Adding histos for the LEGO train
[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)
7455632e 35// May 11: added Flag for transportation of background particles while using
36// SetForceDecay() function (L. Manceau)
37// June 11: added modifications allowing the setting of cuts on HF-hadron children.
38// Quarks, hadrons and decay particles are loaded in the stack outside the loop
39// of HF-hadrons, when the cuts on their children are satisfied (L. Manceau)
40// Oct 11: added Pb-Pb at 2.76 TeV (S. Grigoryan)
826fd892 41//
2c890605 42//-------------------------------------------------------------------------
b33adf51 43// How it works (for the given flavor and p-p energy):
2c890605 44//
5cc3bcd2 45// 1) Reads QQbar kinematical grid (TTree) from the Input file and generates
2c890605 46// quark pairs according to the weights of the cells.
47// It is a 5D grid in y1,y2,pt1,pt2 and deltaphi, with occupancy weights
48// of the cells obtained from Pythia (see details in GetQuarkPair).
49// 2) Reads "soft" and "hard" fragmentation functions (12 2D-histograms each,
50// for 12 pt bins) from the Input file, applies to quarks and produces hadrons
51// (only lower states, with proportions of species obtained from Pythia).
52// Fragmentation functions are the same for all hadron species and depend
53// on 2 variables - light cone energy-momentum fractions:
54// z1=(E_H + Pz_H)/(E_Q + Pz_Q), z2=(E_H - Pz_H)/(E_Q - Pz_Q).
55// "soft" & "hard" FFs correspond to "slower" & "faster" quark of a pair
b33adf51 56// (see details in GetHadronPair). Fragmentation does not depend on p-p energy.
2c890605 57// 3) Decays the hadrons and saves all the particles in the event stack in the
58// following order: HF hadron from Q, then its decay products, then HF hadron
59// from Qbar, then its decay productes, then next HF hadon pair (if any)
60// in the same way, etc...
61// 4) It is fast, e.g., generates the same number of events with a beauty pair
62// ~15 times faster than AliGenPythia with kBeautyppMNRwmi (w/o tracking)
63//
b33adf51 64// An Input file for each quark flavor and p-p energy is in EVGEN/dataCorrHF/
2c890605 65// One can use also user-defined Input files.
66//
67// More details could be found in my presentation at DiMuonNet Workshop, Dec 2006:
b33adf51 68// http://www-dapnia.cea.fr/Sphn/Alice/DiMuonNet.
2c890605 69//
70//-------------------------------------------------------------------------
71// How to use it:
72//
73// add the following typical lines in Config.C
74/*
75 if (!strcmp(option,"corr")) {
9fd56238 76 // An example for correlated charm or beauty hadron pair production at 14 TeV
2c890605 77
b33adf51 78 // AliGenCorrHF *gener = new AliGenCorrHF(1, 4, 14); // for charm, 1 pair per event
79 AliGenCorrHF *gener = new AliGenCorrHF(1, 5, 14); // for beauty, 1 pair per event
2c890605 80
81 gener->SetMomentumRange(0,9999);
9fd56238 82 gener->SetCutOnChild(0); // 1/0 means cuts on children enable/disable
2c890605 83 gener->SetChildThetaRange(171.0,178.0);
84 gener->SetOrigin(0,0,0); //vertex position
85 gener->SetSigma(0,0,0); //Sigma in (X,Y,Z) (cm) on IP position
86 gener->SetForceDecay(kSemiMuonic);
87 gener->SetTrackingFlag(0);
88 gener->Init();
89}
90*/
91// and in aliroot do e.g. gAlice->Run(10,"Config.C") to produce 10 events.
92// One can include AliGenCorrHF in an AliGenCocktail generator.
