[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 1.2  2000/07/11 11:12:34  fca
Some syntax corrections for non standard HP aCC

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 <assert.h>

#include <TRandom.h>
#include <TLorentzVector.h>
#include <TVector3.h>
#include "TDatabasePDG.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);
    }
    mass=gAlice->PDGDB()->GetParticle(fIpart)->Mass();
//  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();
  assert ( id==kProton && id==kNeutron );
  if(id==kProton){
    for(i=0; i<=200; i++){
       if((xx>=fProbintp[i-1]) && (xx<fProbintp[i])) break;
       }
  }
  else {
    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=0, fidiv=0, 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	$Log$
94de3818	18	Revision 1.2 2000/07/11 11:12:34 fca
	19	Some syntax corrections for non standard HP aCC
	20
c0ceba4c	21	Revision 1.1 2000/07/10 13:58:01 fca
	22	New version of ZDC from E.Scomparin & C.Oppedisano
	23
68ca986e	24	Revision 1.7 2000/01/19 17:17:40 fca
	25
	26	Revision 1.6 1999/09/29 09:24:35 fca
	27	Introduction of the Copyright and cvs Log
	28
	29	*/
94de3818	30	#include <assert.h>
94de3818	31
68ca986e	32	#include <TRandom.h>
	33	#include <TLorentzVector.h>
	34	#include <TVector3.h>
94de3818	35	#include "TDatabasePDG.h"
68ca986e	36
	37	#include "AliGenZDC.h"
	38	#include "AliConst.h"
	39	#include "AliPDG.h"
	40	#include "AliRun.h"
	41
	42	ClassImp(AliGenZDC)
	43
	44	//_____________________________________________________________________________
	45	AliGenZDC::AliGenZDC()
	46	:AliGenerator()
	47	{
	48	//
	49	// Default constructor
	50	//
	51	fIpart = 0;
	52	}
	53
	54	//_____________________________________________________________________________
	55	AliGenZDC::AliGenZDC(Int_t npart)
	56	:AliGenerator(npart)
	57	{
	58	//
	59	// Standard constructor
	60	//
	61	fName = "AliGenZDC";
	62	fTitle = "Generation of Test Particles for ZDCs";
	63	fIpart = kNeutron;
	64	fCosx = 0.;
	65	fCosy = 0.;
	66	fCosz = 1.;
	67	fPseudoRapidity = 0.;
	68	fFermiflag = 1;
	69	// LHC values for beam divergence and crossing angle
	70	fBeamDiv = 0.000032;
	71	fBeamCrossAngle = 0.0001;
	72	fBeamCrossPlane = 2;
	73	}
	74
	75	//_____________________________________________________________________________
	76	void AliGenZDC::Init()
	77	{
	78	printf(" Initializing AliGenZDC\n");
	79	printf(" Fermi flag = %d, Beam Divergence = %f, Crossing Angle "
	80	"= %f, Crossing Plane = %d\n\n", fFermiflag, fBeamDiv, fBeamCrossAngle,
	81	fBeamCrossPlane);
	82	//Initialize Fermi momentum distributions for Pb-Pb
	83	FermiTwoGaussian(207.,82.,fPp,fProbintp,fProbintn);
	84	}
	85
