Possibility to force transport of all particles.
[u/mrichter/AliRoot.git] / EVGEN / AliGenCorrHF.cxx
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2c890605 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/* $Id$ */
17
18// Class to generate correlated Heavy Flavor hadron pairs (one or several pairs
19// per event) using paramtrized kinematics of quark pairs from some generator
20// and quark fragmentation functions.
21// Is a generalisation of AliGenParam class for correlated pairs of hadrons.
22// In this version quark pairs and fragmentation functions are obtained from
b33adf51 23// ~2.10^6 Pythia6.214 events generated with kCharmppMNRwmi & kBeautyppMNRwmi,
9fd56238 24// CTEQ5L PDF and Pt_hard = 2.76 GeV/c for p-p collisions at 7, 10 and 14 TeV,
25// and with kCharmppMNR (Pt_hard = 2.10 GeV/c) & kBeautyppMNR (Pt_hard = 2.75 GeV/c),
26// CTEQ4L PDF for Pb-Pb at 3.94 TeV, for p-Pb & Pb-p at 8.8 TeV.
b33adf51 27// Decays are performed by Pythia.
2c890605 28// Author: S. Grigoryan, LPC Clermont-Fd & YerPhI, Smbat.Grigoryan@cern.ch
b44c3901 29// July 07: added quarks in the stack (B. Vulpescu)
b33adf51 30// April 09: added energy choice between 10 and 14 TeV (S. Grigoryan)
9fd56238 31// Sept 09: added hadron pair composition probabilities via 2D histo (X.M. Zhang)
32// Oct 09: added energy choice between 7, 10, 14 TeV (for p-p), 4 TeV (for Pb-Pb),
33// 9 TeV (for p-Pb) and -9 TeV (for Pb-p) (S. Grigoryan)
5cc3bcd2 34// April 10: removed "static" from definition of some variables (B. Vulpescu)
2c890605 35//-------------------------------------------------------------------------
b33adf51 36// How it works (for the given flavor and p-p energy):
2c890605 37//
5cc3bcd2 38// 1) Reads QQbar kinematical grid (TTree) from the Input file and generates
2c890605 39// quark pairs according to the weights of the cells.
40// It is a 5D grid in y1,y2,pt1,pt2 and deltaphi, with occupancy weights
41// of the cells obtained from Pythia (see details in GetQuarkPair).
42// 2) Reads "soft" and "hard" fragmentation functions (12 2D-histograms each,
43// for 12 pt bins) from the Input file, applies to quarks and produces hadrons
44// (only lower states, with proportions of species obtained from Pythia).
45// Fragmentation functions are the same for all hadron species and depend
46// on 2 variables - light cone energy-momentum fractions:
47// z1=(E_H + Pz_H)/(E_Q + Pz_Q), z2=(E_H - Pz_H)/(E_Q - Pz_Q).
48// "soft" & "hard" FFs correspond to "slower" & "faster" quark of a pair
b33adf51 49// (see details in GetHadronPair). Fragmentation does not depend on p-p energy.
2c890605 50// 3) Decays the hadrons and saves all the particles in the event stack in the
51// following order: HF hadron from Q, then its decay products, then HF hadron
52// from Qbar, then its decay productes, then next HF hadon pair (if any)
53// in the same way, etc...
54// 4) It is fast, e.g., generates the same number of events with a beauty pair
55// ~15 times faster than AliGenPythia with kBeautyppMNRwmi (w/o tracking)
56//
b33adf51 57// An Input file for each quark flavor and p-p energy is in EVGEN/dataCorrHF/
2c890605 58// One can use also user-defined Input files.
59//
60// More details could be found in my presentation at DiMuonNet Workshop, Dec 2006:
b33adf51 61// http://www-dapnia.cea.fr/Sphn/Alice/DiMuonNet.