93//--------------------------------------------------------------------------
94
7ca4655f 95#include <Riostream.h>
96#include <TCanvas.h>
97#include <TClonesArray.h>
98#include <TDatabasePDG.h>
2c890605 99#include <TFile.h>
2c890605 100#include <TH2F.h>
2c890605 101#include <TLorentzVector.h>
7ca4655f 102#include <TMath.h>
2c890605 103#include <TParticle.h>
104#include <TParticlePDG.h>
7ca4655f 105#include <TROOT.h>
106#include <TRandom.h>
107#include <TTree.h>
2c890605 108#include <TVirtualMC.h>
b44c3901 109#include <TVector3.h>
2c890605 110
111#include "AliGenCorrHF.h"
112#include "AliLog.h"
113#include "AliConst.h"
114#include "AliDecayer.h"
115#include "AliMC.h"
116#include "AliRun.h"
84555c93 117#include "AliGenEventHeader.h"
2c890605 118
119ClassImp(AliGenCorrHF)
120
121 //Begin_Html
122 /*
123 <img src="picts/AliGenCorrHF.gif">
124 */
125 //End_Html
126
127Double_t AliGenCorrHF::fgdph[19] = {0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180};
128Double_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 129Double_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 130Int_t AliGenCorrHF::fgnptbins = 12;
131Double_t AliGenCorrHF::fgptbmin[12] = {0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9};
132Double_t AliGenCorrHF::fgptbmax[12] = {0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9, 100};
133
2c890605 134//____________________________________________________________
135 AliGenCorrHF::AliGenCorrHF():
136 fFileName(0),
137 fFile(0),
138 fQuark(0),
b33adf51 139 fEnergy(0),
2c890605 140 fBias(0.),
141 fTrials(0),
18e09c20 142 fSelectAll(kFALSE),
5cc3bcd2 143 fDecayer(0),
144 fgIntegral(0)
2c890605 145{
146// Default constructor
147}
148
149//____________________________________________________________
b33adf51 150AliGenCorrHF::AliGenCorrHF(Int_t npart, Int_t idquark, Int_t energy):
2c890605 151 AliGenMC(npart),
152 fFileName(0),
153 fFile(0),
b33adf51 154 fQuark(idquark),
155 fEnergy(energy),
2c890605 156 fBias(0.),
157 fTrials(0),
18e09c20 158 fSelectAll(kFALSE),
5cc3bcd2 159 fDecayer(0),
160 fgIntegral(0)
2c890605 161{
b33adf51 162// Constructor using particle number, quark type, energy & default InputFile
2c890605 163//
b33adf51 164 if (fQuark == 5) {
9fd56238 165 if (fEnergy == 7)
166 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP7PythiaMNRwmi.root";
167 else if (fEnergy == 10)
168 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP10PythiaMNRwmi.root";
169 else if (fEnergy == 14)
170 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPP14PythiaMNRwmi.root";
7455632e 171 else if (fEnergy == 3)
172 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb276PythiaMNR.root";
9fd56238 173 else if (fEnergy == 4)
174 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb394PythiaMNR.root";
175 else if (fEnergy == 9 || fEnergy == -9)
176 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPPb88PythiaMNR.root";
177 else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/BeautyPbPb394PythiaMNR.root";
b33adf51 178 }
179 else {
180 fQuark = 4;
9fd56238 181 if (fEnergy == 7)
182 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP7PythiaMNRwmi.root";
183 else if (fEnergy == 10)
184 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP10PythiaMNRwmi.root";
185 else if (fEnergy == 14)
186 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPP14PythiaMNRwmi.root";
7455632e 187 else if (fEnergy == 3)
188 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb276PythiaMNR.root";
9fd56238 189 else if (fEnergy == 4)
190 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb394PythiaMNR.root";
191 else if (fEnergy == 9 || fEnergy == -9)
