// and quark fragmentation functions.
// Is a generalisation of AliGenParam class for correlated pairs of hadrons.
// In this version quark pairs and fragmentation functions are obtained from
-// Pythia6.124 using 100K events generated with kCharmppMNRwmi&kBeautyppMNRwmi
-// in pp collisions at 14 TeV.
-// Decays are performed by Pythia. Used AliRoot version: v4-04-Release
+// ~2.10^6 Pythia6.214 events generated with kCharmppMNRwmi & kBeautyppMNRwmi,
+// CTEQ5L PDF and Pt_hard = 2.76 GeV/c for p-p collisions at 7, 10 and 14 TeV,
+// and with kCharmppMNR (Pt_hard = 2.10 GeV/c) & kBeautyppMNR (Pt_hard = 2.75 GeV/c),
+// CTEQ4L PDF for Pb-Pb at 3.94 TeV, for p-Pb & Pb-p at 8.8 TeV.
+// Decays are performed by Pythia.
// Author: S. Grigoryan, LPC Clermont-Fd & YerPhI, Smbat.Grigoryan@cern.ch
// July 07: added quarks in the stack (B. Vulpescu)
+// April 09: added energy choice between 10 and 14 TeV (S. Grigoryan)
+// Sept 09: added hadron pair composition probabilities via 2D histo (X.M. Zhang)
+// Oct 09: added energy choice between 7, 10, 14 TeV (for p-p), 4 TeV (for Pb-Pb),
+// 9 TeV (for p-Pb) and -9 TeV (for Pb-p) (S. Grigoryan)
//-------------------------------------------------------------------------
-// How it works (for the given flavor):
+// How it works (for the given flavor and p-p energy):
//
// 1) Reads QQbar kinematical grid from the Input file and generates
// quark pairs according to the weights of the cells.
// on 2 variables - light cone energy-momentum fractions:
// z1=(E_H + Pz_H)/(E_Q + Pz_Q), z2=(E_H - Pz_H)/(E_Q - Pz_Q).
// "soft" & "hard" FFs correspond to "slower" & "faster" quark of a pair
-// (see details in GetHadronPair).
+// (see details in GetHadronPair). Fragmentation does not depend on p-p energy.
// 3) Decays the hadrons and saves all the particles in the event stack in the
// following order: HF hadron from Q, then its decay products, then HF hadron
// from Qbar, then its decay productes, then next HF hadon pair (if any)
// 4) It is fast, e.g., generates the same number of events with a beauty pair
// ~15 times faster than AliGenPythia with kBeautyppMNRwmi (w/o tracking)
//
-// An Input file for each quark flavor is included in EVGEN/dataCorrHF/
+// An Input file for each quark flavor and p-p energy is in EVGEN/dataCorrHF/
// One can use also user-defined Input files.
//
// More details could be found in my presentation at DiMuonNet Workshop, Dec 2006:
-// http://www-dapnia.cea.fr/Sphn/Alice/DiMuonNet
-// and will be published in an Internal Note.
+// http://www-dapnia.cea.fr/Sphn/Alice/DiMuonNet.
