom->GetOuterBoxSize(0) ) ;
    SetBigBox(1, fGeom->GetOuterBoxSize(1) + fGeom->GetPPSDBoxSize(1) ) ; 
    SetBigBox(2, fGeom->GetOuterBoxSize(0) ); 
    
    fNRecParticles = 0 ; 
    fFastRecParticles = new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100) ;

    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 ; 
}

//____________________________________________________________________________
AliPHOSv4::~AliPHOSv4()
{
  // dtor
 
  fFastRecParticles->Delete() ; 
  delete fFastRecParticles ;
  fFastRecParticles = 0 ; 

}

//____________________________________________________________________________
void AliPHOSv4::AddRecParticle(const AliPHOSFastRecParticle & rp)
{  
  // Add a virtually reconstructed particle to the list 

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

//____________________________________________________________________________
void AliPHOSv4::BuildGeometry()
{
  // Build the PHOS geometry for the ROOT display
   //BEGIN_HTML
  /*
    <H2>
     PHOS FAST in ALICE displayed by root
    </H2>
    <H4> All Views </H4>
    <P>
    <CENTER>
    <IMG Align=BOTTOM ALT="Fast All Views" SRC="../images/AliPHOSv4AllViews.gif"> 
    </CENTER></P>
    <H4> Front View </H4>
    <P>
    <CENTER>
    <IMG Align=BOTTOM ALT="Fast Front View" SRC="../images/AliPHOSv4FrontView.gif"> 
    </CENTER></P>
  */
  //END_HTML  
 
  const Int_t kColorPHOS = kRed ;
  
  Double_t const kRADDEG = 180.0 / kPI ;
  
  new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2, 
	     GetBigBox(1)/2, 
	     GetBigBox(2)/2 );
  
  // position PHOS into ALICE

  Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
  Int_t number = 988 ; 
  Float_t pphi =  TMath::ATan( GetBigBox(0)  / ( 2.0 * fGeom->GetIPtoCrystalSurface() ) ) ;
  pphi *= kRADDEG ;
  TNode * top = gAlice->GetGeometry()->GetNode("alice") ;
 
  char * nodename = new char[20] ;  
  char * rotname  = new char[20] ; 

  for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) { 
   Float_t angle = pphi * 2 * ( i - fGeom->GetNModules() / 2.0 - 0.5 ) ;
   sprintf(rotname, "%s%d", "rot", number++) ;
   new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0);
   top->cd();
   sprintf(nodename,"%s%d", "Module", i) ;    
   Float_t x =  r * TMath::Sin( angle / kRADDEG ) ;
   Float_t y = -r * TMath::Cos( angle / kRADDEG ) ;
   TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ;
   bigboxnode->SetLineColor(kColorPHOS) ;
   fNodes->Add(bigboxnode) ;
  }
  delete[] nodename ; 
  delete[] rotname ; 
}

//____________________________________________________________________________
void AliPHOSv4::CreateGeometry()
{
  // Create the geometry for GEANT
  
  AliPHOSv4 *phostmp = (AliPHOSv4*)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 / kPI ;
  
  for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
    
    Float_t angle = fGeom->GetPHOSAngle(i) ;
    AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
 
    Float_t r = fGeom->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 AliPHOSv4::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 AliPHOSv4::GetBigBox(Int_t index)
{
  // 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 AliPHOSv4::MakeBranch(Option_t* opt)
{  
  // Create new branch in the current reconstructed Root Tree
 
  AliDetector::MakeBranch(opt) ;
  
  char branchname[10];
  sprintf(branchname,"%s",GetName());
  char *cd = strstr(opt,"R");
  
  if (fFastRecParticles && gAlice->TreeR() && cd) {
    gAlice->TreeR()->Branch(branchname, &fFastRecParticles, fBufferSize);
  }
}