192 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPPb88PythiaMNR.root";
193 else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/CharmPbPb394PythiaMNR.root";
b33adf51 194 }
2c890605 195 fName = "Default";
196 fTitle= "Generator for correlated pairs of HF hadrons";
197
198 fChildSelect.Set(5);
199 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
200 SetForceDecay();
201 SetCutOnChild();
202 SetChildMomentumRange();
203 SetChildPtRange();
204 SetChildPhiRange();
205 SetChildThetaRange();
206}
207
208//___________________________________________________________________
b33adf51 209AliGenCorrHF::AliGenCorrHF(char* tname, Int_t npart, Int_t idquark, Int_t energy):
2c890605 210 AliGenMC(npart),
211 fFileName(tname),
212 fFile(0),
b33adf51 213 fQuark(idquark),
214 fEnergy(energy),
2c890605 215 fBias(0.),
216 fTrials(0),
18e09c20 217 fSelectAll(kFALSE),
5cc3bcd2 218 fDecayer(0),
219 fgIntegral(0)
2c890605 220{
b33adf51 221// Constructor using particle number, quark type, energy & user-defined InputFile
2c890605 222//
223 if (fQuark != 5) fQuark = 4;
224 fName = "UserDefined";
225 fTitle= "Generator for correlated pairs of HF hadrons";
226
227 fChildSelect.Set(5);
228 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
229 SetForceDecay();
230 SetCutOnChild();
231 SetChildMomentumRange();
232 SetChildPtRange();
233 SetChildPhiRange();
234 SetChildThetaRange();
235}
236
237//____________________________________________________________
2c890605 238AliGenCorrHF::~AliGenCorrHF()
239{
240// Destructor
241 delete fFile;
242}
243
244//____________________________________________________________
245void AliGenCorrHF::Init()
246{
247// Initialisation
826fd892 248 AliInfo(Form("Number of HF-hadron pairs = %d",fNpart));
2c890605 249 AliInfo(Form(" QQbar kinematics and fragm. functions from: %s",fFileName.Data() ));
250 fFile = TFile::Open(fFileName.Data());
251 if(!fFile->IsOpen()){
252 AliError(Form("Could not open file %s",fFileName.Data() ));
253 }
254
255 ComputeIntegral(fFile);
b44c3901 256
2c890605 257 fParentWeight = 1./fNpart; // fNpart is number of HF-hadron pairs
258
259// particle decay related initialization
260
261 if (gMC) fDecayer = gMC->GetDecayer();
262 fDecayer->SetForceDecay(fForceDecay);
263 fDecayer->Init();
264
265//
266 AliGenMC::Init();
267}
2c890605 268//____________________________________________________________
269void AliGenCorrHF::Generate()
270{
271//
cb11fd27 272// Generate fNpart of correlated HF hadron pairs per event
273// in the the desired theta and momentum windows (phi = 0 - 2pi).
84555c93 274//
cb11fd27 275
84555c93 276// Reinitialize decayer
2c890605 277
84555c93 278 fDecayer->SetForceDecay(fForceDecay);
279 fDecayer->Init();
826fd892 280
281 Float_t polar[2][3]; // Polarisation of the parent particle (for GEANT tracking)
282 Float_t origin0[2][3]; // Origin of the generated parent particle (for GEANT tracking)
2c890605 283 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
284 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
826fd892 285 Float_t p[2][3]; // Momenta
286 Int_t nt, i, j, ihad, ipa, ipa0, ipa1, ihadron[2], iquark[2];
287 Float_t wgtp[2], wgtch[2], random[6];
288 Float_t pq[2][3], pc[3]; // Momenta of the two quarks
cb11fd27 289 Double_t tanhy2, qm = 0;
826fd892 290 Int_t np[2];
b44c3901 291 Double_t dphi=0, ptq[2], yq[2], pth[2], plh[2], ph[2], phih[2], phiq[2];
826fd892 292 Int_t ncsel[2];
293 Int_t** pSelected = new Int_t* [2];
294 Int_t** trackIt = new Int_t* [2];
295
2c890605 296 for (i=0; i<2; i++) {
b44c3901 297 ptq[i] =0;
298 yq[i] =0;
299 pth[i] =0;
300 plh[i] =0;
301 phih[i] =0;
302 phiq[i] =0;
2c890605 303 ihadron[i] =0;
84555c93 304 iquark[i] =0;
