2 /**************************************************************************
3 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
5 * Author: The ALICE Off-line Project. *
6 * Contributors are mentioned in the code where appropriate. *
8 * Permission to use, copy, modify and distribute this software and its *
9 * documentation strictly for non-commercial purposes is hereby granted *
10 * without fee, provided that the above copyright notice appears in all *
11 * copies and that both the copyright notice and this permission notice *
12 * appear in the supporting documentation. The authors make no claims *
13 * about the suitability of this software for any purpose. It is *
14 * provided "as is" without express or implied warranty. *
15 **************************************************************************/
19 #include "AliPythia.h"
20 #include "AliPythiaRndm.h"
21 #include "AliFastGlauber.h"
22 #include "AliQuenchingWeights.h"
24 #include "PyquenCommon.h"
29 # define pyclus pyclus_
30 # define pycell pycell_
31 # define pyshow pyshow_
32 # define pyrobo pyrobo_
33 # define pyquen pyquen_
34 # define pyevnw pyevnw_
35 # define pyshowq pyshowq_
36 # define pytune pytune_
37 # define py2ent py2ent_
40 # define pyclus PYCLUS
41 # define pycell PYCELL
42 # define pyrobo PYROBO
43 # define pyquen PYQUEN
44 # define pyevnw PYEVNW
45 # define pyshowq PYSHOWQ
46 # define pytune PYTUNE
47 # define py2ent PY2ENT
48 # define type_of_call _stdcall
51 extern "C" void type_of_call pyclus(Int_t & );
52 extern "C" void type_of_call pycell(Int_t & );
53 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
54 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
55 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
56 extern "C" void type_of_call pyevnw(){;}
57 extern "C" void type_of_call pyshowq(Int_t &, Int_t &, Double_t &);
58 extern "C" void type_of_call pytune(Int_t &);
59 extern "C" void type_of_call py2ent(Int_t &, Int_t&, Int_t&, Double_t&);
61 //_____________________________________________________________________________
63 AliPythia* AliPythia::fgAliPythia=NULL;
65 AliPythia::AliPythia():
77 // Default Constructor
80 if (!AliPythiaRndm::GetPythiaRandom())
81 AliPythiaRndm::SetPythiaRandom(GetRandom());
83 fQuenchingWeights = 0;
86 AliPythia::AliPythia(const AliPythia& pythia):
104 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc, Int_t itune)
106 // Initialise the process to generate
107 if (!AliPythiaRndm::GetPythiaRandom())
108 AliPythiaRndm::SetPythiaRandom(GetRandom());
114 fStrucFunc = strucfunc;
115 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
116 SetMDCY(Pycomp(111) ,1,0); // pi0
117 SetMDCY(Pycomp(310) ,1,0); // K0S
118 SetMDCY(Pycomp(3122),1,0); // kLambda
119 SetMDCY(Pycomp(3112),1,0); // sigma -
120 SetMDCY(Pycomp(3212),1,0); // sigma 0
121 SetMDCY(Pycomp(3222),1,0); // sigma +
122 SetMDCY(Pycomp(3312),1,0); // xi -
123 SetMDCY(Pycomp(3322),1,0); // xi 0
124 SetMDCY(Pycomp(3334),1,0); // omega-
125 // Select structure function
127 SetMSTP(51, AliStructFuncType::PDFsetIndex(strucfunc));
128 // Particles produced in string fragmentation point directly to either of the two endpoints
129 // of the string (depending in the side they were generated from).
133 // Pythia initialisation for selected processes//
137 for (Int_t i=1; i<= 200; i++) {
140 // select charm production
143 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
144 // Multiple interactions on.
146 // Double Gaussian matter distribution.
152 // Reference energy for pT0 and energy rescaling pace.
155 // String drawing almost completely minimizes string length.
158 // ISR and FSR activity.
164 case kPyOldUEQ2ordered2:
165 // Old underlying events with Q2 ordered QCD processes
166 // Multiple interactions on.
168 // Double Gaussian matter distribution.
174 // Reference energy for pT0 and energy rescaling pace.
176 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
177 // String drawing almost completely minimizes string length.
180 // ISR and FSR activity.