2c890605 62//
63//-------------------------------------------------------------------------
64// How to use it:
65//
66// add the following typical lines in Config.C
67/*
68 if (!strcmp(option,"corr")) {
9fd56238 69 // An example for correlated charm or beauty hadron pair production at 14 TeV
2c890605 70
b33adf51 71 // AliGenCorrHF *gener = new AliGenCorrHF(1, 4, 14); // for charm, 1 pair per event
72 AliGenCorrHF *gener = new AliGenCorrHF(1, 5, 14); // for beauty, 1 pair per event
2c890605 73
74 gener->SetMomentumRange(0,9999);
9fd56238 75 gener->SetCutOnChild(0); // 1/0 means cuts on children enable/disable
2c890605 76 gener->SetChildThetaRange(171.0,178.0);
77 gener->SetOrigin(0,0,0); //vertex position
78 gener->SetSigma(0,0,0); //Sigma in (X,Y,Z) (cm) on IP position
79 gener->SetForceDecay(kSemiMuonic);
80 gener->SetTrackingFlag(0);
81 gener->Init();
82}
83*/
84// and in aliroot do e.g. gAlice->Run(10,"Config.C") to produce 10 events.
85// One can include AliGenCorrHF in an AliGenCocktail generator.
86//--------------------------------------------------------------------------
87
7ca4655f 88#include <Riostream.h>
89#include <TCanvas.h>
90#include <TClonesArray.h>
91#include <TDatabasePDG.h>
2c890605 92#include <TFile.h>
2c890605 93#include <TH2F.h>
2c890605 94#include <TLorentzVector.h>
7ca4655f 95#include <TMath.h>
2c890605 96#include <TParticle.h>
97#include <TParticlePDG.h>
7ca4655f 98#include <TROOT.h>
99#include <TRandom.h>
100#include <TTree.h>
2c890605 101#include <TVirtualMC.h>
b44c3901 102#include <TVector3.h>
2c890605 103
104#include "AliGenCorrHF.h"
105#include "AliLog.h"
106#include "AliConst.h"
107#include "AliDecayer.h"
108#include "AliMC.h"
109#include "AliRun.h"
84555c93 110#include "AliGenEventHeader.h"
2c890605 111
112ClassImp(AliGenCorrHF)
113
114 //Begin_Html
115 /*
116 <img src="picts/AliGenCorrHF.gif">
117 */
118 //End_Html
119
120Double_t AliGenCorrHF::fgdph[19] = {0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180};
121Double_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};
b33adf51 122Double_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};
2c890605 123Int_t AliGenCorrHF::fgnptbins = 12;
124Double_t AliGenCorrHF::fgptbmin[12] = {0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9};
125Double_t AliGenCorrHF::fgptbmax[12] = {0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9, 100};
126
2c890605 127//____________________________________________________________
128 AliGenCorrHF::AliGenCorrHF():
129 fFileName(0),
130 fFile(0),
131 fQuark(0),
b33adf51 132 fEnergy(0),
2c890605 133 fBias(0.),
134 fTrials(0),
18e09c20 135 fSelectAll(kFALSE),
5cc3bcd2 136 fDecayer(0),
137 fgIntegral(0)
2c890605 138{
139// Default constructor
140}
141
142//____________________________________________________________
b33adf51 143AliGenCorrHF::AliGenCorrHF(Int_t npart, Int_t idquark, Int_t energy):
2c890605 144 AliGenMC(npart),
145 fFileName(0),
146 fFile(0),
b33adf51 147 fQuark(idquark),
148 fEnergy(energy),
2c890605 149 fBias(0.),
150 fTrials(0),
18e09c20 151 fSelectAll(kFALSE),
5cc3bcd2 152 fDecayer(0),
153 fgIntegral(0)
2c890605 154{
b33adf51 155// Constructor using particle number, quark type, energy & default InputFile
2c890605 156//
b33adf51 157 if (fQuark == 5) {
9fd56238 158 if (fEnergy == 7)
159 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP7PythiaMNRwmi.root";
160 else if (fEnergy == 10)
161 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP10PythiaMNRwmi.root";