826fd892 305 for (j=0; j<3; j++) polar[i][j]=0;
2c890605 306 }
307
cb11fd27 308 // same quarks mass as in the fragmentation functions
309 if (fQuark == 4) qm = 1.20;
310 else qm = 4.75;
2c890605 311
826fd892 312 TClonesArray *particleshad1 = new TClonesArray("TParticle",1000);
313 TClonesArray *particleshad2 = new TClonesArray("TParticle",1000);
84555c93 314
826fd892 315 TList *particleslist = new TList();
316 particleslist->Add(particleshad1);
317 particleslist->Add(particleshad2);
318
319 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
320
84555c93 321 // Calculating vertex position per event
61eb7ba5 322 if (fVertexSmear==kPerEvent) {
323 Vertex();
324 for (i=0;i<2;i++){
826fd892 325 for (j=0;j<3;j++) origin0[i][j]=fVertex[j];
326 }
2c890605 327 }
61eb7ba5 328 else {
329 for (i=0;i<2;i++){
330 for (j=0;j<3;j++) origin0[i][j]=fOrigin[j];
331 }
332 }
2c890605 333
826fd892 334 ipa = 0;
335 ipa1 = 0;
336 ipa0 = 0;
84555c93 337
9fd56238 338 // Generating fNpart HF-hadron pairs
84555c93 339 fNprimaries = 0;
826fd892 340
84555c93 341 while (ipa<2*fNpart) {
826fd892 342
84555c93 343 GetQuarkPair(fFile, fgIntegral, yq[0], yq[1], ptq[0], ptq[1], dphi);
344
345 GetHadronPair(fFile, fQuark, yq[0], yq[1], ptq[0], ptq[1], ihadron[0], ihadron[1], plh[0], plh[1], pth[0], pth[1]);
346
9fd56238 347 if (fEnergy == 9 || fEnergy == -9) { // boost particles from c.m.s. to ALICE lab frame
348 Double_t dyBoost = 0.47;
349 Double_t beta = TMath::TanH(dyBoost);
350 Double_t gamma = 1./TMath::Sqrt((1.-beta)*(1.+beta));
351 Double_t gb = gamma * beta;
352 yq[0] += dyBoost;
353 yq[1] += dyBoost;
354 plh[0] = gb * TMath::Sqrt(plh[0]*plh[0] + pth[0]*pth[0]) + gamma * plh[0];
355 plh[1] = gb * TMath::Sqrt(plh[1]*plh[1] + pth[1]*pth[1]) + gamma * plh[1];
356 if (fEnergy == 9) {
357 yq[0] *= -1;
358 yq[1] *= -1;
359 plh[0] *= -1;
360 plh[1] *= -1;
361 }
362 }
826fd892 363
84555c93 364 // Cuts from AliGenerator
365
366 // Cut on theta
367 theta=TMath::ATan2(pth[0],plh[0]);
b33adf51 368 if (theta<fThetaMin || theta>fThetaMax) continue;
84555c93 369 theta=TMath::ATan2(pth[1],plh[1]);
b33adf51 370 if (theta<fThetaMin || theta>fThetaMax) continue;
84555c93 371
372 // Cut on momentum
373 ph[0]=TMath::Sqrt(pth[0]*pth[0]+plh[0]*plh[0]);
374 if (ph[0]<fPMin || ph[0]>fPMax) continue;
375 ph[1]=TMath::Sqrt(pth[1]*pth[1]+plh[1]*plh[1]);
376 if (ph[1]<fPMin || ph[1]>fPMax) continue;
377
378 // Add the quarks in the stack
379
380 phiq[0] = Rndm()*k2PI;
381 if (Rndm() < 0.5) {
b44c3901 382 phiq[1] = phiq[0] + dphi*kDegrad;
84555c93 383 } else {
384 phiq[1] = phiq[0] - dphi*kDegrad;
385 }
386 if (phiq[1] > k2PI) phiq[1] -= k2PI;
387 if (phiq[1] < 0 ) phiq[1] += k2PI;
388
389 // quarks pdg
390 iquark[0] = +fQuark;
391 iquark[1] = -fQuark;
826fd892 392
84555c93 393 // px and py
394 TVector2 qvect1 = TVector2();
395 TVector2 qvect2 = TVector2();
396 qvect1.SetMagPhi(ptq[0],phiq[0]);
397 qvect2.SetMagPhi(ptq[1],phiq[1]);
398 pq[0][0] = qvect1.Px();
399 pq[0][1] = qvect1.Py();
400 pq[1][0] = qvect2.Px();
401 pq[1][1] = qvect2.Py();
826fd892 402
84555c93 403 // pz
cb11fd27 404 tanhy2 = TMath::TanH(yq[0]);
405 tanhy2 *= tanhy2;
406 pq[0][2] = TMath::Sqrt((ptq[0]*ptq[0]+qm*qm)*tanhy2/(1-tanhy2));
407 pq[0][2] = TMath::Sign((Double_t)pq[0][2],yq[0]);
408 tanhy2 = TMath::TanH(yq[1]);
409 tanhy2 *= tanhy2;
410 pq[1][2] = TMath::Sqrt((ptq[1]*ptq[1]+qm*qm)*tanhy2/(1-tanhy2));
411 pq[1][2] = TMath::Sign((Double_t)pq[1][2],yq[1]);
826fd892 412
84555c93 413 // Here we assume that |phi_H1 - phi_H2| = |phi_Q1 - phi_Q2| = dphi
414 // which is a good approximation for heavy flavors in Pythia
415 // ... moreover, same phi angles as for the quarks ...
416
417 phih[0] = phiq[0];
418 phih[1] = phiq[1];
826fd892 419
420 ipa1 = 0;
b44c3901 421
826fd892 422 for (ihad = 0; ihad < 2; ihad++) {
423 while(1) {
424
425 ipa0=ipa1;
84555c93 426
826fd892 427 // particle type
428 fChildWeight=(fDecayer->GetPartialBranchingRatio(ihadron[ihad]))*fParentWeight;
429 wgtp[ihad]=fParentWeight;
430 wgtch[ihad]=fChildWeight;
431 TParticlePDG *particle = pDataBase->GetParticle(ihadron[ihad]);
432 Float_t am = particle->Mass();
433 phi = phih[ihad];
434 pt = pth[ihad];
435 pl = plh[ihad];
436 ptot=TMath::Sqrt(pt*pt+pl*pl);
84555c93 437
826fd892 438 p[ihad][0]=pt*TMath::Cos(phi);
439 p[ihad][1]=pt*TMath::Sin(phi);
440 p[ihad][2]=pl;
441
442 if(fVertexSmear==kPerTrack) {
443 Rndm(random,6);
444 for (j=0;j<3;j++) {
445 origin0[ihad][j]=
446 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
447 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
448 }
84555c93 449 }
450
826fd892 451 // Looking at fForceDecay :
452 // if fForceDecay != none Primary particle decays using
453 // AliPythia and children are tracked by GEANT
454 //
455 // if fForceDecay == none Primary particle is tracked by GEANT
456 // (In the latest, make sure that GEANT actually does all the decays you want)
457
458 if (fForceDecay != kNoDecay) {
459 // Using lujet to decay particle
460 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
461 TLorentzVector pmom(p[ihad][0], p[ihad][1], p[ihad][2], energy);
462 fDecayer->Decay(ihadron[ihad],&pmom);
463
464 // select decay particles
465
466 np[ihad]=fDecayer->ImportParticles((TClonesArray *)particleslist->At(ihad));
467
468 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
469
470 if (fGeometryAcceptance)
471 if (!CheckAcceptanceGeometry(np[ihad],(TClonesArray*)particleslist->At(ihad))) continue;
472
473 trackIt[ihad] = new Int_t [np[ihad]];
474 pSelected[ihad] = new Int_t [np[ihad]];
475 Int_t* pFlag = new Int_t [np[ihad]];
476
477 for (i=0; i<np[ihad]; i++) {
478 pFlag[i] = 0;
479 pSelected[ihad][i] = 0;
480 }
481
482 if (np[ihad] >1) {
483 TParticle* iparticle = 0;
484 Int_t ipF, ipL;
84555c93 485
826fd892 486 for (i = 1; i<np[ihad] ; i++) {
487 trackIt[ihad][i] = 1;
488 iparticle =
489 (TParticle *) ((TClonesArray *) particleslist->At(ihad))->At(i);
490 Int_t kf = iparticle->GetPdgCode();
491 Int_t ks = iparticle->GetStatusCode();
492 // flagged particle
493 if (pFlag[i] == 1) {
84555c93 494 ipF = iparticle->GetFirstDaughter();
495 ipL = iparticle->GetLastDaughter();
496 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
826fd892 497 continue;
2c890605 498 }
499
826fd892 500 // flag decay products of particles with long life-time (c tau > .3 mum)
501 if (ks != 1) {
502 Double_t lifeTime = fDecayer->GetLifetime(kf);
503 if (lifeTime > (Double_t) fMaxLifeTime) {
504 ipF = iparticle->GetFirstDaughter();
505 ipL = iparticle->GetLastDaughter();
506 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
507 } else {
508 trackIt[ihad][i] = 0;
509 pSelected[ihad][i] = 1;
510 }
511 } // ks==1 ?
512 //
513 // children
514 if ((ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll || fSelectAll) && trackIt[ihad][i])
515 {
516 if (fCutOnChild) {
517 pc[0]=iparticle->Px();
518 pc[1]=iparticle->Py();
519 pc[2]=iparticle->Pz();
520 //printf("px %f py %f pz %f\n",pc[0],pc[1],pc[2]);
521 Bool_t childok = KinematicSelection(iparticle, 1);
522 if(childok) {
523 pSelected[ihad][i] = 1;
524 ncsel[ihad]++;
525 } else {
526 ncsel[ihad]=-1;
527 break;
528 } // child kine cuts
529 } else {
530 pSelected[ihad][i] = 1;
531 ncsel[ihad]++;
532 } // if child selection
533 } // select muon
534 } // decay particle loop
535 } // if decay products
536
537 if ((fCutOnChild && ncsel[ihad] >0) || !fCutOnChild) ipa1++;
538
539 if (pFlag) delete[] pFlag;
540
541 } // kinematic selection
542 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
543 {
544 gAlice->GetMCApp()->
545 PushTrack(fTrackIt,-1,ihadron[ihad],p[ihad],origin0[ihad],polar[ihad],0,kPPrimary,nt,wgtp[ihad]);
546 ipa1++;
547 fNprimaries++;
548
549 }
550 break;
551 } // while(1) loop
552 if (ipa1<ipa0+1){
553 ipa1=0;
554 if (pSelected[ihad]) delete pSelected[ihad];
555 if (trackIt[ihad]) delete trackIt[ihad];
556 particleshad1->Clear();
557 particleshad2->Clear();
558 break;
559 }//go out of loop and generate new pair if at least one hadron is rejected
84555c93 560 } // hadron pair loop
826fd892 561 if(ipa1==2){
562
563 ipa=ipa+ipa1;
564
565 if(fForceDecay != kNoDecay){
566 for(ihad=0;ihad<2;ihad++){
567
568 //load tracks in the stack if both hadrons of the pair accepted
569 LoadTracks(iquark[ihad],pq[ihad],ihadron[ihad],p[ihad],np[ihad],
570 (TClonesArray *)particleslist->At(ihad),origin0[ihad],
571 polar[ihad],wgtp[ihad],wgtch[ihad],nt,ncsel[ihad],
572 pSelected[ihad],trackIt[ihad]);
573
574 if (pSelected[ihad]) delete pSelected[ihad];
575 if (trackIt[ihad]) delete trackIt[ihad];
9fd56238 576
826fd892 577 }
578 particleshad1->Clear();
579 particleshad2->Clear();
580 }
581 }
582 } // while (ipa<2*fNpart) loop
583
2c890605 584 SetHighWaterMark(nt);
84555c93 585
cb11fd27 586 AliGenEventHeader* header = new AliGenEventHeader("CorrHF");
84555c93 587 header->SetPrimaryVertex(fVertex);
588 header->SetNProduced(fNprimaries);
589 AddHeader(header);
826fd892 590
591
592 delete particleshad1;
593 delete particleshad2;
594 delete particleslist;
595
00fce64a 596 delete[] pSelected;
597 delete[] trackIt;
84555c93 598}
2c890605 599//____________________________________________________________________________________
9fd56238 600void AliGenCorrHF::IpCharm(TH2F *hProbHH, Int_t &pdg3, Int_t &pdg4)
2c890605 601{
9fd56238 602// Composition of a lower state charm hadron pair from a ccbar quark pair
603 Int_t pdgH[] = {411, 421, 431, 4122, 4132, 4232, 4332};
604
605 Double_t id3, id4;
606 hProbHH->GetRandom2(id3, id4);
607 pdg3 = pdgH[(Int_t)TMath::Floor(id3)];
608 pdg4 = -1*pdgH[(Int_t)TMath::Floor(id4)];
609
610 return;
2c890605 611}
612
9fd56238 613void AliGenCorrHF::IpBeauty(TH2F *hProbHH, Int_t &pdg3, Int_t &pdg4)
2c890605 614{
9fd56238 615// Composition of a lower state beauty hadron pair from a bbbar quark pair
616 // B-Bbar mixing will be done by Pythia at their decay point
617 Int_t pdgH[] = {511, 521, 531, 5122, 5132, 5232, 5332};
618
619 Double_t id3, id4;
620 hProbHH->GetRandom2(id3, id4);
621 pdg3 = pdgH[(Int_t)TMath::Floor(id3)];
622 pdg4 = -1*pdgH[(Int_t)TMath::Floor(id4)];
623
624 if ( (pdg3== 511) || (pdg3== 521) || (pdg3== 531) ) pdg3 *= -1;
625 if ( (pdg4==-511) || (pdg4==-521) || (pdg4==-531) ) pdg4 *= -1;
626
627 return;
2c890605 628}
629
630//____________________________________________________________________________________