187 // Old production mechanism: Old Popcorn
190 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
192 // (D=1)see can be used to form baryons (BARYON JUNCTION)
198 // heavy quark masses
228 case kPyCharmUnforced:
237 case kPyBeautyUnforced:
247 // Minimum Bias pp-Collisions
250 // select Pythia min. bias model
252 SetMSUB(92,1); // single diffraction AB-->XB
253 SetMSUB(93,1); // single diffraction AB-->AX
254 SetMSUB(94,1); // double diffraction
255 SetMSUB(95,1); // low pt production
260 case kPyMbAtlasTuneMC09:
261 // Minimum Bias pp-Collisions
264 // select Pythia min. bias model
266 SetMSUB(92,1); // single diffraction AB-->XB
267 SetMSUB(93,1); // single diffraction AB-->AX
268 SetMSUB(94,1); // double diffraction
269 SetMSUB(95,1); // low pt production
274 case kPyMbWithDirectPhoton:
275 // Minimum Bias pp-Collisions with direct photon processes added
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
296 // Minimum Bias pp-Collisions
299 // select Pythia min. bias model
301 SetMSUB(92,1); // single diffraction AB-->XB
302 SetMSUB(93,1); // single diffraction AB-->AX
303 SetMSUB(94,1); // double diffraction
304 SetMSUB(95,1); // low pt production
307 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
308 // -> Pythia 6.3 or above is needed
311 SetMSUB(92,1); // single diffraction AB-->XB
312 SetMSUB(93,1); // single diffraction AB-->AX
313 SetMSUB(94,1); // double diffraction
314 SetMSUB(95,1); // low pt production
316 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll)); // CTEQ6ll pdf
320 SetMSTP(81,1); // Multiple Interactions ON
321 SetMSTP(82,4); // Double Gaussian Model
324 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
325 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
326 SetPARP(84,0.5); // Core radius
327 SetPARP(85,0.9); // Regulates gluon prod. mechanism
328 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
332 // Minimum Bias pp-Collisions
335 // select Pythia min. bias model
337 SetMSUB(95,1); // low pt production
344 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
345 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
346 SetPARP(93,5.); // Upper cut-off
348 SetPMAS(4,1,1.2); // Charm quark mass
349 SetPMAS(5,1,4.78); // Beauty quark mass
350 SetPARP(71,4.); // Defaut value
359 // Pythia Tune A (CDF)
361 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
362 SetMSTP(82,4); // Double Gaussian Model
363 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
364 SetPARP(84,0.4); // Core radius
365 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
366 SetPARP(86,0.95); // Regulates gluon prod. mechanism
367 SetPARP(89,1800.); // [GeV] Ref. energy
368 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
373 case kPyCharmPbPbMNR:
375 case kPyDPlusPbPbMNR:
376 case kPyDPlusStrangePbPbMNR:
377 // Tuning of Pythia parameters aimed to get a resonable agreement
378 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
379 // c-cbar single inclusive and double differential distributions.
380 // This parameter settings are meant to work with Pb-Pb collisions
381 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
382 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
383 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
395 case kPyDPlusStrangepPbMNR:
396 // Tuning of Pythia parameters aimed to get a resonable agreement
397 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
398 // c-cbar single inclusive and double differential distributions.
399 // This parameter settings are meant to work with p-Pb collisions
400 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
401 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
402 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
415 case kPyDPlusStrangeppMNR:
416 // Tuning of Pythia parameters aimed to get a resonable agreement
417 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
418 // c-cbar single inclusive and double differential distributions.
419 // This parameter settings are meant to work with pp collisions
420 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
421 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
422 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
432 case kPyCharmppMNRwmi:
433 // Tuning of Pythia parameters aimed to get a resonable agreement
434 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
435 // c-cbar single inclusive and double differential distributions.
436 // This parameter settings are meant to work with pp collisions
437 // and with kCTEQ5L PDFs.
438 // Added multiple interactions according to ATLAS tune settings.
439 // To get a "reasonable" agreement with MNR results, events have to be
440 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
442 // To get a "perfect" agreement with MNR results, events have to be
443 // generated in four ptHard bins with the following relative
459 case kPyBeautyPbPbMNR:
460 // Tuning of Pythia parameters aimed to get a resonable agreement
461 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
462 // b-bbar single inclusive and double differential distributions.
463 // This parameter settings are meant to work with Pb-Pb collisions
464 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
465 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
466 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
478 case kPyBeautypPbMNR:
479 // Tuning of Pythia parameters aimed to get a resonable agreement
480 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
481 // b-bbar single inclusive and double differential distributions.
