[u/mrichter/AliRoot.git] / ZDC / AliGenZDC.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.                  *
 **************************************************************************/

/*
$Log$
Revision 1.1  2000/07/10 13:58:01  fca
New version of ZDC from E.Scomparin & C.Oppedisano

Revision 1.7  2000/01/19 17:17:40  fca

Revision 1.6  1999/09/29 09:24:35  fca
Introduction of the Copyright and cvs Log

*/
#include <TRandom.h>
#include <TLorentzVector.h>
#include <TVector3.h>

#include "AliGenZDC.h"
#include "AliConst.h"
#include "AliPDG.h"
#include "AliRun.h"
 
ClassImp(AliGenZDC)
 
//_____________________________________________________________________________
AliGenZDC::AliGenZDC()
   :AliGenerator()
{
  //
  // Default constructor
  //
  fIpart = 0;
}

//_____________________________________________________________________________
AliGenZDC::AliGenZDC(Int_t npart)
   :AliGenerator(npart)
{
  //
  // Standard constructor
  //
  fName = "AliGenZDC";
  fTitle = "Generation of Test Particles for ZDCs";
  fIpart = kNeutron;
  fCosx  = 0.;
  fCosy  = 0.;
  fCosz  = 1.;
  fPseudoRapidity = 0.;
  fFermiflag = 1;
  // LHC values for beam divergence and crossing angle
  fBeamDiv = 0.000032;
  fBeamCrossAngle = 0.0001;
  fBeamCrossPlane = 2;
}

//_____________________________________________________________________________
void AliGenZDC::Init()
{
  printf("		Initializing AliGenZDC\n");
  printf("	Fermi flag = %d, Beam Divergence = %f, Crossing Angle "
         "= %f, Crossing Plane = %d\n\n", fFermiflag, fBeamDiv, fBeamCrossAngle,
	 fBeamCrossPlane);
  //Initialize Fermi momentum distributions for Pb-Pb
  FermiTwoGaussian(207.,82.,fPp,fProbintp,fProbintn);
}  
  
//_____________________________________________________________________________
void AliGenZDC::Generate()
{
  //
  // Generate one trigger (n or p)
  //
  Int_t i;

  Double_t mass, pLab[3], balp0, balp[3], ddp[3], dddp0, dddp[3];
  Float_t ptot = fPMin;
  Int_t nt;
  
  if(fPseudoRapidity==0.){
    pLab[0] = ptot*fCosx;
    pLab[1] = ptot*fCosy;
    pLab[2] = ptot*fCosz;
  }
  else{
    Float_t scang = 2*TMath::ATan(TMath::Exp(-(fPseudoRapidity)));
    pLab[0] = -ptot*TMath::Sin(scang);
    pLab[1] = 0.;
    pLab[2] = ptot*TMath::Cos(scang);
  }
  for(i=0; i<=2; i++){
     fP[i] = pLab[i];
  }
  
  // Beam divergence and crossing angle
  if(fBeamDiv!=0.) {BeamDivCross(0,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);}
  if(fBeamCrossAngle!=0.) {BeamDivCross(1,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);}
  
  // If required apply the Fermi momentum
  if(fFermiflag==1){
    if((fIpart==kProton) || (fIpart==kNeutron)){
      ExtractFermi(fIpart,fPp,fProbintp,fProbintn,ddp);
    }
    if(fIpart==kProton) {mass = 0.93956563;}
    if(fIpart==kNeutron) {mass = 0.93827231;}
//  printf(" pLABx = %f  pLABy = %f  pLABz = %f \n",pLab[0],pLab[1],pLab[2]); 
    for(i=0; i<=2; i++){
       balp[i] = -pLab[i];
    }
    balp0 = TMath::Sqrt(pLab[0]*pLab[0]+pLab[1]*pLab[1]+pLab[2]*pLab[2]+mass*mass);
    for(i=0; i<=2; i++){
       dddp[i] = ddp[i];
    }
    dddp0 = TMath::Sqrt(dddp[0]*dddp[0]+dddp[1]*dddp[1]+dddp[2]*dddp[2]+mass*mass);
    