162 else if (fEnergy == 14)
163 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP14PythiaMNRwmi.root";
164 else if (fEnergy == 4)
165 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb394PythiaMNR.root";
166 else if (fEnergy == 9 || fEnergy == -9)
167 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPPb88PythiaMNR.root";
168 else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb394PythiaMNR.root";
b33adf51 169 }
170 else {
171 fQuark = 4;
9fd56238 172 if (fEnergy == 7)
173 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP7PythiaMNRwmi.root";
174 else if (fEnergy == 10)
175 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP10PythiaMNRwmi.root";
176 else if (fEnergy == 14)
177 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP14PythiaMNRwmi.root";
178 else if (fEnergy == 4)
179 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb394PythiaMNR.root";
180 else if (fEnergy == 9 || fEnergy == -9)
181 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPPb88PythiaMNR.root";
182 else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb394PythiaMNR.root";
b33adf51 183 }
2c890605 184 fName = "Default";
185 fTitle= "Generator for correlated pairs of HF hadrons";
186
187 fChildSelect.Set(5);
188 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
189 SetForceDecay();
190 SetCutOnChild();
191 SetChildMomentumRange();
192 SetChildPtRange();
193 SetChildPhiRange();
194 SetChildThetaRange();
195}
196
197//___________________________________________________________________
b33adf51 198AliGenCorrHF::AliGenCorrHF(char* tname, Int_t npart, Int_t idquark, Int_t energy):
2c890605 199 AliGenMC(npart),
200 fFileName(tname),
201 fFile(0),
b33adf51 202 fQuark(idquark),
203 fEnergy(energy),
2c890605 204 fBias(0.),
205 fTrials(0),
18e09c20 206 fSelectAll(kFALSE),
5cc3bcd2 207 fDecayer(0),
208 fgIntegral(0)
2c890605 209{
b33adf51 210// Constructor using particle number, quark type, energy & user-defined InputFile
2c890605 211//
212 if (fQuark != 5) fQuark = 4;
213 fName = "UserDefined";
214 fTitle= "Generator for correlated pairs of HF hadrons";
215
216 fChildSelect.Set(5);
217 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
218 SetForceDecay();
219 SetCutOnChild();
220 SetChildMomentumRange();
221 SetChildPtRange();
222 SetChildPhiRange();
223 SetChildThetaRange();
224}
225
226//____________________________________________________________
2c890605 227AliGenCorrHF::~AliGenCorrHF()
228{
229// Destructor
230 delete fFile;
231}
232
233//____________________________________________________________
234void AliGenCorrHF::Init()
235{
236// Initialisation
237
238 AliInfo(Form(" QQbar kinematics and fragm. functions from: %s",fFileName.Data() ));
239 fFile = TFile::Open(fFileName.Data());
240 if(!fFile->IsOpen()){
241 AliError(Form("Could not open file %s",fFileName.Data() ));
242 }
243
244 ComputeIntegral(fFile);
b44c3901 245
2c890605 246 fParentWeight = 1./fNpart; // fNpart is number of HF-hadron pairs
247
248// particle decay related initialization
249
250 if (gMC) fDecayer = gMC->GetDecayer();
251 fDecayer->SetForceDecay(fForceDecay);
252 fDecayer->Init();
253
254//
255 AliGenMC::Init();
256}
2c890605 257//____________________________________________________________
258void AliGenCorrHF::Generate()
259{
260//
cb11fd27 261// Generate fNpart of correlated HF hadron pairs per event
262// in the the desired theta and momentum windows (phi = 0 - 2pi).