//
//-------------------------------------------------------------------------
// How to use it:
// add the following typical lines in Config.C
/*
if (!strcmp(option,"corr")) {
- // Example for correlated charm or beauty hadron pair production
+ // An example for correlated charm or beauty hadron pair production at 14 TeV
- // AliGenCorrHF *gener = new AliGenCorrHF(1, 4); // for charm, 1 pair per event
- AliGenCorrHF *gener = new AliGenCorrHF(1, 5); // for beauty, 1 pair per event
+ // AliGenCorrHF *gener = new AliGenCorrHF(1, 4, 14); // for charm, 1 pair per event
+ AliGenCorrHF *gener = new AliGenCorrHF(1, 5, 14); // for beauty, 1 pair per event
gener->SetMomentumRange(0,9999);
- gener->SetCutOnChild(0); // 1/0 means cuts on children enable/disable
+ gener->SetCutOnChild(0); // 1/0 means cuts on children enable/disable
gener->SetChildThetaRange(171.0,178.0);
gener->SetOrigin(0,0,0); //vertex position
gener->SetSigma(0,0,0); //Sigma in (X,Y,Z) (cm) on IP position
Double_t AliGenCorrHF::fgdph[19] = {0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180};
Double_t AliGenCorrHF::fgy[31] = {-10,-7, -6.5, -6, -5.5, -5, -4.5, -4, -3.5, -3, -2.5, -2,- 1.5, -1, -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 10};
-Double_t AliGenCorrHF::fgpt[33] = {0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.6, 7.2, 7.8, 8.4, 9, 9.6, 10.3, 11.1, 12, 13.1, 14.3, 15.6, 17.1, 19, 21, 24, 28, 35, 50, 100};
+Double_t AliGenCorrHF::fgpt[51] = {0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.6, 7.2, 7.8, 8.4, 9, 9.6, 10.3, 11.1, 12, 13, 14, 15, 16, 17, 18, 19, 20.1, 21.5, 23, 24.5, 26, 27.5, 29.1, 31, 33, 35, 37, 39.2, 42, 45, 48, 51, 55.2, 60, 65, 71, 81, 100};
Int_t AliGenCorrHF::fgnptbins = 12;
Double_t AliGenCorrHF::fgptbmin[12] = {0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9};
Double_t AliGenCorrHF::fgptbmax[12] = {0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9, 100};
fFileName(0),
fFile(0),
fQuark(0),
+ fEnergy(0),
fBias(0.),
fTrials(0),
fDecayer(0)
}
//____________________________________________________________
-AliGenCorrHF::AliGenCorrHF(Int_t npart, Int_t param):
+AliGenCorrHF::AliGenCorrHF(Int_t npart, Int_t idquark, Int_t energy):
AliGenMC(npart),
fFileName(0),
fFile(0),
- fQuark(param),
+ fQuark(idquark),
+ fEnergy(energy),
fBias(0.),
fTrials(0),
// fDecayer(new AliDecayerPythia())
fDecayer(0)
{
-// Constructor using number of particles, quark type & default InputFile
+// Constructor using particle number, quark type, energy & default InputFile
//
- if (fQuark != 5) fQuark = 4;
- fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmppMNRwmiCorr100K.root";
- if (fQuark == 5) fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyppMNRwmiCorr100K.root";
-
+ if (fQuark == 5) {
+ if (fEnergy == 7)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP7PythiaMNRwmi.root";
+ else if (fEnergy == 10)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP10PythiaMNRwmi.root";
+ else if (fEnergy == 14)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP14PythiaMNRwmi.root";
+ else if (fEnergy == 4)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb394PythiaMNR.root";
+ else if (fEnergy == 9 || fEnergy == -9)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPPb88PythiaMNR.root";
+ else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb394PythiaMNR.root";
+ }
+ else {
+ fQuark = 4;
+ if (fEnergy == 7)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP7PythiaMNRwmi.root";
+ else if (fEnergy == 10)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP10PythiaMNRwmi.root";
+ else if (fEnergy == 14)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP14PythiaMNRwmi.root";
+ else if (fEnergy == 4)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb394PythiaMNR.root";
+ else if (fEnergy == 9 || fEnergy == -9)
+ fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPPb88PythiaMNR.root";
+ else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb394PythiaMNR.root";
+ }
fName = "Default";
fTitle= "Generator for correlated pairs of HF hadrons";
}
//___________________________________________________________________
-AliGenCorrHF::AliGenCorrHF(char* tname, Int_t npart, Int_t param):
+AliGenCorrHF::AliGenCorrHF(char* tname, Int_t npart, Int_t idquark, Int_t energy):
AliGenMC(npart),
fFileName(tname),
fFile(0),
- fQuark(param),
+ fQuark(idquark),
+ fEnergy(energy),
fBias(0.),
fTrials(0),
// fDecayer(new AliDecayerPythia())
fDecayer(0)
{
-// Constructor using number of particles, quark type & user-defined InputFile
+// Constructor using particle number, quark type, energy & user-defined InputFile
//
if (fQuark != 5) fQuark = 4;
fName = "UserDefined";
void AliGenCorrHF::Generate()
{
//
-// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
-// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
-// antineutrons in the the desired theta, phi and momentum windows;
-// Gaussian smearing on the vertex is done if selected.
