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
613 SetMSTP(41,1); // all resonance decays switched on
614 Initialize("CMS","p","p",fEcms);
618 Int_t AliPythia6::CheckedLuComp(Int_t kf)
620 // Check Lund particle code (for debugging)
625 void AliPythia6::SetNuclei(Int_t a1, Int_t a2)
627 // Treat protons as inside nuclei with mass numbers a1 and a2
628 // The MSTP array in the PYPARS common block is used to enable and
629 // select the nuclear structure functions.
630 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
631 // =1: internal PYTHIA acording to MSTP(51)
632 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
633 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
634 // MSTP(192) : Mass number of nucleus side 1
635 // MSTP(193) : Mass number of nucleus side 2
642 AliPythia6* AliPythia6::Instance()
644 // Set random number generator
648 fgAliPythia = new AliPythia6();
653 void AliPythia6::PrintParticles()
655 // Print list of particl properties
657 char* name = new char[16];
658 for (Int_t kf=0; kf<1000000; kf++) {
659 for (Int_t c = 1; c > -2; c-=2) {
660 Int_t kc = Pycomp(c*kf);
662 Float_t mass = GetPMAS(kc,1);
663 Float_t width = GetPMAS(kc,2);
664 Float_t tau = GetPMAS(kc,4);
670 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
671 c*kf, name, mass, width, tau);
675 printf("\n Number of particles %d \n \n", np);
678 void AliPythia6::ResetDecayTable()
680 // Set default values for pythia decay switches
682 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
683 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
686 void AliPythia6::SetDecayTable()
688 // Set default values for pythia decay switches
691 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
692 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
695 void AliPythia6::Pyjoin(Int_t& npart, Int_t *ipart)
697 // Call Pythia join alogorithm to set up a string between
698 // npart partons, given by indices in array ipart[npart]
700 pyjoin(npart, ipart);
703 void AliPythia6::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
705 // Call qPythia showering
707 pyshowq(ip1, ip2, qmax);
710 void AliPythia6::Qpygin0()
712 //position of the hard scattering in the nuclear overlapping area.
717 void AliPythia6::Pyclus(Int_t& njet)
719 // Call Pythia clustering algorithm
724 void AliPythia6::Pycell(Int_t& njet)
726 // Call Pythia jet reconstruction algorithm
731 void AliPythia6::GetJet(Int_t i, Float_t& px, Float_t& py, Float_t& pz, Float_t& e)
735 px = GetPyjets()->P[0][n+i];
736 py = GetPyjets()->P[1][n+i];
737 pz = GetPyjets()->P[2][n+i];
738 e = GetPyjets()->P[3][n+i];
741 void AliPythia6::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
743 // Call Pythia showering
745 pyshow(ip1, ip2, qmax);
748 void AliPythia6::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
750 pyrobo(imi, ima, the, phi, bex, bey, bez);
755 void AliPythia6::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
758 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
759 // (2) The nuclear geometry using the Glauber Model
762 fGlauber = AliFastGlauber::Instance();
764 fGlauber->SetCentralityClass(cMin, cMax);
766 fQuenchingWeights = new AliQuenchingWeights();
767 fQuenchingWeights->InitMult();
768 fQuenchingWeights->SetK(k);
769 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
776 void AliPythia6::Quench()
780 // Simple Jet Quenching routine:
781 // =============================
782 // The jet formed by all final state partons radiated by the parton created
783 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
784 // the initial parton reference frame:
785 // (E + p_z)new = (1-z) (E + p_z)old
790 // The lost momentum is first balanced by one gluon with virtuality > 0.
791 // Subsequently the gluon splits to yield two gluons with E = p.
795 static Float_t eMean = 0.;
796 static Int_t icall = 0;
801 Int_t klast[4] = {-1, -1, -1, -1};
803 Int_t numpart = fPyjets->N;
804 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
805 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
807 Double_t wjtKick[4] = {0., 0., 0., 0.};
813 // Sore information about Primary partons
816 // 0, 1 partons from hard scattering
817 // 2, 3 partons from initial state radiation
819 for (Int_t i = 2; i <= 7; i++) {
821 // Skip gluons that participate in hard scattering
822 if (i == 4 || i == 5) continue;
823 // Gluons from hard Scattering
824 if (i == 6 || i == 7) {
826 pxq[j] = fPyjets->P[0][i];
827 pyq[j] = fPyjets->P[1][i];
828 pzq[j] = fPyjets->P[2][i];
829 eq[j] = fPyjets->P[3][i];
830 mq[j] = fPyjets->P[4][i];
832 // Gluons from initial state radiation
834 // Obtain 4-momentum vector from difference between original parton and parton after gluon
835 // radiation. Energy is calculated independently because initial state radition does not
836 // conserve strictly momentum and energy for each partonic system independently.
838 // Not very clean. Should be improved !