84555c93 263//
cb11fd27 264
84555c93 265// Reinitialize decayer
2c890605 266
84555c93 267 fDecayer->SetForceDecay(fForceDecay);
268 fDecayer->Init();
269
270 //
2c890605 271 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
272 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
273 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
274 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
275 Float_t p[3], pc[3], och[3];// Momentum, polarisation and origin of the children particles from lujet
84555c93 276 Int_t nt, i, j, ipa, ihadron[2], iquark[2];
277 Float_t wgtp, wgtch, random[6];
278 Float_t pq[2][3]; // Momenta of the two quarks
279 Int_t ntq[2] = {-1, -1};
cb11fd27 280 Double_t tanhy2, qm = 0;
2c890605 281
b44c3901 282 Double_t dphi=0, ptq[2], yq[2], pth[2], plh[2], ph[2], phih[2], phiq[2];
2c890605 283 for (i=0; i<2; i++) {
b44c3901 284 ptq[i] =0;
285 yq[i] =0;
286 pth[i] =0;
287 plh[i] =0;
288 phih[i] =0;
289 phiq[i] =0;
2c890605 290 ihadron[i] =0;
84555c93 291 iquark[i] =0;
2c890605 292 }
293
cb11fd27 294 // same quarks mass as in the fragmentation functions
295 if (fQuark == 4) qm = 1.20;
296 else qm = 4.75;
297
5cc3bcd2 298 TClonesArray *particles = new TClonesArray("TParticle",1000);
2c890605 299
84555c93 300 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
301 //
302
303 // Calculating vertex position per event
2c890605 304 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
b33adf51 305 if (fVertexSmear==kPerEvent) {
84555c93 306 Vertex();
307 for (j=0;j<3;j++) origin0[j]=fVertex[j];
2c890605 308 }
309
84555c93 310 ipa=0;
311
9fd56238 312 // Generating fNpart HF-hadron pairs
84555c93 313 fNprimaries = 0;
314
315 while (ipa<2*fNpart) {
316
317 GetQuarkPair(fFile, fgIntegral, yq[0], yq[1], ptq[0], ptq[1], dphi);
318
319 GetHadronPair(fFile, fQuark, yq[0], yq[1], ptq[0], ptq[1], ihadron[0], ihadron[1], plh[0], plh[1], pth[0], pth[1]);
320
9fd56238 321 if (fEnergy == 9 || fEnergy == -9) { // boost particles from c.m.s. to ALICE lab frame
322 Double_t dyBoost = 0.47;
323 Double_t beta = TMath::TanH(dyBoost);
324 Double_t gamma = 1./TMath::Sqrt((1.-beta)*(1.+beta));
325 Double_t gb = gamma * beta;
326 yq[0] += dyBoost;
327 yq[1] += dyBoost;
328 plh[0] = gb * TMath::Sqrt(plh[0]*plh[0] + pth[0]*pth[0]) + gamma * plh[0];
329 plh[1] = gb * TMath::Sqrt(plh[1]*plh[1] + pth[1]*pth[1]) + gamma * plh[1];
330 if (fEnergy == 9) {
331 yq[0] *= -1;
332 yq[1] *= -1;
333 plh[0] *= -1;
334 plh[1] *= -1;
335 }
336 }
337
84555c93 338 // Cuts from AliGenerator
339
340 // Cut on theta
341 theta=TMath::ATan2(pth[0],plh[0]);
b33adf51 342 if (theta<fThetaMin || theta>fThetaMax) continue;
84555c93 343 theta=TMath::ATan2(pth[1],plh[1]);
b33adf51 344 if (theta<fThetaMin || theta>fThetaMax) continue;
84555c93 345
346 // Cut on momentum
347 ph[0]=TMath::Sqrt(pth[0]*pth[0]+plh[0]*plh[0]);
348 if (ph[0]<fPMin || ph[0]>fPMax) continue;
349 ph[1]=TMath::Sqrt(pth[1]*pth[1]+plh[1]*plh[1]);
350 if (ph[1]<fPMin || ph[1]>fPMax) continue;
351
352 // Add the quarks in the stack
353
354 phiq[0] = Rndm()*k2PI;
355 if (Rndm() < 0.5) {
b44c3901 356 phiq[1] = phiq[0] + dphi*kDegrad;
84555c93 357 } else {
358 phiq[1] = phiq[0] - dphi*kDegrad;
359 }
360 if (phiq[1] > k2PI) phiq[1] -= k2PI;
361 if (phiq[1] < 0 ) phiq[1] += k2PI;
362
363 // quarks pdg
364 iquark[0] = +fQuark;
365 iquark[1] = -fQuark;
366
367 // px and py
368 TVector2 qvect1 = TVector2();
369 TVector2 qvect2 = TVector2();
370 qvect1.SetMagPhi(ptq[0],phiq[0]);
371 qvect2.SetMagPhi(ptq[1],phiq[1]);
372 pq[0][0] = qvect1.Px();
373 pq[0][1] = qvect1.Py();
374 pq[1][0] = qvect2.Px();
375 pq[1][1] = qvect2.Py();
376
377 // pz
cb11fd27 378 tanhy2 = TMath::TanH(yq[0]);
379 tanhy2 *= tanhy2;
380 pq[0][2] = TMath::Sqrt((ptq[0]*ptq[0]+qm*qm)*tanhy2/(1-tanhy2));
381 pq[0][2] = TMath::Sign((Double_t)pq[0][2],yq[0]);
382 tanhy2 = TMath::TanH(yq[1]);
383 tanhy2 *= tanhy2;
384 pq[1][2] = TMath::Sqrt((ptq[1]*ptq[1]+qm*qm)*tanhy2/(1-tanhy2));
385 pq[1][2] = TMath::Sign((Double_t)pq[1][2],yq[1]);
84555c93 386
387 // Here we assume that |phi_H1 - phi_H2| = |phi_Q1 - phi_Q2| = dphi
388 // which is a good approximation for heavy flavors in Pythia
389 // ... moreover, same phi angles as for the quarks ...
