1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
16 /* $Id: AliPythia.cxx,v 1.40 2007/10/09 08:43:24 morsch Exp $ */
18 #include "AliPythia6.h"
20 #include "AliPythiaRndm.h"
21 #include "AliFastGlauber.h"
22 #include "AliQuenchingWeights.h"
25 #include "TParticle.h"
26 #include "PyquenCommon.h"
31 # define pyclus pyclus_
32 # define pycell pycell_
33 # define pyshow pyshow_
34 # define pyshowq pyshowq_
35 # define pyrobo pyrobo_
36 # define pyquen pyquen_
37 # define pyevnw pyevnw_
38 # define pyjoin pyjoin_
39 # define qpygin0 qpygin0_
42 # define pyclus PYCLUS
43 # define pycell PYCELL
44 # define pyshow PYSHOW
45 # define pyshowq PYSHOWQ
46 # define pyrobo PYROBO
47 # define pyquen PYQUEN
48 # define pyevnw PYEVNW
49 # define pyjoin PYJOIN
50 # define qpygin0 QPYGIN0
51 # define type_of_call _stdcall
54 extern "C" void type_of_call pyjoin(Int_t &, Int_t * );
55 extern "C" void type_of_call pyclus(Int_t & );
56 extern "C" void type_of_call pycell(Int_t & );
57 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
58 extern "C" void type_of_call pyshowq(Int_t &, Int_t &, Double_t &);
59 extern "C" void type_of_call qpygin0();
60 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
61 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
62 extern "C" void type_of_call pyevnw();
65 //_____________________________________________________________________________
67 AliPythia6* AliPythia6::fgAliPythia=NULL;
69 AliPythia6::AliPythia6():
82 // Default Constructor
86 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
87 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
88 for (i = 0; i < 4; i++) fZQuench[i] = 0;
90 if (!AliPythiaRndm::GetPythiaRandom())
91 AliPythiaRndm::SetPythiaRandom(GetRandom());
93 fQuenchingWeights = 0;
96 AliPythia6::AliPythia6(const AliPythia6& pythia):
111 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
112 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
113 for (i = 0; i < 4; i++) fZQuench[i] = 0;
117 void AliPythia6::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc, Int_t /*tune*/)
119 // Initialise the process to generate
120 if (!AliPythiaRndm::GetPythiaRandom())
121 AliPythiaRndm::SetPythiaRandom(GetRandom());
125 fStrucFunc = strucfunc;
126 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
127 SetMDCY(Pycomp(111) ,1,0);
128 SetMDCY(Pycomp(310) ,1,0);
129 SetMDCY(Pycomp(3122),1,0);
130 SetMDCY(Pycomp(3112),1,0);
131 SetMDCY(Pycomp(3212),1,0);
132 SetMDCY(Pycomp(3222),1,0);
133 SetMDCY(Pycomp(3312),1,0);
134 SetMDCY(Pycomp(3322),1,0);
135 SetMDCY(Pycomp(3334),1,0);
136 // Select structure function
138 SetMSTP(51,AliStructFuncType::PDFsetIndex(strucfunc));
139 // Particles produced in string fragmentation point directly to either of the two endpoints
140 // of the string (depending in the side they were generated from).
144 // Pythia initialisation for selected processes//
148 for (Int_t i=1; i<= 200; i++) {
151 // select charm production
154 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
155 // Multiple interactions on.
157 // Double Gaussian matter distribution.
163 // Reference energy for pT0 and energy rescaling pace.
166 // String drawing almost completely minimizes string length.
169 // ISR and FSR activity.
175 case kPyOldUEQ2ordered2:
176 // Old underlying events with Q2 ordered QCD processes
177 // Multiple interactions on.
179 // Double Gaussian matter distribution.
185 // Reference energy for pT0 and energy rescaling pace.
187 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
188 // String drawing almost completely minimizes string length.
191 // ISR and FSR activity.