-// The decay of heavy mesons is done using lujet,
-// and the childern particle are tracked by GEANT
-// However, light mesons are directly tracked by GEANT
-// setting fForceDecay = nodecay (SetForceDecay(nodecay))
-//
+// Generate fNpart of correlated HF hadron pairs per event
+// in the the desired theta and momentum windows (phi = 0 - 2pi).
//
+
// Reinitialize decayer
fDecayer->SetForceDecay(fForceDecay);
Float_t wgtp, wgtch, random[6];
Float_t pq[2][3]; // Momenta of the two quarks
Int_t ntq[2] = {-1, -1};
- Float_t tanhy, qm;
+ Double_t tanhy2, qm = 0;
Double_t dphi=0, ptq[2], yq[2], pth[2], plh[2], ph[2], phih[2], phiq[2];
for (i=0; i<2; i++) {
iquark[i] =0;
}
+ // same quarks mass as in the fragmentation functions
+ if (fQuark == 4) qm = 1.20;
+ else qm = 4.75;
+
static TClonesArray *particles;
//
if(!particles) particles = new TClonesArray("TParticle",1000);
// Calculating vertex position per event
for (j=0;j<3;j++) origin0[j]=fOrigin[j];
- if(fVertexSmear==kPerEvent) {
+ if (fVertexSmear==kPerEvent) {
Vertex();
for (j=0;j<3;j++) origin0[j]=fVertex[j];
}
ipa=0;
- // Generating fNpart particles
+ // Generating fNpart HF-hadron pairs
fNprimaries = 0;
while (ipa<2*fNpart) {
GetHadronPair(fFile, fQuark, yq[0], yq[1], ptq[0], ptq[1], ihadron[0], ihadron[1], plh[0], plh[1], pth[0], pth[1]);
+ if (fEnergy == 9 || fEnergy == -9) { // boost particles from c.m.s. to ALICE lab frame
+ Double_t dyBoost = 0.47;
+ Double_t beta = TMath::TanH(dyBoost);
+ Double_t gamma = 1./TMath::Sqrt((1.-beta)*(1.+beta));
+ Double_t gb = gamma * beta;
+ yq[0] += dyBoost;
+ yq[1] += dyBoost;
+ plh[0] = gb * TMath::Sqrt(plh[0]*plh[0] + pth[0]*pth[0]) + gamma * plh[0];
+ plh[1] = gb * TMath::Sqrt(plh[1]*plh[1] + pth[1]*pth[1]) + gamma * plh[1];
+ if (fEnergy == 9) {
+ yq[0] *= -1;
+ yq[1] *= -1;
+ plh[0] *= -1;
+ plh[1] *= -1;
+ }
+ }
+
// Cuts from AliGenerator
// Cut on theta
theta=TMath::ATan2(pth[0],plh[0]);
- if(theta<fThetaMin || theta>fThetaMax) continue;
+ if (theta<fThetaMin || theta>fThetaMax) continue;
theta=TMath::ATan2(pth[1],plh[1]);
- if(theta<fThetaMin || theta>fThetaMax) continue;
+ if (theta<fThetaMin || theta>fThetaMax) continue;
// Cut on momentum
ph[0]=TMath::Sqrt(pth[0]*pth[0]+plh[0]*plh[0]);
pq[1][1] = qvect2.Py();
// pz
- tanhy = TMath::TanH(yq[0]);
- qm = pDataBase->GetParticle(iquark[0])->Mass();
- pq[0][2] = TMath::Sqrt((ptq[0]*ptq[0]+qm*qm)*tanhy/(1-tanhy));
- tanhy = TMath::TanH(yq[1]);
- qm = pDataBase->GetParticle(iquark[1])->Mass();
- pq[1][2] = TMath::Sqrt((ptq[1]*ptq[1]+qm*qm)*tanhy/(1-tanhy));
-
- // set special value shift to have a signature of this generator
- pq[0][0] += 1000000.0;
- pq[0][1] += 1000000.0;
- pq[0][2] += 1000000.0;
- pq[1][0] += 1000000.0;
- pq[1][1] += 1000000.0;
- pq[1][2] += 1000000.0;
+ tanhy2 = TMath::TanH(yq[0]);
+ tanhy2 *= tanhy2;
+ pq[0][2] = TMath::Sqrt((ptq[0]*ptq[0]+qm*qm)*tanhy2/(1-tanhy2));
