* 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
+/* $Id$ */
-Revision 1.7 2000/01/19 17:17:40 fca
+//////////////////////////////////////////////////////////////////////
+// // //
+// Generator of spectator nucleons (either protons or neutrons)//
+// computes beam crossing and divergence and Fermi momentum //
+// //
+/////////////////////////////////////////////////////////////////////
-Revision 1.6 1999/09/29 09:24:35 fca
-Introduction of the Copyright and cvs Log
+#include <assert.h>
-*/
-#include <TRandom.h>
+#include <TDatabasePDG.h>
#include <TLorentzVector.h>
+#include <TMCProcess.h>
+#include <TPDGCode.h>
+#include <TRandom.h>
#include <TVector3.h>
-#include "AliGenZDC.h"
#include "AliConst.h"
-#include "AliPDG.h"
+#include "AliGenZDC.h"
#include "AliRun.h"
+#include "AliMC.h"
ClassImp(AliGenZDC)
//_____________________________________________________________________________
AliGenZDC::AliGenZDC()
- :AliGenerator()
+ :AliGenerator(),
+ fIpart(0),
+ fCosx(0),
+ fCosy(0),
+ fCosz(0),
+ fPseudoRapidity(0),
+ fFermiflag(0),
+ fBeamDiv(0),
+ fBeamCrossAngle(0),
+ fBeamCrossPlane(0),
+ fDebugOpt(0)
{
//
// Default constructor
//
- fIpart = 0;
}
//_____________________________________________________________________________
AliGenZDC::AliGenZDC(Int_t npart)
- :AliGenerator(npart)
+ :AliGenerator(npart),
+ fIpart(kNeutron),
+ fCosx(0.),
+ fCosy(0.),
+ fCosz(1.),
+ fPseudoRapidity(0.),
+ fFermiflag(1),
+ fBeamDiv(0.000032),
+ fBeamCrossAngle(0.0001),
+ fBeamCrossPlane(2),
+ fDebugOpt(0)
{
//
// 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;
+
+ 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;
}
//_____________________________________________________________________________
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);
+ //
+ printf("\n\n AliGenZDC initialization:\n");
+ printf(" Particle: %d, Track cosines: x = %f, y = %f, z = %f \n",
+ fIpart,fCosx,fCosy,fCosz);
+ printf(" Fermi flag = %d, Beam divergence = %f, Crossing angle "
+ "= %f, Crossing plane = %d\n\n", fFermiflag, fBeamDiv, fBeamCrossAngle,
+ fBeamCrossPlane);
+
+ FermiTwoGaussian(208.);
}
//_____________________________________________________________________________
//
Int_t i;
- Double_t mass, pLab[3], balp0, balp[3], ddp[3], dddp0, dddp[3];
- Float_t ptot = fPMin;
+ 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(i=0; i<=2; i++){
- fP[i] = pLab[i];
+ for(i=0; i<=2; i++) fP[i] = pLab[i];
+ if(fDebugOpt == 1){
+ printf("\n\n Particle momentum before divergence and crossing\n");
+ for(i=0; i<=2; i++)printf(" pLab[%d] = %f\n",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(fBeamCrossAngle!=0.) {
+ BeamDivCross(1, pLab);
+ for(i=0; i<=2; i++) fP[i] = pLab[i];
+ }
+ if(fBeamDiv!=0.) {
+ BeamDivCross(0, 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(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];
- }
+ if((fIpart==kProton) || (fIpart==kNeutron))
+ ExtractFermi(fIpart, ddp);
+ mass=TDatabasePDG::Instance()->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);
- 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(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->GetMCApp()->PushTrack(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]);
+ }
+ else if(fDebugOpt == 2){
+ FILE *file;
+ if((file = fopen("SpectMomentum.dat","a")) == NULL){
+ printf("Cannot open file SpectMomentum.dat\n");
+ return;
+ }
+ fprintf(file," %f \t %f \t %f \n",fPTrack[0],fPTrack[1],fPTrack[2]);
+ fclose(file);
+ }
+
}
//_____________________________________________________________________________
-void AliGenZDC::FermiTwoGaussian(Double_t A, Float_t Z, Double_t* fPp, Double_t*
- fProbintp, Double_t* fProbintn)
+void AliGenZDC::FermiTwoGaussian(Float_t A)
{
//
// 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));
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 *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++){
+ for(i=1; 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)
+void AliGenZDC::BeamDivCross(Int_t icross, Double_t *pLab)
{
- Double_t tetpart, fipart, tetdiv, fidiv, angleSum[2], tetsum, fisum, dplab[3];
+ // Applying beam divergence and crossing angle
+ //
+ Double_t tetpart, fipart, tetdiv=0, fidiv=0, angleSum[2], tetsum, fisum;
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];
- }
+ Int_t 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){
+ if(icross==0){ // ##### Beam divergence
rvec = gRandom->Gaus(0.0,1.0);
tetdiv = fBeamDiv * TMath::Abs(rvec);
fidiv = (gRandom->Rndm())*k2PI;
}
- else if(icross==1){
- if(fBeamCrossPlane==0.){
+ else if(icross==1){ // ##### Crossing angle
+ if(fBeamCrossPlane==0){
tetdiv = 0.;
fidiv = 0.;
}
- else if(fBeamCrossPlane==1.){
+ else if(fBeamCrossPlane==1){ // Horizontal crossing plane
tetdiv = fBeamCrossAngle;
fidiv = 0.;
}
- else if(fBeamCrossPlane==2.){
+ else if(fBeamCrossPlane==2){ // Vertical crossing plane
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.;
- }
+
+ tetpart = TMath::ATan2(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(i=0; i<=2; i++){
- fDivP[i] = pLab[i];
+ if(fDebugOpt == 1){
+ if(icross==0) printf("\n\n Beam divergence \n");
+ else printf("\n\n Beam crossing \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)
+{
+ // Calculating the sum of 2 angles
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;
}
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