//____________________________________________________________________________
Double_t AliPHOSv4::MakeEnergy(const 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 AliPHOSv4::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const 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 AliPHOSv4::MakeRecParticle(const Int_t modid, const 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 + fGeom->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 AliPHOSv4::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() ; 

  switch (test) { 

  case 22:    // it's a photon
    ran = fRan.Rndm() ; 
    if ( ran <= 0.5 )  // 50 % 
      rv =  AliPHOSFastRecParticle::kGAMMA ; 
    else {
      ran = fRan.Rndm() ; 
      if( ran <= 0.9498 )
	rv =  AliPHOSFastRecParticle::kNEUTRALEM ; 
      else
	rv =  AliPHOSFastRecParticle::kNEUTRALHA ; 
    }     
    break ; 

  case 2112:  // it's a neutron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9998 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHA ; 
    else 
      rv = AliPHOSFastRecParticle::kNEUTRALEM ; 
    break ; 

  case -2112: // it's a anti-neutron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9984 )
      rv =  AliPHOSFastRecParticle::kNEUTRALHA ; 
    else 
      rv =  AliPHOSFastRecParticle::kNEUTRALEM ; 
    break ; 
    
  case 11:    // it's a electron
    ran = fRan.Rndm() ; 
    if ( ran <= 0.9996 )
      rv =  AliPHOSFastRecParticle::kELECTRON ; 
    else 
      rv =  AliPHOSFastRecParticle::kCHARGEDHA ; 
    break; 

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

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

    break ; 
  }
    
  
  return rv ;
}

//___________________________________________________________________________
void AliPHOSv4::ResetPoints()
{
  // This overloads the method in AliDetector
  
  ResetFastRecParticles() ; 
}

//___________________________________________________________________________
void AliPHOSv4::ResetFastRecParticles()
{
  // Resets the list of virtual reconstructed particles
 
  if (fFastRecParticles) 
    fFastRecParticles->Clear() ;
  fNRecParticles = 0 ; 
}

//___________________________________________________________________________
void AliPHOSv4::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 AliPHOSv4::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 AliPHOSv4::SigmaP(Double_t energy, Int_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 AliPHOSv4::StepManager(void)
{
  // Only verifies if the particle reaches PHOS and stops the tracking 

  Int_t primary =  gAlice->GetPrimary( gAlice->CurrentTrack() ); 

  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) ;
    rp.SetPrimary(primary) ; 