842 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
843 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
844 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
845 mq[j] = fPyjets->P[4][i];
846 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
849 // Calculate some kinematic variables
851 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
852 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
853 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
854 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
855 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
856 qPdg[j] = fPyjets->K[1][i];
862 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
864 for (Int_t j = 0; j < 4; j++) {
866 // Quench only central jets and with E > 10.
870 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
871 // Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
872 Double_t eloss = fQuenchingWeights->GetELossRandomK(itype, int0[j], int1[j], eq[j]);
874 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
877 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
883 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
884 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
886 // Fractional energy loss
887 fZQuench[j] = eloss / eq[j];
889 // Avoid complete loss
891 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
893 // Some debug printing
896 // 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",
897 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
899 // fZQuench[j] = 0.8;
900 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
903 quenched[j] = (fZQuench[j] > 0.01);
908 Double_t pNew[1000][4];
915 for (Int_t isys = 0; isys < 4; isys++) {
916 // Skip to next system if not quenched.
917 if (!quenched[isys]) continue;
919 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
920 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
921 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
922 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
928 Double_t pg[4] = {0., 0., 0., 0.};
931 // Loop on radiation events
933 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
936 for (Int_t k = 0; k < 4; k++)
943 for (Int_t i = 0; i < numpart; i++)
945 imo = fPyjets->K[2][i];
946 kst = fPyjets->K[0][i];
947 pdg = fPyjets->K[1][i];
951 // Quarks and gluons only
952 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
953 // Particles from hard scattering only
955 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
956 Int_t imom = imo % 1000;
957 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
958 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
961 // Skip comment lines
962 if (kst != 1 && kst != 2) continue;
965 px = fPyjets->P[0][i];
966 py = fPyjets->P[1][i];
967 pz = fPyjets->P[2][i];
968 e = fPyjets->P[3][i];
969 m = fPyjets->P[4][i];
970 pt = TMath::Sqrt(px * px + py * py);
971 p = TMath::Sqrt(px * px + py * py + pz * pz);
972 phi = TMath::Pi() + TMath::ATan2(-py, -px);
973 theta = TMath::ATan2(pt, pz);
976 // Save 4-momentum sum for balancing
987 // Fractional energy loss
988 Double_t z = zquench[index];
991 // Don't fully quench radiated gluons
994 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
999 // printf("z: %d %f\n", imo, z);
1006 // Transform into frame in which initial parton is along z-axis
1008 TVector3 v(px, py, pz);
1009 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1010 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1012 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1013 Double_t mt2 = jt * jt + m * m;
1016 // Kinematic limit on z
1018 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1020 // Change light-cone kinematics rel. to initial parton
1022 Double_t eppzOld = e + pl;
1023 Double_t empzOld = e - pl;
1025 Double_t eppzNew = (1. - z) * eppzOld;
1026 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1027 Double_t eNew = 0.5 * (eppzNew + empzNew);
1028 Double_t plNew = 0.5 * (eppzNew - empzNew);
1032 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1033 Double_t mt2New = eppzNew * empzNew;
1034 if (mt2New < 1.e-8) mt2New = 0.;
1036 if (m * m > mt2New) {
1038 // This should not happen
1040 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1043 jtNew = TMath::Sqrt(mt2New - m * m);
1046 // If pT is to small (probably a leading massive particle) we scale only the energy
1047 // This can cause negative masses of the radiated gluon
1048 // Let's hope for the best ...
1050 eNew = TMath::Sqrt(plNew * plNew + mt2);
1054 // Calculate new px, py
1060 pxNew = jtNew / jt * pxs;
1061 pyNew = jtNew / jt * pys;
1064 // Double_t dpx = pxs - pxNew;
1065 // Double_t dpy = pys - pyNew;
1066 // Double_t dpz = pl - plNew;
1067 // Double_t de = e - eNew;
1068 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1069 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1070 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1074 TVector3 w(pxNew, pyNew, plNew);
1075 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1076 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1078 p1[index][0] += pxNew;