	86	//_____________________________________________________________________________
	87	void AliGenZDC::Generate()
	88	{
	89	//
	90	// Generate one trigger (n or p)
	91	//
c0ceba4c	92	Int_t i;
c0ceba4c	93
68ca986e	94	Double_t mass, pLab[3], balp0, balp[3], ddp[3], dddp0, dddp[3];
	95	Float_t ptot = fPMin;
	96	Int_t nt;
	97
	98	if(fPseudoRapidity==0.){
	99	pLab[0] = ptot*fCosx;
	100	pLab[1] = ptot*fCosy;
	101	pLab[2] = ptot*fCosz;
	102	}
	103	else{
	104	Float_t scang = 2*TMath::ATan(TMath::Exp(-(fPseudoRapidity)));
	105	pLab[0] = -ptot*TMath::Sin(scang);
	106	pLab[1] = 0.;
	107	pLab[2] = ptot*TMath::Cos(scang);
	108	}
c0ceba4c	109	for(i=0; i<=2; i++){
68ca986e	110	fP[i] = pLab[i];
	111	}
	112
	113	// Beam divergence and crossing angle
	114	if(fBeamDiv!=0.) {BeamDivCross(0,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);}
	115	if(fBeamCrossAngle!=0.) {BeamDivCross(1,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);}
	116
	117	// If required apply the Fermi momentum
	118	if(fFermiflag==1){
	119	if((fIpart==kProton) \|\| (fIpart==kNeutron)){
	120	ExtractFermi(fIpart,fPp,fProbintp,fProbintn,ddp);
	121	}
94de3818	122	mass=gAlice->PDGDB()->GetParticle(fIpart)->Mass();
68ca986e	123	// printf(" pLABx = %f pLABy = %f pLABz = %f \n",pLab[0],pLab[1],pLab[2]);
c0ceba4c	124	for(i=0; i<=2; i++){
68ca986e	125	balp[i] = -pLab[i];
	126	}
	127	balp0 = TMath::Sqrt(pLab[0]pLab[0]+pLab[1]pLab[1]+pLab[2]pLab[2]+massmass);
c0ceba4c	128	for(i=0; i<=2; i++){
68ca986e	129	dddp[i] = ddp[i];
	130	}
	131	dddp0 = TMath::Sqrt(dddp[0]dddp[0]+dddp[1]dddp[1]+dddp[2]dddp[2]+massmass);
	132
	133	TVector3 b(balp[0]/balp0, balp[1]/balp0, balp[2]/balp0);
	134	TLorentzVector pFermi(dddp[0], dddp[1], dddp[2], dddp0);
	135
	136	// printf(" pmu -> pLABx = %f pLABy = %f pLABz = %f E = %f\n",
	137	// balp[0],balp[1],balp[2],balp0);
	138	// printf(" Beta -> bx = %f by = %f bz = %f\n", b[0], b[1], b[2]);
	139	// printf(" pFermi -> px = %f, py = %f, pz = %f\n", pFermi[0], pFermi[1], pFermi[2]);
	140
	141	pFermi.Boost(b);
	142
	143	// printf(" Boosted momentum -> px = %f, py = %f, pz = %f\n",
	144	// pFermi[0], pFermi[1], pFermi[2]);
c0ceba4c	145	for(i=0; i<=2; i++){
68ca986e	146	fBoostP[i] = pFermi[i];
	147	}
	148
	149	}
	150
	151	Float_t polar[3] = {0,0,0};
	152	gAlice->SetTrack(fTrackIt,-1,fIpart,fBoostP,fOrigin.GetArray(),polar,0,
	153	"Primary",nt);
	154	}
	155
	156	//_____________________________________________________________________________
	157	void AliGenZDC::FermiTwoGaussian(Double_t A, Float_t Z, Double_t* fPp, Double_t*
	158	fProbintp, Double_t* fProbintn)
	159	{
	160	//
	161	// Momenta distributions according to the "double-gaussian"
