/*
$Log$
+Revision 1.8 2001/04/20 10:10:25 coppedis
+Minor changes
+
+Revision 1.7 2001/03/15 16:13:28 coppedis
+Code review
+
+Revision 1.6 2000/11/30 17:16:14 coppedis
+Changes suggested by fca
+
+Revision 1.5 2000/11/22 11:30:12 coppedis
+Major code revision
+
+Revision 1.4 2000/10/05 08:02:47 fca
+Correction of the generator direction
+
+Revision 1.3 2000/10/02 21:28:20 fca
+Removal of useless dependecies via forward declarations
+
+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"
+#include "AliMCProcess.h"
ClassImp(AliGenZDC)
fCosy = 0.;
fCosz = 1.;
fPseudoRapidity = 0.;
+
fFermiflag = 1;
// LHC values for beam divergence and crossing angle
fBeamDiv = 0.000032;
fBeamCrossAngle = 0.0001;
fBeamCrossPlane = 2;
+
+ Int_t i, j;
+ for(i=0; i<201; i++){
+ fProbintp[i] = 0;
+ fProbintn[i] = 0;
+ }
+ for(j=0; j<3; j++){
+ fPp[i] = 0;
+ }
+ fDebugOpt = 0;
}
//_____________________________________________________________________________
void AliGenZDC::Init()
{
- printf(" Initializing AliGenZDC\n");
- printf(" Fermi flag = %d, Beam Divergence = %f, Crossing Angle "
+ printf("\n\n AliGenZDC initialized with:\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);
}
//
// Generate one trigger (n or p)
//
- Double_t mass, pLab[3], balp0, balp[3], ddp[3], dddp0, dddp[3];
- Float_t ptot = fPMin;
+ Int_t i;
+
+ Double_t Mass, pLab[3], fP0, fP[3], fBoostP[3], ddp[3], dddp0, dddp[3];
+ Float_t fPTrack[3], ptot = fPMin;
Int_t nt;
- if(fPseudoRapidity==0.){
+ if(fPseudoRapidity==0.){
pLab[0] = ptot*fCosx;
pLab[1] = ptot*fCosy;
pLab[2] = ptot*fCosz;
pLab[1] = 0.;
pLab[2] = ptot*TMath::Cos(scang);
}
- for(Int_t i=0; i<=2; i++){
+ 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);}
+ // Beam divergence and crossing angle
+ if(fBeamCrossAngle!=0.) {
+ BeamDivCross(1,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);
+ for(i=0; i<=2; i++){
+ fP[i] = pLab[i];
+ }
+ }
+ if(fBeamDiv!=0.) {
+ BeamDivCross(0,fBeamDiv,fBeamCrossAngle,fBeamCrossPlane,pLab);
+ for(i=0; i<=2; i++){
+ fP[i] = pLab[i];
+ }
+ }
+
// 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(Int_t 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(Int_t i=0; i<=2; i++){
+ Mass=gAlice->PDGDB()->GetParticle(fIpart)->Mass();
+ fP0 = TMath::Sqrt(fP[0]*fP[0]+fP[1]*fP[1]+fP[2]*fP[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);
+ 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);
+ TVector3 b(fP[0]/fP0, fP[1]/fP0, fP[2]/fP0);
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(Int_t i=0; i<=2; i++){
+ for(i=0; i<=2; i++){
fBoostP[i] = pFermi[i];
+ fP[i] = pFermi[i];
}
}
-
+
+ for(i=0; i<=2; i++){
+ fPTrack[i] = fP[i];
+ }
+
Float_t polar[3] = {0,0,0};
- gAlice->SetTrack(fTrackIt,-1,fIpart,fBoostP,fOrigin.GetArray(),polar,0,
- "Primary",nt);
+ gAlice->SetTrack(fTrackIt,-1,fIpart,fPTrack,fOrigin.GetArray(),polar,0,
+ kPPrimary,nt);
+ if(fDebugOpt == 1){
+ printf("\n\n Track momentum:\n");
+ printf("\n fPTrack = %f, %f, %f \n",fPTrack[0],fPTrack[1],fPTrack[2]);
+ }
}
//_____________________________________________________________________________
-void AliGenZDC::FermiTwoGaussian(Double_t A, Float_t Z, Double_t* fPp, Double_t*
- fProbintp, Double_t* fProbintn)
+void AliGenZDC::FermiTwoGaussian(Float_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;
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]);
+ }
+ if(fDebugOpt == 1){
+ printf("\n\n Initialization of Fermi momenta distribution \n");
+ for(Int_t i=0; i<=200; i++){
+ printf(" fProbintp[%d] = %f, fProbintn[%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)
+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 if(id==kNeutron){
+ else {
for(i=0; i<=200; i++){
if((xx>=fProbintn[i-1]) && (xx<fProbintn[i])) break;
}
ddp[0] = pext*TMath::Sin(tet)*TMath::Cos(phi);
ddp[1] = pext*TMath::Sin(tet)*TMath::Sin(phi);
ddp[2] = pext*cost;
+
+ if(fDebugOpt == 1){
+ printf("\n\n Extraction of Fermi momentum\n");
+ printf("\n pxFermi = %f pyFermi = %f pzFermi = %f \n",ddp[0],ddp[1],ddp[2]);
+ }
}
//_____________________________________________________________________________
void AliGenZDC::BeamDivCross(Int_t icross, Float_t fBeamDiv, Float_t fBeamCrossAngle,
- Int_t fBeamCrossPlane, Double_t* pLab)
+ Int_t fBeamCrossPlane, Double_t *pLab)
{
- Double_t tetpart, fipart, tetdiv, fidiv, angleSum[2], tetsum, fisum, dplab[3];
+ Double_t tetpart, fipart, tetdiv=0, fidiv=0, angleSum[2], tetsum, fisum;
Double_t rvec;
-
+
+ Int_t i;
Double_t pmq = 0.;
- for(int i=0; i<=2; i++){
- dplab[i] = pLab[i];
+ for(i=0; i<=2; 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 = 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]);
+
+ tetpart = TMath::ATan(TMath::Sqrt(pLab[0]*pLab[0]+pLab[1]*pLab[1])/pLab[2]);
+ if(pLab[1]!=0. || pLab[0]!=0.){
+ fipart = TMath::ATan2(pLab[1],pLab[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;
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(Int_t i=0; i<=2; i++){
- fDivP[i] = pLab[i];
+ if(fDebugOpt == 1){
+ printf("\n\n Beam divergence and crossing angle\n");
+ for(i=0; i<=2; i++){
+ printf(" pLab[%d] = %f\n",i,pLab[i]);
+ }
}
}
//_____________________________________________________________________________
void AliGenZDC::AddAngle(Double_t theta1, Double_t phi1, Double_t theta2,
- Double_t phi2, Double_t* angleSum)
+ 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;
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;
}