631Double_t AliGenCorrHF::ComputeIntegral(TFile* fG) // needed by GetQuarkPair
632{
633 // Read QQbar kinematical 5D grid's cell occupancy weights
4c111067 634 Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
2c890605 635 TTree* tG = (TTree*) fG->Get("tGqq");
4c111067 636 tG->GetBranch("cell")->SetAddress(&cell);
2c890605 637 Int_t nbins = tG->GetEntries();
638
639 // delete previously computed integral (if any)
640 if(fgIntegral) delete [] fgIntegral;
641
642 fgIntegral = new Double_t[nbins+1];
643 fgIntegral[0] = 0;
644 Int_t bin;
645 for(bin=0;bin<nbins;bin++) {
646 tG->GetEvent(bin);
647 fgIntegral[bin+1] = fgIntegral[bin] + cell[0];
648 }
649 // Normalize integral to 1
650 if (fgIntegral[nbins] == 0 ) {
651 return 0;
652 }
653 for (bin=1;bin<=nbins;bin++) fgIntegral[bin] /= fgIntegral[nbins];
654
655 return fgIntegral[nbins];
656}
657
826fd892 658
2c890605 659//____________________________________________________________________________________
660void AliGenCorrHF::GetQuarkPair(TFile* fG, Double_t* fInt, Double_t &y1, Double_t &y2, Double_t &pt1, Double_t &pt2, Double_t &dphi)
661 // modification of ROOT's TH3::GetRandom3 for 5D
662{
663 // Read QQbar kinematical 5D grid's cell coordinates
4c111067 664 Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
2c890605 665 TTree* tG = (TTree*) fG->Get("tGqq");
4c111067 666 tG->GetBranch("cell")->SetAddress(&cell);
2c890605 667 Int_t nbins = tG->GetEntries();
668 Double_t rand[6];
669 gRandom->RndmArray(6,rand);
670 Int_t ibin = TMath::BinarySearch(nbins,fInt,rand[0]);
671 tG->GetEvent(ibin);
672 y1 = fgy[cell[1]] + (fgy[cell[1]+1]-fgy[cell[1]])*rand[1];
673 y2 = fgy[cell[2]] + (fgy[cell[2]+1]-fgy[cell[2]])*rand[2];
674 pt1 = fgpt[cell[3]] + (fgpt[cell[3]+1]-fgpt[cell[3]])*rand[3];
675 pt2 = fgpt[cell[4]] + (fgpt[cell[4]+1]-fgpt[cell[4]])*rand[4];
676 dphi = fgdph[cell[5]]+ (fgdph[cell[5]+1]-fgdph[cell[5]])*rand[5];
677}
678
679//____________________________________________________________________________________
680void 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)
681{
682 // Generate a hadron pair
9fd56238 683 void (*fIpParaFunc)(TH2F *, Int_t &, Int_t &);//Pointer to hadron pair composition function
2c890605 684 fIpParaFunc = IpCharm;
685 Double_t mq = 1.2; // c & b quark masses (used in AliPythia)
686 if (idq == 5) {
687 fIpParaFunc = IpBeauty;
688 mq = 4.75;
689 }
08bffa4d 690 Double_t z11 = 0.;
691 Double_t z12 = 0.;
692 Double_t z21 = 0.;
693 Double_t z22 = 0.;
694 Double_t pz1, pz2, e1, e2, mh, ptemp, rand[2];
2c890605 695 char tag[100];
9fd56238 696 TH2F *h2h[12], *h2s[12], *hProbHH; // hard & soft fragmentation and HH-probability functions
2c890605 697 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
09298f0c 698 snprintf(tag,100, "h2h_pt%d",ipt);
2c890605 699 h2h[ipt] = (TH2F*) fG->Get(tag);
09298f0c 700 snprintf(tag,100, "h2s_pt%d",ipt);
2c890605 701 h2s[ipt] = (TH2F*) fG->Get(tag);
702 }
703
704 if (y1*y2 < 0) {
705 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
706 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
707 h2h[ipt]->GetRandom2(z11, z21);
708 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
709 h2h[ipt]->GetRandom2(z12, z22);
710 }
711 }
712 else {
713 if (TMath::Abs(y1) > TMath::Abs(y2)) {
714 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
715 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
716 h2h[ipt]->GetRandom2(z11, z21);
717 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
718 h2s[ipt]->GetRandom2(z12, z22);
719 }
720 }
721 else {
722 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
723 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