390
391 phih[0] = phiq[0];
392 phih[1] = phiq[1];
b44c3901 393
84555c93 394 for (Int_t ihad = 0; ihad < 2; ihad++) {
395 while(1) {
396 //
397 // particle type
398 Int_t iPart = ihadron[ihad];
399 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
400 wgtp=fParentWeight;
401 wgtch=fChildWeight;
402 TParticlePDG *particle = pDataBase->GetParticle(iPart);
403 Float_t am = particle->Mass();
404 phi = phih[ihad];
405 pt = pth[ihad];
406 pl = plh[ihad];
407 ptot=TMath::Sqrt(pt*pt+pl*pl);
408
409 p[0]=pt*TMath::Cos(phi);
410 p[1]=pt*TMath::Sin(phi);
411 p[2]=pl;
b44c3901 412
2c890605 413 if(fVertexSmear==kPerTrack) {
84555c93 414 Rndm(random,6);
415 for (j=0;j<3;j++) {
416 origin0[j]=
417 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
418 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
2c890605 419 }
420 }
84555c93 421
422 // Looking at fForceDecay :
423 // if fForceDecay != none Primary particle decays using
424 // AliPythia and children are tracked by GEANT
425 //
426 // if fForceDecay == none Primary particle is tracked by GEANT
427 // (In the latest, make sure that GEANT actually does all the decays you want)
428 //
429
430 if (fForceDecay != kNoDecay) {
431 // Using lujet to decay particle
432 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
433 TLorentzVector pmom(p[0], p[1], p[2], energy);
434 fDecayer->Decay(iPart,&pmom);
435 //
436 // select decay particles
437 Int_t np=fDecayer->ImportParticles(particles);
438
439 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
440 if (fGeometryAcceptance)
441 if (!CheckAcceptanceGeometry(np,particles)) continue;
442 Int_t ncsel=0;
443 Int_t* pFlag = new Int_t[np];
444 Int_t* pParent = new Int_t[np];
445 Int_t* pSelected = new Int_t[np];
446 Int_t* trackIt = new Int_t[np];
447
448 for (i=0; i<np; i++) {
449 pFlag[i] = 0;
450 pSelected[i] = 0;
451 pParent[i] = -1;
452 }
453
454 if (np >1) {
08bffa4d 455 TParticle* iparticle = 0;
84555c93 456 Int_t ipF, ipL;
457 for (i = 1; i<np ; i++) {
458 trackIt[i] = 1;
459 iparticle = (TParticle *) particles->At(i);
460 Int_t kf = iparticle->GetPdgCode();
461 Int_t ks = iparticle->GetStatusCode();
462 // flagged particle
463
464 if (pFlag[i] == 1) {
465 ipF = iparticle->GetFirstDaughter();
466 ipL = iparticle->GetLastDaughter();
467 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
468 continue;
469 }
470
471 // flag decay products of particles with long life-time (c tau > .3 mum)
472
473 if (ks != 1) {
474 //TParticlePDG *particle = pDataBase->GetParticle(kf);
475
476 Double_t lifeTime = fDecayer->GetLifetime(kf);
477 //Double_t mass = particle->Mass();
478 //Double_t width = particle->Width();
479 if (lifeTime > (Double_t) fMaxLifeTime) {
480 ipF = iparticle->GetFirstDaughter();
481 ipL = iparticle->GetLastDaughter();
482 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
b33adf51 483 } else {
84555c93 484 trackIt[i] = 0;
485 pSelected[i] = 1;
2c890605 486 }
84555c93 487 } // ks==1 ?