198 // Old production mechanism: Old Popcorn
201 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
203 // (D=1)see can be used to form baryons (BARYON JUNCTION)
209 // heavy quark masses
239 case kPyCharmUnforced:
248 case kPyBeautyUnforced:
258 // Minimum Bias pp-Collisions
261 // select Pythia min. bias model
263 SetMSUB(92,1); // single diffraction AB-->XB
264 SetMSUB(93,1); // single diffraction AB-->AX
265 SetMSUB(94,1); // double diffraction
266 SetMSUB(95,1); // low pt production
270 case kPyMbAtlasTuneMC09:
271 // Minimum Bias pp-Collisions
274 // select Pythia min. bias model
276 SetMSUB(92,1); // single diffraction AB-->XB
277 SetMSUB(93,1); // single diffraction AB-->AX
278 SetMSUB(94,1); // double diffraction
279 SetMSUB(95,1); // low pt production
284 case kPyMbWithDirectPhoton:
285 // Minimum Bias pp-Collisions with direct photon processes added
288 // select Pythia min. bias model
290 SetMSUB(92,1); // single diffraction AB-->XB
291 SetMSUB(93,1); // single diffraction AB-->AX
292 SetMSUB(94,1); // double diffraction
293 SetMSUB(95,1); // low pt production
306 // Minimum Bias pp-Collisions
309 // select Pythia min. bias model
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
318 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
319 // -> Pythia 6.3 or above is needed
322 SetMSUB(92,1); // single diffraction AB-->XB
323 SetMSUB(93,1); // single diffraction AB-->AX
324 SetMSUB(94,1); // double diffraction
325 SetMSUB(95,1); // low pt production
326 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll));
330 SetMSTP(81,1); // Multiple Interactions ON
331 SetMSTP(82,4); // Double Gaussian Model
334 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
335 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
336 SetPARP(84,0.5); // Core radius
337 SetPARP(85,0.9); // Regulates gluon prod. mechanism
338 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
342 // Minimum Bias pp-Collisions
345 // select Pythia min. bias model
347 SetMSUB(95,1); // low pt production
354 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
355 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
356 SetPARP(93,5.); // Upper cut-off
358 SetPMAS(4,1,1.2); // Charm quark mass
359 SetPMAS(5,1,4.78); // Beauty quark mass
360 SetPARP(71,4.); // Defaut value
369 // Pythia Tune A (CDF)
371 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
372 SetMSTP(82,4); // Double Gaussian Model
373 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
374 SetPARP(84,0.4); // Core radius
375 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
376 SetPARP(86,0.95); // Regulates gluon prod. mechanism
377 SetPARP(89,1800.); // [GeV] Ref. energy
378 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
383 case kPyCharmPbPbMNR:
385 case kPyDPlusPbPbMNR:
386 case kPyDPlusStrangePbPbMNR:
387 // Tuning of Pythia parameters aimed to get a resonable agreement
388 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
389 // c-cbar single inclusive and double differential distributions.
390 // This parameter settings are meant to work with Pb-Pb collisions
391 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
392 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
393 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
405 case kPyDPlusStrangepPbMNR:
406 // Tuning of Pythia parameters aimed to get a resonable agreement
407 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
408 // c-cbar single inclusive and double differential distributions.
409 // This parameter settings are meant to work with p-Pb collisions
410 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
411 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
412 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
425 case kPyDPlusStrangeppMNR:
426 case kPyLambdacppMNR:
427 // Tuning of Pythia parameters aimed to get a resonable agreement
428 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
429 // c-cbar single inclusive and double differential distributions.
430 // This parameter settings are meant to work with pp collisions
431 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
432 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
433 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
443 case kPyCharmppMNRwmi:
444 // Tuning of Pythia parameters aimed to get a resonable agreement
445 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
446 // c-cbar single inclusive and double differential distributions.
447 // This parameter settings are meant to work with pp collisions
448 // and with kCTEQ5L PDFs.
449 // Added multiple interactions according to ATLAS tune settings.