    TVector3 b(balp[0]/balp0, balp[1]/balp0, balp[2]/balp0);
    TLorentzVector pFermi(dddp[0], dddp[1], dddp[2], dddp0);

//    printf(" pmu -> pLABx = %f  pLABy = %f  pLABz = %f  E = %f\n",
//           balp[0],balp[1],balp[2],balp0); 
//    printf(" Beta -> bx = %f  by = %f  bz = %f\n", b[0], b[1], b[2]);  
//    printf(" pFermi -> px = %f, py = %f, pz = %f\n", pFermi[0], pFermi[1], pFermi[2]);
    
    pFermi.Boost(b);

//    printf(" Boosted momentum -> px = %f, py = %f, pz = %f\n",
//	     pFermi[0], pFermi[1], pFermi[2]);
    for(i=0; i<=2; i++){
       fBoostP[i] = pFermi[i];
    }

  }
    
  Float_t polar[3] = {0,0,0};
  gAlice->SetTrack(fTrackIt,-1,fIpart,fBoostP,fOrigin.GetArray(),polar,0,
  		   "Primary",nt);
}

//_____________________________________________________________________________
void AliGenZDC::FermiTwoGaussian(Double_t A, Float_t Z, Double_t* fPp, Double_t*
  		fProbintp, Double_t* fProbintn)
{
//
// Momenta distributions according to the "double-gaussian"
// distribution (Ilinov) - equal for protons and neutrons
//
//   printf("		Initialization of Fermi momenta distribution\n");
   fProbintp[0] = 0;
   fProbintn[0] = 0;
   Double_t sig1 = 0.113;
   Double_t sig2 = 0.250;
   Double_t alfa = 0.18*(TMath::Power((A/12.),(Float_t)1/3));
   Double_t xk = (2*k2PI)/((1.+alfa)*(TMath::Power(k2PI,1.5)));
   
   for(Int_t i=1; i<=200; i++){
      Double_t p = i*0.005;
      fPp[i] = p;
//      printf(" fPp[%d] = %f\n",i,fPp[i]);
      Double_t e1 = (p*p)/(2.*sig1*sig1);
      Double_t e2 = (p*p)/(2.*sig2*sig2);
      Double_t f1 = TMath::Exp(-(e1));
      Double_t f2 = TMath::Exp(-(e2));
      Double_t probp = xk*p*p*(f1/(TMath::Power(sig1,3.))+
                      alfa*f2/(TMath::Power(sig2,3.)))*0.005;
//      printf(" 	probp = %f\n",probp);
      fProbintp[i] = fProbintp[i-1] + probp;
      fProbintn[i] = fProbintp[i];
//      printf(" fProbintp[%d] = %f, fProbintp[%d] = %f\n",i,fProbintp[i],i,fProbintn[i]);
   }
} 
//_____________________________________________________________________________
void AliGenZDC::ExtractFermi(Int_t id, Double_t* fPp, Double_t* fProbintp,
                Double_t* fProbintn, Double_t* ddp)
{
//
// Compute Fermi momentum for spectator nucleons
//
  Int_t i;
  Float_t xx = gRandom->Rndm();
  if(id==kProton){
    for(i=0; i<=200; i++){
       if((xx>=fProbintp[i-1]) && (xx<fProbintp[i])) break;
       }
  }
  else if(id==kNeutron){
    for(i=0; i<=200; i++){
       if((xx>=fProbintn[i-1]) && (xx<fProbintn[i])) break;
       }
   }
         Float_t pext = fPp[i]+0.001;
	 Float_t phi = k2PI*(gRandom->Rndm());
	 Float_t cost = (1.-2.*(gRandom->Rndm()));
	 Float_t tet = TMath::ACos(cost);
	 ddp[0] = pext*TMath::Sin(tet)*TMath::Cos(phi);
	 ddp[1] = pext*TMath::Sin(tet)*TMath::Sin(phi);
	 ddp[2] = pext*cost;
}

//_____________________________________________________________________________
void AliGenZDC::BeamDivCross(Int_t icross, Float_t fBeamDiv, Float_t fBeamCrossAngle, 
                Int_t fBeamCrossPlane, Double_t* pLab)
{
  Double_t tetpart, fipart, tetdiv, fidiv, angleSum[2], tetsum, fisum, dplab[3];
  Double_t rvec;

  Int_t i;
  
  Double_t pmq = 0.;
  for(i=0; i<=2; i++){
     dplab[i] = pLab[i];
     pmq = pmq+pLab[i]*pLab[i];
  }
  Double_t pmod = TMath::Sqrt(pmq);
//  printf("	pmod = %f\n",pmod);

//  printf("	icross = %d, fBeamDiv = %f\n",icross,fBeamDiv);
  if(icross==0){
    rvec = gRandom->Gaus(0.0,1.0);
    tetdiv = fBeamDiv * TMath::Abs(rvec);
    fidiv = (gRandom->Rndm())*k2PI;
  }
  else if(icross==1){
    if(fBeamCrossPlane==0.){
      tetdiv = 0.;
      fidiv = 0.;
    }
    else if(fBeamCrossPlane==1.){
      tetdiv = fBeamCrossAngle;
      fidiv = 0.;
    }
    else if(fBeamCrossPlane==2.){
      tetdiv = fBeamCrossAngle;
      fidiv = k2PI/4.;
    }
  }
//  printf("	tetdiv = %f, fidiv = %f\n",tetdiv,fidiv);
  tetpart = TMath::ATan(TMath::Sqrt(dplab[0]*dplab[0]+dplab[1]*dplab[1])/dplab[2]);
  if(dplab[1]!=0. || dplab[0]!=0.){
    fipart = TMath::ATan2(dplab[1],dplab[0]);
  }
  else{
    fipart = 0.;
  }
  if(fipart<0.) {fipart = fipart+k2PI;}
//  printf("	tetpart = %f, fipart = %f\n",tetpart,fipart);
  tetdiv = tetdiv*kRaddeg;
  fidiv = fidiv*kRaddeg;
  tetpart = tetpart*kRaddeg;
  fipart = fipart*kRaddeg;
  AddAngle(tetpart,fipart,tetdiv,fidiv,angleSum);
  tetsum = angleSum[0];
  fisum  = angleSum[1];
//  printf("	tetsum = %f, fisum = %f\n",tetsum,fisum);
  tetsum = tetsum*kDegrad;
  fisum = fisum*kDegrad;
  pLab[0] = pmod*TMath::Sin(tetsum)*TMath::Cos(fisum);
  pLab[1] = pmod*TMath::Sin(tetsum)*TMath::Sin(fisum);
  pLab[2] = pmod*TMath::Cos(tetsum);
//  printf("	pLab[0] = %f pLab[1] = %f pLab[2] = %f \n\n",
//         pLab[0],pLab[1],pLab[2]);
  for(i=0; i<=2; i++){
     fDivP[i] = pLab[i];
  }
}
  
//_____________________________________________________________________________
void  AliGenZDC::AddAngle(Double_t theta1, Double_t phi1, Double_t theta2,
  	       Double_t phi2, Double_t* angleSum)
{
  Double_t temp, conv, cx, cy, cz, ct1, st1, ct2, st2, cp1, sp1, cp2, sp2;
  Double_t rtetsum, tetsum, fisum;
  
  temp = -1.;
  conv = 180./TMath::ACos(temp);
  
  ct1 = TMath::Cos(theta1/conv);
  st1 = TMath::Sin(theta1/conv);
  cp1 = TMath::Cos(phi1/conv);
  sp1 = TMath::Sin(phi1/conv);
  ct2 = TMath::Cos(theta2/conv);
  st2 = TMath::Sin(theta2/conv);
  cp2 = TMath::Cos(phi2/conv);
  sp2 = TMath::Sin(phi2/conv);
  cx = ct1*cp1*st2*cp2+st1*cp1*ct2-sp1*st2*sp2;
  cy = ct1*sp1*st2*cp2+st1*sp1*ct2+cp1*st2*sp2;
  cz = ct1*ct2-st1*st2*cp2;
  
  rtetsum = TMath::ACos(cz);
  tetsum = conv*rtetsum;
  if(tetsum==0. || tetsum==180.){
    fisum = 0.;
    return;
  }
  temp = cx/TMath::Sin(rtetsum);
  if(temp>1.) temp=1.;
  if(temp<-1.) temp=-1.;
  fisum = conv*TMath::ACos(temp);
  if(cy<0) {fisum = 360.-fisum;}
//  printf("	AddAngle -> tetsum = %f, fisum = %f\n",tetsum, fisum); 
  angleSum[0] = tetsum;
  angleSum[1] = fisum;
}
Commit	Line	Data
68ca986e	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	/*
	17	$Log$
c0ceba4c	18	Revision 1.1 2000/07/10 13:58:01 fca
	19	New version of ZDC from E.Scomparin & C.Oppedisano
	20
68ca986e	21	Revision 1.7 2000/01/19 17:17:40 fca
	22
	23	Revision 1.6 1999/09/29 09:24:35 fca
	24	Introduction of the Copyright and cvs Log
	25
	26	*/
	27	#include <TRandom.h>
	28	#include <TLorentzVector.h>
	29	#include <TVector3.h>
	30
	31	#include "AliGenZDC.h"
	32	#include "AliConst.h"
	33	#include "AliPDG.h"
	34	#include "AliRun.h"
	35
	36	ClassImp(AliGenZDC)
	37
	38	//_____________________________________________________________________________
	39	AliGenZDC::AliGenZDC()
	40	:AliGenerator()
	41	{
	42	//
	43	// Default constructor
	44	//
	45	fIpart = 0;
	46	}
	47
	48	//_____________________________________________________________________________
	49	AliGenZDC::AliGenZDC(Int_t npart)
	50	:AliGenerator(npart)
	51	{
	52	//
	53	// Standard constructor
	54	//
	55	fName = "AliGenZDC";
	56	fTitle = "Generation of Test Particles for ZDCs";
	57	fIpart = kNeutron;
	58	fCosx = 0.;
	59	fCosy = 0.;
	60	fCosz = 1.;
	61	fPseudoRapidity = 0.;
	62	fFermiflag = 1;
	63	// LHC values for beam divergence and crossing angle
	64	fBeamDiv = 0.000032;
	65	fBeamCrossAngle = 0.0001;
	66	fBeamCrossPlane = 2;
	67	}
	68
	69	//_____________________________________________________________________________
	70	void AliGenZDC::Init()
	71	{
	72	printf(" Initializing AliGenZDC\n");
	73	printf(" Fermi flag = %d, Beam Divergence = %f, Crossing Angle "
	74	"= %f, Crossing Plane = %d\n\n", fFermiflag, fBeamDiv, fBeamCrossAngle,
	75	fBeamCrossPlane);
	76	//Initialize Fermi momentum distributions for Pb-Pb
	77	FermiTwoGaussian(207.,82.,fPp,fProbintp,fProbintn);
	78	}
	79
	80	//_____________________________________________________________________________
	81	void AliGenZDC::Generate()
	82	{
	83	//
	84	// Generate one trigger (n or p)
85	//
c0ceba4c	86	Int_t i;
c0ceba4c	87
68ca986e	88	Double_t mass, pLab[3], balp0, balp[3], ddp[3], dddp0, dddp[3];
	89	Float_t ptot = fPMin;
	90	Int_t nt;
	91
	92	if(fPseudoRapidity==0.){
	93	pLab[0] = ptot*fCosx;
	94	pLab[1] = ptot*fCosy;
	95	pLab[2] = ptot*fCosz;
	96	}
	97	else{
	98	Float_t scang = 2*TMath::ATan(TMath::Exp(-(fPseudoRapidity)));
	99	pLab[0] = -ptot*TMath::Sin(scang);
	100	pLab[1] = 0.;
	101	pLab[2] = ptot*TMath::Cos(scang);
	102	}
c0ceba4c	103	for(i=0; i<=2; i++){
68ca986e	104	fP[i] = pLab[i];
	105	}
	106
	107	// Beam divergence and crossing angle
	108	if(fBeamDiv!=0.) {BeamDivCross(0,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);}
	109	if(fBeamCrossAngle!=0.) {BeamDivCross(1,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);}
	110
	111	// If required apply the Fermi momentum
	112	if(fFermiflag==1){
	113	if((fIpart==kProton) \|\| (fIpart==kNeutron)){
	114	ExtractFermi(fIpart,fPp,fProbintp,fProbintn,ddp);
	115	}
	116	if(fIpart==kProton) {mass = 0.93956563;}
	117	if(fIpart==kNeutron) {mass = 0.93827231;}
	118	// printf(" pLABx = %f pLABy = %f pLABz = %f \n",pLab[0],pLab[1],pLab[2]);
c0ceba4c	119	for(i=0; i<=2; i++){
68ca986e	120	balp[i] = -pLab[i];
	121	}
	122	balp0 = TMath::Sqrt(pLab[0]pLab[0]+pLab[1]pLab[1]+pLab[2]pLab[2]+massmass);
c0ceba4c	123	for(i=0; i<=2; i++){
68ca986e	124	dddp[i] = ddp[i];
	125	}
	126	dddp0 = TMath::Sqrt(dddp[0]dddp[0]+dddp[1]dddp[1]+dddp[2]dddp[2]+massmass);
	127
	128	TVector3 b(balp[0]/balp0, balp[1]/balp0, balp[2]/balp0);
	129	TLorentzVector pFermi(dddp[0], dddp[1], dddp[2], dddp0);
	130
	131	// printf(" pmu -> pLABx = %f pLABy = %f pLABz = %f E = %f\n",
	132	// balp[0],balp[1],balp[2],balp0);
	133	// printf(" Beta -> bx = %f by = %f bz = %f\n", b[0], b[1], b[2]);
	134	// printf(" pFermi -> px = %f, py = %f, pz = %f\n", pFermi[0], pFermi[1], pFermi[2]);
	135
	136	pFermi.Boost(b);
	137
	138	// printf(" Boosted momentum -> px = %f, py = %f, pz = %f\n",
	139	// pFermi[0], pFermi[1], pFermi[2]);
c0ceba4c	140	for(i=0; i<=2; i++){
68ca986e	141	fBoostP[i] = pFermi[i];
	142	}
	143
	144	}
	145
	146	Float_t polar[3] = {0,0,0};
	147	gAlice->SetTrack(fTrackIt,-1,fIpart,fBoostP,fOrigin.GetArray(),polar,0,
	148	"Primary",nt);
	149	}
	150
	151	//_____________________________________________________________________________
	152	void AliGenZDC::FermiTwoGaussian(Double_t A, Float_t Z, Double_t* fPp, Double_t*
	153	fProbintp, Double_t* fProbintn)
	154	{
	155	//
	156	// Momenta distributions according to the "double-gaussian"
	157	// distribution (Ilinov) - equal for protons and neutrons
	158	//
	159	// printf(" Initialization of Fermi momenta distribution\n");
	160	fProbintp[0] = 0;
	161	fProbintn[0] = 0;
	162	Double_t sig1 = 0.113;
	163	Double_t sig2 = 0.250;
	164	Double_t alfa = 0.18*(TMath::Power((A/12.),(Float_t)1/3));
	165	Double_t xk = (2k2PI)/((1.+alfa)(TMath::Power(k2PI,1.5)));
	166
	167	for(Int_t i=1; i<=200; i++){
	168	Double_t p = i*0.005;
	169	fPp[i] = p;
	170	// printf(" fPp[%d] = %f\n",i,fPp[i]);
	171	Double_t e1 = (pp)/(2.sig1*sig1);
	172	Double_t e2 = (pp)/(2.sig2*sig2);
	173	Double_t f1 = TMath::Exp(-(e1));
	174	Double_t f2 = TMath::Exp(-(e2));
	175	Double_t probp = xkpp*(f1/(TMath::Power(sig1,3.))+
	176	alfaf2/(TMath::Power(sig2,3.)))0.005;
	177	// printf(" probp = %f\n",probp);
	178	fProbintp[i] = fProbintp[i-1] + probp;
	179	fProbintn[i] = fProbintp[i];
	180	// printf(" fProbintp[%d] = %f, fProbintp[%d] = %f\n",i,fProbintp[i],i,fProbintn[i]);
	181	}
	182	}
	183	//_____________________________________________________________________________
	184	void AliGenZDC::ExtractFermi(Int_t id, Double_t* fPp, Double_t* fProbintp,
	185	Double_t* fProbintn, Double_t* ddp)
	186	{
	187	//
	188	// Compute Fermi momentum for spectator nucleons
	189	//
	190	Int_t i;
	191	Float_t xx = gRandom->Rndm();
	192	if(id==kProton){
	193	for(i=0; i<=200; i++){
	194	if((xx>=fProbintp[i-1]) && (xx<fProbintp[i])) break;
	195	}
	196	}
	197	else if(id==kNeutron){
	198	for(i=0; i<=200; i++){
	199	if((xx>=fProbintn[i-1]) && (xx<fProbintn[i])) break;
	200	}
	201	}
	202	Float_t pext = fPp[i]+0.001;
	203	Float_t phi = k2PI*(gRandom->Rndm());
	204	Float_t cost = (1.-2.*(gRandom->Rndm()));
205	Float_t tet = TMath::ACos(cost);
206	ddp[0] = pextTMath::Sin(tet)TMath::Cos(phi);
207	ddp[1] = pextTMath::Sin(tet)TMath::Sin(phi);
208	ddp[2] = pext*cost;
209	}
210
211	//_____________________________________________________________________________
212	void AliGenZDC::BeamDivCross(Int_t icross, Float_t fBeamDiv, Float_t fBeamCrossAngle,
213	Int_t fBeamCrossPlane, Double_t* pLab)
214	{
215	Double_t tetpart, fipart, tetdiv, fidiv, angleSum[2], tetsum, fisum, dplab[3];
216	Double_t rvec;
c0ceba4c	217
c0ceba4c	218	Int_t i;
68ca986e	219
68ca986e	220	Double_t pmq = 0.;
c0ceba4c	221	for(i=0; i<=2; i++){
68ca986e	222	dplab[i] = pLab[i];
	223	pmq = pmq+pLab[i]*pLab[i];
	224	}
	225	Double_t pmod = TMath::Sqrt(pmq);
	226	// printf(" pmod = %f\n",pmod);
	227
	228	// printf(" icross = %d, fBeamDiv = %f\n",icross,fBeamDiv);
	229	if(icross==0){
	230	rvec = gRandom->Gaus(0.0,1.0);
	231	tetdiv = fBeamDiv * TMath::Abs(rvec);
	232	fidiv = (gRandom->Rndm())*k2PI;
	233	}
	234	else if(icross==1){
	235	if(fBeamCrossPlane==0.){
	236	tetdiv = 0.;
	237	fidiv = 0.;
	238	}
	239	else if(fBeamCrossPlane==1.){
	240	tetdiv = fBeamCrossAngle;
	241	fidiv = 0.;
	242	}
	243	else if(fBeamCrossPlane==2.){
	244	tetdiv = fBeamCrossAngle;
	245	fidiv = k2PI/4.;
	246	}
	247	}
	248	// printf(" tetdiv = %f, fidiv = %f\n",tetdiv,fidiv);
	249	tetpart = TMath::ATan(TMath::Sqrt(dplab[0]dplab[0]+dplab[1]dplab[1])/dplab[2]);
	250	if(dplab[1]!=0. \|\| dplab[0]!=0.){
	251	fipart = TMath::ATan2(dplab[1],dplab[0]);
	252	}
	253	else{
	254	fipart = 0.;
	255	}
	256	if(fipart<0.) {fipart = fipart+k2PI;}
	257	// printf(" tetpart = %f, fipart = %f\n",tetpart,fipart);
	258	tetdiv = tetdiv*kRaddeg;
	259	fidiv = fidiv*kRaddeg;
	260	tetpart = tetpart*kRaddeg;
	261	fipart = fipart*kRaddeg;
	262	AddAngle(tetpart,fipart,tetdiv,fidiv,angleSum);
	263	tetsum = angleSum[0];
	264	fisum = angleSum[1];
	265	// printf(" tetsum = %f, fisum = %f\n",tetsum,fisum);
	266	tetsum = tetsum*kDegrad;
	267	fisum = fisum*kDegrad;
	268	pLab[0] = pmodTMath::Sin(tetsum)TMath::Cos(fisum);
	269	pLab[1] = pmodTMath::Sin(tetsum)TMath::Sin(fisum);
	270	pLab[2] = pmod*TMath::Cos(tetsum);
	271	// printf(" pLab[0] = %f pLab[1] = %f pLab[2] = %f \n\n",
	272	// pLab[0],pLab[1],pLab[2]);
c0ceba4c	273	for(i=0; i<=2; i++){
68ca986e	274	fDivP[i] = pLab[i];
	275	}
	276	}
	277
	278	//_____________________________________________________________________________
	279	void AliGenZDC::AddAngle(Double_t theta1, Double_t phi1, Double_t theta2,
	280	Double_t phi2, Double_t* angleSum)
	281	{
	282	Double_t temp, conv, cx, cy, cz, ct1, st1, ct2, st2, cp1, sp1, cp2, sp2;
	283	Double_t rtetsum, tetsum, fisum;
	284
	285	temp = -1.;
	286	conv = 180./TMath::ACos(temp);
	287
	288	ct1 = TMath::Cos(theta1/conv);
	289	st1 = TMath::Sin(theta1/conv);
	290	cp1 = TMath::Cos(phi1/conv);
	291	sp1 = TMath::Sin(phi1/conv);
	292	ct2 = TMath::Cos(theta2/conv);
	293	st2 = TMath::Sin(theta2/conv);
	294	cp2 = TMath::Cos(phi2/conv);
	295	sp2 = TMath::Sin(phi2/conv);
	296	cx = ct1cp1st2cp2+st1cp1ct2-sp1st2*sp2;
	297	cy = ct1sp1st2cp2+st1sp1ct2+cp1st2*sp2;
	298	cz = ct1ct2-st1st2*cp2;
	299
	300	rtetsum = TMath::ACos(cz);
	301	tetsum = conv*rtetsum;
	302	if(tetsum==0. \|\| tetsum==180.){
	303	fisum = 0.;
	304	return;
	305	}
	306	temp = cx/TMath::Sin(rtetsum);
	307	if(temp>1.) temp=1.;
	308	if(temp<-1.) temp=-1.;
	309	fisum = conv*TMath::ACos(temp);
	310	if(cy<0) {fisum = 360.-fisum;}
	311	// printf(" AddAngle -> tetsum = %f, fisum = %f\n",tetsum, fisum);
	312	angleSum[0] = tetsum;
	313	angleSum[1] = fisum;
	314	}
	315