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_
40 # define setpowwght setpowwght_
43 # define pyclus PYCLUS
44 # define pycell PYCELL
45 # define pyshow PYSHOW
46 # define pyshowq PYSHOWQ
47 # define pyrobo PYROBO
48 # define pyquen PYQUEN
49 # define pyevnw PYEVNW
50 # define pyjoin PYJOIN
51 # define qpygin0 QPYGIN0
52 # define setpowwght SETPOWWGHT
53 # define type_of_call _stdcall
56 extern "C" void type_of_call pyjoin(Int_t &, Int_t * );
57 extern "C" void type_of_call pyclus(Int_t & );
58 extern "C" void type_of_call pycell(Int_t & );
59 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
60 extern "C" void type_of_call pyshowq(Int_t &, Int_t &, Double_t &);
61 extern "C" void type_of_call qpygin0();
62 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
63 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
64 extern "C" void type_of_call pyevnw();
65 extern "C" void type_of_call setpowwght(Double_t &);
68 //_____________________________________________________________________________
70 AliPythia6* AliPythia6::fgAliPythia=NULL;
72 AliPythia6::AliPythia6():
87 // Default Constructor
91 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
92 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
93 for (i = 0; i < 4; i++) fZQuench[i] = 0;
95 if (!AliPythiaRndm::GetPythiaRandom())
96 AliPythiaRndm::SetPythiaRandom(GetRandom());
98 fQuenchingWeights = 0;
101 AliPythia6::AliPythia6(const AliPythia6& pythia):
118 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
119 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
120 for (i = 0; i < 4; i++) fZQuench[i] = 0;
124 void AliPythia6::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc, Int_t /*tune*/)
126 // Initialise the process to generate
127 if (!AliPythiaRndm::GetPythiaRandom())
128 AliPythiaRndm::SetPythiaRandom(GetRandom());
132 fStrucFunc = strucfunc;
133 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
134 SetMDCY(Pycomp(111) ,1,0);
135 SetMDCY(Pycomp(310) ,1,0);
136 SetMDCY(Pycomp(3122),1,0);
137 SetMDCY(Pycomp(3112),1,0);
138 SetMDCY(Pycomp(3212),1,0);
139 SetMDCY(Pycomp(3222),1,0);
140 SetMDCY(Pycomp(3312),1,0);
141 SetMDCY(Pycomp(3322),1,0);
142 SetMDCY(Pycomp(3334),1,0);
143 // Select structure function
145 SetMSTP(51,AliStructFuncType::PDFsetIndex(strucfunc));
146 // Particles produced in string fragmentation point directly to either of the two endpoints
147 // of the string (depending in the side they were generated from).
151 // Pythia initialisation for selected processes//
155 for (Int_t i=1; i<= 200; i++) {
158 // select charm production
161 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
162 // Multiple interactions on.
164 // Double Gaussian matter distribution.
170 // Reference energy for pT0 and energy rescaling pace.
173 // String drawing almost completely minimizes string length.
176 // ISR and FSR activity.
182 case kPyOldUEQ2ordered2:
183 // Old underlying events with Q2 ordered QCD processes
184 // Multiple interactions on.
186 // Double Gaussian matter distribution.
192 // Reference energy for pT0 and energy rescaling pace.
194 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
195 // String drawing almost completely minimizes string length.
198 // ISR and FSR activity.