+ pq[0][2] = TMath::Sign((Double_t)pq[0][2],yq[0]);
+ tanhy2 = TMath::TanH(yq[1]);
+ tanhy2 *= tanhy2;
+ pq[1][2] = TMath::Sqrt((ptq[1]*ptq[1]+qm*qm)*tanhy2/(1-tanhy2));
+ pq[1][2] = TMath::Sign((Double_t)pq[1][2],yq[1]);
// Here we assume that |phi_H1 - phi_H2| = |phi_Q1 - phi_Q2| = dphi
// which is a good approximation for heavy flavors in Pythia
ipF = iparticle->GetFirstDaughter();
ipL = iparticle->GetLastDaughter();
if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
- } else{
+ } else {
trackIt[i] = 0;
pSelected[i] = 1;
}
//
// children
- if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
+ if ((ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll) && trackIt[i])
{
if (fCutOnChild) {
pc[0]=iparticle->Px();
PushTrack(0, -1, iquark[ihad], pq[ihad], origin0, polar, 0, kPPrimary, nt, wgtp);
KeepTrack(nt);
ntq[ihad] = nt;
- //printf("PushTrack: Q \t%5d trackit %1d part %8d name %10s \t from %3d \n",nt,0,iquark[ihad],pDataBase->GetParticle(iquark[ihad])->GetName(),-1);
// hadron
PushTrack(0, ntq[ihad], iPart, p, origin0, polar, 0, kPDecay, nt, wgtp);
pParent[0] = nt;
KeepTrack(nt);
fNprimaries++;
- //printf("PushTrack: P \t%5d trackit %1d part %8d name %10s \t from %3d \n",nt,0,iPart,pDataBase->GetParticle(iPart)->GetName(),ntq[ihad]);
//
// Decay Products
if (pSelected[i]) {
TParticle* iparticle = (TParticle *) particles->At(i);
Int_t kf = iparticle->GetPdgCode();
- Int_t ipa = iparticle->GetFirstMother()-1;
+ Int_t jpa = iparticle->GetFirstMother()-1;
och[0] = origin0[0]+iparticle->Vx()/10;
och[1] = origin0[1]+iparticle->Vy()/10;
pc[1] = iparticle->Py();
pc[2] = iparticle->Pz();
- if (ipa > -1) {
- iparent = pParent[ipa];
+ if (jpa > -1) {
+ iparent = pParent[jpa];
} else {
iparent = -1;
}
PushTrack(fTrackIt*trackIt[i], iparent, kf,
pc, och, polar,
0, kPDecay, nt, wgtch);
- //printf("PushTrack: DD \t%5d trackit %1d part %8d name %10s \t from %3d \n",nt,fTrackIt*trackIt[i],kf,pDataBase->GetParticle(kf)->GetName(),iparent);
pParent[i] = nt;
KeepTrack(nt);
fNprimaries++;
fNprimaries++;
}
break;
- } // while(1)
+ } // while(1) loop
} // hadron pair loop
- } // event loop
-
+ } // while (ipa<2*fNpart) loop
+
SetHighWaterMark(nt);
- AliGenEventHeader* header = new AliGenEventHeader("PARAM");
+ AliGenEventHeader* header = new AliGenEventHeader("CorrHF");
header->SetPrimaryVertex(fVertex);
header->SetNProduced(fNprimaries);
AddHeader(header);
}
//____________________________________________________________________________________
-Int_t AliGenCorrHF::IpCharm(TRandom* ran)
+void AliGenCorrHF::IpCharm(TH2F *hProbHH, Int_t &pdg3, Int_t &pdg4)
{
-// Composition of lower state charm hadrons, containing a c-quark
- Float_t random;
- Int_t ip; // +- 411,421,431,4122,4132,4232,4332
- random = ran->Rndm();
-// Rates from Pythia6.214 using 100Kevents with kPyCharmppMNRwmi at 14 TeV.