482 // This parameter settings are meant to work with p-Pb collisions
483 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
484 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
485 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
498 // Tuning of Pythia parameters aimed to get a resonable agreement
499 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
500 // b-bbar single inclusive and double differential distributions.
501 // This parameter settings are meant to work with pp collisions
502 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
503 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
504 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
519 case kPyBeautyppMNRwmi:
520 // Tuning of Pythia parameters aimed to get a resonable agreement
521 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
522 // b-bbar single inclusive and double differential distributions.
523 // This parameter settings are meant to work with pp collisions
524 // and with kCTEQ5L PDFs.
525 // Added multiple interactions according to ATLAS tune settings.
526 // To get a "reasonable" agreement with MNR results, events have to be
527 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
529 // To get a "perfect" agreement with MNR results, events have to be
530 // generated in four ptHard bins with the following relative
553 //Inclusive production of W+/-
559 // //f fbar -> gamma W+
566 // Initial/final parton shower on (Pythia default)
567 // With parton showers on we are generating "W inclusive process"
568 SetMSTP(61,1); //Initial QCD & QED showers on
569 SetMSTP(71,1); //Final QCD & QED showers on
575 //Inclusive production of Z
580 // // f fbar -> g Z/gamma
582 // // f fbar -> gamma Z/gamma
584 // // f g -> f Z/gamma
586 // // f gamma -> f Z/gamma
589 //only Z included, not gamma
592 // Initial/final parton shower on (Pythia default)
593 // With parton showers on we are generating "Z inclusive process"
594 SetMSTP(61,1); //Initial QCD & QED showers on
595 SetMSTP(71,1); //Final QCD & QED showers on
604 if (itune > -1) Pytune(itune);
607 SetMSTP(41,1); // all resonance decays switched on
608 Initialize("CMS","p","p",fEcms);
612 Int_t AliPythia::CheckedLuComp(Int_t kf)
614 // Check Lund particle code (for debugging)
616 printf("\n Lucomp kf,kc %d %d",kf,kc);
620 void AliPythia::SetNuclei(Int_t a1, Int_t a2, Int_t pdf)
622 // Treat protons as inside nuclei with mass numbers a1 and a2
623 // The MSTP array in the PYPARS common block is used to enable and
624 // select the nuclear structure functions.
625 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
626 // =1: internal PYTHIA acording to MSTP(51)
627 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
628 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
629 // MSTP(192) : Mass number of nucleus side 1
630 // MSTP(193) : Mass number of nucleus side 2
631 // MSTP(194) : Nuclear structure function: 0: EKS98 1:EPS08
639 AliPythia* AliPythia::Instance()
641 // Set random number generator
645 fgAliPythia = new AliPythia();
650 void AliPythia::PrintParticles()
652 // Print list of particl properties
654 char* name = new char[16];
655 for (Int_t kf=0; kf<1000000; kf++) {
656 for (Int_t c = 1; c > -2; c-=2) {
657 Int_t kc = Pycomp(c*kf);
659 Float_t mass = GetPMAS(kc,1);
660 Float_t width = GetPMAS(kc,2);
661 Float_t tau = GetPMAS(kc,4);
667 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
668 c*kf, name, mass, width, tau);
672 printf("\n Number of particles %d \n \n", np);
675 void AliPythia::ResetDecayTable()
677 // Set default values for pythia decay switches
679 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
680 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
683 void AliPythia::SetDecayTable()
685 // Set default values for pythia decay switches
688 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
689 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
692 void AliPythia::Pyclus(Int_t& njet)
694 // Call Pythia clustering algorithm
699 void AliPythia::Pycell(Int_t& njet)
701 // Call Pythia jet reconstruction algorithm
706 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
708 // Call Pythia jet reconstruction algorithm
710 pyshow(ip1, ip2, qmax);
713 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
715 pyrobo(imi, ima, the, phi, bex, bey, bez);
718 void AliPythia::Pytune(Int_t itune)
