1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
16 /* $Id: AliPythia.cxx,v 1.40 2007/10/09 08:43:24 morsch Exp $ */
18 #include "AliPythia6.h"
20 #include "AliPythiaRndm.h"
21 #include "AliFastGlauber.h"
22 #include "AliQuenchingWeights.h"
25 #include "TParticle.h"
26 #include "PyquenCommon.h"
31 # define pyclus pyclus_
32 # define pycell pycell_
33 # define pyshow pyshow_
34 # define pyshowq pyshowq_
35 # define pyrobo pyrobo_
36 # define pyquen pyquen_
37 # define pyevnw pyevnw_
38 # define pyjoin pyjoin_
39 # define qpygin0 qpygin0_
42 # define pyclus PYCLUS
43 # define pycell PYCELL
44 # define pyshow PYSHOW
45 # define pyshowq PYSHOWQ
46 # define pyrobo PYROBO
47 # define pyquen PYQUEN
48 # define pyevnw PYEVNW
49 # define pyjoin PYJOIN
50 # define qpygin0 QPYGIN0
51 # define type_of_call _stdcall
54 extern "C" void type_of_call pyjoin(Int_t &, Int_t * );
55 extern "C" void type_of_call pyclus(Int_t & );
56 extern "C" void type_of_call pycell(Int_t & );
57 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
58 extern "C" void type_of_call pyshowq(Int_t &, Int_t &, Double_t &);
59 extern "C" void type_of_call qpygin0();
60 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
61 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
62 extern "C" void type_of_call pyevnw();
65 //_____________________________________________________________________________
67 AliPythia6* AliPythia6::fgAliPythia=NULL;
69 AliPythia6::AliPythia6():
84 // Default Constructor
88 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
89 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
90 for (i = 0; i < 4; i++) fZQuench[i] = 0;
92 if (!AliPythiaRndm::GetPythiaRandom())
93 AliPythiaRndm::SetPythiaRandom(GetRandom());
95 fQuenchingWeights = 0;
98 AliPythia6::AliPythia6(const AliPythia6& pythia):
115 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
116 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
117 for (i = 0; i < 4; i++) fZQuench[i] = 0;
121 void AliPythia6::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc, Int_t /*tune*/)
123 // Initialise the process to generate
124 if (!AliPythiaRndm::GetPythiaRandom())
125 AliPythiaRndm::SetPythiaRandom(GetRandom());
129 fStrucFunc = strucfunc;
130 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
131 SetMDCY(Pycomp(111) ,1,0);
132 SetMDCY(Pycomp(310) ,1,0);
133 SetMDCY(Pycomp(3122),1,0);
134 SetMDCY(Pycomp(3112),1,0);
135 SetMDCY(Pycomp(3212),1,0);
136 SetMDCY(Pycomp(3222),1,0);
137 SetMDCY(Pycomp(3312),1,0);
138 SetMDCY(Pycomp(3322),1,0);
139 SetMDCY(Pycomp(3334),1,0);
140 // Select structure function
142 SetMSTP(51,AliStructFuncType::PDFsetIndex(strucfunc));
143 // Particles produced in string fragmentation point directly to either of the two endpoints
144 // of the string (depending in the side they were generated from).
148 // Pythia initialisation for selected processes//
152 for (Int_t i=1; i<= 200; i++) {
155 // select charm production
158 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
159 // Multiple interactions on.
161 // Double Gaussian matter distribution.
167 // Reference energy for pT0 and energy rescaling pace.
170 // String drawing almost completely minimizes string length.
173 // ISR and FSR activity.
179 case kPyOldUEQ2ordered2:
180 // Old underlying events with Q2 ordered QCD processes
181 // Multiple interactions on.
183 // Double Gaussian matter distribution.
189 // Reference energy for pT0 and energy rescaling pace.
191 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
192 // String drawing almost completely minimizes string length.
195 // ISR and FSR activity.
202 // Old production mechanism: Old Popcorn
205 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
207 // (D=1)see can be used to form baryons (BARYON JUNCTION)
213 // heavy quark masses
243 case kPyCharmUnforced:
252 case kPyBeautyUnforced:
262 // Minimum Bias pp-Collisions
265 // select Pythia min. bias model
267 SetMSUB(92,1); // single diffraction AB-->XB
268 SetMSUB(93,1); // single diffraction AB-->AX
269 SetMSUB(94,1); // double diffraction
270 SetMSUB(95,1); // low pt production
274 case kPyMbAtlasTuneMC09:
275 // Minimum Bias pp-Collisions
278 // select Pythia min. bias model
280 SetMSUB(92,1); // single diffraction AB-->XB
281 SetMSUB(93,1); // single diffraction AB-->AX
282 SetMSUB(94,1); // double diffraction
283 SetMSUB(95,1); // low pt production
288 case kPyMbWithDirectPhoton:
289 // Minimum Bias pp-Collisions with direct photon processes added
292 // select Pythia min. bias model
294 SetMSUB(92,1); // single diffraction AB-->XB
295 SetMSUB(93,1); // single diffraction AB-->AX
296 SetMSUB(94,1); // double diffraction
297 SetMSUB(95,1); // low pt production
310 // Minimum Bias pp-Collisions
313 // select Pythia min. bias model
315 SetMSUB(92,1); // single diffraction AB-->XB
316 SetMSUB(93,1); // single diffraction AB-->AX
317 SetMSUB(94,1); // double diffraction
318 SetMSUB(95,1); // low pt production
322 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
323 // -> Pythia 6.3 or above is needed
326 SetMSUB(92,1); // single diffraction AB-->XB
327 SetMSUB(93,1); // single diffraction AB-->AX
328 SetMSUB(94,1); // double diffraction
329 SetMSUB(95,1); // low pt production
330 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll));
334 SetMSTP(81,1); // Multiple Interactions ON
335 SetMSTP(82,4); // Double Gaussian Model
338 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
339 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
340 SetPARP(84,0.5); // Core radius
341 SetPARP(85,0.9); // Regulates gluon prod. mechanism
342 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
346 // Minimum Bias pp-Collisions
349 // select Pythia min. bias model
351 SetMSUB(95,1); // low pt production
358 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
359 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
360 SetPARP(93,5.); // Upper cut-off
362 SetPMAS(4,1,1.2); // Charm quark mass
363 SetPMAS(5,1,4.78); // Beauty quark mass
364 SetPARP(71,4.); // Defaut value
373 // Pythia Tune A (CDF)
375 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
376 SetMSTP(82,4); // Double Gaussian Model
377 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
378 SetPARP(84,0.4); // Core radius
379 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
380 SetPARP(86,0.95); // Regulates gluon prod. mechanism
381 SetPARP(89,1800.); // [GeV] Ref. energy
382 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
387 case kPyCharmPbPbMNR:
389 case kPyDPlusPbPbMNR:
390 case kPyDPlusStrangePbPbMNR:
391 // Tuning of Pythia parameters aimed to get a resonable agreement
392 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
393 // c-cbar single inclusive and double differential distributions.
394 // This parameter settings are meant to work with Pb-Pb collisions
395 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
396 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
397 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
409 case kPyDPlusStrangepPbMNR:
410 // Tuning of Pythia parameters aimed to get a resonable agreement
411 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
412 // c-cbar single inclusive and double differential distributions.
413 // This parameter settings are meant to work with p-Pb collisions
414 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
415 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
416 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
429 case kPyDPlusStrangeppMNR:
430 case kPyLambdacppMNR:
431 // Tuning of Pythia parameters aimed to get a resonable agreement
432 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
433 // c-cbar single inclusive and double differential distributions.
434 // This parameter settings are meant to work with pp collisions
435 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
436 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
437 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
447 case kPyCharmppMNRwmi:
448 // Tuning of Pythia parameters aimed to get a resonable agreement
449 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
450 // c-cbar single inclusive and double differential distributions.
451 // This parameter settings are meant to work with pp collisions
452 // and with kCTEQ5L PDFs.
453 // Added multiple interactions according to ATLAS tune settings.
454 // To get a "reasonable" agreement with MNR results, events have to be
455 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
457 // To get a "perfect" agreement with MNR results, events have to be
458 // generated in four ptHard bins with the following relative
474 case kPyBeautyPbPbMNR:
475 // Tuning of Pythia parameters aimed to get a resonable agreement
476 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
477 // b-bbar single inclusive and double differential distributions.
