Background subraction disabled since not correct. (Elena Bruna)
[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,
24// CTEQ5L PDF and Pt_hard = 2.76 GeV/c in p-p collisions at 10 and 14 TeV.
25// Decays are performed by Pythia.
2c890605 26// Author: S. Grigoryan, LPC Clermont-Fd & YerPhI, Smbat.Grigoryan@cern.ch
b44c3901 27// July 07: added quarks in the stack (B. Vulpescu)
b33adf51 28// April 09: added energy choice between 10 and 14 TeV (S. Grigoryan)
2c890605 29//-------------------------------------------------------------------------
b33adf51 30// How it works (for the given flavor and p-p energy):
2c890605 31//
32// 1) Reads QQbar kinematical grid from the Input file and generates
33// quark pairs according to the weights of the cells.
34// It is a 5D grid in y1,y2,pt1,pt2 and deltaphi, with occupancy weights
35// of the cells obtained from Pythia (see details in GetQuarkPair).
36// 2) Reads "soft" and "hard" fragmentation functions (12 2D-histograms each,
37// for 12 pt bins) from the Input file, applies to quarks and produces hadrons
38// (only lower states, with proportions of species obtained from Pythia).
39// Fragmentation functions are the same for all hadron species and depend
40// on 2 variables - light cone energy-momentum fractions:
41// z1=(E_H + Pz_H)/(E_Q + Pz_Q), z2=(E_H - Pz_H)/(E_Q - Pz_Q).
42// "soft" & "hard" FFs correspond to "slower" & "faster" quark of a pair
b33adf51 43// (see details in GetHadronPair). Fragmentation does not depend on p-p energy.
2c890605 44// 3) Decays the hadrons and saves all the particles in the event stack in the
45// following order: HF hadron from Q, then its decay products, then HF hadron
46// from Qbar, then its decay productes, then next HF hadon pair (if any)
47// in the same way, etc...
48// 4) It is fast, e.g., generates the same number of events with a beauty pair
49// ~15 times faster than AliGenPythia with kBeautyppMNRwmi (w/o tracking)
50//
b33adf51 51// An Input file for each quark flavor and p-p energy is in EVGEN/dataCorrHF/
2c890605 52// One can use also user-defined Input files.
53//
54// More details could be found in my presentation at DiMuonNet Workshop, Dec 2006:
b33adf51 55// http://www-dapnia.cea.fr/Sphn/Alice/DiMuonNet.
2c890605 56//
57//-------------------------------------------------------------------------
58// How to use it:
59//
60// add the following typical lines in Config.C
61/*
62 if (!strcmp(option,"corr")) {
b33adf51 63 // Example for correlated charm or beauty hadron pair production at 14 TeV
2c890605 64
b33adf51 65 // AliGenCorrHF *gener = new AliGenCorrHF(1, 4, 14); // for charm, 1 pair per event
66 AliGenCorrHF *gener = new AliGenCorrHF(1, 5, 14); // for beauty, 1 pair per event
2c890605 67
68 gener->SetMomentumRange(0,9999);
69 gener->SetCutOnChild(0); // 1/0 means cuts on children enable/disable
70 gener->SetChildThetaRange(171.0,178.0);
71 gener->SetOrigin(0,0,0); //vertex position
72 gener->SetSigma(0,0,0); //Sigma in (X,Y,Z) (cm) on IP position
73 gener->SetForceDecay(kSemiMuonic);
74 gener->SetTrackingFlag(0);
75 gener->Init();
76}
77*/
78// and in aliroot do e.g. gAlice->Run(10,"Config.C") to produce 10 events.
79// One can include AliGenCorrHF in an AliGenCocktail generator.