722 C ITUNE NAME (detailed descriptions below)
723 C 0 Default : No settings changed => linked Pythia version's defaults.
724 C ====== Old UE, Q2-ordered showers ==========================================
725 C 100 A : Rick Field's CDF Tune A
726 C 101 AW : Rick Field's CDF Tune AW
727 C 102 BW : Rick Field's CDF Tune BW
728 C 103 DW : Rick Field's CDF Tune DW
729 C 104 DWT : Rick Field's CDF Tune DW with slower UE energy scaling
730 C 105 QW : Rick Field's CDF Tune QW (NB: needs CTEQ6.1M pdfs externally)
731 C 106 ATLAS-DC2: Arthur Moraes' (old) ATLAS tune (ATLAS DC2 / Rome)
732 C 107 ACR : Tune A modified with annealing CR
733 C 108 D6 : Rick Field's CDF Tune D6 (NB: needs CTEQ6L pdfs externally)
734 C 109 D6T : Rick Field's CDF Tune D6T (NB: needs CTEQ6L pdfs externally)
735 C ====== Intermediate Models =================================================
736 C 200 IM 1 : Intermediate model: new UE, Q2-ordered showers, annealing CR
737 C 201 APT : Tune A modified to use pT-ordered final-state showers
738 C ====== New UE, interleaved pT-ordered showers, annealing CR ================
739 C 300 S0 : Sandhoff-Skands Tune 0
740 C 301 S1 : Sandhoff-Skands Tune 1
741 C 302 S2 : Sandhoff-Skands Tune 2
742 C 303 S0A : S0 with "Tune A" UE energy scaling
743 C 304 NOCR : New UE "best try" without colour reconnections
744 C 305 Old : New UE, original (primitive) colour reconnections
745 C 306 ATLAS-CSC: Arthur Moraes' (new) ATLAS tune (needs CTEQ6L externally)
746 C ======= The Uppsala models =================================================
747 C ( NB! must be run with special modified Pythia 6.215 version )
748 C ( available from http://www.isv.uu.se/thep/MC/scigal/ )
749 C 400 GAL 0 : Generalized area-law model. Old parameters
750 C 401 SCI 0 : Soft-Colour-Interaction model. Old parameters
751 C 402 GAL 1 : Generalized area-law model. Tevatron MB retuned (Skands)
756 void AliPythia::Py2ent(Int_t idx, Int_t pdg1, Int_t pdg2, Double_t p){
757 // Inset 2-parton system at line idx
758 py2ent(idx, pdg1, pdg2, p);
762 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
765 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
766 // (2) The nuclear geometry using the Glauber Model
769 fGlauber = AliFastGlauber::Instance();
771 fGlauber->SetCentralityClass(cMin, cMax);
773 fQuenchingWeights = new AliQuenchingWeights();
774 fQuenchingWeights->InitMult();
775 fQuenchingWeights->SetK(k);
776 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
783 void AliPythia::Quench()
787 // Simple Jet Quenching routine:
788 // =============================
789 // The jet formed by all final state partons radiated by the parton created
790 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
791 // the initial parton reference frame:
792 // (E + p_z)new = (1-z) (E + p_z)old
797 // The lost momentum is first balanced by one gluon with virtuality > 0.
798 // Subsequently the gluon splits to yield two gluons with E = p.
802 static Float_t eMean = 0.;
803 static Int_t icall = 0;
808 Int_t klast[4] = {-1, -1, -1, -1};
810 Int_t numpart = fPyjets->N;
811 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
812 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
820 // Sore information about Primary partons
823 // 0, 1 partons from hard scattering
824 // 2, 3 partons from initial state radiation
826 for (Int_t i = 2; i <= 7; i++) {
828 // Skip gluons that participate in hard scattering
829 if (i == 4 || i == 5) continue;
830 // Gluons from hard Scattering
831 if (i == 6 || i == 7) {
833 pxq[j] = fPyjets->P[0][i];
834 pyq[j] = fPyjets->P[1][i];
835 pzq[j] = fPyjets->P[2][i];
836 eq[j] = fPyjets->P[3][i];
837 mq[j] = fPyjets->P[4][i];
839 // Gluons from initial state radiation
841 // Obtain 4-momentum vector from difference between original parton and parton after gluon
842 // radiation. Energy is calculated independently because initial state radition does not
843 // conserve strictly momentum and energy for each partonic system independently.
845 // Not very clean. Should be improved !