488 //
489 // children
490
18e09c20 491 if ((ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll || fSelectAll) && trackIt[i])
84555c93 492 {
493 if (fCutOnChild) {
494 pc[0]=iparticle->Px();
495 pc[1]=iparticle->Py();
496 pc[2]=iparticle->Pz();
497 Bool_t childok = KinematicSelection(iparticle, 1);
498 if(childok) {
499 pSelected[i] = 1;
500 ncsel++;
501 } else {
502 ncsel=-1;
503 break;
504 } // child kine cuts
505 } else {
506 pSelected[i] = 1;
507 ncsel++;
508 } // if child selection
509 } // select muon
510 } // decay particle loop
511 } // if decay products
512
513 Int_t iparent;
514 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
515 ipa++;
516 //
517 // Parent
518 // quark
519 PushTrack(0, -1, iquark[ihad], pq[ihad], origin0, polar, 0, kPPrimary, nt, wgtp);
520 KeepTrack(nt);
521 ntq[ihad] = nt;
84555c93 522 // hadron
523 PushTrack(0, ntq[ihad], iPart, p, origin0, polar, 0, kPDecay, nt, wgtp);
524 pParent[0] = nt;
525 KeepTrack(nt);
526 fNprimaries++;
84555c93 527
528 //
529 // Decay Products
530 //
531 for (i = 1; i < np; i++) {
532 if (pSelected[i]) {
533 TParticle* iparticle = (TParticle *) particles->At(i);
534 Int_t kf = iparticle->GetPdgCode();
7f11c778 535 Int_t jpa = iparticle->GetFirstMother()-1;
2c890605 536
84555c93 537 och[0] = origin0[0]+iparticle->Vx()/10;
538 och[1] = origin0[1]+iparticle->Vy()/10;
539 och[2] = origin0[2]+iparticle->Vz()/10;
540 pc[0] = iparticle->Px();
541 pc[1] = iparticle->Py();
542 pc[2] = iparticle->Pz();
2c890605 543
7f11c778 544 if (jpa > -1) {
545 iparent = pParent[jpa];
84555c93 546 } else {
547 iparent = -1;
548 }
549
550 PushTrack(fTrackIt*trackIt[i], iparent, kf,
551 pc, och, polar,
552 0, kPDecay, nt, wgtch);
84555c93 553 pParent[i] = nt;
554 KeepTrack(nt);
555 fNprimaries++;
556 } // Selected
557 } // Particle loop
558 } // Decays by Lujet
559 particles->Clear();
560 if (pFlag) delete[] pFlag;
561 if (pParent) delete[] pParent;
562 if (pSelected) delete[] pSelected;
563 if (trackIt) delete[] trackIt;
564 } // kinematic selection
565 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
566 {
567 gAlice->GetMCApp()->
568 PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
569 ipa++;
570 fNprimaries++;
571 }
2c890605 572 break;
9fd56238 573 } // while(1) loop
84555c93 574 } // hadron pair loop
9fd56238 575 } // while (ipa<2*fNpart) loop
576
2c890605 577 SetHighWaterMark(nt);
84555c93 578
cb11fd27 579 AliGenEventHeader* header = new AliGenEventHeader("CorrHF");
84555c93 580 header->SetPrimaryVertex(fVertex);
581 header->SetNProduced(fNprimaries);
582 AddHeader(header);
2c890605 583
5cc3bcd2 584 delete particles;
585
84555c93 586}
2c890605 587//____________________________________________________________________________________
9fd56238 588void AliGenCorrHF::IpCharm(TH2F *hProbHH, Int_t &pdg3, Int_t &pdg4)
2c890605 589{
9fd56238 590// Composition of a lower state charm hadron pair from a ccbar quark pair
591 Int_t pdgH[] = {411, 421, 431, 4122, 4132, 4232, 4332};
592
593 Double_t id3, id4;
594 hProbHH->GetRandom2(id3, id4);
595 pdg3 = pdgH[(Int_t)TMath::Floor(id3)];
596 pdg4 = -1*pdgH[(Int_t)TMath::Floor(id4)];
597
598 return;
