[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"

// --- Standard library ---

#include <stdio.h>

// --- AliRoot header files ---

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