849 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
850 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
851 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
852 mq[j] = fPyjets->P[4][i];
853 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
856 // Calculate some kinematic variables
858 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
859 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
860 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
861 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
862 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
863 qPdg[j] = fPyjets->K[1][i];
869 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
871 for (Int_t j = 0; j < 4; j++) {
873 // Quench only central jets and with E > 10.
877 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
878 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
880 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
883 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
889 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
890 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
892 // Fractional energy loss
893 fZQuench[j] = eloss / eq[j];
895 // Avoid complete loss
897 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
899 // Some debug printing
902 // 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",
903 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
905 // fZQuench[j] = 0.8;
906 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
909 quenched[j] = (fZQuench[j] > 0.01);
914 Double_t pNew[1000][4];
921 for (Int_t isys = 0; isys < 4; isys++) {
922 // Skip to next system if not quenched.
923 if (!quenched[isys]) continue;
925 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
926 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
927 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
928 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
934 Double_t pg[4] = {0., 0., 0., 0.};
937 // Loop on radiation events
939 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
942 for (Int_t k = 0; k < 4; k++)
949 for (Int_t i = 0; i < numpart; i++)
951 imo = fPyjets->K[2][i];
952 kst = fPyjets->K[0][i];
953 pdg = fPyjets->K[1][i];
957 // Quarks and gluons only
958 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
959 // Particles from hard scattering only
961 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
962 Int_t imom = imo % 1000;
963 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
964 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
967 // Skip comment lines
968 if (kst != 1 && kst != 2) continue;
971 px = fPyjets->P[0][i];
972 py = fPyjets->P[1][i];
973 pz = fPyjets->P[2][i];
974 e = fPyjets->P[3][i];
975 m = fPyjets->P[4][i];
976 pt = TMath::Sqrt(px * px + py * py);
977 p = TMath::Sqrt(px * px + py * py + pz * pz);
978 phi = TMath::Pi() + TMath::ATan2(-py, -px);
979 theta = TMath::ATan2(pt, pz);
982 // Save 4-momentum sum for balancing
993 // Fractional energy loss
994 Double_t z = zquench[index];
997 // Don't fully quench radiated gluons
1000 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1005 // printf("z: %d %f\n", imo, z);
1012 // Transform into frame in which initial parton is along z-axis
1014 TVector3 v(px, py, pz);
1015 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1016 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1018 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1019 Double_t mt2 = jt * jt + m * m;
1022 // Kinematic limit on z
1024 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1026 // Change light-cone kinematics rel. to initial parton
1028 Double_t eppzOld = e + pl;
1029 Double_t empzOld = e - pl;
1031 Double_t eppzNew = (1. - z) * eppzOld;
1032 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1033 Double_t eNew = 0.5 * (eppzNew + empzNew);
1034 Double_t plNew = 0.5 * (eppzNew - empzNew);
1038 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1039 Double_t mt2New = eppzNew * empzNew;
1040 if (mt2New < 1.e-8) mt2New = 0.;
1042 if (m * m > mt2New) {
1044 // This should not happen
1046 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1049 jtNew = TMath::Sqrt(mt2New - m * m);
1052 // If pT is to small (probably a leading massive particle) we scale only the energy
1053 // This can cause negative masses of the radiated gluon
1054 // Let's hope for the best ...