2c890605 599}
600
9fd56238 601void AliGenCorrHF::IpBeauty(TH2F *hProbHH, Int_t &pdg3, Int_t &pdg4)
2c890605 602{
9fd56238 603// Composition of a lower state beauty hadron pair from a bbbar quark pair
604 // B-Bbar mixing will be done by Pythia at their decay point
605 Int_t pdgH[] = {511, 521, 531, 5122, 5132, 5232, 5332};
606
607 Double_t id3, id4;
608 hProbHH->GetRandom2(id3, id4);
609 pdg3 = pdgH[(Int_t)TMath::Floor(id3)];
610 pdg4 = -1*pdgH[(Int_t)TMath::Floor(id4)];
611
612 if ( (pdg3== 511) || (pdg3== 521) || (pdg3== 531) ) pdg3 *= -1;
613 if ( (pdg4==-511) || (pdg4==-521) || (pdg4==-531) ) pdg4 *= -1;
614
615 return;
2c890605 616}
617
618//____________________________________________________________________________________
619Double_t AliGenCorrHF::ComputeIntegral(TFile* fG) // needed by GetQuarkPair
620{
621 // Read QQbar kinematical 5D grid's cell occupancy weights
4c111067 622 Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
2c890605 623 TTree* tG = (TTree*) fG->Get("tGqq");
4c111067 624 tG->GetBranch("cell")->SetAddress(&cell);
2c890605 625 Int_t nbins = tG->GetEntries();
626
627 // delete previously computed integral (if any)
628 if(fgIntegral) delete [] fgIntegral;
629
630 fgIntegral = new Double_t[nbins+1];
631 fgIntegral[0] = 0;
632 Int_t bin;
633 for(bin=0;bin<nbins;bin++) {
634 tG->GetEvent(bin);
635 fgIntegral[bin+1] = fgIntegral[bin] + cell[0];
636 }
637 // Normalize integral to 1
638 if (fgIntegral[nbins] == 0 ) {
639 return 0;
640 }
641 for (bin=1;bin<=nbins;bin++) fgIntegral[bin] /= fgIntegral[nbins];
642
643 return fgIntegral[nbins];
644}
645
646//____________________________________________________________________________________
647void AliGenCorrHF::GetQuarkPair(TFile* fG, Double_t* fInt, Double_t &y1, Double_t &y2, Double_t &pt1, Double_t &pt2, Double_t &dphi)
648 // modification of ROOT's TH3::GetRandom3 for 5D
649{
650 // Read QQbar kinematical 5D grid's cell coordinates
4c111067 651 Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
2c890605 652 TTree* tG = (TTree*) fG->Get("tGqq");
4c111067 653 tG->GetBranch("cell")->SetAddress(&cell);
2c890605 654 Int_t nbins = tG->GetEntries();
655 Double_t rand[6];
656 gRandom->RndmArray(6,rand);
657 Int_t ibin = TMath::BinarySearch(nbins,fInt,rand[0]);
658 tG->GetEvent(ibin);
659 y1 = fgy[cell[1]] + (fgy[cell[1]+1]-fgy[cell[1]])*rand[1];
660 y2 = fgy[cell[2]] + (fgy[cell[2]+1]-fgy[cell[2]])*rand[2];
661 pt1 = fgpt[cell[3]] + (fgpt[cell[3]+1]-fgpt[cell[3]])*rand[3];
662 pt2 = fgpt[cell[4]] + (fgpt[cell[4]+1]-fgpt[cell[4]])*rand[4];
663 dphi = fgdph[cell[5]]+ (fgdph[cell[5]+1]-fgdph[cell[5]])*rand[5];
664}
665
666//____________________________________________________________________________________
667void 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)
668{
669 // Generate a hadron pair
9fd56238 670 void (*fIpParaFunc)(TH2F *, Int_t &, Int_t &);//Pointer to hadron pair composition function
2c890605 671 fIpParaFunc = IpCharm;
672 Double_t mq = 1.2; // c & b quark masses (used in AliPythia)
673 if (idq == 5) {
674 fIpParaFunc = IpBeauty;
675 mq = 4.75;
676 }
08bffa4d 677 Double_t z11 = 0.;
678 Double_t z12 = 0.;