    // 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
5f20d3fb	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	/* $Id$ */
	17
	18	//_________________________________________________________________________
	19	// Implementation of the PHOS manager class for fast simulations
	20	// Tracks particles until the reach a grossly designed PHOS module
	21	// Modify the particles property (momentum, energy, type) according to
	22	// the PHOS response function. The result is called a virtual reconstructed
	23	// particle.
	24	//
	25	//*-- Author: Yves Schutz (SUBATECH)
	26
	27	// --- ROOT system ---
	28
	29	#include "TBRIK.h"
	30	#include "TNode.h"
	31	#include "TParticle.h"
94de3818	32	#include "TTree.h"
94de3818	33	#include "TGeometry.h"
5f20d3fb	34
	35	// --- Standard library ---
	36
	37	#include <stdio.h>
	38
	39	// --- AliRoot header files ---
	40
	41	#include "AliPHOSv4.h"
	42	#include "AliRun.h"
	43	#include "AliConst.h"
94de3818	44	#include "AliMC.h"
5f20d3fb	45
	46	ClassImp(AliPHOSv4)
	47
5f20d3fb	48	//____________________________________________________________________________
	49	AliPHOSv4::AliPHOSv4(const char name, const char title):
	50	AliPHOS(name,title)
	51	{
	52	// ctor
	53
	54	// gets an instance of the geometry parameters class
5cbba5aa	55	if (strcmp(GetTitle(),"") != 0 )
5cbba5aa	56	fGeom = AliPHOSGeometry::GetInstance(GetTitle(), "") ;
e04976bd	57
aafe457d	58
	59	SetBigBox(0, fGeom->GetOuterBoxSize(0) ) ;
	60	SetBigBox(1, fGeom->GetOuterBoxSize(1) + fGeom->GetPPSDBoxSize(1) ) ;
	61	SetBigBox(2, fGeom->GetOuterBoxSize(0) );
	62
	63	fNRecParticles = 0 ;
	64	fFastRecParticles = new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100) ;
5cbba5aa	65
aafe457d	66	fResPara1 = 0.030 ; // GeV
	67	fResPara2 = 0.00003 ;
	68	fResPara3 = 0.00001 ;
	69
	70	fPosParaA0 = 2.87 ; // mm
	71	fPosParaA1 = -0.0975 ;
	72	fPosParaB0 = 0.257 ;
	73	fPosParaB1 = 0.137 ;
	74	fPosParaB2 = 0.00619 ;
5f20d3fb	75	}
	76
	77	//____________________________________________________________________________
	78	AliPHOSv4::~AliPHOSv4()
	79	{
	80	// dtor
	81
	82	fFastRecParticles->Delete() ;
	83	delete fFastRecParticles ;
	84	fFastRecParticles = 0 ;
	85
	86	}
	87
	88	//____________________________________________________________________________
	89	void AliPHOSv4::AddRecParticle(const AliPHOSFastRecParticle & rp)
	90	{
	91	// Add a virtually reconstructed particle to the list
	92
	93	new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
	94	fNRecParticles++ ;
	95	}
	96
	97	//____________________________________________________________________________
	98	void AliPHOSv4::BuildGeometry()
	99	{
	100	// Build the PHOS geometry for the ROOT display
	101	//BEGIN_HTML
	102	/*
	103	<H2>
	104	PHOS FAST in ALICE displayed by root
	105	</H2>
	106	<H4> All Views </H4>
	107	<P>
	108	<CENTER>
	109	<IMG Align=BOTTOM ALT="Fast All Views" SRC="../images/AliPHOSv4AllViews.gif">
	110	</CENTER></P>
	111	<H4> Front View </H4>
	112	<P>
	113	<CENTER>
	114	<IMG Align=BOTTOM ALT="Fast Front View" SRC="../images/AliPHOSv4FrontView.gif">
	115	</CENTER></P>
	116	*/
	117	//END_HTML
	118
	119	const Int_t kColorPHOS = kRed ;
	120
	121	Double_t const kRADDEG = 180.0 / kPI ;
	122
	123	new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2,
	124	GetBigBox(1)/2,
	125	GetBigBox(2)/2 );
	126
	127	// position PHOS into ALICE
	128
	129	Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
	130	Int_t number = 988 ;
	131	Float_t pphi = TMath::ATan( GetBigBox(0) / ( 2.0 * fGeom->GetIPtoCrystalSurface() ) ) ;
	132	pphi *= kRADDEG ;
	133	TNode * top = gAlice->GetGeometry()->GetNode("alice") ;
	134
	135	char * nodename = new char[20] ;
	136	char * rotname = new char[20] ;
	137
	138	for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
139	Float_t angle = pphi * 2 * ( i - fGeom->GetNModules() / 2.0 - 0.5 ) ;
140	sprintf(rotname, "%s%d", "rot", number++) ;
141	new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0);
142	top->cd();
143	sprintf(nodename,"%s%d", "Module", i) ;
144	Float_t x = r * TMath::Sin( angle / kRADDEG ) ;
145	Float_t y = -r * TMath::Cos( angle / kRADDEG ) ;
146	TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ;
147	bigboxnode->SetLineColor(kColorPHOS) ;
148	fNodes->Add(bigboxnode) ;
149	}
150	delete[] nodename ;
151	delete[] rotname ;
152	}
153
154	//____________________________________________________________________________
155	void AliPHOSv4::CreateGeometry()
156	{
157	// Create the geometry for GEANT
158
159	AliPHOSv4 phostmp = (AliPHOSv4)gAlice->GetModule("PHOS") ;
160
161	if ( phostmp == NULL ) {
162
163	fprintf(stderr, "PHOS detector not found!\n") ;
164	return ;
165
166	}
167
168	// Get pointer to the array containing media indeces