1056 eNew = TMath::Sqrt(plNew * plNew + mt2);
1060 // Calculate new px, py
1066 pxNew = jtNew / jt * pxs;
1067 pyNew = jtNew / jt * pys;
1069 // Double_t dpx = pxs - pxNew;
1070 // Double_t dpy = pys - pyNew;
1071 // Double_t dpz = pl - plNew;
1072 // Double_t de = e - eNew;
1073 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1074 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1075 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1079 TVector3 w(pxNew, pyNew, plNew);
1080 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1081 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1083 p1[index][0] += pxNew;
1084 p1[index][1] += pyNew;
1085 p1[index][2] += plNew;
1086 p1[index][3] += eNew;
1088 // Updated 4-momentum vectors
1090 pNew[icount][0] = pxNew;
1091 pNew[icount][1] = pyNew;
1092 pNew[icount][2] = plNew;
1093 pNew[icount][3] = eNew;
1098 // Check if there was phase-space for quenching
1101 if (icount == 0) quenched[isys] = kFALSE;
1102 if (!quenched[isys]) break;
1104 for (Int_t j = 0; j < 4; j++)
1106 p2[isys][j] = p0[isys][j] - p1[isys][j];
1108 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];
1109 if (p2[isys][4] > 0.) {
1110 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1113 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1114 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]);
1115 if (p2[isys][4] < -0.01) {
1116 printf("Negative mass squared !\n");
1117 // Here we have to put the gluon back to mass shell
1118 // This will lead to a small energy imbalance
1120 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1129 printf("zHeavy lowered to %f\n", zHeavy);
1130 if (zHeavy < 0.01) {
1131 printf("No success ! \n");
1133 quenched[isys] = kFALSE;
1137 } // iteration on z (while)
1139 // Update event record
1140 for (Int_t k = 0; k < icount; k++) {
1141 // 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] );
1142 fPyjets->P[0][kNew[k]] = pNew[k][0];
1143 fPyjets->P[1][kNew[k]] = pNew[k][1];
1144 fPyjets->P[2][kNew[k]] = pNew[k][2];
1145 fPyjets->P[3][kNew[k]] = pNew[k][3];
1152 if (!quenched[isys]) continue;
1154 // Last parton from shower i
1155 Int_t in = klast[isys];
1157 // Continue if no parton in shower i selected
1158 if (in == -1) continue;
1160 // If this is the second initial parton and it is behind the first move pointer by previous ish
1161 if (isys == 1 && klast[1] > klast[0]) in += ish;
1166 // How many additional gluons will be generated
1168 if (p2[isys][4] > 0.05) ish = 2;
1170 // Position of gluons
1172 if (iglu == 0) igMin = iGlu;
1175 (fPyjets->N) += ish;
1178 fPyjets->P[0][iGlu] = p2[isys][0];
1179 fPyjets->P[1][iGlu] = p2[isys][1];
1180 fPyjets->P[2][iGlu] = p2[isys][2];
1181 fPyjets->P[3][iGlu] = p2[isys][3];
1182 fPyjets->P[4][iGlu] = p2[isys][4];
1184 fPyjets->K[0][iGlu] = 1;
1185 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1186 fPyjets->K[1][iGlu] = 21;
1187 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1188 fPyjets->K[3][iGlu] = -1;
1189 fPyjets->K[4][iGlu] = -1;
1191 pg[0] += p2[isys][0];
1192 pg[1] += p2[isys][1];
1193 pg[2] += p2[isys][2];
1194 pg[3] += p2[isys][3];
1197 // Split gluon in rest frame.
1199 Double_t bx = p2[isys][0] / p2[isys][3];
1200 Double_t by = p2[isys][1] / p2[isys][3];
1201 Double_t bz = p2[isys][2] / p2[isys][3];
1202 Double_t pst = p2[isys][4] / 2.;
1204 // Isotropic decay ????
1205 Double_t cost = 2. * gRandom->Rndm() - 1.;
1206 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1207 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1209 Double_t pz1 = pst * cost;
1210 Double_t pz2 = -pst * cost;
1211 Double_t pt1 = pst * sint;
1212 Double_t pt2 = -pst * sint;
1213 Double_t px1 = pt1 * TMath::Cos(phis);
1214 Double_t py1 = pt1 * TMath::Sin(phis);
1215 Double_t px2 = pt2 * TMath::Cos(phis);
1216 Double_t py2 = pt2 * TMath::Sin(phis);
1218 fPyjets->P[0][iGlu] = px1;
1219 fPyjets->P[1][iGlu] = py1;
1220 fPyjets->P[2][iGlu] = pz1;
1221 fPyjets->P[3][iGlu] = pst;
1222 fPyjets->P[4][iGlu] = 0.;
1224 fPyjets->K[0][iGlu] = 1 ;
1225 fPyjets->K[1][iGlu] = 21;
1226 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1227 fPyjets->K[3][iGlu] = -1;
1228 fPyjets->K[4][iGlu] = -1;
1230 fPyjets->P[0][iGlu+1] = px2;
1231 fPyjets->P[1][iGlu+1] = py2;
1232 fPyjets->P[2][iGlu+1] = pz2;
1233 fPyjets->P[3][iGlu+1] = pst;
1234 fPyjets->P[4][iGlu+1] = 0.;
1236 fPyjets->K[0][iGlu+1] = 1;
1237 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1238 fPyjets->K[1][iGlu+1] = 21;
1239 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1240 fPyjets->K[3][iGlu+1] = -1;
1241 fPyjets->K[4][iGlu+1] = -1;