-
- if (random < 0.6027) {
- ip=421;
- } else if (random < 0.7962) {
- ip=411;
- } else if (random < 0.9127) {
- ip=431;
- } else if (random < 0.9899) {
- ip=4122;
- } else if (random < 0.9948) {
- ip=4132;
- } else if (random < 0.9999) {
- ip=4232;
- } else {
- ip=4332;
- }
-
- return ip;
+// Composition of a lower state charm hadron pair from a ccbar quark pair
+ Int_t pdgH[] = {411, 421, 431, 4122, 4132, 4232, 4332};
+
+ Double_t id3, id4;
+ hProbHH->GetRandom2(id3, id4);
+ pdg3 = pdgH[(Int_t)TMath::Floor(id3)];
+ pdg4 = -1*pdgH[(Int_t)TMath::Floor(id4)];
+
+ return;
}
-Int_t AliGenCorrHF::IpBeauty(TRandom* ran)
+void AliGenCorrHF::IpBeauty(TH2F *hProbHH, Int_t &pdg3, Int_t &pdg4)
{
-// Composition of lower state beauty hadrons, containing a b-quark
- Float_t random;
- Int_t ip; // +- 511,521,531,5122,5132,5232,5332
- random = ran->Rndm();
-// Rates from Pythia6.214 using 100Kevents with kPyBeautyppMNRwmi at 14 TeV.
- // B-Bbar mixing will be done by Pythia at the decay point
- if (random < 0.3965) {
- ip=-511;
- } else if (random < 0.7930) {
- ip=-521;
- } else if (random < 0.9112) {
- ip=-531;
- } else if (random < 0.9887) {
- ip=5122;
- } else if (random < 0.9943) {
- ip=5132;
- } else if (random < 0.9999) {
- ip=5232;
- } else {
- ip=5332;
- }
-
- return ip;
+// Composition of a lower state beauty hadron pair from a bbbar quark pair
+ // B-Bbar mixing will be done by Pythia at their decay point
+ Int_t pdgH[] = {511, 521, 531, 5122, 5132, 5232, 5332};
+
+ Double_t id3, id4;
+ hProbHH->GetRandom2(id3, id4);
+ pdg3 = pdgH[(Int_t)TMath::Floor(id3)];
+ pdg4 = -1*pdgH[(Int_t)TMath::Floor(id4)];
+
+ if ( (pdg3== 511) || (pdg3== 521) || (pdg3== 531) ) pdg3 *= -1;
+ if ( (pdg4==-511) || (pdg4==-521) || (pdg4==-531) ) pdg4 *= -1;
+
+ return;
}
//____________________________________________________________________________________
Double_t AliGenCorrHF::ComputeIntegral(TFile* fG) // needed by GetQuarkPair
{
// Read QQbar kinematical 5D grid's cell occupancy weights
- Int_t* cell = new Int_t[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
+ Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
TTree* tG = (TTree*) fG->Get("tGqq");
- tG->GetBranch("cell")->SetAddress(cell);
+ tG->GetBranch("cell")->SetAddress(&cell);
Int_t nbins = tG->GetEntries();
// delete previously computed integral (if any)
// modification of ROOT's TH3::GetRandom3 for 5D
{
// Read QQbar kinematical 5D grid's cell coordinates
- Int_t* cell = new Int_t[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
+ Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