478 // This parameter settings are meant to work with Pb-Pb collisions
479 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
480 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
481 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
493 case kPyBeautypPbMNR:
494 // Tuning of Pythia parameters aimed to get a resonable agreement
495 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
496 // b-bbar single inclusive and double differential distributions.
497 // This parameter settings are meant to work with p-Pb collisions
498 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
499 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
500 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
513 // Tuning of Pythia parameters aimed to get a resonable agreement
514 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
515 // b-bbar single inclusive and double differential distributions.
516 // This parameter settings are meant to work with pp collisions
517 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
518 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
519 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
534 case kPyBeautyppMNRwmi:
535 // Tuning of Pythia parameters aimed to get a resonable agreement
536 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
537 // b-bbar single inclusive and double differential distributions.
538 // This parameter settings are meant to work with pp collisions
539 // and with kCTEQ5L PDFs.
540 // Added multiple interactions according to ATLAS tune settings.
541 // To get a "reasonable" agreement with MNR results, events have to be
542 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
544 // To get a "perfect" agreement with MNR results, events have to be
545 // generated in four ptHard bins with the following relative
568 //Inclusive production of W+/-
574 // //f fbar -> gamma W+
581 // Initial/final parton shower on (Pythia default)
582 // With parton showers on we are generating "W inclusive process"
583 SetMSTP(61,1); //Initial QCD & QED showers on
584 SetMSTP(71,1); //Final QCD & QED showers on
590 //Inclusive production of Z
595 // // f fbar -> g Z/gamma
597 // // f fbar -> gamma Z/gamma
599 // // f g -> f Z/gamma
601 // // f gamma -> f Z/gamma
604 //only Z included, not gamma
607 // Initial/final parton shower on (Pythia default)
608 // With parton showers on we are generating "Z inclusive process"
609 SetMSTP(61,1); //Initial QCD & QED showers on
610 SetMSTP(71,1); //Final QCD & QED showers on
612 case kPyMBRSingleDiffraction:
613 case kPyMBRDoubleDiffraction:
614 case kPyMBRCentralDiffraction:
619 // For the case of jet production the following parameter setting
620 // limits the transverse momentum of secondary scatterings, due
621 // to multiple parton interactions, to be less than that of the
622 // primary interaction (see POWHEG Dijet paper arXiv:1012.3380
623 // [hep-ph] sec. 4.1 and also the PYTHIA Manual).
625 // maximum number of errors before pythia aborts (def=10)
627 // number of warnings printed on the shell
633 SetMSTP(41,1); // all resonance decays switched on
634 if (process == kPyJetsPWHG || process == kPyCharmPWHG || process == kPyBeautyPWHG) {
635 Initialize("USER","","",0.);
637 Initialize("CMS",fProjectile,fTarget,fEcms);
641 Int_t AliPythia6::CheckedLuComp(Int_t kf)
643 // Check Lund particle code (for debugging)
648 void AliPythia6::SetNuclei(Int_t a1, Int_t a2)
650 // Treat protons as inside nuclei with mass numbers a1 and a2
651 // The MSTP array in the PYPARS common block is used to enable and
652 // select the nuclear structure functions.
653 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
654 // =1: internal PYTHIA acording to MSTP(51)
655 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
656 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
657 // MSTP(192) : Mass number of nucleus side 1
658 // MSTP(193) : Mass number of nucleus side 2
665 AliPythia6* AliPythia6::Instance()
667 // Set random number generator
671 fgAliPythia = new AliPythia6();
676 void AliPythia6::PrintParticles()
678 // Print list of particl properties
680 char* name = new char[16];
681 for (Int_t kf=0; kf<1000000; kf++) {
682 for (Int_t c = 1; c > -2; c-=2) {
683 Int_t kc = Pycomp(c*kf);
685 Float_t mass = GetPMAS(kc,1);
686 Float_t width = GetPMAS(kc,2);
687 Float_t tau = GetPMAS(kc,4);
693 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
694 c*kf, name, mass, width, tau);
698 printf("\n Number of particles %d \n \n", np);
701 void AliPythia6::ResetDecayTable()
703 // Set default values for pythia decay switches
705 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
706 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
709 void AliPythia6::SetDecayTable()
711 // Set default values for pythia decay switches
714 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
715 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
718 void AliPythia6::Pyjoin(Int_t& npart, Int_t *ipart)
720 // Call Pythia join alogorithm to set up a string between
721 // npart partons, given by indices in array ipart[npart]
723 pyjoin(npart, ipart);
726 void AliPythia6::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
728 // Call qPythia showering
730 pyshowq(ip1, ip2, qmax);
733 void AliPythia6::Qpygin0()
735 //position of the hard scattering in the nuclear overlapping area.
740 void AliPythia6::Pyclus(Int_t& njet)
742 // Call Pythia clustering algorithm
747 void AliPythia6::Pycell(Int_t& njet)
749 // Call Pythia jet reconstruction algorithm
754 void AliPythia6::GetJet(Int_t i, Float_t& px, Float_t& py, Float_t& pz, Float_t& e)
758 px = GetPyjets()->P[0][n+i];
759 py = GetPyjets()->P[1][n+i];
760 pz = GetPyjets()->P[2][n+i];
761 e = GetPyjets()->P[3][n+i];
764 void AliPythia6::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
766 // Call Pythia showering
768 pyshow(ip1, ip2, qmax);
771 void AliPythia6::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
773 pyrobo(imi, ima, the, phi, bex, bey, bez);
778 void AliPythia6::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
781 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
782 // (2) The nuclear geometry using the Glauber Model
785 fGlauber = AliFastGlauber::Instance();
787 fGlauber->SetCentralityClass(cMin, cMax);
789 fQuenchingWeights = new AliQuenchingWeights();
790 fQuenchingWeights->InitMult();
791 fQuenchingWeights->SetK(k);
792 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
799 void AliPythia6::Quench()
803 // Simple Jet Quenching routine:
804 // =============================
805 // The jet formed by all final state partons radiated by the parton created
806 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
807 // the initial parton reference frame:
808 // (E + p_z)new = (1-z) (E + p_z)old
813 // The lost momentum is first balanced by one gluon with virtuality > 0.
814 // Subsequently the gluon splits to yield two gluons with E = p.
818 static Float_t eMean = 0.;
819 static Int_t icall = 0;
824 Int_t klast[4] = {-1, -1, -1, -1};
826 Int_t numpart = fPyjets->N;
827 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
828 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
830 Double_t wjtKick[4] = {0., 0., 0., 0.};
836 // Sore information about Primary partons
839 // 0, 1 partons from hard scattering
840 // 2, 3 partons from initial state radiation
842 for (Int_t i = 2; i <= 7; i++) {
844 // Skip gluons that participate in hard scattering
845 if (i == 4 || i == 5) continue;
846 // Gluons from hard Scattering
847 if (i == 6 || i == 7) {
849 pxq[j] = fPyjets->P[0][i];
850 pyq[j] = fPyjets->P[1][i];
851 pzq[j] = fPyjets->P[2][i];
852 eq[j] = fPyjets->P[3][i];
853 mq[j] = fPyjets->P[4][i];
855 // Gluons from initial state radiation
857 // Obtain 4-momentum vector from difference between original parton and parton after gluon
858 // radiation. Energy is calculated independently because initial state radition does not
859 // conserve strictly momentum and energy for each partonic system independently.
861 // Not very clean. Should be improved !
865 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
866 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
867 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
868 mq[j] = fPyjets->P[4][i];
869 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
872 // Calculate some kinematic variables
874 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
875 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
876 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
877 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
878 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
879 qPdg[j] = fPyjets->K[1][i];
885 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
887 for (Int_t j = 0; j < 4; j++) {
889 // Quench only central jets and with E > 10.
893 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
894 // Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
895 Double_t eloss = fQuenchingWeights->GetELossRandomK(itype, int0[j], int1[j], eq[j]);
897 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
900 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
906 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
907 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
909 // Fractional energy loss
910 fZQuench[j] = eloss / eq[j];
912 // Avoid complete loss
914 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
916 // Some debug printing
919 // printf("Initial parton # %3d, Type %3d Energy %10.3f Phi %10.3f Length %10.3f Loss %10.3f Kick %10.3f Mean: %10.3f %10.3f\n",
920 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
922 // fZQuench[j] = 0.8;
923 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
926 quenched[j] = (fZQuench[j] > 0.01);
931 Double_t pNew[1000][4];
938 for (Int_t isys = 0; isys < 4; isys++) {
939 // Skip to next system if not quenched.
940 if (!quenched[isys]) continue;
942 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
943 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
944 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
945 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
951 Double_t pg[4] = {0., 0., 0., 0.};
954 // Loop on radiation events
956 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
959 for (Int_t k = 0; k < 4; k++)
966 for (Int_t i = 0; i < numpart; i++)
968 imo = fPyjets->K[2][i];
969 kst = fPyjets->K[0][i];
970 pdg = fPyjets->K[1][i];
974 // Quarks and gluons only
975 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
976 // Particles from hard scattering only
978 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
979 Int_t imom = imo % 1000;
980 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
981 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
984 // Skip comment lines
985 if (kst != 1 && kst != 2) continue;
988 px = fPyjets->P[0][i];
989 py = fPyjets->P[1][i];
990 pz = fPyjets->P[2][i];
991 e = fPyjets->P[3][i];
992 m = fPyjets->P[4][i];
993 pt = TMath::Sqrt(px * px + py * py);
994 p = TMath::Sqrt(px * px + py * py + pz * pz);
995 phi = TMath::Pi() + TMath::ATan2(-py, -px);
996 theta = TMath::ATan2(pt, pz);
999 // Save 4-momentum sum for balancing
1010 // Fractional energy loss
1011 Double_t z = zquench[index];
1014 // Don't fully quench radiated gluons
1017 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1022 // printf("z: %d %f\n", imo, z);
1029 // Transform into frame in which initial parton is along z-axis
1031 TVector3 v(px, py, pz);
1032 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1033 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1035 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1036 Double_t mt2 = jt * jt + m * m;
1039 // Kinematic limit on z
1041 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1043 // Change light-cone kinematics rel. to initial parton
1045 Double_t eppzOld = e + pl;
1046 Double_t empzOld = e - pl;
1048 Double_t eppzNew = (1. - z) * eppzOld;
1049 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1050 Double_t eNew = 0.5 * (eppzNew + empzNew);
1051 Double_t plNew = 0.5 * (eppzNew - empzNew);
1055 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1056 Double_t mt2New = eppzNew * empzNew;
1057 if (mt2New < 1.e-8) mt2New = 0.;
1059 if (m * m > mt2New) {
1061 // This should not happen
1063 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1066 jtNew = TMath::Sqrt(mt2New - m * m);
1069 // If pT is to small (probably a leading massive particle) we scale only the energy
1070 // This can cause negative masses of the radiated gluon
1071 // Let's hope for the best ...
1073 eNew = TMath::Sqrt(plNew * plNew + mt2);
1077 // Calculate new px, py
1083 pxNew = jtNew / jt * pxs;
1084 pyNew = jtNew / jt * pys;
1087 // Double_t dpx = pxs - pxNew;
1088 // Double_t dpy = pys - pyNew;
1089 // Double_t dpz = pl - plNew;
1090 // Double_t de = e - eNew;
1091 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1092 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1093 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1097 TVector3 w(pxNew, pyNew, plNew);
1098 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1099 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1101 p1[index][0] += pxNew;
1102 p1[index][1] += pyNew;
1103 p1[index][2] += plNew;
1104 p1[index][3] += eNew;
1106 // Updated 4-momentum vectors
1108 pNew[icount][0] = pxNew;
1109 pNew[icount][1] = pyNew;
1110 pNew[icount][2] = plNew;
1111 pNew[icount][3] = eNew;
1116 // Check if there was phase-space for quenching
1119 if (icount == 0) quenched[isys] = kFALSE;
1120 if (!quenched[isys]) break;
1122 for (Int_t j = 0; j < 4; j++)
1124 p2[isys][j] = p0[isys][j] - p1[isys][j];
1126 p2[isys][4] = p2[isys][3] * p2[isys][3] - p2[isys][0] * p2[isys][0] - p2[isys][1] * p2[isys][1] - p2[isys][2] * p2[isys][2];
1127 if (p2[isys][4] > 0.) {
1128 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1131 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1132 printf("4-Momentum: %10.3e %10.3e %10.3e %10.3e %10.3e \n", p2[isys][0], p2[isys][1], p2[isys][2], p2[isys][3], p2[isys][4]);
1133 if (p2[isys][4] < -0.01) {
1134 printf("Negative mass squared !\n");
1135 // Here we have to put the gluon back to mass shell
1136 // This will lead to a small energy imbalance
1138 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1147 printf("zHeavy lowered to %f\n", zHeavy);
1148 if (zHeavy < 0.01) {
1149 printf("No success ! \n");
1151 quenched[isys] = kFALSE;
1155 } // iteration on z (while)
1157 // Update event record
1158 for (Int_t k = 0; k < icount; k++) {
1159 // printf("%6d %6d %10.3e %10.3e %10.3e %10.3e\n", k, kNew[k], pNew[k][0],pNew[k][1], pNew[k][2], pNew[k][3] );
1160 fPyjets->P[0][kNew[k]] = pNew[k][0];
1161 fPyjets->P[1][kNew[k]] = pNew[k][1];
1162 fPyjets->P[2][kNew[k]] = pNew[k][2];
1163 fPyjets->P[3][kNew[k]] = pNew[k][3];
1170 if (!quenched[isys]) continue;
1172 // Last parton from shower i
1173 Int_t in = klast[isys];
1175 // Continue if no parton in shower i selected
1176 if (in == -1) continue;
1178 // If this is the second initial parton and it is behind the first move pointer by previous ish
1179 if (isys == 1 && klast[1] > klast[0]) in += ish;
1184 // How many additional gluons will be generated
1186 if (p2[isys][4] > 0.05) ish = 2;
1188 // Position of gluons
1190 if (iglu == 0) igMin = iGlu;
1193 (fPyjets->N) += ish;
1196 fPyjets->P[0][iGlu] = p2[isys][0];
1197 fPyjets->P[1][iGlu] = p2[isys][1];
1198 fPyjets->P[2][iGlu] = p2[isys][2];
1199 fPyjets->P[3][iGlu] = p2[isys][3];
1200 fPyjets->P[4][iGlu] = p2[isys][4];
1202 fPyjets->K[0][iGlu] = 1;
1203 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1204 fPyjets->K[1][iGlu] = 21;
1205 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1206 fPyjets->K[3][iGlu] = -1;
1207 fPyjets->K[4][iGlu] = -1;
1209 pg[0] += p2[isys][0];
1210 pg[1] += p2[isys][1];
1211 pg[2] += p2[isys][2];
1212 pg[3] += p2[isys][3];
1215 // Split gluon in rest frame.
1217 Double_t bx = p2[isys][0] / p2[isys][3];
1218 Double_t by = p2[isys][1] / p2[isys][3];
1219 Double_t bz = p2[isys][2] / p2[isys][3];
1220 Double_t pst = p2[isys][4] / 2.;
1222 // Isotropic decay ????
1223 Double_t cost = 2. * gRandom->Rndm() - 1.;
1224 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1225 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1227 Double_t pz1 = pst * cost;
1228 Double_t pz2 = -pst * cost;
1229 Double_t pt1 = pst * sint;
1230 Double_t pt2 = -pst * sint;
1231 Double_t px1 = pt1 * TMath::Cos(phis);
1232 Double_t py1 = pt1 * TMath::Sin(phis);
1233 Double_t px2 = pt2 * TMath::Cos(phis);
1234 Double_t py2 = pt2 * TMath::Sin(phis);
1236 fPyjets->P[0][iGlu] = px1;
1237 fPyjets->P[1][iGlu] = py1;
1238 fPyjets->P[2][iGlu] = pz1;
1239 fPyjets->P[3][iGlu] = pst;
1240 fPyjets->P[4][iGlu] = 0.;
1242 fPyjets->K[0][iGlu] = 1 ;
1243 fPyjets->K[1][iGlu] = 21;
1244 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1245 fPyjets->K[3][iGlu] = -1;
1246 fPyjets->K[4][iGlu] = -1;
1248 fPyjets->P[0][iGlu+1] = px2;
1249 fPyjets->P[1][iGlu+1] = py2;
1250 fPyjets->P[2][iGlu+1] = pz2;
1251 fPyjets->P[3][iGlu+1] = pst;
1252 fPyjets->P[4][iGlu+1] = 0.;
1254 fPyjets->K[0][iGlu+1] = 1;
1255 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1256 fPyjets->K[1][iGlu+1] = 21;
1257 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1258 fPyjets->K[3][iGlu+1] = -1;
1259 fPyjets->K[4][iGlu+1] = -1;
1265 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1268 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1269 Double_t px, py, pz;
1270 px = fPyjets->P[0][ig];
1271 py = fPyjets->P[1][ig];
1272 pz = fPyjets->P[2][ig];
1273 TVector3 v(px, py, pz);
1274 v.RotateZ(-phiq[isys]);
1275 v.RotateY(-thetaq[isys]);
1276 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1277 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1278 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1279 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1280 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1281 pxs += jtKick * TMath::Cos(phiKick);
1282 pys += jtKick * TMath::Sin(phiKick);
1283 TVector3 w(pxs, pys, pzs);
1284 w.RotateY(thetaq[isys]);
1285 w.RotateZ(phiq[isys]);
1286 fPyjets->P[0][ig] = w.X();
1287 fPyjets->P[1][ig] = w.Y();
1288 fPyjets->P[2][ig] = w.Z();
1289 fPyjets->P[2][ig] = w.Mag();
1295 // Check energy conservation
1299 Double_t es = 14000.;
1301 for (Int_t i = 0; i < numpart; i++)
1303 kst = fPyjets->K[0][i];
1304 if (kst != 1 && kst != 2) continue;
1305 pxs += fPyjets->P[0][i];
1306 pys += fPyjets->P[1][i];
1307 pzs += fPyjets->P[2][i];
1308 es -= fPyjets->P[3][i];
1310 if (TMath::Abs(pxs) > 1.e-2 ||
1311 TMath::Abs(pys) > 1.e-2 ||
1312 TMath::Abs(pzs) > 1.e-1) {
1313 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1314 // Fatal("Quench()", "4-Momentum non-conservation");
1317 } // end quenching loop (systems)
1319 for (Int_t i = 0; i < numpart; i++)
1321 imo = fPyjets->K[2][i];
1323 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1330 void AliPythia6::Pyquen(Double_t a, Int_t ibf, Double_t b)
1332 // Igor Lokthine's quenching routine
1333 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1338 void AliPythia6::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1340 // Set the parameters for the PYQUEN package.
1341 // See comments in PyquenCommon.h
1347 PYQPAR.iengl = iengl;
1348 PYQPAR.iangl = iangl;
1351 void AliPythia6::LoadEvent(AliStack* stack, Int_t flag, Int_t reHadr)
1354 // Load event into Pythia Common Block
1357 Int_t npart = stack -> GetNprimary();
1361 GetPyjets()->N = npart;
1363 n0 = GetPyjets()->N;
1364 GetPyjets()->N = n0 + npart;
1368 for (Int_t part = 0; part < npart; part++) {
1369 TParticle *mPart = stack->Particle(part);
1371 Int_t kf = mPart->GetPdgCode();
1372 Int_t ks = mPart->GetStatusCode();
1373 Int_t idf = mPart->GetFirstDaughter();
1374 Int_t idl = mPart->GetLastDaughter();
1377 if (ks == 11 || ks == 12) {
1384 Float_t px = mPart->Px();
1385 Float_t py = mPart->Py();
1386 Float_t pz = mPart->Pz();
1387 Float_t e = mPart->Energy();
1388 Float_t m = mPart->GetCalcMass();
1391 (GetPyjets())->P[0][part+n0] = px;
1392 (GetPyjets())->P[1][part+n0] = py;
1393 (GetPyjets())->P[2][part+n0] = pz;
1394 (GetPyjets())->P[3][part+n0] = e;
1395 (GetPyjets())->P[4][part+n0] = m;
1397 (GetPyjets())->K[1][part+n0] = kf;
1398 (GetPyjets())->K[0][part+n0] = ks;
1399 (GetPyjets())->K[3][part+n0] = idf + 1;
1400 (GetPyjets())->K[4][part+n0] = idl + 1;
1401 (GetPyjets())->K[2][part+n0] = mPart->GetFirstMother() + 1;
1406 void AliPythia6::Pyevnw()
1408 // New multiple interaction scenario
1412 void AliPythia6::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1414 // Return event specific quenching parameters
1417 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1421 void AliPythia6::ConfigHeavyFlavor()
1424 // Default configuration for Heavy Flavor production
1426 // All QCD processes
1430 // No multiple interactions
1434 // Initial/final parton shower on (Pythia default)
1438 // 2nd order alpha_s
1446 void AliPythia6::AtlasTuning()
1449 // Configuration for the ATLAS tuning
1450 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ5L));
1451 SetMSTP(81,1); // Multiple Interactions ON
1452 SetMSTP(82,4); // Double Gaussian Model