724 h2s[ipt]->GetRandom2(z11, z21);
725 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
726 h2h[ipt]->GetRandom2(z12, z22);
727 }
728 }
729 }
730 gRandom->RndmArray(2,rand);
731 ptemp = TMath::Sqrt(pt1*pt1 + mq*mq);
732 pz1 = ptemp*TMath::SinH(y1);
733 e1 = ptemp*TMath::CosH(y1);
734 ptemp = TMath::Sqrt(pt2*pt2 + mq*mq);
735 pz2 = ptemp*TMath::SinH(y2);
736 e2 = ptemp*TMath::CosH(y2);
737
9fd56238 738 hProbHH = (TH2F*)fG->Get("hProbHH");
739 fIpParaFunc(hProbHH, id3, id4);
2c890605 740 mh = TDatabasePDG::Instance()->GetParticle(id3)->Mass();
741 ptemp = z11*z21*(e1*e1-pz1*pz1) - mh*mh;
b33adf51 742 if (idq==5) pt3 = pt1; // an approximation at low pt, try better
9fd56238 743 else pt3 = rand[0]; // pt3=pt1 gives less D-hadrons at low pt
2c890605 744 if (ptemp > 0) pt3 = TMath::Sqrt(ptemp);
745 if (pz1 > 0) pz3 = (z11*(e1 + pz1) - z21*(e1 - pz1)) / 2;
746 else pz3 = (z21*(e1 + pz1) - z11*(e1 - pz1)) / 2;
747 e1 = TMath::Sqrt(pz3*pz3 + pt3*pt3 + mh*mh);
748
2c890605 749 mh = TDatabasePDG::Instance()->GetParticle(id4)->Mass();
750 ptemp = z12*z22*(e2*e2-pz2*pz2) - mh*mh;
b33adf51 751 if (idq==5) pt4 = pt2; // an approximation at low pt, try better
752 else pt4 = rand[1];
2c890605 753 if (ptemp > 0) pt4 = TMath::Sqrt(ptemp);
754 if (pz2 > 0) pz4 = (z12*(e2 + pz2) - z22*(e2 - pz2)) / 2;
755 else pz4 = (z22*(e2 + pz2) - z12*(e2 - pz2)) / 2;
756 e2 = TMath::Sqrt(pz4*pz4 + pt4*pt4 + mh*mh);
757
758 // small corr. instead of using Frag. Func. depending on yQ (in addition to ptQ)
759 Float_t ycorr = 0.2, y3, y4;
760 gRandom->RndmArray(2,rand);
761 y3 = 0.5 * TMath::Log((e1 + pz3 + 1.e-13)/(e1 - pz3 + 1.e-13));
762 y4 = 0.5 * TMath::Log((e2 + pz4 + 1.e-13)/(e2 - pz4 + 1.e-13));
763 if(TMath::Abs(y3)<ycorr && TMath::Abs(y4)<ycorr && rand[0]>0.5) {
bfd20868 764 ptemp = TMath::Sqrt((e1-pz3)*(e1+pz3));
2c890605 765 y3 = 4*(1 - 2*rand[1]);
766 pz3 = ptemp*TMath::SinH(y3);
767 pz4 = pz3;
768 }
769}
5cc3bcd2 770
826fd892 771
772//____________________________________________________________________________________
773void AliGenCorrHF::LoadTracks(Int_t iquark, Float_t *pq,
774 Int_t iPart, Float_t *p,
775 Int_t np, TClonesArray *particles,
776 Float_t *origin0, Float_t *polar,
777 Float_t wgtp, Float_t wgtch,
778 Int_t &nt, Int_t ncsel, Int_t *pSelected,
779 Int_t *trackIt){
780 Int_t i;
781 Int_t ntq=-1;
782 Int_t* pParent = new Int_t[np];
783 Float_t pc[3], och[3];
784 Int_t iparent;
785
786 for(i=0;i<np;i++) pParent[i]=-1;
787
788 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
789 // Parents
790 // quark
791 PushTrack(0, -1, iquark, pq, origin0, polar, 0, kPPrimary, nt, wgtp);
792 KeepTrack(nt);
793 ntq = nt;
794 // hadron
795 PushTrack(0, ntq, iPart, p, origin0, polar, 0, kPDecay, nt, wgtp);
796 pParent[0] = nt;
797 KeepTrack(nt);
798 fNprimaries++;
799
800 // Decay Products
801 for (i = 1; i < np; i++) {
802 if (pSelected[i]) {
803
804 TParticle* iparticle = (TParticle *) particles->At(i);
805 Int_t kf = iparticle->GetPdgCode();
806 Int_t jpa = iparticle->GetFirstMother()-1;
807
808 och[0] = origin0[0]+iparticle->Vx()/10;
809 och[1] = origin0[1]+iparticle->Vy()/10;
810 och[2] = origin0[2]+iparticle->Vz()/10;
811 pc[0] = iparticle->Px();
812 pc[1] = iparticle->Py();
813 pc[2] = iparticle->Pz();
814
815 if (jpa > -1) {
816 iparent = pParent[jpa];
817 } else {
818 iparent = -1;
819 }
820
821 PushTrack(fTrackIt*trackIt[i], iparent, kf,
822 pc, och, polar,
823 0, kPDecay, nt, wgtch);
824 pParent[i] = nt;
825 KeepTrack(nt);
826 fNprimaries++;
827
828 } // Selected
829 } // Particle loop
830 }
831 if (pParent) delete[] pParent;
832
833 return;
834}
835