80//--------------------------------------------------------------------------
81
7ca4655f 82#include <Riostream.h>
83#include <TCanvas.h>
84#include <TClonesArray.h>
85#include <TDatabasePDG.h>
2c890605 86#include <TFile.h>
2c890605 87#include <TH2F.h>
2c890605 88#include <TLorentzVector.h>
7ca4655f 89#include <TMath.h>
2c890605 90#include <TParticle.h>
91#include <TParticlePDG.h>
7ca4655f 92#include <TROOT.h>
93#include <TRandom.h>
94#include <TTree.h>
2c890605 95#include <TVirtualMC.h>
b44c3901 96#include <TVector3.h>
2c890605 97
98#include "AliGenCorrHF.h"
99#include "AliLog.h"
100#include "AliConst.h"
101#include "AliDecayer.h"
102#include "AliMC.h"
103#include "AliRun.h"
84555c93 104#include "AliGenEventHeader.h"
2c890605 105
106ClassImp(AliGenCorrHF)
107
108 //Begin_Html
109 /*
110 <img src="picts/AliGenCorrHF.gif">
111 */
112 //End_Html
113
114Double_t AliGenCorrHF::fgdph[19] = {0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180};
115Double_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 116Double_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 117Int_t AliGenCorrHF::fgnptbins = 12;
118Double_t AliGenCorrHF::fgptbmin[12] = {0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9};
119Double_t AliGenCorrHF::fgptbmax[12] = {0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 9, 100};
120
121Double_t* AliGenCorrHF::fgIntegral = 0;
122
123//____________________________________________________________
124 AliGenCorrHF::AliGenCorrHF():
125 fFileName(0),
126 fFile(0),
127 fQuark(0),
b33adf51 128 fEnergy(0),
2c890605 129 fBias(0.),
130 fTrials(0),
131 fDecayer(0)
132{
133// Default constructor
134}
135
136//____________________________________________________________
b33adf51 137AliGenCorrHF::AliGenCorrHF(Int_t npart, Int_t idquark, Int_t energy):
2c890605 138 AliGenMC(npart),
139 fFileName(0),
140 fFile(0),
b33adf51 141 fQuark(idquark),
142 fEnergy(energy),
2c890605 143 fBias(0.),
144 fTrials(0),
145 // fDecayer(new AliDecayerPythia())
146 fDecayer(0)
147{
b33adf51 148// Constructor using particle number, quark type, energy & default InputFile
2c890605 149//
b33adf51 150 if (fQuark == 5) {
151 if (fEnergy == 10)
152 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/Beautypp10MNRwmiCorr.root";
153 else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/Beautypp14MNRwmiCorr.root";
154 }
155 else {
156 fQuark = 4;
157 if (fEnergy == 10)
158 fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/Charmpp10MNRwmiCorr.root";
159 else fFileName = "$ALICE_ROOT/EVGEN/dataCorrHF/Charmpp14MNRwmiCorr.root";
160 }
2c890605 161 fName = "Default";
162 fTitle= "Generator for correlated pairs of HF hadrons";
163
164 fChildSelect.Set(5);
165 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
166 SetForceDecay();
167 SetCutOnChild();
168 SetChildMomentumRange();
169 SetChildPtRange();
170 SetChildPhiRange();
171 SetChildThetaRange();
172}
173
174//___________________________________________________________________
b33adf51 175AliGenCorrHF::AliGenCorrHF(char* tname, Int_t npart, Int_t idquark, Int_t energy):
2c890605 176 AliGenMC(npart),
177 fFileName(tname),
178 fFile(0),
b33adf51 179 fQuark(idquark),
180 fEnergy(energy),
2c890605 181 fBias(0.),
182 fTrials(0),
183 // fDecayer(new AliDecayerPythia())
184 fDecayer(0)
185{
b33adf51 186// Constructor using particle number, quark type, energy & user-defined InputFile
2c890605 187//
188 if (fQuark != 5) fQuark = 4;
189 fName = "UserDefined";
190 fTitle= "Generator for correlated pairs of HF hadrons";
191
192 fChildSelect.Set(5);
193 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
194 SetForceDecay();
195 SetCutOnChild();
196 SetChildMomentumRange();
197 SetChildPtRange();
198 SetChildPhiRange();
199 SetChildThetaRange();
200}
201
202//____________________________________________________________
2c890605 203AliGenCorrHF::~AliGenCorrHF()
204{
205// Destructor
206 delete fFile;
207}
208
209//____________________________________________________________
210void AliGenCorrHF::Init()
211{
212// Initialisation
213
214 AliInfo(Form(" QQbar kinematics and fragm. functions from: %s",fFileName.Data() ));
215 fFile = TFile::Open(fFileName.Data());
216 if(!fFile->IsOpen()){
217 AliError(Form("Could not open file %s",fFileName.Data() ));
218 }
219
220 ComputeIntegral(fFile);
b44c3901 221
2c890605 222 fParentWeight = 1./fNpart; // fNpart is number of HF-hadron pairs
223
224// particle decay related initialization
225
226 if (gMC) fDecayer = gMC->GetDecayer();
227 fDecayer->SetForceDecay(fForceDecay);
228 fDecayer->Init();
229
230//
231 AliGenMC::Init();
232}
2c890605 233//____________________________________________________________
234void AliGenCorrHF::Generate()
235{
236//
cb11fd27 237// Generate fNpart of correlated HF hadron pairs per event
238// in the the desired theta and momentum windows (phi = 0 - 2pi).
84555c93 239//
cb11fd27 240
84555c93 241// Reinitialize decayer
2c890605 242
84555c93 243 fDecayer->SetForceDecay(fForceDecay);
244 fDecayer->Init();
245
246 //
2c890605 247 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
248 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
249 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
250 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
251 Float_t p[3], pc[3], och[3];// Momentum, polarisation and origin of the children particles from lujet
84555c93 252 Int_t nt, i, j, ipa, ihadron[2], iquark[2];
253 Float_t wgtp, wgtch, random[6];
254 Float_t pq[2][3]; // Momenta of the two quarks
255 Int_t ntq[2] = {-1, -1};
cb11fd27 256 Double_t tanhy2, qm = 0;
2c890605 257
b44c3901 258 Double_t dphi=0, ptq[2], yq[2], pth[2], plh[2], ph[2], phih[2], phiq[2];
2c890605 259 for (i=0; i<2; i++) {
b44c3901 260 ptq[i] =0;
261 yq[i] =0;
262 pth[i] =0;
263 plh[i] =0;
264 phih[i] =0;
265 phiq[i] =0;
2c890605 266 ihadron[i] =0;
84555c93 267 iquark[i] =0;
2c890605 268 }
269
cb11fd27 270 // same quarks mass as in the fragmentation functions
271 if (fQuark == 4) qm = 1.20;
272 else qm = 4.75;
273
2c890605 274 static TClonesArray *particles;
275 //
276 if(!particles) particles = new TClonesArray("TParticle",1000);
277
84555c93 278 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
279 //
280
281 // Calculating vertex position per event
2c890605 282 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
b33adf51 283 if (fVertexSmear==kPerEvent) {
84555c93 284 Vertex();
285 for (j=0;j<3;j++) origin0[j]=fVertex[j];
2c890605 286 }
287
84555c93 288 ipa=0;
289
290 // Generating fNpart particles
291 fNprimaries = 0;
292
293 while (ipa<2*fNpart) {
294
295 GetQuarkPair(fFile, fgIntegral, yq[0], yq[1], ptq[0], ptq[1], dphi);
296
297 GetHadronPair(fFile, fQuark, yq[0], yq[1], ptq[0], ptq[1], ihadron[0], ihadron[1], plh[0], plh[1], pth[0], pth[1]);
298
299 // Cuts from AliGenerator
300
301 // Cut on theta
302 theta=TMath::ATan2(pth[0],plh[0]);
b33adf51 303 if (theta<fThetaMin || theta>fThetaMax) continue;
84555c93 304 theta=TMath::ATan2(pth[1],plh[1]);
b33adf51 305 if (theta<fThetaMin || theta>fThetaMax) continue;
84555c93 306
307 // Cut on momentum
308 ph[0]=TMath::Sqrt(pth[0]*pth[0]+plh[0]*plh[0]);
309 if (ph[0]<fPMin || ph[0]>fPMax) continue;
310 ph[1]=TMath::Sqrt(pth[1]*pth[1]+plh[1]*plh[1]);
311 if (ph[1]<fPMin || ph[1]>fPMax) continue;
312
313 // Add the quarks in the stack
314
315 phiq[0] = Rndm()*k2PI;
316 if (Rndm() < 0.5) {
b44c3901 317 phiq[1] = phiq[0] + dphi*kDegrad;
84555c93 318 } else {
319 phiq[1] = phiq[0] - dphi*kDegrad;
320 }
321 if (phiq[1] > k2PI) phiq[1] -= k2PI;
322 if (phiq[1] < 0 ) phiq[1] += k2PI;
323
324 // quarks pdg
325 iquark[0] = +fQuark;
326 iquark[1] = -fQuark;
327
328 // px and py
329 TVector2 qvect1 = TVector2();
330 TVector2 qvect2 = TVector2();
331 qvect1.SetMagPhi(ptq[0],phiq[0]);
332 qvect2.SetMagPhi(ptq[1],phiq[1]);
333 pq[0][0] = qvect1.Px();
334 pq[0][1] = qvect1.Py();
335 pq[1][0] = qvect2.Px();
336 pq[1][1] = qvect2.Py();
337
338 // pz
cb11fd27 339 tanhy2 = TMath::TanH(yq[0]);
340 tanhy2 *= tanhy2;
341 pq[0][2] = TMath::Sqrt((ptq[0]*ptq[0]+qm*qm)*tanhy2/(1-tanhy2));
342 pq[0][2] = TMath::Sign((Double_t)pq[0][2],yq[0]);
343 tanhy2 = TMath::TanH(yq[1]);
344 tanhy2 *= tanhy2;
345 pq[1][2] = TMath::Sqrt((ptq[1]*ptq[1]+qm*qm)*tanhy2/(1-tanhy2));
346 pq[1][2] = TMath::Sign((Double_t)pq[1][2],yq[1]);
84555c93 347
348 // Here we assume that |phi_H1 - phi_H2| = |phi_Q1 - phi_Q2| = dphi
349 // which is a good approximation for heavy flavors in Pythia
350 // ... moreover, same phi angles as for the quarks ...
351
352 phih[0] = phiq[0];
353 phih[1] = phiq[1];
b44c3901 354
84555c93 355 for (Int_t ihad = 0; ihad < 2; ihad++) {
356 while(1) {
357 //
358 // particle type
359 Int_t iPart = ihadron[ihad];
360 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
361 wgtp=fParentWeight;
362 wgtch=fChildWeight;
363 TParticlePDG *particle = pDataBase->GetParticle(iPart);
364 Float_t am = particle->Mass();
365 phi = phih[ihad];
366 pt = pth[ihad];
367 pl = plh[ihad];
368 ptot=TMath::Sqrt(pt*pt+pl*pl);
369
370 p[0]=pt*TMath::Cos(phi);
371 p[1]=pt*TMath::Sin(phi);
372 p[2]=pl;
b44c3901 373
2c890605 374 if(fVertexSmear==kPerTrack) {
84555c93 375 Rndm(random,6);
376 for (j=0;j<3;j++) {
377 origin0[j]=
378 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
379 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
2c890605 380 }
381 }
84555c93 382
383 // Looking at fForceDecay :
384 // if fForceDecay != none Primary particle decays using
385 // AliPythia and children are tracked by GEANT
386 //
387 // if fForceDecay == none Primary particle is tracked by GEANT
388 // (In the latest, make sure that GEANT actually does all the decays you want)
389 //
390
391 if (fForceDecay != kNoDecay) {
392 // Using lujet to decay particle
393 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
394 TLorentzVector pmom(p[0], p[1], p[2], energy);
395 fDecayer->Decay(iPart,&pmom);
396 //
397 // select decay particles
398 Int_t np=fDecayer->ImportParticles(particles);
399
400 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
401 if (fGeometryAcceptance)
402 if (!CheckAcceptanceGeometry(np,particles)) continue;
403 Int_t ncsel=0;
404 Int_t* pFlag = new Int_t[np];
405 Int_t* pParent = new Int_t[np];
406 Int_t* pSelected = new Int_t[np];
407 Int_t* trackIt = new Int_t[np];
408
409 for (i=0; i<np; i++) {
410 pFlag[i] = 0;
411 pSelected[i] = 0;
412 pParent[i] = -1;
413 }
414
415 if (np >1) {
416 TParticle* iparticle = (TParticle *) particles->At(0);
417 Int_t ipF, ipL;
418 for (i = 1; i<np ; i++) {
419 trackIt[i] = 1;
420 iparticle = (TParticle *) particles->At(i);
421 Int_t kf = iparticle->GetPdgCode();
422 Int_t ks = iparticle->GetStatusCode();
423 // flagged particle
424
425 if (pFlag[i] == 1) {
426 ipF = iparticle->GetFirstDaughter();
427 ipL = iparticle->GetLastDaughter();
428 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
429 continue;
430 }
431
432 // flag decay products of particles with long life-time (c tau > .3 mum)
433
434 if (ks != 1) {
435 //TParticlePDG *particle = pDataBase->GetParticle(kf);
436
437 Double_t lifeTime = fDecayer->GetLifetime(kf);
438 //Double_t mass = particle->Mass();
439 //Double_t width = particle->Width();
440 if (lifeTime > (Double_t) fMaxLifeTime) {
441 ipF = iparticle->GetFirstDaughter();
442 ipL = iparticle->GetLastDaughter();
443 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
b33adf51 444 } else {
84555c93 445 trackIt[i] = 0;
446 pSelected[i] = 1;
2c890605 447 }
84555c93 448 } // ks==1 ?
449 //
450 // children
451
f7b22746 452 if ((ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll) && trackIt[i])
84555c93 453 {
454 if (fCutOnChild) {
455 pc[0]=iparticle->Px();
456 pc[1]=iparticle->Py();
457 pc[2]=iparticle->Pz();
458 Bool_t childok = KinematicSelection(iparticle, 1);
459 if(childok) {
460 pSelected[i] = 1;
461 ncsel++;
462 } else {
463 ncsel=-1;
464 break;
465 } // child kine cuts
466 } else {
467 pSelected[i] = 1;
468 ncsel++;
469 } // if child selection
470 } // select muon
471 } // decay particle loop
472 } // if decay products
473
474 Int_t iparent;
475 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
476 ipa++;
477 //
478 // Parent
479 // quark
480 PushTrack(0, -1, iquark[ihad], pq[ihad], origin0, polar, 0, kPPrimary, nt, wgtp);
481 KeepTrack(nt);
482 ntq[ihad] = nt;
84555c93 483 // hadron
484 PushTrack(0, ntq[ihad], iPart, p, origin0, polar, 0, kPDecay, nt, wgtp);
485 pParent[0] = nt;
486 KeepTrack(nt);
487 fNprimaries++;
84555c93 488
489 //
490 // Decay Products
491 //
492 for (i = 1; i < np; i++) {
493 if (pSelected[i]) {
494 TParticle* iparticle = (TParticle *) particles->At(i);
495 Int_t kf = iparticle->GetPdgCode();
7f11c778 496 Int_t jpa = iparticle->GetFirstMother()-1;
2c890605 497
84555c93 498 och[0] = origin0[0]+iparticle->Vx()/10;
499 och[1] = origin0[1]+iparticle->Vy()/10;
500 och[2] = origin0[2]+iparticle->Vz()/10;
501 pc[0] = iparticle->Px();
502 pc[1] = iparticle->Py();
503 pc[2] = iparticle->Pz();
2c890605 504
7f11c778 505 if (jpa > -1) {
506 iparent = pParent[jpa];
84555c93 507 } else {
508 iparent = -1;
509 }
510
511 PushTrack(fTrackIt*trackIt[i], iparent, kf,
512 pc, och, polar,
513 0, kPDecay, nt, wgtch);
84555c93 514 pParent[i] = nt;
515 KeepTrack(nt);
516 fNprimaries++;
517 } // Selected
518 } // Particle loop
519 } // Decays by Lujet
520 particles->Clear();
521 if (pFlag) delete[] pFlag;
522 if (pParent) delete[] pParent;
523 if (pSelected) delete[] pSelected;
524 if (trackIt) delete[] trackIt;
525 } // kinematic selection
526 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
527 {
528 gAlice->GetMCApp()->
529 PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
530 ipa++;
531 fNprimaries++;
532 }
2c890605 533 break;
534 } // while(1)
84555c93 535 } // hadron pair loop
536 } // event loop
537
2c890605 538 SetHighWaterMark(nt);
84555c93 539
cb11fd27 540 AliGenEventHeader* header = new AliGenEventHeader("CorrHF");
84555c93 541 header->SetPrimaryVertex(fVertex);
542 header->SetNProduced(fNprimaries);
543 AddHeader(header);
2c890605 544
84555c93 545}
2c890605 546//____________________________________________________________________________________
2c890605 547Int_t AliGenCorrHF::IpCharm(TRandom* ran)
548{
549// Composition of lower state charm hadrons, containing a c-quark
550 Float_t random;
551 Int_t ip; // +- 411,421,431,4122,4132,4232,4332
552 random = ran->Rndm();
553// Rates from Pythia6.214 using 100Kevents with kPyCharmppMNRwmi at 14 TeV.
554
555 if (random < 0.6027) {
556 ip=421;
557 } else if (random < 0.7962) {
558 ip=411;
559 } else if (random < 0.9127) {
560 ip=431;
561 } else if (random < 0.9899) {
562 ip=4122;
563 } else if (random < 0.9948) {
564 ip=4132;
565 } else if (random < 0.9999) {
566 ip=4232;
567 } else {
568 ip=4332;
569 }
570
571 return ip;
572}
573
574Int_t AliGenCorrHF::IpBeauty(TRandom* ran)
575{
576// Composition of lower state beauty hadrons, containing a b-quark
577 Float_t random;
578 Int_t ip; // +- 511,521,531,5122,5132,5232,5332
579 random = ran->Rndm();
580// Rates from Pythia6.214 using 100Kevents with kPyBeautyppMNRwmi at 14 TeV.
581 // B-Bbar mixing will be done by Pythia at the decay point
582 if (random < 0.3965) {
583 ip=-511;
584 } else if (random < 0.7930) {
585 ip=-521;
586 } else if (random < 0.9112) {
587 ip=-531;
588 } else if (random < 0.9887) {
589 ip=5122;
590 } else if (random < 0.9943) {
591 ip=5132;
592 } else if (random < 0.9999) {
593 ip=5232;
594 } else {
595 ip=5332;
596 }
597
598 return ip;
599}
600
601//____________________________________________________________________________________
602Double_t AliGenCorrHF::ComputeIntegral(TFile* fG) // needed by GetQuarkPair
603{
604 // Read QQbar kinematical 5D grid's cell occupancy weights
4c111067 605 Int_t cell[6]; // cell[6]={wght,iy1,iy2,ipt1,ipt2,idph}
2c890605 606 TTree* tG = (TTree*) fG->Get("tGqq");
4c111067 607 tG->GetBranch("cell")->SetAddress(&cell);
2c890605 608 Int_t nbins = tG->GetEntries();
609
610 // delete previously computed integral (if any)
611 if(fgIntegral) delete [] fgIntegral;
612
613 fgIntegral = new Double_t[nbins+1];
614 fgIntegral[0] = 0;
615 Int_t bin;
616 for(bin=0;bin<nbins;bin++) {
617 tG->GetEvent(bin);
618 fgIntegral[bin+1] = fgIntegral[bin] + cell[0];
619 }
620 // Normalize integral to 1
621 if (fgIntegral[nbins] == 0 ) {
622 return 0;
623 }
624 for (bin=1;bin<=nbins;bin++) fgIntegral[bin] /= fgIntegral[nbins];
625
626 return fgIntegral[nbins];
627}
628
629//____________________________________________________________________________________
630void AliGenCorrHF::GetQuarkPair(TFile* fG, Double_t* fInt, Double_t &y1, Double_t &y2, Double_t &pt1, Double_t &pt2, Double_t &dphi)
631 // modification of ROOT's TH3::GetRandom3 for 5D
632{
633 // Read QQbar kinematical 5D grid's cell coordinates
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 Double_t rand[6];
639 gRandom->RndmArray(6,rand);
640 Int_t ibin = TMath::BinarySearch(nbins,fInt,rand[0]);
641 tG->GetEvent(ibin);
642 y1 = fgy[cell[1]] + (fgy[cell[1]+1]-fgy[cell[1]])*rand[1];
643 y2 = fgy[cell[2]] + (fgy[cell[2]+1]-fgy[cell[2]])*rand[2];
644 pt1 = fgpt[cell[3]] + (fgpt[cell[3]+1]-fgpt[cell[3]])*rand[3];
645 pt2 = fgpt[cell[4]] + (fgpt[cell[4]+1]-fgpt[cell[4]])*rand[4];
646 dphi = fgdph[cell[5]]+ (fgdph[cell[5]+1]-fgdph[cell[5]])*rand[5];
647}
648
649//____________________________________________________________________________________
650void 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)
651{
652 // Generate a hadron pair