450 // To get a "reasonable" agreement with MNR results, events have to be
451 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
453 // To get a "perfect" agreement with MNR results, events have to be
454 // generated in four ptHard bins with the following relative
470 case kPyBeautyPbPbMNR:
471 // Tuning of Pythia parameters aimed to get a resonable agreement
472 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
473 // b-bbar single inclusive and double differential distributions.
474 // This parameter settings are meant to work with Pb-Pb collisions
475 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
476 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
477 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
489 case kPyBeautypPbMNR:
490 // Tuning of Pythia parameters aimed to get a resonable agreement
491 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
492 // b-bbar single inclusive and double differential distributions.
493 // This parameter settings are meant to work with p-Pb collisions
494 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
495 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
496 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
509 // Tuning of Pythia parameters aimed to get a resonable agreement
510 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
511 // b-bbar single inclusive and double differential distributions.
512 // This parameter settings are meant to work with pp collisions
513 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
514 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
515 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
530 case kPyBeautyppMNRwmi:
531 // Tuning of Pythia parameters aimed to get a resonable agreement
532 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
533 // b-bbar single inclusive and double differential distributions.
534 // This parameter settings are meant to work with pp collisions
535 // and with kCTEQ5L PDFs.
536 // Added multiple interactions according to ATLAS tune settings.
537 // To get a "reasonable" agreement with MNR results, events have to be
538 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
540 // To get a "perfect" agreement with MNR results, events have to be
541 // generated in four ptHard bins with the following relative
564 //Inclusive production of W+/-
570 // //f fbar -> gamma W+
577 // Initial/final parton shower on (Pythia default)
578 // With parton showers on we are generating "W inclusive process"
579 SetMSTP(61,1); //Initial QCD & QED showers on
580 SetMSTP(71,1); //Final QCD & QED showers on
586 //Inclusive production of Z
591 // // f fbar -> g Z/gamma
593 // // f fbar -> gamma Z/gamma
595 // // f g -> f Z/gamma
597 // // f gamma -> f Z/gamma
600 //only Z included, not gamma
603 // Initial/final parton shower on (Pythia default)
604 // With parton showers on we are generating "Z inclusive process"
605 SetMSTP(61,1); //Initial QCD & QED showers on
606 SetMSTP(71,1); //Final QCD & QED showers on
608 case kPyMBRSingleDiffraction:
609 case kPyMBRDoubleDiffraction:
610 case kPyMBRCentralDiffraction:
616 SetMSTP(41,1); // all resonance decays switched on
617 Initialize("CMS","p","p",fEcms);
621 Int_t AliPythia6::CheckedLuComp(Int_t kf)
623 // Check Lund particle code (for debugging)
628 void AliPythia6::SetNuclei(Int_t a1, Int_t a2)
630 // Treat protons as inside nuclei with mass numbers a1 and a2
631 // The MSTP array in the PYPARS common block is used to enable and
632 // select the nuclear structure functions.
633 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
634 // =1: internal PYTHIA acording to MSTP(51)
635 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
636 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
637 // MSTP(192) : Mass number of nucleus side 1
638 // MSTP(193) : Mass number of nucleus side 2
645 AliPythia6* AliPythia6::Instance()
647 // Set random number generator
651 fgAliPythia = new AliPythia6();
656 void AliPythia6::PrintParticles()
658 // Print list of particl properties
660 char* name = new char[16];
661 for (Int_t kf=0; kf<1000000; kf++) {
662 for (Int_t c = 1; c > -2; c-=2) {
663 Int_t kc = Pycomp(c*kf);
665 Float_t mass = GetPMAS(kc,1);
666 Float_t width = GetPMAS(kc,2);
667 Float_t tau = GetPMAS(kc,4);
673 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
674 c*kf, name, mass, width, tau);
678 printf("\n Number of particles %d \n \n", np);
681 void AliPythia6::ResetDecayTable()
683 // Set default values for pythia decay switches
685 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
686 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
689 void AliPythia6::SetDecayTable()
691 // Set default values for pythia decay switches
694 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
695 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
698 void AliPythia6::Pyjoin(Int_t& npart, Int_t *ipart)
700 // Call Pythia join alogorithm to set up a string between
701 // npart partons, given by indices in array ipart[npart]
703 pyjoin(npart, ipart);
706 void AliPythia6::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
708 // Call qPythia showering
710 pyshowq(ip1, ip2, qmax);
713 void AliPythia6::Qpygin0()
715 //position of the hard scattering in the nuclear overlapping area.