	162	// distribution (Ilinov) - equal for protons and neutrons
	163	//
	164	// printf(" Initialization of Fermi momenta distribution\n");
	165	fProbintp[0] = 0;
	166	fProbintn[0] = 0;
	167	Double_t sig1 = 0.113;
	168	Double_t sig2 = 0.250;
	169	Double_t alfa = 0.18*(TMath::Power((A/12.),(Float_t)1/3));
	170	Double_t xk = (2k2PI)/((1.+alfa)(TMath::Power(k2PI,1.5)));
	171
	172	for(Int_t i=1; i<=200; i++){
	173	Double_t p = i*0.005;
	174	fPp[i] = p;
	175	// printf(" fPp[%d] = %f\n",i,fPp[i]);
	176	Double_t e1 = (pp)/(2.sig1*sig1);
	177	Double_t e2 = (pp)/(2.sig2*sig2);
	178	Double_t f1 = TMath::Exp(-(e1));
	179	Double_t f2 = TMath::Exp(-(e2));
	180	Double_t probp = xkpp*(f1/(TMath::Power(sig1,3.))+
	181	alfaf2/(TMath::Power(sig2,3.)))0.005;
	182	// printf(" probp = %f\n",probp);
	183	fProbintp[i] = fProbintp[i-1] + probp;
	184	fProbintn[i] = fProbintp[i];
	185	// printf(" fProbintp[%d] = %f, fProbintp[%d] = %f\n",i,fProbintp[i],i,fProbintn[i]);
	186	}
	187	}
	188	//_____________________________________________________________________________
	189	void AliGenZDC::ExtractFermi(Int_t id, Double_t* fPp, Double_t* fProbintp,
	190	Double_t* fProbintn, Double_t* ddp)
	191	{
	192	//
	193	// Compute Fermi momentum for spectator nucleons
	194	//
	195	Int_t i;
	196	Float_t xx = gRandom->Rndm();
94de3818	197	assert ( id==kProton && id==kNeutron );
68ca986e	198	if(id==kProton){
	199	for(i=0; i<=200; i++){
	200	if((xx>=fProbintp[i-1]) && (xx<fProbintp[i])) break;
	201	}
	202	}
94de3818	203	else {
68ca986e	204	for(i=0; i<=200; i++){
	205	if((xx>=fProbintn[i-1]) && (xx<fProbintn[i])) break;
	206	}
	207	}
	208	Float_t pext = fPp[i]+0.001;
	209	Float_t phi = k2PI*(gRandom->Rndm());
	210	Float_t cost = (1.-2.*(gRandom->Rndm()));
	211	Float_t tet = TMath::ACos(cost);
	212	ddp[0] = pextTMath::Sin(tet)TMath::Cos(phi);
	213	ddp[1] = pextTMath::Sin(tet)TMath::Sin(phi);
	214	ddp[2] = pext*cost;
	215	}
	216
	217	//_____________________________________________________________________________
	218	void AliGenZDC::BeamDivCross(Int_t icross, Float_t fBeamDiv, Float_t fBeamCrossAngle,
	219	Int_t fBeamCrossPlane, Double_t* pLab)
	220	{
94de3818	221	Double_t tetpart, fipart, tetdiv=0, fidiv=0, angleSum[2], tetsum, fisum, dplab[3];
68ca986e	222	Double_t rvec;
c0ceba4c	223
c0ceba4c	224	Int_t i;
68ca986e	225
68ca986e	226	Double_t pmq = 0.;
c0ceba4c	227	for(i=0; i<=2; i++){
68ca986e	228	dplab[i] = pLab[i];
	229	pmq = pmq+pLab[i]*pLab[i];
	230	}
	231	Double_t pmod = TMath::Sqrt(pmq);
	232	// printf(" pmod = %f\n",pmod);
	233
	234	// printf(" icross = %d, fBeamDiv = %f\n",icross,fBeamDiv);
	235	if(icross==0){
	236	rvec = gRandom->Gaus(0.0,1.0);
	237	tetdiv = fBeamDiv * TMath::Abs(rvec);
	238	fidiv = (gRandom->Rndm())*k2PI;
	239	}
	240	else if(icross==1){
	241	if(fBeamCrossPlane==0.){
	242	tetdiv = 0.;
	243	fidiv = 0.;
	244	}
	245	else if(fBeamCrossPlane==1.){
	246	tetdiv = fBeamCrossAngle;
	247	fidiv = 0.;
	248	}
	249	else if(fBeamCrossPlane==2.){
	250	tetdiv = fBeamCrossAngle;
	251	fidiv = k2PI/4.;
	252	}
	253	}
	254	// printf(" tetdiv = %f, fidiv = %f\n",tetdiv,fidiv);
	255	tetpart = TMath::ATan(TMath::Sqrt(dplab[0]dplab[0]+dplab[1]dplab[1])/dplab[2]);
	256	if(dplab[1]!=0. \|\| dplab[0]!=0.){
	257	fipart = TMath::ATan2(dplab[1],dplab[0]);
	258	}
	259	else{
	260	fipart = 0.;
	261	}
	262	if(fipart<0.) {fipart = fipart+k2PI;}
	263	// printf(" tetpart = %f, fipart = %f\n",tetpart,fipart);
	264	tetdiv = tetdiv*kRaddeg;
	265	fidiv = fidiv*kRaddeg;
	266	tetpart = tetpart*kRaddeg;
	267	fipart = fipart*kRaddeg;
	268	AddAngle(tetpart,fipart,tetdiv,fidiv,angleSum);
	269	tetsum = angleSum[0];
	270	fisum = angleSum[1];
	271	// printf(" tetsum = %f, fisum = %f\n",tetsum,fisum);
	272	tetsum = tetsum*kDegrad;
	273	fisum = fisum*kDegrad;
	274	pLab[0] = pmodTMath::Sin(tetsum)TMath::Cos(fisum);
	275	pLab[1] = pmodTMath::Sin(tetsum)TMath::Sin(fisum);
	276	pLab[2] = pmod*TMath::Cos(tetsum);
	277	// printf(" pLab[0] = %f pLab[1] = %f pLab[2] = %f \n\n",
	278	// pLab[0],pLab[1],pLab[2]);
c0ceba4c	279	for(i=0; i<=2; i++){
68ca986e	280	fDivP[i] = pLab[i];
	281	}
	282	}
	283
	284	//_____________________________________________________________________________
	285	void AliGenZDC::AddAngle(Double_t theta1, Double_t phi1, Double_t theta2,
	286	Double_t phi2, Double_t* angleSum)
	287	{
	288	Double_t temp, conv, cx, cy, cz, ct1, st1, ct2, st2, cp1, sp1, cp2, sp2;
	289	Double_t rtetsum, tetsum, fisum;
	290
	291	temp = -1.;
	292	conv = 180./TMath::ACos(temp);
	293
	294	ct1 = TMath::Cos(theta1/conv);
	295	st1 = TMath::Sin(theta1/conv);
	296	cp1 = TMath::Cos(phi1/conv);
	297	sp1 = TMath::Sin(phi1/conv);
	298	ct2 = TMath::Cos(theta2/conv);
	299	st2 = TMath::Sin(theta2/conv);
	300	cp2 = TMath::Cos(phi2/conv);
	301	sp2 = TMath::Sin(phi2/conv);
	302	cx = ct1cp1st2cp2+st1cp1ct2-sp1st2*sp2;
	303	cy = ct1sp1st2cp2+st1sp1ct2+cp1st2*sp2;
	304	cz = ct1ct2-st1st2*cp2;
	305
	306	rtetsum = TMath::ACos(cz);
	307	tetsum = conv*rtetsum;
	308	if(tetsum==0. \|\| tetsum==180.){
	309	fisum = 0.;
	310	return;
	311	}
	312	temp = cx/TMath::Sin(rtetsum);
	313	if(temp>1.) temp=1.;
	314	if(temp<-1.) temp=-1.;
	315	fisum = conv*TMath::ACos(temp);
	316	if(cy<0) {fisum = 360.-fisum;}
	317	// printf(" AddAngle -> tetsum = %f, fisum = %f\n",tetsum, fisum);
	318	angleSum[0] = tetsum;
	319	angleSum[1] = fisum;
	320	}
	321