1247 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1250 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1251 Double_t px, py, pz;
1252 px = fPyjets->P[0][ig];
1253 py = fPyjets->P[1][ig];
1254 pz = fPyjets->P[2][ig];
1255 TVector3 v(px, py, pz);
1256 v.RotateZ(-phiq[isys]);
1257 v.RotateY(-thetaq[isys]);
1258 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1259 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1260 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1261 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1262 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1263 pxs += jtKick * TMath::Cos(phiKick);
1264 pys += jtKick * TMath::Sin(phiKick);
1265 TVector3 w(pxs, pys, pzs);
1266 w.RotateY(thetaq[isys]);
1267 w.RotateZ(phiq[isys]);
1268 fPyjets->P[0][ig] = w.X();
1269 fPyjets->P[1][ig] = w.Y();
1270 fPyjets->P[2][ig] = w.Z();
1271 fPyjets->P[2][ig] = w.Mag();
1277 // Check energy conservation
1281 Double_t es = 14000.;
1283 for (Int_t i = 0; i < numpart; i++)
1285 kst = fPyjets->K[0][i];
1286 if (kst != 1 && kst != 2) continue;
1287 pxs += fPyjets->P[0][i];
1288 pys += fPyjets->P[1][i];
1289 pzs += fPyjets->P[2][i];
1290 es -= fPyjets->P[3][i];
1292 if (TMath::Abs(pxs) > 1.e-2 ||
1293 TMath::Abs(pys) > 1.e-2 ||
1294 TMath::Abs(pzs) > 1.e-1) {
1295 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1296 // Fatal("Quench()", "4-Momentum non-conservation");
1299 } // end quenching loop (systems)
1301 for (Int_t i = 0; i < numpart; i++)
1303 imo = fPyjets->K[2][i];
1305 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1312 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1314 // Igor Lokthine's quenching routine
1315 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1320 void AliPythia::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1322 // Set the parameters for the PYQUEN package.
1323 // See comments in PyquenCommon.h
1329 PYQPAR.iengl = iengl;
1330 PYQPAR.iangl = iangl;
1334 void AliPythia::Pyevnw()
1336 // New multiple interaction scenario
1340 void AliPythia::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
1342 // Call medium-modified Pythia jet reconstruction algorithm
1344 pyshowq(ip1, ip2, qmax);
1347 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1349 // Return event specific quenching parameters
1352 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1356 void AliPythia::ConfigHeavyFlavor()
1359 // Default configuration for Heavy Flavor production
1361 // All QCD processes
1365 // No multiple interactions
1369 // Initial/final parton shower on (Pythia default)
1373 // 2nd order alpha_s
1381 void AliPythia::AtlasTuning()
1384 // Configuration for the ATLAS tuning
1385 if (fItune > -1) return;
1386 printf("ATLAS TUNE \n");
1388 SetMSTP(51, AliStructFuncType::PDFsetIndex(kCTEQ5L)); // CTEQ5L pdf
1389 SetMSTP(81,1); // Multiple Interactions ON
1390 SetMSTP(82,4); // Double Gaussian Model
1391 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1392 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1393 SetPARP(89,1000.); // [GeV] Ref. energy
1394 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1395 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1396 SetPARP(84,0.5); // Core radius
1397 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1398 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1399 SetPARP(67,1); // Regulates Initial State Radiation
1402 void AliPythia::AtlasTuning_MC09()
1405 // Configuration for the ATLAS tuning
1406 if (fItune > -1) return;
1407 printf("ATLAS New TUNE MC09\n");
1408 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1409 SetMSTP(82, 4); // Double Gaussian Model
1410 SetMSTP(52, 2); // External PDF
1411 SetMSTP(51, 20650); // MRST LO*
1414 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1415 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1416 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1417 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1419 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1420 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1421 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1422 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1423 SetPARP(84, 0.7); // Core radius
1424 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1425 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1428 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1430 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1431 SetPARP(89,1800.); // [GeV] Ref. energy
1434 AliPythia& AliPythia::operator=(const AliPythia& rhs)
1436 // Assignment operator
1441 void AliPythia::Copy(TObject&) const
1446 Fatal("Copy","Not implemented!\n");