720 void AliPythia6::Pyclus(Int_t& njet)
722 // Call Pythia clustering algorithm
727 void AliPythia6::Pycell(Int_t& njet)
729 // Call Pythia jet reconstruction algorithm
734 void AliPythia6::GetJet(Int_t i, Float_t& px, Float_t& py, Float_t& pz, Float_t& e)
738 px = GetPyjets()->P[0][n+i];
739 py = GetPyjets()->P[1][n+i];
740 pz = GetPyjets()->P[2][n+i];
741 e = GetPyjets()->P[3][n+i];
744 void AliPythia6::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
746 // Call Pythia showering
748 pyshow(ip1, ip2, qmax);
751 void AliPythia6::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
753 pyrobo(imi, ima, the, phi, bex, bey, bez);
758 void AliPythia6::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
761 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
762 // (2) The nuclear geometry using the Glauber Model
765 fGlauber = AliFastGlauber::Instance();
767 fGlauber->SetCentralityClass(cMin, cMax);
769 fQuenchingWeights = new AliQuenchingWeights();
770 fQuenchingWeights->InitMult();
771 fQuenchingWeights->SetK(k);
772 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
779 void AliPythia6::Quench()
783 // Simple Jet Quenching routine:
784 // =============================
785 // The jet formed by all final state partons radiated by the parton created
786 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
787 // the initial parton reference frame:
788 // (E + p_z)new = (1-z) (E + p_z)old
793 // The lost momentum is first balanced by one gluon with virtuality > 0.
794 // Subsequently the gluon splits to yield two gluons with E = p.
798 static Float_t eMean = 0.;
799 static Int_t icall = 0;
804 Int_t klast[4] = {-1, -1, -1, -1};
806 Int_t numpart = fPyjets->N;
807 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
808 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
810 Double_t wjtKick[4] = {0., 0., 0., 0.};
816 // Sore information about Primary partons
819 // 0, 1 partons from hard scattering
820 // 2, 3 partons from initial state radiation
822 for (Int_t i = 2; i <= 7; i++) {
824 // Skip gluons that participate in hard scattering
825 if (i == 4 || i == 5) continue;
826 // Gluons from hard Scattering
827 if (i == 6 || i == 7) {
829 pxq[j] = fPyjets->P[0][i];
830 pyq[j] = fPyjets->P[1][i];
831 pzq[j] = fPyjets->P[2][i];
832 eq[j] = fPyjets->P[3][i];
833 mq[j] = fPyjets->P[4][i];
835 // Gluons from initial state radiation
837 // Obtain 4-momentum vector from difference between original parton and parton after gluon
838 // radiation. Energy is calculated independently because initial state radition does not
839 // conserve strictly momentum and energy for each partonic system independently.
841 // Not very clean. Should be improved !
845 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
846 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
847 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
848 mq[j] = fPyjets->P[4][i];
849 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
852 // Calculate some kinematic variables
854 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
855 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
856 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
857 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
858 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
859 qPdg[j] = fPyjets->K[1][i];
865 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
867 for (Int_t j = 0; j < 4; j++) {
869 // Quench only central jets and with E > 10.
873 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
874 // Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
875 Double_t eloss = fQuenchingWeights->GetELossRandomK(itype, int0[j], int1[j], eq[j]);
877 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
880 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
886 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
887 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
889 // Fractional energy loss
890 fZQuench[j] = eloss / eq[j];
892 // Avoid complete loss
894 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
896 // Some debug printing
899 // 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",
900 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
902 // fZQuench[j] = 0.8;
903 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
906 quenched[j] = (fZQuench[j] > 0.01);
911 Double_t pNew[1000][4];
918 for (Int_t isys = 0; isys < 4; isys++) {
919 // Skip to next system if not quenched.