169	Int_t *idtmed = fIdtmed->GetArray() - 699 ;
170
171	Float_t bigbox[3] ;
172	bigbox[0] = GetBigBox(0) / 2.0 ;
173	bigbox[1] = GetBigBox(1) / 2.0 ;
174	bigbox[2] = GetBigBox(2) / 2.0 ;
175
176	gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
177
178	// --- Position PHOS mdules in ALICE setup ---
179
180	Int_t idrotm[99] ;
181	Double_t const kRADDEG = 180.0 / kPI ;
182
183	for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
184
185	Float_t angle = fGeom->GetPHOSAngle(i) ;
186	AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
187
188	Float_t r = fGeom->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
189
190	Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
191	Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
192	gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
193
194	} // for GetNModules
195
196	}
197
198
199	//____________________________________________________________________________
200	void AliPHOSv4::Init(void)
201	{
202	// Prints out an information message
203
204	Int_t i;
205
206	printf("\n");
207	for(i=0;i<35;i++) printf("*");
208	printf(" FAST PHOS_INIT ");
209	for(i=0;i<35;i++) printf("*");
210	printf("\n");
211
212	// Here the PHOS initialisation code (if any!)
213
214	for(i=0;i<80;i++) printf("*");
215	printf("\n");
216
217	}
218
219	//___________________________________________________________________________
220	Float_t AliPHOSv4::GetBigBox(Int_t index)
221	{
222	// Get the X, Y or Z dimension of the box describing a PHOS module
223
224	Float_t rv = 0 ;
225
226	switch (index) {
227	case 0:
228	rv = fBigBoxX ;
229	break ;
230	case 1:
231	rv = fBigBoxY ;
232	break ;
233	case 2:
234	rv = fBigBoxZ ;
235	break ;
236	}
237	return rv ;
238	}
239
240	//___________________________________________________________________________
241	void AliPHOSv4::MakeBranch(Option_t* opt)
242	{
243	// Create new branch in the current reconstructed Root Tree
244
245	AliDetector::MakeBranch(opt) ;
246
247	char branchname[10];
248	sprintf(branchname,"%s",GetName());
249	char *cd = strstr(opt,"R");
250
251	if (fFastRecParticles && gAlice->TreeR() && cd) {
252	gAlice->TreeR()->Branch(branchname, &fFastRecParticles, fBufferSize);
253	}
254	}
255
256	//____________________________________________________________________________
257	Double_t AliPHOSv4::MakeEnergy(const Double_t energy)
258	{
259	// Smears the energy according to the energy dependent energy resolution.
260	// A gaussian distribution is assumed
261
262	Double_t sigma = SigmaE(energy) ;
263	return fRan.Gaus(energy, sigma) ;
264	}
265
266	//____________________________________________________________________________
267	TVector3 AliPHOSv4::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const Double_t phi)
268	{
269	// Smears the impact position according to the energy dependent position resolution
270	// A gaussian position distribution is assumed
271
272	TVector3 newpos ;
273	Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
274	Double_t x = fRan.Gaus( pos.X(), sigma ) ;
275	sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
276	Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
277	Double_t y = pos.Y() ;
278
279	newpos.SetX(x) ;
280	newpos.SetY(y) ;
281	newpos.SetZ(z) ;
282
283	return newpos ;
284	}
285
286	//____________________________________________________________________________
287	void AliPHOSv4::MakeRecParticle(const Int_t modid, const TVector3 pos, AliPHOSFastRecParticle & rp)
288	{
289	// Modify the primary particle properties according
290	// 1. the response function of PHOS
291	// 2. the performance of the EMC+PPSD setup
292
293	Int_t type = MakeType( rp ) ;
294	rp.SetType(type) ;
295
296
297	// get the detected energy
298
299	TLorentzVector momentum ;
300	rp.Momentum(momentum) ;
301	Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ;
302	Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
303	Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)
304	+ TMath::Power( rp.GetMass(), 2) ) ;
305
306	// get the angle of incidence
307
308	Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ;
309	Double_t incidencephi = ( 270 + fGeom->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;
310
311	// get the detected direction
312
313	TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ;
314	modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ;
315
316	// Set the modified 4-momentum of the reconstructed particle
317
318	rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ;
319
320	}
321
322	//____________________________________________________________________________
323	Int_t AliPHOSv4::MakeType(AliPHOSFastRecParticle & rp )
324	{
325	// Generate a particle type using the performance of the EMC+PPSD setup
326