1453 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1454 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1455 SetPARP(89,1000.); // [GeV] Ref. energy
1456 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1457 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1458 SetPARP(84,0.5); // Core radius
1459 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1460 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1461 SetPARP(67,1); // Regulates Initial State Radiation
1464 void AliPythia6::AtlasTuningMC09()
1467 // Configuration for the ATLAS tuning
1468 printf("ATLAS New TUNE MC09\n");
1469 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1470 SetMSTP(82, 4); // Double Gaussian Model
1471 SetMSTP(52, 2); // External PDF
1472 SetMSTP(51, 20650); // MRST LO*
1475 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1476 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1477 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1478 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1480 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1481 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1482 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1483 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1484 SetPARP(84, 0.7); // Core radius
1485 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1486 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1489 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1491 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1492 SetPARP(89,1800.); // [GeV] Ref. energy
1495 void AliPythia6::SetPtHardRange(Float_t ptmin, Float_t ptmax)
1497 // Set the pt hard range
1502 void AliPythia6::SetYHardRange(Float_t ymin, Float_t ymax)
1504 // Set the y hard range
1510 void AliPythia6::SetFragmentation(Int_t flag)
1512 // Switch fragmentation on/off
1516 void AliPythia6::SetInitialAndFinalStateRadiation(Int_t flag1, Int_t flag2)
1518 // initial state radiation
1520 // final state radiation
1524 void AliPythia6::SetIntrinsicKt(Float_t kt)
1526 // Set the inreinsic kt
1530 SetPARP(93, 4. * kt);
1536 void AliPythia6::SwitchHFOff()
1538 // Switch off heavy flavor
1539 // Maximum number of quark flavours used in pdf
1541 // Maximum number of flavors that can be used in showers
1545 void AliPythia6::SetPycellParameters(Float_t etamax, Int_t neta, Int_t nphi,
1546 Float_t thresh, Float_t etseed, Float_t minet, Float_t r)
1548 // Set pycell parameters
1549 SetPARU(51, etamax);
1552 SetPARU(58, thresh);
1553 SetPARU(52, etseed);
1559 void AliPythia6::ModifiedSplitting()
1561 // Modified splitting probability as a model for quenching
1563 SetMSTJ(41, 1); // QCD radiation only
1564 SetMSTJ(42, 2); // angular ordering
1565 SetMSTJ(44, 2); // option to run alpha_s
1566 SetMSTJ(47, 0); // No correction back to hard scattering element
1567 SetMSTJ(50, 0); // No coherence in first branching
1568 SetPARJ(82, 1.); // Cut off for parton showers
1571 void AliPythia6::SwitchHadronisationOff()
1573 // Switch off hadronisarion
1577 void AliPythia6::SwitchHadronisationOn()
1579 // Switch on hadronisarion
1584 void AliPythia6::GetXandQ(Float_t& x1, Float_t& x2, Float_t& q)
1586 // Get x1, x2 and Q for this event
1593 Float_t AliPythia6::GetXSection()
1595 // Get the total cross-section
1596 return (GetPARI(1));
1599 Float_t AliPythia6::GetPtHard()
1601 // Get the pT hard for this event
1605 Int_t AliPythia6::ProcessCode()
1607 // Get the subprocess code
1611 void AliPythia6::PrintStatistics()
1613 // End of run statistics
1617 void AliPythia6::EventListing()
1619 // End of run statistics
1623 AliPythia6& AliPythia6::operator=(const AliPythia6& rhs)
1625 // Assignment operator
1630 void AliPythia6::Copy(TObject&) const
1635 Fatal("Copy","Not implemented!\n");