TTree* tG = (TTree*) fG->Get("tGqq");
- tG->GetBranch("cell")->SetAddress(cell);
+ tG->GetBranch("cell")->SetAddress(&cell);
Int_t nbins = tG->GetEntries();
Double_t rand[6];
gRandom->RndmArray(6,rand);
void AliGenCorrHF::GetHadronPair(TFile* fG, Int_t idq, Double_t y1, Double_t y2, Double_t pt1, Double_t pt2, Int_t &id3, Int_t &id4, Double_t &pz3, Double_t &pz4, Double_t &pt3, Double_t &pt4)
{
// Generate a hadron pair
- Int_t (*fIpParaFunc )(TRandom*);//Pointer to particle type parametrisation function
+ void (*fIpParaFunc)(TH2F *, Int_t &, Int_t &);//Pointer to hadron pair composition function
fIpParaFunc = IpCharm;
Double_t mq = 1.2; // c & b quark masses (used in AliPythia)
if (idq == 5) {
}
Double_t z11, z12, z21, z22, pz1, pz2, e1, e2, mh, ptemp, rand[2];
char tag[100];
- TH2F *h2h[12], *h2s[12]; // hard & soft Fragmentation Functions
+ TH2F *h2h[12], *h2s[12], *hProbHH; // hard & soft fragmentation and HH-probability functions
for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
sprintf(tag,"h2h_pt%d",ipt);
h2h[ipt] = (TH2F*) fG->Get(tag);
pz2 = ptemp*TMath::SinH(y2);
e2 = ptemp*TMath::CosH(y2);
- id3 = fIpParaFunc(gRandom);
+ hProbHH = (TH2F*)fG->Get("hProbHH");
+ fIpParaFunc(hProbHH, id3, id4);
mh = TDatabasePDG::Instance()->GetParticle(id3)->Mass();
ptemp = z11*z21*(e1*e1-pz1*pz1) - mh*mh;
- pt3 = (idq-3)*rand[0]; // some smearing at low pt, try better
+ if (idq==5) pt3 = pt1; // an approximation at low pt, try better
+ else pt3 = rand[0]; // pt3=pt1 gives less D-hadrons at low pt
if (ptemp > 0) pt3 = TMath::Sqrt(ptemp);
if (pz1 > 0) pz3 = (z11*(e1 + pz1) - z21*(e1 - pz1)) / 2;
else pz3 = (z21*(e1 + pz1) - z11*(e1 - pz1)) / 2;
e1 = TMath::Sqrt(pz3*pz3 + pt3*pt3 + mh*mh);
- id4 = - fIpParaFunc(gRandom);
mh = TDatabasePDG::Instance()->GetParticle(id4)->Mass();
ptemp = z12*z22*(e2*e2-pz2*pz2) - mh*mh;
- pt4 = (idq-3)*rand[1]; // some smearing at low pt, try better
+ if (idq==5) pt4 = pt2; // an approximation at low pt, try better
+ else pt4 = rand[1];
if (ptemp > 0) pt4 = TMath::Sqrt(ptemp);
if (pz2 > 0) pz4 = (z12*(e2 + pz2) - z22*(e2 - pz2)) / 2;
else pz4 = (z22*(e2 + pz2) - z12*(e2 - pz2)) / 2;
y3 = 0.5 * TMath::Log((e1 + pz3 + 1.e-13)/(e1 - pz3 + 1.e-13));
y4 = 0.5 * TMath::Log((e2 + pz4 + 1.e-13)/(e2 - pz4 + 1.e-13));
if(TMath::Abs(y3)<ycorr && TMath::Abs(y4)<ycorr && rand[0]>0.5) {
- ptemp = TMath::Sqrt(e1*e1 - pz3*pz3);
+ ptemp = TMath::Sqrt((e1-pz3)*(e1+pz3));
y3 = 4*(1 - 2*rand[1]);
pz3 = ptemp*TMath::SinH(y3);
pz4 = pz3;
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff