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 **************************************************************************/
18 #include "AliPythia.h"
19 #include "AliPythiaRndm.h"
20 #include "AliFastGlauber.h"
21 #include "AliQuenchingWeights.h"
22 #include "AliOmegaDalitz.h"
24 #include "TLorentzVector.h"
25 #include "PyquenCommon.h"
30 # define pyclus pyclus_
31 # define pycell pycell_
32 # define pyshow pyshow_
33 # define pyrobo pyrobo_
34 # define pyquen pyquen_
35 # define pyevnw pyevnw_
36 # define pyshowq pyshowq_
37 # define qpygin0 qpygin0_
38 # define pytune pytune_
39 # define py2ent py2ent_
42 # define pyclus PYCLUS
43 # define pycell PYCELL
44 # define pyrobo PYROBO
45 # define pyquen PYQUEN
46 # define pyevnw PYEVNW
47 # define pyshowq PYSHOWQ
48 # define qpygin0 QPYGIN0
49 # define pytune PYTUNE
50 # define py2ent PY2ENT
51 # define type_of_call _stdcall
54 extern "C" void type_of_call pyclus(Int_t & );
55 extern "C" void type_of_call pycell(Int_t & );
56 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
57 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
58 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
59 extern "C" void type_of_call pyevnw(){;}
60 extern "C" void type_of_call pyshowq(Int_t &, Int_t &, Double_t &);
61 extern "C" void type_of_call pytune(Int_t &);
62 extern "C" void type_of_call py2ent(Int_t &, Int_t&, Int_t&, Double_t&);
63 extern "C" void type_of_call qpygin0();
64 //_____________________________________________________________________________
66 AliPythia* AliPythia::fgAliPythia=NULL;
68 AliPythia::AliPythia():
81 // Default Constructor
84 if (!AliPythiaRndm::GetPythiaRandom())
85 AliPythiaRndm::SetPythiaRandom(GetRandom());
87 fQuenchingWeights = 0;
90 AliPythia::AliPythia(const AliPythia& pythia):
101 fQuenchingWeights(0),
109 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc, Int_t itune)
111 // Initialise the process to generate
112 if (!AliPythiaRndm::GetPythiaRandom())
113 AliPythiaRndm::SetPythiaRandom(GetRandom());
119 fStrucFunc = strucfunc;
120 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
121 SetMDCY(Pycomp(111) ,1,0); // pi0
122 SetMDCY(Pycomp(310) ,1,0); // K0S
123 SetMDCY(Pycomp(3122),1,0); // kLambda
124 SetMDCY(Pycomp(3112),1,0); // sigma -
125 SetMDCY(Pycomp(3222),1,0); // sigma +
126 SetMDCY(Pycomp(3312),1,0); // xi -
127 SetMDCY(Pycomp(3322),1,0); // xi 0
128 SetMDCY(Pycomp(3334),1,0); // omega-
129 // Select structure function
131 SetMSTP(51, AliStructFuncType::PDFsetIndex(strucfunc));
132 // Particles produced in string fragmentation point directly to either of the two endpoints
133 // of the string (depending in the side they were generated from).
137 // Pythia initialisation for selected processes//
141 for (Int_t i=1; i<= 200; i++) {
144 // select charm production
147 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
148 // Multiple interactions on.
150 // Double Gaussian matter distribution.
156 // Reference energy for pT0 and energy rescaling pace.
159 // String drawing almost completely minimizes string length.
162 // ISR and FSR activity.
168 case kPyOldUEQ2ordered2:
169 // Old underlying events with Q2 ordered QCD processes
170 // Multiple interactions on.
172 // Double Gaussian matter distribution.
178 // Reference energy for pT0 and energy rescaling pace.
180 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
181 // String drawing almost completely minimizes string length.
184 // ISR and FSR activity.
191 // Old production mechanism: Old Popcorn
194 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
196 // (D=1)see can be used to form baryons (BARYON JUNCTION)
202 // heavy quark masses
232 case kPyCharmUnforced:
241 case kPyBeautyUnforced:
251 // Minimum Bias pp-Collisions
254 // select Pythia min. bias model
256 SetMSUB(92,1); // single diffraction AB-->XB
257 SetMSUB(93,1); // single diffraction AB-->AX
258 SetMSUB(94,1); // double diffraction
259 SetMSUB(95,1); // low pt production
264 case kPyMbAtlasTuneMC09:
265 // Minimum Bias pp-Collisions
268 // select Pythia min. bias model
270 SetMSUB(92,1); // single diffraction AB-->XB
271 SetMSUB(93,1); // single diffraction AB-->AX
272 SetMSUB(94,1); // double diffraction
273 SetMSUB(95,1); // low pt production
278 case kPyMbWithDirectPhoton:
279 // Minimum Bias pp-Collisions with direct photon processes added
282 // select Pythia min. bias model
284 SetMSUB(92,1); // single diffraction AB-->XB
285 SetMSUB(93,1); // single diffraction AB-->AX
286 SetMSUB(94,1); // double diffraction
287 SetMSUB(95,1); // low pt production
300 // Minimum Bias pp-Collisions
303 // select Pythia min. bias model
305 SetMSUB(92,1); // single diffraction AB-->XB
306 SetMSUB(93,1); // single diffraction AB-->AX
307 SetMSUB(94,1); // double diffraction
308 SetMSUB(95,1); // low pt production
311 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
312 // -> Pythia 6.3 or above is needed
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
320 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll)); // CTEQ6ll pdf
324 SetMSTP(81,1); // Multiple Interactions ON
325 SetMSTP(82,4); // Double Gaussian Model
328 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
329 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
330 SetPARP(84,0.5); // Core radius
331 SetPARP(85,0.9); // Regulates gluon prod. mechanism
332 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
336 // Minimum Bias pp-Collisions
339 // select Pythia min. bias model
341 SetMSUB(95,1); // low pt production
348 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
349 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
350 SetPARP(93,5.); // Upper cut-off
352 SetPMAS(4,1,1.2); // Charm quark mass
353 SetPMAS(5,1,4.78); // Beauty quark mass
354 SetPARP(71,4.); // Defaut value
363 // Pythia Tune A (CDF)
365 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
366 SetMSTP(82,4); // Double Gaussian Model
367 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
368 SetPARP(84,0.4); // Core radius
369 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
370 SetPARP(86,0.95); // Regulates gluon prod. mechanism
371 SetPARP(89,1800.); // [GeV] Ref. energy
372 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
377 case kPyCharmPbPbMNR:
379 case kPyDPlusPbPbMNR:
380 case kPyDPlusStrangePbPbMNR:
381 // Tuning of Pythia parameters aimed to get a resonable agreement
382 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
383 // c-cbar single inclusive and double differential distributions.
384 // This parameter settings are meant to work with Pb-Pb collisions
385 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
386 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
387 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
399 case kPyDPlusStrangepPbMNR:
400 // Tuning of Pythia parameters aimed to get a resonable agreement
401 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
402 // c-cbar single inclusive and double differential distributions.
403 // This parameter settings are meant to work with p-Pb collisions
404 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
405 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
406 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
419 case kPyDPlusStrangeppMNR:
420 case kPyLambdacppMNR:
421 // Tuning of Pythia parameters aimed to get a resonable agreement
422 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
423 // c-cbar single inclusive and double differential distributions.
424 // This parameter settings are meant to work with pp collisions
425 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
426 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
427 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
437 case kPyCharmppMNRwmi:
438 // Tuning of Pythia parameters aimed to get a resonable agreement
439 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
440 // c-cbar single inclusive and double differential distributions.
441 // This parameter settings are meant to work with pp collisions
442 // and with kCTEQ5L PDFs.
443 // Added multiple interactions according to ATLAS tune settings.
444 // To get a "reasonable" agreement with MNR results, events have to be
445 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
447 // To get a "perfect" agreement with MNR results, events have to be
448 // generated in four ptHard bins with the following relative
464 case kPyBeautyPbPbMNR:
465 // Tuning of Pythia parameters aimed to get a resonable agreement
466 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
467 // b-bbar single inclusive and double differential distributions.
468 // This parameter settings are meant to work with Pb-Pb collisions
469 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
470 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
471 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
483 case kPyBeautypPbMNR:
484 // Tuning of Pythia parameters aimed to get a resonable agreement
485 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
486 // b-bbar single inclusive and double differential distributions.
487 // This parameter settings are meant to work with p-Pb collisions
488 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
489 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
490 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
503 // Tuning of Pythia parameters aimed to get a resonable agreement
504 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
505 // b-bbar single inclusive and double differential distributions.
506 // This parameter settings are meant to work with pp collisions
507 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
508 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
509 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
524 case kPyBeautyppMNRwmi:
525 // Tuning of Pythia parameters aimed to get a resonable agreement
526 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
527 // b-bbar single inclusive and double differential distributions.
528 // This parameter settings are meant to work with pp collisions
529 // and with kCTEQ5L PDFs.
530 // Added multiple interactions according to ATLAS tune settings.
531 // To get a "reasonable" agreement with MNR results, events have to be
532 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
534 // To get a "perfect" agreement with MNR results, events have to be
535 // generated in four ptHard bins with the following relative
558 //Inclusive production of W+/-
564 // //f fbar -> gamma W+
571 // Initial/final parton shower on (Pythia default)
572 // With parton showers on we are generating "W inclusive process"
573 SetMSTP(61,1); //Initial QCD & QED showers on
574 SetMSTP(71,1); //Final QCD & QED showers on
580 //Inclusive production of Z
585 // // f fbar -> g Z/gamma
587 // // f fbar -> gamma Z/gamma
589 // // f g -> f Z/gamma
591 // // f gamma -> f Z/gamma
594 //only Z included, not gamma
597 // Initial/final parton shower on (Pythia default)
598 // With parton showers on we are generating "Z inclusive process"
599 SetMSTP(61,1); //Initial QCD & QED showers on
600 SetMSTP(71,1); //Final QCD & QED showers on
609 if (itune > -1) Pytune(itune);
612 SetMSTP(41,1); // all resonance decays switched on
613 Initialize("CMS","p","p",fEcms);
617 Int_t AliPythia::CheckedLuComp(Int_t kf)
619 // Check Lund particle code (for debugging)
621 printf("\n Lucomp kf,kc %d %d",kf,kc);
625 void AliPythia::SetNuclei(Int_t a1, Int_t a2, Int_t pdf)
627 // Treat protons as inside nuclei with mass numbers a1 and a2
628 // The MSTP array in the PYPARS common block is used to enable and
629 // select the nuclear structure functions.
630 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
631 // =1: internal PYTHIA acording to MSTP(51)
632 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
633 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
634 // MSTP(192) : Mass number of nucleus side 1
635 // MSTP(193) : Mass number of nucleus side 2
636 // MSTP(194) : Nuclear structure function: 0: EKS98 1:EPS08
644 AliPythia* AliPythia::Instance()
646 // Set random number generator
650 fgAliPythia = new AliPythia();
655 void AliPythia::PrintParticles()
657 // Print list of particl properties
659 char* name = new char[16];
660 for (Int_t kf=0; kf<1000000; kf++) {
661 for (Int_t c = 1; c > -2; c-=2) {
662 Int_t kc = Pycomp(c*kf);
664 Float_t mass = GetPMAS(kc,1);
665 Float_t width = GetPMAS(kc,2);
666 Float_t tau = GetPMAS(kc,4);
672 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
673 c*kf, name, mass, width, tau);
677 printf("\n Number of particles %d \n \n", np);
680 void AliPythia::ResetDecayTable()
682 // Set default values for pythia decay switches
684 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
685 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
688 void AliPythia::SetDecayTable()
690 // Set default values for pythia decay switches
693 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
694 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
697 void AliPythia::Pyclus(Int_t& njet)
699 // Call Pythia clustering algorithm
704 void AliPythia::Pycell(Int_t& njet)
706 // Call Pythia jet reconstruction algorithm
711 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
713 // Call Pythia jet reconstruction algorithm
715 pyshow(ip1, ip2, qmax);
718 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
720 pyrobo(imi, ima, the, phi, bex, bey, bez);
723 void AliPythia::Pytune(Int_t itune)
727 C ITUNE NAME (detailed descriptions below)
728 C 0 Default : No settings changed => linked Pythia version's defaults.
729 C ====== Old UE, Q2-ordered showers ==========================================
730 C 100 A : Rick Field's CDF Tune A
731 C 101 AW : Rick Field's CDF Tune AW
732 C 102 BW : Rick Field's CDF Tune BW
733 C 103 DW : Rick Field's CDF Tune DW
734 C 104 DWT : Rick Field's CDF Tune DW with slower UE energy scaling
735 C 105 QW : Rick Field's CDF Tune QW (NB: needs CTEQ6.1M pdfs externally)
736 C 106 ATLAS-DC2: Arthur Moraes' (old) ATLAS tune (ATLAS DC2 / Rome)
737 C 107 ACR : Tune A modified with annealing CR
738 C 108 D6 : Rick Field's CDF Tune D6 (NB: needs CTEQ6L pdfs externally)
739 C 109 D6T : Rick Field's CDF Tune D6T (NB: needs CTEQ6L pdfs externally)
740 C ====== Intermediate Models =================================================
741 C 200 IM 1 : Intermediate model: new UE, Q2-ordered showers, annealing CR
742 C 201 APT : Tune A modified to use pT-ordered final-state showers
743 C ====== New UE, interleaved pT-ordered showers, annealing CR ================
744 C 300 S0 : Sandhoff-Skands Tune 0
745 C 301 S1 : Sandhoff-Skands Tune 1
746 C 302 S2 : Sandhoff-Skands Tune 2
747 C 303 S0A : S0 with "Tune A" UE energy scaling
748 C 304 NOCR : New UE "best try" without colour reconnections
749 C 305 Old : New UE, original (primitive) colour reconnections
750 C 306 ATLAS-CSC: Arthur Moraes' (new) ATLAS tune (needs CTEQ6L externally)
751 C ======= The Uppsala models =================================================
752 C ( NB! must be run with special modified Pythia 6.215 version )
753 C ( available from http://www.isv.uu.se/thep/MC/scigal/ )
754 C 400 GAL 0 : Generalized area-law model. Old parameters
755 C 401 SCI 0 : Soft-Colour-Interaction model. Old parameters
756 C 402 GAL 1 : Generalized area-law model. Tevatron MB retuned (Skands)
761 void AliPythia::Py2ent(Int_t idx, Int_t pdg1, Int_t pdg2, Double_t p){
762 // Inset 2-parton system at line idx
763 py2ent(idx, pdg1, pdg2, p);
767 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
770 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
771 // (2) The nuclear geometry using the Glauber Model
774 fGlauber = AliFastGlauber::Instance();
776 fGlauber->SetCentralityClass(cMin, cMax);
778 fQuenchingWeights = new AliQuenchingWeights();
779 fQuenchingWeights->InitMult();
780 fQuenchingWeights->SetK(k);
781 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
788 void AliPythia::Quench()
792 // Simple Jet Quenching routine:
793 // =============================
794 // The jet formed by all final state partons radiated by the parton created
795 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
796 // the initial parton reference frame:
797 // (E + p_z)new = (1-z) (E + p_z)old
802 // The lost momentum is first balanced by one gluon with virtuality > 0.
803 // Subsequently the gluon splits to yield two gluons with E = p.
807 static Float_t eMean = 0.;
808 static Int_t icall = 0;
813 Int_t klast[4] = {-1, -1, -1, -1};
815 Int_t numpart = fPyjets->N;
816 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
817 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
825 // Sore information about Primary partons
828 // 0, 1 partons from hard scattering
829 // 2, 3 partons from initial state radiation
831 for (Int_t i = 2; i <= 7; i++) {
833 // Skip gluons that participate in hard scattering
834 if (i == 4 || i == 5) continue;
835 // Gluons from hard Scattering
836 if (i == 6 || i == 7) {
838 pxq[j] = fPyjets->P[0][i];
839 pyq[j] = fPyjets->P[1][i];
840 pzq[j] = fPyjets->P[2][i];
841 eq[j] = fPyjets->P[3][i];
842 mq[j] = fPyjets->P[4][i];
844 // Gluons from initial state radiation
846 // Obtain 4-momentum vector from difference between original parton and parton after gluon
847 // radiation. Energy is calculated independently because initial state radition does not
848 // conserve strictly momentum and energy for each partonic system independently.
850 // Not very clean. Should be improved !
854 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
855 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
856 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
857 mq[j] = fPyjets->P[4][i];
858 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
861 // Calculate some kinematic variables
863 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
864 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
865 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
866 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
867 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
868 qPdg[j] = fPyjets->K[1][i];
874 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
876 for (Int_t j = 0; j < 4; j++) {
878 // Quench only central jets and with E > 10.
882 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
883 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
885 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
888 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
894 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
895 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
897 // Fractional energy loss
898 fZQuench[j] = eloss / eq[j];
900 // Avoid complete loss
902 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
904 // Some debug printing
907 // 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",
908 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
910 // fZQuench[j] = 0.8;
911 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
914 quenched[j] = (fZQuench[j] > 0.01);
919 Double_t pNew[1000][4];
926 for (Int_t isys = 0; isys < 4; isys++) {
927 // Skip to next system if not quenched.
928 if (!quenched[isys]) continue;
930 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
931 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
932 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
933 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
939 Double_t pg[4] = {0., 0., 0., 0.};
942 // Loop on radiation events
944 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
947 for (Int_t k = 0; k < 4; k++)
954 for (Int_t i = 0; i < numpart; i++)
956 imo = fPyjets->K[2][i];
957 kst = fPyjets->K[0][i];
958 pdg = fPyjets->K[1][i];
962 // Quarks and gluons only
963 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
964 // Particles from hard scattering only
966 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
967 Int_t imom = imo % 1000;
968 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
969 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
972 // Skip comment lines
973 if (kst != 1 && kst != 2) continue;
976 px = fPyjets->P[0][i];
977 py = fPyjets->P[1][i];
978 pz = fPyjets->P[2][i];
979 e = fPyjets->P[3][i];
980 m = fPyjets->P[4][i];
981 pt = TMath::Sqrt(px * px + py * py);
982 p = TMath::Sqrt(px * px + py * py + pz * pz);
983 phi = TMath::Pi() + TMath::ATan2(-py, -px);
984 theta = TMath::ATan2(pt, pz);
987 // Save 4-momentum sum for balancing
998 // Fractional energy loss
999 Double_t z = zquench[index];
1002 // Don't fully quench radiated gluons
1005 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1010 // printf("z: %d %f\n", imo, z);
1017 // Transform into frame in which initial parton is along z-axis
1019 TVector3 v(px, py, pz);
1020 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1021 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1023 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1024 Double_t mt2 = jt * jt + m * m;
1027 // Kinematic limit on z
1029 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1031 // Change light-cone kinematics rel. to initial parton
1033 Double_t eppzOld = e + pl;
1034 Double_t empzOld = e - pl;
1036 Double_t eppzNew = (1. - z) * eppzOld;
1037 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1038 Double_t eNew = 0.5 * (eppzNew + empzNew);
1039 Double_t plNew = 0.5 * (eppzNew - empzNew);
1043 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1044 Double_t mt2New = eppzNew * empzNew;
1045 if (mt2New < 1.e-8) mt2New = 0.;
1047 if (m * m > mt2New) {
1049 // This should not happen
1051 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1054 jtNew = TMath::Sqrt(mt2New - m * m);
1057 // If pT is to small (probably a leading massive particle) we scale only the energy
1058 // This can cause negative masses of the radiated gluon
1059 // Let's hope for the best ...
1061 eNew = TMath::Sqrt(plNew * plNew + mt2);
1065 // Calculate new px, py
1071 pxNew = jtNew / jt * pxs;
1072 pyNew = jtNew / jt * pys;
1074 // Double_t dpx = pxs - pxNew;
1075 // Double_t dpy = pys - pyNew;
1076 // Double_t dpz = pl - plNew;
1077 // Double_t de = e - eNew;
1078 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1079 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1080 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1084 TVector3 w(pxNew, pyNew, plNew);
1085 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1086 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1088 p1[index][0] += pxNew;
1089 p1[index][1] += pyNew;
1090 p1[index][2] += plNew;
1091 p1[index][3] += eNew;
1093 // Updated 4-momentum vectors
1095 pNew[icount][0] = pxNew;
1096 pNew[icount][1] = pyNew;
1097 pNew[icount][2] = plNew;
1098 pNew[icount][3] = eNew;
1103 // Check if there was phase-space for quenching
1106 if (icount == 0) quenched[isys] = kFALSE;
1107 if (!quenched[isys]) break;
1109 for (Int_t j = 0; j < 4; j++)
1111 p2[isys][j] = p0[isys][j] - p1[isys][j];
1113 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];
1114 if (p2[isys][4] > 0.) {
1115 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1118 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1119 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]);
1120 if (p2[isys][4] < -0.01) {
1121 printf("Negative mass squared !\n");
1122 // Here we have to put the gluon back to mass shell
1123 // This will lead to a small energy imbalance
1125 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1134 printf("zHeavy lowered to %f\n", zHeavy);
1135 if (zHeavy < 0.01) {
1136 printf("No success ! \n");
1138 quenched[isys] = kFALSE;
1142 } // iteration on z (while)
1144 // Update event record
1145 for (Int_t k = 0; k < icount; k++) {
1146 // 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] );
1147 fPyjets->P[0][kNew[k]] = pNew[k][0];
1148 fPyjets->P[1][kNew[k]] = pNew[k][1];
1149 fPyjets->P[2][kNew[k]] = pNew[k][2];
1150 fPyjets->P[3][kNew[k]] = pNew[k][3];
1157 if (!quenched[isys]) continue;
1159 // Last parton from shower i
1160 Int_t in = klast[isys];
1162 // Continue if no parton in shower i selected
1163 if (in == -1) continue;
1165 // If this is the second initial parton and it is behind the first move pointer by previous ish
1166 if (isys == 1 && klast[1] > klast[0]) in += ish;
1171 // How many additional gluons will be generated
1173 if (p2[isys][4] > 0.05) ish = 2;
1175 // Position of gluons
1177 if (iglu == 0) igMin = iGlu;
1180 (fPyjets->N) += ish;
1183 fPyjets->P[0][iGlu] = p2[isys][0];
1184 fPyjets->P[1][iGlu] = p2[isys][1];
1185 fPyjets->P[2][iGlu] = p2[isys][2];
1186 fPyjets->P[3][iGlu] = p2[isys][3];
1187 fPyjets->P[4][iGlu] = p2[isys][4];
1189 fPyjets->K[0][iGlu] = 1;
1190 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1191 fPyjets->K[1][iGlu] = 21;
1192 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1193 fPyjets->K[3][iGlu] = -1;
1194 fPyjets->K[4][iGlu] = -1;
1196 pg[0] += p2[isys][0];
1197 pg[1] += p2[isys][1];
1198 pg[2] += p2[isys][2];
1199 pg[3] += p2[isys][3];
1202 // Split gluon in rest frame.
1204 Double_t bx = p2[isys][0] / p2[isys][3];
1205 Double_t by = p2[isys][1] / p2[isys][3];
1206 Double_t bz = p2[isys][2] / p2[isys][3];
1207 Double_t pst = p2[isys][4] / 2.;
1209 // Isotropic decay ????
1210 Double_t cost = 2. * gRandom->Rndm() - 1.;
1211 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1212 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1214 Double_t pz1 = pst * cost;
1215 Double_t pz2 = -pst * cost;
1216 Double_t pt1 = pst * sint;
1217 Double_t pt2 = -pst * sint;
1218 Double_t px1 = pt1 * TMath::Cos(phis);
1219 Double_t py1 = pt1 * TMath::Sin(phis);
1220 Double_t px2 = pt2 * TMath::Cos(phis);
1221 Double_t py2 = pt2 * TMath::Sin(phis);
1223 fPyjets->P[0][iGlu] = px1;
1224 fPyjets->P[1][iGlu] = py1;
1225 fPyjets->P[2][iGlu] = pz1;
1226 fPyjets->P[3][iGlu] = pst;
1227 fPyjets->P[4][iGlu] = 0.;
1229 fPyjets->K[0][iGlu] = 1 ;
1230 fPyjets->K[1][iGlu] = 21;
1231 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1232 fPyjets->K[3][iGlu] = -1;
1233 fPyjets->K[4][iGlu] = -1;
1235 fPyjets->P[0][iGlu+1] = px2;
1236 fPyjets->P[1][iGlu+1] = py2;
1237 fPyjets->P[2][iGlu+1] = pz2;
1238 fPyjets->P[3][iGlu+1] = pst;
1239 fPyjets->P[4][iGlu+1] = 0.;
1241 fPyjets->K[0][iGlu+1] = 1;
1242 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1243 fPyjets->K[1][iGlu+1] = 21;
1244 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1245 fPyjets->K[3][iGlu+1] = -1;
1246 fPyjets->K[4][iGlu+1] = -1;
1252 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1255 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1256 Double_t px, py, pz;
1257 px = fPyjets->P[0][ig];
1258 py = fPyjets->P[1][ig];
1259 pz = fPyjets->P[2][ig];
1260 TVector3 v(px, py, pz);
1261 v.RotateZ(-phiq[isys]);
1262 v.RotateY(-thetaq[isys]);
1263 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1264 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1265 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1266 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1267 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1268 pxs += jtKick * TMath::Cos(phiKick);
1269 pys += jtKick * TMath::Sin(phiKick);
1270 TVector3 w(pxs, pys, pzs);
1271 w.RotateY(thetaq[isys]);
1272 w.RotateZ(phiq[isys]);
1273 fPyjets->P[0][ig] = w.X();
1274 fPyjets->P[1][ig] = w.Y();
1275 fPyjets->P[2][ig] = w.Z();
1276 fPyjets->P[2][ig] = w.Mag();
1282 // Check energy conservation
1286 Double_t es = 14000.;
1288 for (Int_t i = 0; i < numpart; i++)
1290 kst = fPyjets->K[0][i];
1291 if (kst != 1 && kst != 2) continue;
1292 pxs += fPyjets->P[0][i];
1293 pys += fPyjets->P[1][i];
1294 pzs += fPyjets->P[2][i];
1295 es -= fPyjets->P[3][i];
1297 if (TMath::Abs(pxs) > 1.e-2 ||
1298 TMath::Abs(pys) > 1.e-2 ||
1299 TMath::Abs(pzs) > 1.e-1) {
1300 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1301 // Fatal("Quench()", "4-Momentum non-conservation");
1304 } // end quenching loop (systems)
1306 for (Int_t i = 0; i < numpart; i++)
1308 imo = fPyjets->K[2][i];
1310 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1317 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1319 // Igor Lokthine's quenching routine
1320 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1325 void AliPythia::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1327 // Set the parameters for the PYQUEN package.
1328 // See comments in PyquenCommon.h
1334 PYQPAR.iengl = iengl;
1335 PYQPAR.iangl = iangl;
1339 void AliPythia::Pyevnw()
1341 // New multiple interaction scenario
1345 void AliPythia::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
1347 // Call medium-modified Pythia jet reconstruction algorithm
1349 pyshowq(ip1, ip2, qmax);
1351 void AliPythia::Qpygin0()
1353 // New multiple interaction scenario
1357 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1359 // Return event specific quenching parameters
1362 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1366 void AliPythia::ConfigHeavyFlavor()
1369 // Default configuration for Heavy Flavor production
1371 // All QCD processes
1377 // No multiple interactions
1382 // Initial/final parton shower on (Pythia default)
1386 // 2nd order alpha_s
1394 void AliPythia::AtlasTuning()
1397 // Configuration for the ATLAS tuning
1398 if (fItune > -1) return;
1399 printf("ATLAS TUNE \n");
1401 SetMSTP(51, AliStructFuncType::PDFsetIndex(kCTEQ5L)); // CTEQ5L pdf
1402 SetMSTP(81,1); // Multiple Interactions ON
1403 SetMSTP(82,4); // Double Gaussian Model
1404 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1405 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1406 SetPARP(89,1000.); // [GeV] Ref. energy
1407 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1408 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1409 SetPARP(84,0.5); // Core radius
1410 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1411 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1412 SetPARP(67,1); // Regulates Initial State Radiation
1415 void AliPythia::AtlasTuning_MC09()
1418 // Configuration for the ATLAS tuning
1419 if (fItune > -1) return;
1420 printf("ATLAS New TUNE MC09\n");
1421 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1422 SetMSTP(82, 4); // Double Gaussian Model
1423 SetMSTP(52, 2); // External PDF
1424 SetMSTP(51, 20650); // MRST LO*
1427 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1428 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1429 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1430 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1432 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1433 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1434 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1435 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1436 SetPARP(84, 0.7); // Core radius
1437 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1438 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1441 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1443 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1444 SetPARP(89,1800.); // [GeV] Ref. energy
1447 AliPythia& AliPythia::operator=(const AliPythia& rhs)
1449 // Assignment operator
1454 void AliPythia::Copy(TObject&) const
1459 Fatal("Copy","Not implemented!\n");
1462 void AliPythia::DalitzDecays()
1466 // Replace all omega dalitz decays with the correct matrix element decays
1468 Int_t nt = fPyjets->N;
1469 for (Int_t i = 0; i < nt; i++) {
1470 if (fPyjets->K[1][i] != 223) continue;
1471 Int_t fd = fPyjets->K[3][i] - 1;
1472 Int_t ld = fPyjets->K[4][i] - 1;
1473 if (fd < 0) continue;
1474 if ((ld - fd) != 2) continue;
1475 if ((fPyjets->K[1][fd] != 111) ||
1476 ((TMath::Abs(fPyjets->K[1][fd+1]) != 11) && (TMath::Abs(fPyjets->K[1][fd+1]) != 13)))
1478 TLorentzVector omega(fPyjets->P[0][i], fPyjets->P[1][i], fPyjets->P[2][i], fPyjets->P[3][i]);
1479 Int_t pdg = TMath::Abs(fPyjets->K[1][fd+1]);
1480 fOmegaDalitz.Decay(pdg, &omega);
1481 for (Int_t j = 0; j < 3; j++) {
1482 for (Int_t k = 0; k < 4; k++) {
1483 TLorentzVector vec = (fOmegaDalitz.Products())[2-j];
1484 fPyjets->P[k][fd+j] = vec[k];