327	Int_t rv = AliPHOSFastRecParticle::kUNDEFINED ;
328	Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
329	Int_t test ;
330	Float_t ran ;
331	if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) )
332	test = - 1 ;
333	else
334	test = rp.GetPdgCode() ;
335
336	switch (test) {
337
338	case 22: // it's a photon
339	ran = fRan.Rndm() ;
340	if ( ran <= 0.5 ) // 50 %
341	rv = AliPHOSFastRecParticle::kGAMMA ;
342	else {
343	ran = fRan.Rndm() ;
344	if( ran <= 0.9498 )
345	rv = AliPHOSFastRecParticle::kNEUTRALEM ;
346	else
347	rv = AliPHOSFastRecParticle::kNEUTRALHA ;
348	}
349	break ;
350
351	case 2112: // it's a neutron
352	ran = fRan.Rndm() ;
353	if ( ran <= 0.9998 )
354	rv = AliPHOSFastRecParticle::kNEUTRALHA ;
355	else
356	rv = AliPHOSFastRecParticle::kNEUTRALEM ;
357	break ;
358
359	case -2112: // it's a anti-neutron
360	ran = fRan.Rndm() ;
361	if ( ran <= 0.9984 )
362	rv = AliPHOSFastRecParticle::kNEUTRALHA ;
363	else
364	rv = AliPHOSFastRecParticle::kNEUTRALEM ;
365	break ;
366
367	case 11: // it's a electron
368	ran = fRan.Rndm() ;
369	if ( ran <= 0.9996 )
370	rv = AliPHOSFastRecParticle::kELECTRON ;
371	else
372	rv = AliPHOSFastRecParticle::kCHARGEDHA ;
373	break;
374
375	case -11: // it's a positon
376	ran = fRan.Rndm() ;
377	if ( ran <= 0.9996 )
378	rv = AliPHOSFastRecParticle::kELECTRON ;
379	else
380	rv = AliPHOSFastRecParticle::kCHARGEDHA ;
381	break;
382
383	case -1: // it's a charged
384	ran = fRan.Rndm() ;
385	if ( ran <= 0.9996 )
386	rv = AliPHOSFastRecParticle::kCHARGEDHA ;
387	else
388	rv = AliPHOSFastRecParticle::kGAMMA ;
389
390	break ;
391	}
392
393
394	return rv ;
395	}
396
397	//___________________________________________________________________________
398	void AliPHOSv4::ResetPoints()
399	{
400	// This overloads the method in AliDetector
401
402	ResetFastRecParticles() ;
403	}
404
405	//___________________________________________________________________________
406	void AliPHOSv4::ResetFastRecParticles()
407	{
408	// Resets the list of virtual reconstructed particles
409
410	if (fFastRecParticles)
411	fFastRecParticles->Clear() ;
412	fNRecParticles = 0 ;
413	}
414
415	//___________________________________________________________________________
416	void AliPHOSv4::SetBigBox(Int_t index, Float_t value)
417	{
418	// Set the size of the Box describing a PHOS module
419
420	switch (index) {
421	case 0:
422	fBigBoxX = value ;
423	break ;
424	case 1:
425	fBigBoxY = value ;
426	break ;
427	case 2:
428	fBigBoxZ = value ;
429	break ;
430	}
431
432	}
433
434	//____________________________________________________________________________
435	Double_t AliPHOSv4::SigmaE(Double_t energy)
436	{
437	// Calculates the energy dependent energy resolution
438
439	Double_t rv = -1 ;
440
441	rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2)
442	+ TMath::Power(fResPara2/TMath::Sqrt(energy), 2)
443	+ TMath::Power(fResPara3, 2) ) ;
444
445	return rv * energy ;
446	}
447
448	//____________________________________________________________________________
449	Double_t AliPHOSv4::SigmaP(Double_t energy, Int_t incidence)
450	{
451	// Calculates the energy dependent position resolution
452
453	Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ;
454	Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ;
455
456	return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm
457	}
458
459	//____________________________________________________________________________
460	void AliPHOSv4::StepManager(void)
461	{
462	// Only verifies if the particle reaches PHOS and stops the tracking
5cbba5aa	463
5f20d3fb	464	Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
5cbba5aa	465
5f20d3fb	466	TLorentzVector lv ;
	467	gMC->TrackPosition(lv) ;
	468	TVector3 pos = lv.Vect() ;
	469	Int_t modid ;
	470	gMC->CurrentVolID(modid);
	471
5cbba5aa	472	Float_t Energy = gMC->Etot() ; //Total energy of current track
	473
	474	//Calculating mass of current particle
	475	TDatabasePDG * PDG = TDatabasePDG::Instance() ;
	476	TParticlePDG * partPDG = PDG->GetParticle(gMC->TrackPid()) ;
	477	Float_t mass = partPDG->Mass() ;
5f20d3fb	478
5cbba5aa	479	if(Energy > mass){
	480	pos.SetMag(TMath::Sqrt(EnergyEnergy-massmass)) ;
	481	TLorentzVector pTrack(pos,Energy) ;
	482
	483	TParticle * part = new TParticle(gMC->TrackPid(), 0,-1,-1,-1,-1, pTrack, lv) ;
	484
	485	AliPHOSFastRecParticle rp(*part) ;
	486	rp.SetPrimary(primary) ;
	487
	488	// Adds the response of PHOS to the particle
	489	MakeRecParticle(modid, pos, rp) ;
	490
	491	// add the `track' particle to the FastRecParticles list
5f20d3fb	492
5cbba5aa	493	AddRecParticle(rp) ;
5f20d3fb	494
5cbba5aa	495	part->Delete() ;
5cbba5aa	496	}
5f20d3fb	497	// stop the track as soon PHOS is reached
	498
	499	gMC->StopTrack() ;
	500
	501	}
	502