205 // Old production mechanism: Old Popcorn
208 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
210 // (D=1)see can be used to form baryons (BARYON JUNCTION)
216 // heavy quark masses
246 case kPyCharmUnforced:
255 case kPyBeautyUnforced:
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
277 case kPyMbAtlasTuneMC09:
278 // Minimum Bias pp-Collisions
281 // select Pythia min. bias model
283 SetMSUB(92,1); // single diffraction AB-->XB
284 SetMSUB(93,1); // single diffraction AB-->AX
285 SetMSUB(94,1); // double diffraction
286 SetMSUB(95,1); // low pt production
291 case kPyMbWithDirectPhoton:
292 // Minimum Bias pp-Collisions with direct photon processes added
295 // select Pythia min. bias model
297 SetMSUB(92,1); // single diffraction AB-->XB
298 SetMSUB(93,1); // single diffraction AB-->AX
299 SetMSUB(94,1); // double diffraction
300 SetMSUB(95,1); // low pt production
313 // Minimum Bias pp-Collisions
316 // select Pythia min. bias model
318 SetMSUB(92,1); // single diffraction AB-->XB
319 SetMSUB(93,1); // single diffraction AB-->AX
320 SetMSUB(94,1); // double diffraction
321 SetMSUB(95,1); // low pt production
325 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
326 // -> Pythia 6.3 or above is needed
329 SetMSUB(92,1); // single diffraction AB-->XB
330 SetMSUB(93,1); // single diffraction AB-->AX
331 SetMSUB(94,1); // double diffraction
332 SetMSUB(95,1); // low pt production
333 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll));
337 SetMSTP(81,1); // Multiple Interactions ON
338 SetMSTP(82,4); // Double Gaussian Model
341 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
342 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
343 SetPARP(84,0.5); // Core radius
344 SetPARP(85,0.9); // Regulates gluon prod. mechanism
345 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
349 // Minimum Bias pp-Collisions
352 // select Pythia min. bias model
354 SetMSUB(95,1); // low pt production
361 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
362 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
363 SetPARP(93,5.); // Upper cut-off
365 SetPMAS(4,1,1.2); // Charm quark mass
366 SetPMAS(5,1,4.78); // Beauty quark mass
367 SetPARP(71,4.); // Defaut value
376 // Pythia Tune A (CDF)
378 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
379 SetMSTP(82,4); // Double Gaussian Model
380 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
381 SetPARP(84,0.4); // Core radius
382 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
383 SetPARP(86,0.95); // Regulates gluon prod. mechanism
384 SetPARP(89,1800.); // [GeV] Ref. energy
385 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
390 case kPyCharmPbPbMNR:
392 case kPyDPlusPbPbMNR:
393 case kPyDPlusStrangePbPbMNR:
394 // Tuning of Pythia parameters aimed to get a resonable agreement
395 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
396 // c-cbar single inclusive and double differential distributions.
397 // This parameter settings are meant to work with Pb-Pb collisions
398 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
399 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
400 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
412 case kPyDPlusStrangepPbMNR:
413 // Tuning of Pythia parameters aimed to get a resonable agreement
414 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
415 // c-cbar single inclusive and double differential distributions.
416 // This parameter settings are meant to work with p-Pb collisions
417 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
418 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
419 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
432 case kPyDPlusStrangeppMNR:
433 case kPyLambdacppMNR:
434 // Tuning of Pythia parameters aimed to get a resonable agreement
435 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
436 // c-cbar single inclusive and double differential distributions.
437 // This parameter settings are meant to work with pp collisions
438 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
439 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
440 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
450 case kPyCharmppMNRwmi:
451 // Tuning of Pythia parameters aimed to get a resonable agreement
452 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
453 // c-cbar single inclusive and double differential distributions.
454 // This parameter settings are meant to work with pp collisions
455 // and with kCTEQ5L PDFs.
456 // Added multiple interactions according to ATLAS tune settings.
457 // To get a "reasonable" agreement with MNR results, events have to be
458 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
460 // To get a "perfect" agreement with MNR results, events have to be
461 // generated in four ptHard bins with the following relative
477 case kPyBeautyPbPbMNR:
478 // Tuning of Pythia parameters aimed to get a resonable agreement
479 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
480 // b-bbar single inclusive and double differential distributions.
481 // This parameter settings are meant to work with Pb-Pb collisions
482 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
483 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
484 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
496 case kPyBeautypPbMNR:
497 // Tuning of Pythia parameters aimed to get a resonable agreement
498 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
499 // b-bbar single inclusive and double differential distributions.
500 // This parameter settings are meant to work with p-Pb collisions
501 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
502 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
503 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
516 // Tuning of Pythia parameters aimed to get a resonable agreement
517 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
518 // b-bbar single inclusive and double differential distributions.
519 // This parameter settings are meant to work with pp collisions
520 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
521 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
522 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
537 case kPyBeautyppMNRwmi:
538 // Tuning of Pythia parameters aimed to get a resonable agreement
539 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
540 // b-bbar single inclusive and double differential distributions.
541 // This parameter settings are meant to work with pp collisions
542 // and with kCTEQ5L PDFs.
543 // Added multiple interactions according to ATLAS tune settings.
544 // To get a "reasonable" agreement with MNR results, events have to be
545 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
547 // To get a "perfect" agreement with MNR results, events have to be
548 // generated in four ptHard bins with the following relative
571 //Inclusive production of W+/-
577 // //f fbar -> gamma W+
584 // Initial/final parton shower on (Pythia default)
585 // With parton showers on we are generating "W inclusive process"
586 SetMSTP(61,1); //Initial QCD & QED showers on
587 SetMSTP(71,1); //Final QCD & QED showers on
593 //Inclusive production of Z
598 // // f fbar -> g Z/gamma
600 // // f fbar -> gamma Z/gamma
602 // // f g -> f Z/gamma
604 // // f gamma -> f Z/gamma
607 //only Z included, not gamma
610 // Initial/final parton shower on (Pythia default)
611 // With parton showers on we are generating "Z inclusive process"
612 SetMSTP(61,1); //Initial QCD & QED showers on
613 SetMSTP(71,1); //Final QCD & QED showers on
616 //Inclusive production of Z
620 // Initial/final parton shower on (Pythia default)
621 // With parton showers on we are generating "Z inclusive process"
622 SetMSTP(61,1); //Initial QCD & QED showers on
623 SetMSTP(71,1); //Final QCD & QED showers on
625 case kPyMBRSingleDiffraction:
626 case kPyMBRDoubleDiffraction:
627 case kPyMBRCentralDiffraction:
632 // For the case of jet production the following parameter setting
633 // limits the transverse momentum of secondary scatterings, due
634 // to multiple parton interactions, to be less than that of the
635 // primary interaction (see POWHEG Dijet paper arXiv:1012.3380
636 // [hep-ph] sec. 4.1 and also the PYTHIA Manual).
638 // maximum number of errors before pythia aborts (def=10)
640 // number of warnings printed on the shell
646 // number of warnings printed on the shell
652 SetMSTP(41,1); // all resonance decays switched on
653 if (process == kPyJetsPWHG || process == kPyCharmPWHG || process == kPyBeautyPWHG || process == kPyWPWHG) {
654 Initialize("USER","","",0.);
656 Initialize("CMS",fProjectile,fTarget,fEcms);
660 Int_t AliPythia6::CheckedLuComp(Int_t kf)
662 // Check Lund particle code (for debugging)
667 void AliPythia6::SetNuclei(Int_t a1, Int_t a2)
669 // Treat protons as inside nuclei with mass numbers a1 and a2
670 // The MSTP array in the PYPARS common block is used to enable and
671 // select the nuclear structure functions.
672 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
673 // =1: internal PYTHIA acording to MSTP(51)
674 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
675 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
676 // MSTP(192) : Mass number of nucleus side 1
677 // MSTP(193) : Mass number of nucleus side 2
684 AliPythia6* AliPythia6::Instance()
686 // Set random number generator
690 fgAliPythia = new AliPythia6();
695 void AliPythia6::PrintParticles()
697 // Print list of particl properties
699 char* name = new char[16];
700 for (Int_t kf=0; kf<1000000; kf++) {
701 for (Int_t c = 1; c > -2; c-=2) {
702 Int_t kc = Pycomp(c*kf);
704 Float_t mass = GetPMAS(kc,1);
705 Float_t width = GetPMAS(kc,2);
706 Float_t tau = GetPMAS(kc,4);
712 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
713 c*kf, name, mass, width, tau);
717 printf("\n Number of particles %d \n \n", np);
720 void AliPythia6::ResetDecayTable()
722 // Set default values for pythia decay switches
724 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
725 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
728 void AliPythia6::SetDecayTable()
730 // Set default values for pythia decay switches
733 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
734 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
737 void AliPythia6::Pyjoin(Int_t& npart, Int_t *ipart)
739 // Call Pythia join alogorithm to set up a string between
740 // npart partons, given by indices in array ipart[npart]
742 pyjoin(npart, ipart);
745 void AliPythia6::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
747 // Call qPythia showering
749 pyshowq(ip1, ip2, qmax);
752 void AliPythia6::Qpygin0()
754 //position of the hard scattering in the nuclear overlapping area.
759 void AliPythia6::Pyclus(Int_t& njet)
761 // Call Pythia clustering algorithm
766 void AliPythia6::Pycell(Int_t& njet)
768 // Call Pythia jet reconstruction algorithm
773 void AliPythia6::GetJet(Int_t i, Float_t& px, Float_t& py, Float_t& pz, Float_t& e)
777 px = GetPyjets()->P[0][n+i];
778 py = GetPyjets()->P[1][n+i];
779 pz = GetPyjets()->P[2][n+i];
780 e = GetPyjets()->P[3][n+i];
783 void AliPythia6::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
785 // Call Pythia showering
787 pyshow(ip1, ip2, qmax);
790 void AliPythia6::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
792 pyrobo(imi, ima, the, phi, bex, bey, bez);
797 void AliPythia6::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
800 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
801 // (2) The nuclear geometry using the Glauber Model
804 fGlauber = AliFastGlauber::Instance();
806 fGlauber->SetCentralityClass(cMin, cMax);
808 fQuenchingWeights = new AliQuenchingWeights();
809 fQuenchingWeights->InitMult();
810 fQuenchingWeights->SetK(k);
811 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
818 void AliPythia6::Quench()
822 // Simple Jet Quenching routine:
823 // =============================
824 // The jet formed by all final state partons radiated by the parton created
825 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
826 // the initial parton reference frame:
827 // (E + p_z)new = (1-z) (E + p_z)old
832 // The lost momentum is first balanced by one gluon with virtuality > 0.
833 // Subsequently the gluon splits to yield two gluons with E = p.
837 static Float_t eMean = 0.;
838 static Int_t icall = 0;
843 Int_t klast[4] = {-1, -1, -1, -1};
845 Int_t numpart = fPyjets->N;
846 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
847 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
849 Double_t wjtKick[4] = {0., 0., 0., 0.};
855 // Sore information about Primary partons
858 // 0, 1 partons from hard scattering
859 // 2, 3 partons from initial state radiation
861 for (Int_t i = 2; i <= 7; i++) {
863 // Skip gluons that participate in hard scattering
864 if (i == 4 || i == 5) continue;
865 // Gluons from hard Scattering
866 if (i == 6 || i == 7) {
868 pxq[j] = fPyjets->P[0][i];
869 pyq[j] = fPyjets->P[1][i];
870 pzq[j] = fPyjets->P[2][i];
871 eq[j] = fPyjets->P[3][i];
872 mq[j] = fPyjets->P[4][i];
874 // Gluons from initial state radiation
876 // Obtain 4-momentum vector from difference between original parton and parton after gluon
877 // radiation. Energy is calculated independently because initial state radition does not
878 // conserve strictly momentum and energy for each partonic system independently.
880 // Not very clean. Should be improved !
884 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
885 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
886 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
887 mq[j] = fPyjets->P[4][i];
888 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
891 // Calculate some kinematic variables
893 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
894 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
895 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
896 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
897 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
898 qPdg[j] = fPyjets->K[1][i];
904 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
906 for (Int_t j = 0; j < 4; j++) {
908 // Quench only central jets and with E > 10.
912 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
913 // Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
914 Double_t eloss = fQuenchingWeights->GetELossRandomK(itype, int0[j], int1[j], eq[j]);
916 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
919 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
925 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
926 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
928 // Fractional energy loss
929 fZQuench[j] = eloss / eq[j];
931 // Avoid complete loss
933 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
935 // Some debug printing
938 // 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",
939 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
941 // fZQuench[j] = 0.8;
942 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
945 quenched[j] = (fZQuench[j] > 0.01);
950 Double_t pNew[1000][4];
957 for (Int_t isys = 0; isys < 4; isys++) {
958 // Skip to next system if not quenched.
959 if (!quenched[isys]) continue;
961 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
962 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
963 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
964 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
970 Double_t pg[4] = {0., 0., 0., 0.};
973 // Loop on radiation events
975 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
978 for (Int_t k = 0; k < 4; k++)
985 for (Int_t i = 0; i < numpart; i++)
987 imo = fPyjets->K[2][i];
988 kst = fPyjets->K[0][i];
989 pdg = fPyjets->K[1][i];
993 // Quarks and gluons only
994 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
995 // Particles from hard scattering only
997 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
998 Int_t imom = imo % 1000;
999 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
1000 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
1003 // Skip comment lines
1004 if (kst != 1 && kst != 2) continue;
1007 px = fPyjets->P[0][i];
1008 py = fPyjets->P[1][i];
1009 pz = fPyjets->P[2][i];
1010 e = fPyjets->P[3][i];
1011 m = fPyjets->P[4][i];
1012 pt = TMath::Sqrt(px * px + py * py);
1013 p = TMath::Sqrt(px * px + py * py + pz * pz);
1014 phi = TMath::Pi() + TMath::ATan2(-py, -px);
1015 theta = TMath::ATan2(pt, pz);
1018 // Save 4-momentum sum for balancing
1029 // Fractional energy loss
1030 Double_t z = zquench[index];
1033 // Don't fully quench radiated gluons
1036 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1041 // printf("z: %d %f\n", imo, z);
1048 // Transform into frame in which initial parton is along z-axis
1050 TVector3 v(px, py, pz);
1051 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1052 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1054 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1055 Double_t mt2 = jt * jt + m * m;
1058 // Kinematic limit on z
1060 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1062 // Change light-cone kinematics rel. to initial parton
1064 Double_t eppzOld = e + pl;
1065 Double_t empzOld = e - pl;
1067 Double_t eppzNew = (1. - z) * eppzOld;
1068 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1069 Double_t eNew = 0.5 * (eppzNew + empzNew);
1070 Double_t plNew = 0.5 * (eppzNew - empzNew);
1074 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1075 Double_t mt2New = eppzNew * empzNew;
1076 if (mt2New < 1.e-8) mt2New = 0.;
1078 if (m * m > mt2New) {
1080 // This should not happen
1082 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1085 jtNew = TMath::Sqrt(mt2New - m * m);
1088 // If pT is to small (probably a leading massive particle) we scale only the energy
1089 // This can cause negative masses of the radiated gluon
1090 // Let's hope for the best ...
1092 eNew = TMath::Sqrt(plNew * plNew + mt2);
1096 // Calculate new px, py
1102 pxNew = jtNew / jt * pxs;
1103 pyNew = jtNew / jt * pys;
1106 // Double_t dpx = pxs - pxNew;
1107 // Double_t dpy = pys - pyNew;
1108 // Double_t dpz = pl - plNew;
1109 // Double_t de = e - eNew;
1110 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1111 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1112 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1116 TVector3 w(pxNew, pyNew, plNew);
1117 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1118 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1120 p1[index][0] += pxNew;
1121 p1[index][1] += pyNew;
1122 p1[index][2] += plNew;
1123 p1[index][3] += eNew;
1125 // Updated 4-momentum vectors
1127 pNew[icount][0] = pxNew;
1128 pNew[icount][1] = pyNew;
1129 pNew[icount][2] = plNew;
1130 pNew[icount][3] = eNew;
1135 // Check if there was phase-space for quenching
1138 if (icount == 0) quenched[isys] = kFALSE;
1139 if (!quenched[isys]) break;
1141 for (Int_t j = 0; j < 4; j++)
1143 p2[isys][j] = p0[isys][j] - p1[isys][j];
1145 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];
1146 if (p2[isys][4] > 0.) {
1147 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1150 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1151 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]);
1152 if (p2[isys][4] < -0.01) {
1153 printf("Negative mass squared !\n");
1154 // Here we have to put the gluon back to mass shell
1155 // This will lead to a small energy imbalance
1157 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1166 printf("zHeavy lowered to %f\n", zHeavy);
1167 if (zHeavy < 0.01) {
1168 printf("No success ! \n");
1170 quenched[isys] = kFALSE;
1174 } // iteration on z (while)
1176 // Update event record
1177 for (Int_t k = 0; k < icount; k++) {
1178 // 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] );
1179 fPyjets->P[0][kNew[k]] = pNew[k][0];
1180 fPyjets->P[1][kNew[k]] = pNew[k][1];
1181 fPyjets->P[2][kNew[k]] = pNew[k][2];
1182 fPyjets->P[3][kNew[k]] = pNew[k][3];
1189 if (!quenched[isys]) continue;
1191 // Last parton from shower i
1192 Int_t in = klast[isys];
1194 // Continue if no parton in shower i selected
1195 if (in == -1) continue;
1197 // If this is the second initial parton and it is behind the first move pointer by previous ish
1198 if (isys == 1 && klast[1] > klast[0]) in += ish;
1203 // How many additional gluons will be generated
1205 if (p2[isys][4] > 0.05) ish = 2;
1207 // Position of gluons
1209 if (iglu == 0) igMin = iGlu;
1212 (fPyjets->N) += ish;
1215 fPyjets->P[0][iGlu] = p2[isys][0];
1216 fPyjets->P[1][iGlu] = p2[isys][1];
1217 fPyjets->P[2][iGlu] = p2[isys][2];
1218 fPyjets->P[3][iGlu] = p2[isys][3];
1219 fPyjets->P[4][iGlu] = p2[isys][4];
1221 fPyjets->K[0][iGlu] = 1;
1222 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1223 fPyjets->K[1][iGlu] = 21;
1224 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1225 fPyjets->K[3][iGlu] = -1;
1226 fPyjets->K[4][iGlu] = -1;
1228 pg[0] += p2[isys][0];
1229 pg[1] += p2[isys][1];
1230 pg[2] += p2[isys][2];
1231 pg[3] += p2[isys][3];
1234 // Split gluon in rest frame.
1236 Double_t bx = p2[isys][0] / p2[isys][3];
1237 Double_t by = p2[isys][1] / p2[isys][3];
1238 Double_t bz = p2[isys][2] / p2[isys][3];
1239 Double_t pst = p2[isys][4] / 2.;
1241 // Isotropic decay ????
1242 Double_t cost = 2. * gRandom->Rndm() - 1.;
1243 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1244 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1246 Double_t pz1 = pst * cost;
1247 Double_t pz2 = -pst * cost;
1248 Double_t pt1 = pst * sint;
1249 Double_t pt2 = -pst * sint;
1250 Double_t px1 = pt1 * TMath::Cos(phis);
1251 Double_t py1 = pt1 * TMath::Sin(phis);
1252 Double_t px2 = pt2 * TMath::Cos(phis);
1253 Double_t py2 = pt2 * TMath::Sin(phis);
1255 fPyjets->P[0][iGlu] = px1;
1256 fPyjets->P[1][iGlu] = py1;
1257 fPyjets->P[2][iGlu] = pz1;
1258 fPyjets->P[3][iGlu] = pst;
1259 fPyjets->P[4][iGlu] = 0.;
1261 fPyjets->K[0][iGlu] = 1 ;
1262 fPyjets->K[1][iGlu] = 21;
1263 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1264 fPyjets->K[3][iGlu] = -1;
1265 fPyjets->K[4][iGlu] = -1;
1267 fPyjets->P[0][iGlu+1] = px2;
1268 fPyjets->P[1][iGlu+1] = py2;
1269 fPyjets->P[2][iGlu+1] = pz2;
1270 fPyjets->P[3][iGlu+1] = pst;
1271 fPyjets->P[4][iGlu+1] = 0.;
1273 fPyjets->K[0][iGlu+1] = 1;
1274 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1275 fPyjets->K[1][iGlu+1] = 21;
1276 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1277 fPyjets->K[3][iGlu+1] = -1;
1278 fPyjets->K[4][iGlu+1] = -1;
1284 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1287 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1288 Double_t px, py, pz;
1289 px = fPyjets->P[0][ig];
1290 py = fPyjets->P[1][ig];
1291 pz = fPyjets->P[2][ig];
1292 TVector3 v(px, py, pz);
1293 v.RotateZ(-phiq[isys]);
1294 v.RotateY(-thetaq[isys]);
1295 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1296 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1297 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1298 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1299 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1300 pxs += jtKick * TMath::Cos(phiKick);
1301 pys += jtKick * TMath::Sin(phiKick);
1302 TVector3 w(pxs, pys, pzs);
1303 w.RotateY(thetaq[isys]);
1304 w.RotateZ(phiq[isys]);
1305 fPyjets->P[0][ig] = w.X();
1306 fPyjets->P[1][ig] = w.Y();
1307 fPyjets->P[2][ig] = w.Z();
1308 fPyjets->P[2][ig] = w.Mag();
1314 // Check energy conservation
1318 Double_t es = 14000.;
1320 for (Int_t i = 0; i < numpart; i++)
1322 kst = fPyjets->K[0][i];
1323 if (kst != 1 && kst != 2) continue;
1324 pxs += fPyjets->P[0][i];
1325 pys += fPyjets->P[1][i];
1326 pzs += fPyjets->P[2][i];
1327 es -= fPyjets->P[3][i];
1329 if (TMath::Abs(pxs) > 1.e-2 ||
1330 TMath::Abs(pys) > 1.e-2 ||
1331 TMath::Abs(pzs) > 1.e-1) {
1332 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1333 // Fatal("Quench()", "4-Momentum non-conservation");
1336 } // end quenching loop (systems)
1338 for (Int_t i = 0; i < numpart; i++)
1340 imo = fPyjets->K[2][i];
1342 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1349 void AliPythia6::Pyquen(Double_t a, Int_t ibf, Double_t b)
1351 // Igor Lokthine's quenching routine
1352 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1357 void AliPythia6::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1359 // Set the parameters for the PYQUEN package.
1360 // See comments in PyquenCommon.h
1366 PYQPAR.iengl = iengl;
1367 PYQPAR.iangl = iangl;
1370 void AliPythia6::LoadEvent(AliStack* stack, Int_t flag, Int_t reHadr)
1373 // Load event into Pythia Common Block
1376 Int_t npart = stack -> GetNprimary();
1380 GetPyjets()->N = npart;
1382 n0 = GetPyjets()->N;
1383 GetPyjets()->N = n0 + npart;
1387 for (Int_t part = 0; part < npart; part++) {
1388 TParticle *mPart = stack->Particle(part);
1390 Int_t kf = mPart->GetPdgCode();
1391 Int_t ks = mPart->GetStatusCode();
1392 Int_t idf = mPart->GetFirstDaughter();
1393 Int_t idl = mPart->GetLastDaughter();
1396 if (ks == 11 || ks == 12) {
1403 Float_t px = mPart->Px();
1404 Float_t py = mPart->Py();
1405 Float_t pz = mPart->Pz();
1406 Float_t e = mPart->Energy();
1407 Float_t m = mPart->GetCalcMass();
1410 (GetPyjets())->P[0][part+n0] = px;
1411 (GetPyjets())->P[1][part+n0] = py;
1412 (GetPyjets())->P[2][part+n0] = pz;
1413 (GetPyjets())->P[3][part+n0] = e;
1414 (GetPyjets())->P[4][part+n0] = m;
1416 (GetPyjets())->K[1][part+n0] = kf;
1417 (GetPyjets())->K[0][part+n0] = ks;
1418 (GetPyjets())->K[3][part+n0] = idf + 1;
1419 (GetPyjets())->K[4][part+n0] = idl + 1;
1420 (GetPyjets())->K[2][part+n0] = mPart->GetFirstMother() + 1;
1425 void AliPythia6::Pyevnw()
1427 // New multiple interaction scenario
1431 void AliPythia6::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1433 // Return event specific quenching parameters
1436 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1440 void AliPythia6::ConfigHeavyFlavor()
1443 // Default configuration for Heavy Flavor production
1445 // All QCD processes
1449 // No multiple interactions
1453 // Initial/final parton shower on (Pythia default)
1457 // 2nd order alpha_s
1465 void AliPythia6::AtlasTuning()
1468 // Configuration for the ATLAS tuning
1469 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ5L));
1470 SetMSTP(81,1); // Multiple Interactions ON
1471 SetMSTP(82,4); // Double Gaussian Model
1472 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1473 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1474 SetPARP(89,1000.); // [GeV] Ref. energy
1475 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1476 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1477 SetPARP(84,0.5); // Core radius
1478 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1479 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1480 SetPARP(67,1); // Regulates Initial State Radiation
1483 void AliPythia6::AtlasTuningMC09()
1486 // Configuration for the ATLAS tuning
1487 printf("ATLAS New TUNE MC09\n");
1488 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1489 SetMSTP(82, 4); // Double Gaussian Model
1490 SetMSTP(52, 2); // External PDF
1491 SetMSTP(51, 20650); // MRST LO*
1494 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1495 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1496 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1497 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1499 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1500 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1501 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1502 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1503 SetPARP(84, 0.7); // Core radius
1504 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1505 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1508 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1510 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1511 SetPARP(89,1800.); // [GeV] Ref. energy
1514 void AliPythia6::SetWeightPower(Double_t pow)
1517 SetMSTP(142, 1); // Tell Pythia to use pyevwt to calculate event wghts
1520 void AliPythia6::SetPtHardRange(Float_t ptmin, Float_t ptmax)
1522 // Set the pt hard range
1527 void AliPythia6::SetYHardRange(Float_t ymin, Float_t ymax)
1529 // Set the y hard range
1535 void AliPythia6::SetFragmentation(Int_t flag)
1537 // Switch fragmentation on/off
1541 void AliPythia6::SetInitialAndFinalStateRadiation(Int_t flag1, Int_t flag2)
1543 // initial state radiation
1545 // final state radiation
1549 void AliPythia6::SetIntrinsicKt(Float_t kt)
1551 // Set the inreinsic kt
1555 SetPARP(93, 4. * kt);
1561 void AliPythia6::SwitchHFOff()
1563 // Switch off heavy flavor
1564 // Maximum number of quark flavours used in pdf
1566 // Maximum number of flavors that can be used in showers
1570 void AliPythia6::SetPycellParameters(Float_t etamax, Int_t neta, Int_t nphi,
1571 Float_t thresh, Float_t etseed, Float_t minet, Float_t r)
1573 // Set pycell parameters
1574 SetPARU(51, etamax);
1577 SetPARU(58, thresh);
1578 SetPARU(52, etseed);
1584 void AliPythia6::ModifiedSplitting()
1586 // Modified splitting probability as a model for quenching
1588 SetMSTJ(41, 1); // QCD radiation only
1589 SetMSTJ(42, 2); // angular ordering
1590 SetMSTJ(44, 2); // option to run alpha_s
1591 SetMSTJ(47, 0); // No correction back to hard scattering element
1592 SetMSTJ(50, 0); // No coherence in first branching
1593 SetPARJ(82, 1.); // Cut off for parton showers
1596 void AliPythia6::SwitchHadronisationOff()
1598 // Switch off hadronisarion
1602 void AliPythia6::SwitchHadronisationOn()
1604 // Switch on hadronisarion
1609 void AliPythia6::GetXandQ(Float_t& x1, Float_t& x2, Float_t& q)
1611 // Get x1, x2 and Q for this event
1618 Float_t AliPythia6::GetXSection()
1620 // Get the total cross-section
1621 return (GetPARI(1));
1624 Float_t AliPythia6::GetPtHard()
1626 // Get the pT hard for this event
1630 Int_t AliPythia6::ProcessCode()
1632 // Get the subprocess code
1636 void AliPythia6::PrintStatistics()
1638 // End of run statistics
1642 void AliPythia6::EventListing()
1644 // End of run statistics
1648 AliPythia6& AliPythia6::operator=(const AliPythia6& rhs)
1650 // Assignment operator
1655 void AliPythia6::Copy(TObject&) const
1660 Fatal("Copy","Not implemented!\n");