679 Double_t z21 = 0.;
680 Double_t z22 = 0.;
681 Double_t pz1, pz2, e1, e2, mh, ptemp, rand[2];
2c890605 682 char tag[100];
9fd56238 683 TH2F *h2h[12], *h2s[12], *hProbHH; // hard & soft fragmentation and HH-probability functions
2c890605 684 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
09298f0c 685 snprintf(tag,100, "h2h_pt%d",ipt);
2c890605 686 h2h[ipt] = (TH2F*) fG->Get(tag);
09298f0c 687 snprintf(tag,100, "h2s_pt%d",ipt);
2c890605 688 h2s[ipt] = (TH2F*) fG->Get(tag);
689 }
690
691 if (y1*y2 < 0) {
692 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
693 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
694 h2h[ipt]->GetRandom2(z11, z21);
695 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
696 h2h[ipt]->GetRandom2(z12, z22);
697 }
698 }
699 else {
700 if (TMath::Abs(y1) > TMath::Abs(y2)) {
701 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
702 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
703 h2h[ipt]->GetRandom2(z11, z21);
704 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
705 h2s[ipt]->GetRandom2(z12, z22);
706 }
707 }
708 else {
709 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
710 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
711 h2s[ipt]->GetRandom2(z11, z21);
712 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
713 h2h[ipt]->GetRandom2(z12, z22);
714 }
715 }
716 }
717 gRandom->RndmArray(2,rand);
718 ptemp = TMath::Sqrt(pt1*pt1 + mq*mq);
719 pz1 = ptemp*TMath::SinH(y1);
720 e1 = ptemp*TMath::CosH(y1);
721 ptemp = TMath::Sqrt(pt2*pt2 + mq*mq);
722 pz2 = ptemp*TMath::SinH(y2);
723 e2 = ptemp*TMath::CosH(y2);
724
9fd56238 725 hProbHH = (TH2F*)fG->Get("hProbHH");
726 fIpParaFunc(hProbHH, id3, id4);
2c890605 727 mh = TDatabasePDG::Instance()->GetParticle(id3)->Mass();
728 ptemp = z11*z21*(e1*e1-pz1*pz1) - mh*mh;
b33adf51 729 if (idq==5) pt3 = pt1; // an approximation at low pt, try better
9fd56238 730 else pt3 = rand[0]; // pt3=pt1 gives less D-hadrons at low pt
2c890605 731 if (ptemp > 0) pt3 = TMath::Sqrt(ptemp);
732 if (pz1 > 0) pz3 = (z11*(e1 + pz1) - z21*(e1 - pz1)) / 2;
733 else pz3 = (z21*(e1 + pz1) - z11*(e1 - pz1)) / 2;
734 e1 = TMath::Sqrt(pz3*pz3 + pt3*pt3 + mh*mh);
735
2c890605 736 mh = TDatabasePDG::Instance()->GetParticle(id4)->Mass();
737 ptemp = z12*z22*(e2*e2-pz2*pz2) - mh*mh;
b33adf51 738 if (idq==5) pt4 = pt2; // an approximation at low pt, try better
739 else pt4 = rand[1];
2c890605 740 if (ptemp > 0) pt4 = TMath::Sqrt(ptemp);
741 if (pz2 > 0) pz4 = (z12*(e2 + pz2) - z22*(e2 - pz2)) / 2;
742 else pz4 = (z22*(e2 + pz2) - z12*(e2 - pz2)) / 2;
743 e2 = TMath::Sqrt(pz4*pz4 + pt4*pt4 + mh*mh);
744
745 // small corr. instead of using Frag. Func. depending on yQ (in addition to ptQ)
746 Float_t ycorr = 0.2, y3, y4;
747 gRandom->RndmArray(2,rand);
748 y3 = 0.5 * TMath::Log((e1 + pz3 + 1.e-13)/(e1 - pz3 + 1.e-13));
749 y4 = 0.5 * TMath::Log((e2 + pz4 + 1.e-13)/(e2 - pz4 + 1.e-13));
750 if(TMath::Abs(y3)<ycorr && TMath::Abs(y4)<ycorr && rand[0]>0.5) {
bfd20868 751 ptemp = TMath::Sqrt((e1-pz3)*(e1+pz3));
2c890605 752 y3 = 4*(1 - 2*rand[1]);
753 pz3 = ptemp*TMath::SinH(y3);
754 pz4 = pz3;
755 }
756}
5cc3bcd2 757