920 if (!quenched[isys]) continue;
922 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
923 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
924 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
925 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
931 Double_t pg[4] = {0., 0., 0., 0.};
934 // Loop on radiation events
936 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
939 for (Int_t k = 0; k < 4; k++)
946 for (Int_t i = 0; i < numpart; i++)
948 imo = fPyjets->K[2][i];
949 kst = fPyjets->K[0][i];
950 pdg = fPyjets->K[1][i];
954 // Quarks and gluons only
955 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
956 // Particles from hard scattering only
958 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
959 Int_t imom = imo % 1000;
960 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
961 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
964 // Skip comment lines
965 if (kst != 1 && kst != 2) continue;
968 px = fPyjets->P[0][i];
969 py = fPyjets->P[1][i];
970 pz = fPyjets->P[2][i];
971 e = fPyjets->P[3][i];
972 m = fPyjets->P[4][i];
973 pt = TMath::Sqrt(px * px + py * py);
974 p = TMath::Sqrt(px * px + py * py + pz * pz);
975 phi = TMath::Pi() + TMath::ATan2(-py, -px);
976 theta = TMath::ATan2(pt, pz);
979 // Save 4-momentum sum for balancing
990 // Fractional energy loss
991 Double_t z = zquench[index];
994 // Don't fully quench radiated gluons
997 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1002 // printf("z: %d %f\n", imo, z);
1009 // Transform into frame in which initial parton is along z-axis
1011 TVector3 v(px, py, pz);
1012 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1013 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1015 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1016 Double_t mt2 = jt * jt + m * m;
1019 // Kinematic limit on z
1021 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1023 // Change light-cone kinematics rel. to initial parton
1025 Double_t eppzOld = e + pl;
1026 Double_t empzOld = e - pl;
1028 Double_t eppzNew = (1. - z) * eppzOld;
1029 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1030 Double_t eNew = 0.5 * (eppzNew + empzNew);
1031 Double_t plNew = 0.5 * (eppzNew - empzNew);
1035 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1036 Double_t mt2New = eppzNew * empzNew;
1037 if (mt2New < 1.e-8) mt2New = 0.;
1039 if (m * m > mt2New) {
1041 // This should not happen
1043 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1046 jtNew = TMath::Sqrt(mt2New - m * m);
1049 // If pT is to small (probably a leading massive particle) we scale only the energy
1050 // This can cause negative masses of the radiated gluon
1051 // Let's hope for the best ...
1053 eNew = TMath::Sqrt(plNew * plNew + mt2);
1057 // Calculate new px, py
1063 pxNew = jtNew / jt * pxs;
1064 pyNew = jtNew / jt * pys;
1067 // Double_t dpx = pxs - pxNew;
1068 // Double_t dpy = pys - pyNew;
1069 // Double_t dpz = pl - plNew;
1070 // Double_t de = e - eNew;
1071 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1072 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1073 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1077 TVector3 w(pxNew, pyNew, plNew);
1078 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1079 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1081 p1[index][0] += pxNew;
1082 p1[index][1] += pyNew;
1083 p1[index][2] += plNew;
1084 p1[index][3] += eNew;
1086 // Updated 4-momentum vectors
1088 pNew[icount][0] = pxNew;
1089 pNew[icount][1] = pyNew;
1090 pNew[icount][2] = plNew;
1091 pNew[icount][3] = eNew;
1096 // Check if there was phase-space for quenching
1099 if (icount == 0) quenched[isys] = kFALSE;
1100 if (!quenched[isys]) break;