653 Int_t (*fIpParaFunc )(TRandom*);//Pointer to particle type parametrisation function
654 fIpParaFunc = IpCharm;
655 Double_t mq = 1.2; // c & b quark masses (used in AliPythia)
656 if (idq == 5) {
657 fIpParaFunc = IpBeauty;
658 mq = 4.75;
659 }
660 Double_t z11, z12, z21, z22, pz1, pz2, e1, e2, mh, ptemp, rand[2];
661 char tag[100];
662 TH2F *h2h[12], *h2s[12]; // hard & soft Fragmentation Functions
663 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
664 sprintf(tag,"h2h_pt%d",ipt);
665 h2h[ipt] = (TH2F*) fG->Get(tag);
666 sprintf(tag,"h2s_pt%d",ipt);
667 h2s[ipt] = (TH2F*) fG->Get(tag);
668 }
669
670 if (y1*y2 < 0) {
671 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
672 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
673 h2h[ipt]->GetRandom2(z11, z21);
674 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
675 h2h[ipt]->GetRandom2(z12, z22);
676 }
677 }
678 else {
679 if (TMath::Abs(y1) > TMath::Abs(y2)) {
680 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
681 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
682 h2h[ipt]->GetRandom2(z11, z21);
683 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
684 h2s[ipt]->GetRandom2(z12, z22);
685 }
686 }
687 else {
688 for (Int_t ipt = 0; ipt<fgnptbins; ipt++) {
689 if(pt1 >= fgptbmin[ipt] && pt1 < fgptbmax[ipt])
690 h2s[ipt]->GetRandom2(z11, z21);
691 if(pt2 >= fgptbmin[ipt] && pt2 < fgptbmax[ipt])
692 h2h[ipt]->GetRandom2(z12, z22);
693 }
694 }
695 }
696 gRandom->RndmArray(2,rand);
697 ptemp = TMath::Sqrt(pt1*pt1 + mq*mq);
698 pz1 = ptemp*TMath::SinH(y1);
699 e1 = ptemp*TMath::CosH(y1);
700 ptemp = TMath::Sqrt(pt2*pt2 + mq*mq);
701 pz2 = ptemp*TMath::SinH(y2);
702 e2 = ptemp*TMath::CosH(y2);
703
704 id3 = fIpParaFunc(gRandom);
705 mh = TDatabasePDG::Instance()->GetParticle(id3)->Mass();
706 ptemp = z11*z21*(e1*e1-pz1*pz1) - mh*mh;
b33adf51 707 if (idq==5) pt3 = pt1; // an approximation at low pt, try better
708 else pt3 = rand[0];
2c890605 709 if (ptemp > 0) pt3 = TMath::Sqrt(ptemp);
710 if (pz1 > 0) pz3 = (z11*(e1 + pz1) - z21*(e1 - pz1)) / 2;
711 else pz3 = (z21*(e1 + pz1) - z11*(e1 - pz1)) / 2;
712 e1 = TMath::Sqrt(pz3*pz3 + pt3*pt3 + mh*mh);
713
714 id4 = - fIpParaFunc(gRandom);
715 mh = TDatabasePDG::Instance()->GetParticle(id4)->Mass();
716 ptemp = z12*z22*(e2*e2-pz2*pz2) - mh*mh;
b33adf51 717 if (idq==5) pt4 = pt2; // an approximation at low pt, try better
718 else pt4 = rand[1];
2c890605 719 if (ptemp > 0) pt4 = TMath::Sqrt(ptemp);
720 if (pz2 > 0) pz4 = (z12*(e2 + pz2) - z22*(e2 - pz2)) / 2;
721 else pz4 = (z22*(e2 + pz2) - z12*(e2 - pz2)) / 2;
722 e2 = TMath::Sqrt(pz4*pz4 + pt4*pt4 + mh*mh);
723
724 // small corr. instead of using Frag. Func. depending on yQ (in addition to ptQ)
725 Float_t ycorr = 0.2, y3, y4;
726 gRandom->RndmArray(2,rand);
727 y3 = 0.5 * TMath::Log((e1 + pz3 + 1.e-13)/(e1 - pz3 + 1.e-13));
728 y4 = 0.5 * TMath::Log((e2 + pz4 + 1.e-13)/(e2 - pz4 + 1.e-13));
729 if(TMath::Abs(y3)<ycorr && TMath::Abs(y4)<ycorr && rand[0]>0.5) {
730 ptemp = TMath::Sqrt(e1*e1 - pz3*pz3);
731 y3 = 4*(1 - 2*rand[1]);
732 pz3 = ptemp*TMath::SinH(y3);
733 pz4 = pz3;
734 }
735}