1102 for (Int_t j = 0; j < 4; j++)
1104 p2[isys][j] = p0[isys][j] - p1[isys][j];
1106 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];
1107 if (p2[isys][4] > 0.) {
1108 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1111 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1112 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]);
1113 if (p2[isys][4] < -0.01) {
1114 printf("Negative mass squared !\n");
1115 // Here we have to put the gluon back to mass shell
1116 // This will lead to a small energy imbalance
1118 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1127 printf("zHeavy lowered to %f\n", zHeavy);
1128 if (zHeavy < 0.01) {
1129 printf("No success ! \n");
1131 quenched[isys] = kFALSE;
1135 } // iteration on z (while)
1137 // Update event record
1138 for (Int_t k = 0; k < icount; k++) {
1139 // 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] );
1140 fPyjets->P[0][kNew[k]] = pNew[k][0];
1141 fPyjets->P[1][kNew[k]] = pNew[k][1];
1142 fPyjets->P[2][kNew[k]] = pNew[k][2];
1143 fPyjets->P[3][kNew[k]] = pNew[k][3];
1150 if (!quenched[isys]) continue;
1152 // Last parton from shower i
1153 Int_t in = klast[isys];
1155 // Continue if no parton in shower i selected
1156 if (in == -1) continue;
1158 // If this is the second initial parton and it is behind the first move pointer by previous ish
1159 if (isys == 1 && klast[1] > klast[0]) in += ish;
1164 // How many additional gluons will be generated
1166 if (p2[isys][4] > 0.05) ish = 2;
1168 // Position of gluons
1170 if (iglu == 0) igMin = iGlu;
1173 (fPyjets->N) += ish;
1176 fPyjets->P[0][iGlu] = p2[isys][0];
1177 fPyjets->P[1][iGlu] = p2[isys][1];
1178 fPyjets->P[2][iGlu] = p2[isys][2];
1179 fPyjets->P[3][iGlu] = p2[isys][3];
1180 fPyjets->P[4][iGlu] = p2[isys][4];
1182 fPyjets->K[0][iGlu] = 1;
1183 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1184 fPyjets->K[1][iGlu] = 21;
1185 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1186 fPyjets->K[3][iGlu] = -1;
1187 fPyjets->K[4][iGlu] = -1;
1189 pg[0] += p2[isys][0];
1190 pg[1] += p2[isys][1];
1191 pg[2] += p2[isys][2];
1192 pg[3] += p2[isys][3];
1195 // Split gluon in rest frame.
1197 Double_t bx = p2[isys][0] / p2[isys][3];
1198 Double_t by = p2[isys][1] / p2[isys][3];
1199 Double_t bz = p2[isys][2] / p2[isys][3];
1200 Double_t pst = p2[isys][4] / 2.;
1202 // Isotropic decay ????
1203 Double_t cost = 2. * gRandom->Rndm() - 1.;
1204 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1205 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1207 Double_t pz1 = pst * cost;
1208 Double_t pz2 = -pst * cost;
1209 Double_t pt1 = pst * sint;
1210 Double_t pt2 = -pst * sint;
1211 Double_t px1 = pt1 * TMath::Cos(phis);
1212 Double_t py1 = pt1 * TMath::Sin(phis);
1213 Double_t px2 = pt2 * TMath::Cos(phis);
1214 Double_t py2 = pt2 * TMath::Sin(phis);
1216 fPyjets->P[0][iGlu] = px1;
1217 fPyjets->P[1][iGlu] = py1;
1218 fPyjets->P[2][iGlu] = pz1;
1219 fPyjets->P[3][iGlu] = pst;
1220 fPyjets->P[4][iGlu] = 0.;
1222 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 fPyjets->P[0][iGlu+1] = px2;
1229 fPyjets->P[1][iGlu+1] = py2;
1230 fPyjets->P[2][iGlu+1] = pz2;
1231 fPyjets->P[3][iGlu+1] = pst;
1232 fPyjets->P[4][iGlu+1] = 0.;
1234 fPyjets->K[0][iGlu+1] = 1;
1235 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1236 fPyjets->K[1][iGlu+1] = 21;
1237 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1238 fPyjets->K[3][iGlu+1] = -1;
1239 fPyjets->K[4][iGlu+1] = -1;
1245 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1248 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1249 Double_t px, py, pz;
1250 px = fPyjets->P[0][ig];
1251 py = fPyjets->P[1][ig];
1252 pz = fPyjets->P[2][ig];
1253 TVector3 v(px, py, pz);
1254 v.RotateZ(-phiq[isys]);
1255 v.RotateY(-thetaq[isys]);
1256 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1257 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1258 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1259 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1260 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1261 pxs += jtKick * TMath::Cos(phiKick);
1262 pys += jtKick * TMath::Sin(phiKick);
1263 TVector3 w(pxs, pys, pzs);
1264 w.RotateY(thetaq[isys]);
1265 w.RotateZ(phiq[isys]);
1266 fPyjets->P[0][ig] = w.X();
1267 fPyjets->P[1][ig] = w.Y();
1268 fPyjets->P[2][ig] = w.Z();
1269 fPyjets->P[2][ig] = w.Mag();
1275 // Check energy conservation
1279 Double_t es = 14000.;
1281 for (Int_t i = 0; i < numpart; i++)
1283 kst = fPyjets->K[0][i];
1284 if (kst != 1 && kst != 2) continue;
1285 pxs += fPyjets->P[0][i];
1286 pys += fPyjets->P[1][i];
1287 pzs += fPyjets->P[2][i];
1288 es -= fPyjets->P[3][i];
1290 if (TMath::Abs(pxs) > 1.e-2 ||
1291 TMath::Abs(pys) > 1.e-2 ||
1292 TMath::Abs(pzs) > 1.e-1) {
1293 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1294 // Fatal("Quench()", "4-Momentum non-conservation");
1297 } // end quenching loop (systems)
1299 for (Int_t i = 0; i < numpart; i++)
1301 imo = fPyjets->K[2][i];
1303 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1310 void AliPythia6::Pyquen(Double_t a, Int_t ibf, Double_t b)
1312 // Igor Lokthine's quenching routine
1313 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1318 void AliPythia6::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1320 // Set the parameters for the PYQUEN package.
1321 // See comments in PyquenCommon.h
1327 PYQPAR.iengl = iengl;
1328 PYQPAR.iangl = iangl;
1331 void AliPythia6::LoadEvent(AliStack* stack, Int_t flag, Int_t reHadr)
1334 // Load event into Pythia Common Block
1337 Int_t npart = stack -> GetNprimary();
1341 GetPyjets()->N = npart;
1343 n0 = GetPyjets()->N;
1344 GetPyjets()->N = n0 + npart;
1348 for (Int_t part = 0; part < npart; part++) {
1349 TParticle *mPart = stack->Particle(part);
1351 Int_t kf = mPart->GetPdgCode();
1352 Int_t ks = mPart->GetStatusCode();
1353 Int_t idf = mPart->GetFirstDaughter();
1354 Int_t idl = mPart->GetLastDaughter();
1357 if (ks == 11 || ks == 12) {
1364 Float_t px = mPart->Px();
1365 Float_t py = mPart->Py();
1366 Float_t pz = mPart->Pz();
1367 Float_t e = mPart->Energy();
1368 Float_t m = mPart->GetCalcMass();
1371 (GetPyjets())->P[0][part+n0] = px;
1372 (GetPyjets())->P[1][part+n0] = py;
1373 (GetPyjets())->P[2][part+n0] = pz;
1374 (GetPyjets())->P[3][part+n0] = e;
1375 (GetPyjets())->P[4][part+n0] = m;
1377 (GetPyjets())->K[1][part+n0] = kf;
1378 (GetPyjets())->K[0][part+n0] = ks;
1379 (GetPyjets())->K[3][part+n0] = idf + 1;
1380 (GetPyjets())->K[4][part+n0] = idl + 1;
1381 (GetPyjets())->K[2][part+n0] = mPart->GetFirstMother() + 1;
1386 void AliPythia6::Pyevnw()
1388 // New multiple interaction scenario
1392 void AliPythia6::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1394 // Return event specific quenching parameters
1397 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1401 void AliPythia6::ConfigHeavyFlavor()
1404 // Default configuration for Heavy Flavor production
1406 // All QCD processes
1410 // No multiple interactions
1414 // Initial/final parton shower on (Pythia default)
1418 // 2nd order alpha_s
1426 void AliPythia6::AtlasTuning()
1429 // Configuration for the ATLAS tuning
1430 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ5L));
1431 SetMSTP(81,1); // Multiple Interactions ON
1432 SetMSTP(82,4); // Double Gaussian Model
1433 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1434 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1435 SetPARP(89,1000.); // [GeV] Ref. energy
1436 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1437 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1438 SetPARP(84,0.5); // Core radius
1439 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1440 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1441 SetPARP(67,1); // Regulates Initial State Radiation
1444 void AliPythia6::AtlasTuningMC09()
1447 // Configuration for the ATLAS tuning
1448 printf("ATLAS New TUNE MC09\n");
1449 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1450 SetMSTP(82, 4); // Double Gaussian Model
1451 SetMSTP(52, 2); // External PDF
1452 SetMSTP(51, 20650); // MRST LO*
1455 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1456 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1457 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1458 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1460 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1461 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1462 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1463 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1464 SetPARP(84, 0.7); // Core radius
1465 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1466 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1469 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1471 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1472 SetPARP(89,1800.); // [GeV] Ref. energy
1475 void AliPythia6::SetPtHardRange(Float_t ptmin, Float_t ptmax)
1477 // Set the pt hard range
1482 void AliPythia6::SetYHardRange(Float_t ymin, Float_t ymax)
1484 // Set the y hard range
1490 void AliPythia6::SetFragmentation(Int_t flag)
1492 // Switch fragmentation on/off
1496 void AliPythia6::SetInitialAndFinalStateRadiation(Int_t flag1, Int_t flag2)
1498 // initial state radiation
1500 // final state radiation
1504 void AliPythia6::SetIntrinsicKt(Float_t kt)
1506 // Set the inreinsic kt
1510 SetPARP(93, 4. * kt);
1516 void AliPythia6::SwitchHFOff()
1518 // Switch off heavy flavor
1519 // Maximum number of quark flavours used in pdf
1521 // Maximum number of flavors that can be used in showers
1525 void AliPythia6::SetPycellParameters(Float_t etamax, Int_t neta, Int_t nphi,
1526 Float_t thresh, Float_t etseed, Float_t minet, Float_t r)
1528 // Set pycell parameters
1529 SetPARU(51, etamax);
1532 SetPARU(58, thresh);
1533 SetPARU(52, etseed);
1539 void AliPythia6::ModifiedSplitting()
1541 // Modified splitting probability as a model for quenching
1543 SetMSTJ(41, 1); // QCD radiation only
1544 SetMSTJ(42, 2); // angular ordering
1545 SetMSTJ(44, 2); // option to run alpha_s
1546 SetMSTJ(47, 0); // No correction back to hard scattering element
1547 SetMSTJ(50, 0); // No coherence in first branching
1548 SetPARJ(82, 1.); // Cut off for parton showers
1551 void AliPythia6::SwitchHadronisationOff()
1553 // Switch off hadronisarion
1557 void AliPythia6::SwitchHadronisationOn()
1559 // Switch on hadronisarion
1564 void AliPythia6::GetXandQ(Float_t& x1, Float_t& x2, Float_t& q)
1566 // Get x1, x2 and Q for this event
1573 Float_t AliPythia6::GetXSection()
1575 // Get the total cross-section
1576 return (GetPARI(1));
1579 Float_t AliPythia6::GetPtHard()
1581 // Get the pT hard for this event
1585 Int_t AliPythia6::ProcessCode()
1587 // Get the subprocess code
1591 void AliPythia6::PrintStatistics()
1593 // End of run statistics
1597 void AliPythia6::EventListing()
1599 // End of run statistics
1603 AliPythia6& AliPythia6::operator=(const AliPythia6& rhs)
1605 // Assignment operator
1610 void AliPythia6::Copy(TObject&) const
1615 Fatal("Copy","Not implemented!\n");