1079 p1[index][1] += pyNew;
1080 p1[index][2] += plNew;
1081 p1[index][3] += eNew;
1083 // Updated 4-momentum vectors
1085 pNew[icount][0] = pxNew;
1086 pNew[icount][1] = pyNew;
1087 pNew[icount][2] = plNew;
1088 pNew[icount][3] = eNew;
1093 // Check if there was phase-space for quenching
1096 if (icount == 0) quenched[isys] = kFALSE;
1097 if (!quenched[isys]) break;
1099 for (Int_t j = 0; j < 4; j++)
1101 p2[isys][j] = p0[isys][j] - p1[isys][j];
1103 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];
1104 if (p2[isys][4] > 0.) {
1105 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1108 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1109 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]);
1110 if (p2[isys][4] < -0.01) {
1111 printf("Negative mass squared !\n");
1112 // Here we have to put the gluon back to mass shell
1113 // This will lead to a small energy imbalance
1115 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1124 printf("zHeavy lowered to %f\n", zHeavy);
1125 if (zHeavy < 0.01) {
1126 printf("No success ! \n");
1128 quenched[isys] = kFALSE;
1132 } // iteration on z (while)
1134 // Update event record
1135 for (Int_t k = 0; k < icount; k++) {
1136 // 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] );
1137 fPyjets->P[0][kNew[k]] = pNew[k][0];
1138 fPyjets->P[1][kNew[k]] = pNew[k][1];
1139 fPyjets->P[2][kNew[k]] = pNew[k][2];
1140 fPyjets->P[3][kNew[k]] = pNew[k][3];
1147 if (!quenched[isys]) continue;
1149 // Last parton from shower i
1150 Int_t in = klast[isys];
1152 // Continue if no parton in shower i selected
1153 if (in == -1) continue;
1155 // If this is the second initial parton and it is behind the first move pointer by previous ish
1156 if (isys == 1 && klast[1] > klast[0]) in += ish;
1161 // How many additional gluons will be generated
1163 if (p2[isys][4] > 0.05) ish = 2;
1165 // Position of gluons
1167 if (iglu == 0) igMin = iGlu;
1170 (fPyjets->N) += ish;
1173 fPyjets->P[0][iGlu] = p2[isys][0];
1174 fPyjets->P[1][iGlu] = p2[isys][1];
1175 fPyjets->P[2][iGlu] = p2[isys][2];
1176 fPyjets->P[3][iGlu] = p2[isys][3];
1177 fPyjets->P[4][iGlu] = p2[isys][4];
1179 fPyjets->K[0][iGlu] = 1;
1180 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1181 fPyjets->K[1][iGlu] = 21;
1182 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1183 fPyjets->K[3][iGlu] = -1;
1184 fPyjets->K[4][iGlu] = -1;
1186 pg[0] += p2[isys][0];
1187 pg[1] += p2[isys][1];
1188 pg[2] += p2[isys][2];
1189 pg[3] += p2[isys][3];
1192 // Split gluon in rest frame.
1194 Double_t bx = p2[isys][0] / p2[isys][3];
1195 Double_t by = p2[isys][1] / p2[isys][3];
1196 Double_t bz = p2[isys][2] / p2[isys][3];
1197 Double_t pst = p2[isys][4] / 2.;
1199 // Isotropic decay ????
1200 Double_t cost = 2. * gRandom->Rndm() - 1.;
1201 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1202 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1204 Double_t pz1 = pst * cost;
1205 Double_t pz2 = -pst * cost;
1206 Double_t pt1 = pst * sint;
1207 Double_t pt2 = -pst * sint;
1208 Double_t px1 = pt1 * TMath::Cos(phis);
1209 Double_t py1 = pt1 * TMath::Sin(phis);
1210 Double_t px2 = pt2 * TMath::Cos(phis);
1211 Double_t py2 = pt2 * TMath::Sin(phis);
1213 fPyjets->P[0][iGlu] = px1;
1214 fPyjets->P[1][iGlu] = py1;
1215 fPyjets->P[2][iGlu] = pz1;
1216 fPyjets->P[3][iGlu] = pst;
1217 fPyjets->P[4][iGlu] = 0.;
1219 fPyjets->K[0][iGlu] = 1 ;
1220 fPyjets->K[1][iGlu] = 21;
1221 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1222 fPyjets->K[3][iGlu] = -1;
1223 fPyjets->K[4][iGlu] = -1;
1225 fPyjets->P[0][iGlu+1] = px2;
1226 fPyjets->P[1][iGlu+1] = py2;
1227 fPyjets->P[2][iGlu+1] = pz2;
1228 fPyjets->P[3][iGlu+1] = pst;
1229 fPyjets->P[4][iGlu+1] = 0.;
1231 fPyjets->K[0][iGlu+1] = 1;
1232 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1233 fPyjets->K[1][iGlu+1] = 21;
1234 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1235 fPyjets->K[3][iGlu+1] = -1;
1236 fPyjets->K[4][iGlu+1] = -1;
1242 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1245 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1246 Double_t px, py, pz;
1247 px = fPyjets->P[0][ig];
1248 py = fPyjets->P[1][ig];
1249 pz = fPyjets->P[2][ig];
1250 TVector3 v(px, py, pz);
1251 v.RotateZ(-phiq[isys]);
1252 v.RotateY(-thetaq[isys]);
1253 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1254 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1255 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1256 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1257 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1258 pxs += jtKick * TMath::Cos(phiKick);
1259 pys += jtKick * TMath::Sin(phiKick);
1260 TVector3 w(pxs, pys, pzs);
1261 w.RotateY(thetaq[isys]);
1262 w.RotateZ(phiq[isys]);
1263 fPyjets->P[0][ig] = w.X();
1264 fPyjets->P[1][ig] = w.Y();
1265 fPyjets->P[2][ig] = w.Z();
1266 fPyjets->P[2][ig] = w.Mag();
1272 // Check energy conservation
1276 Double_t es = 14000.;
1278 for (Int_t i = 0; i < numpart; i++)
1280 kst = fPyjets->K[0][i];
1281 if (kst != 1 && kst != 2) continue;
1282 pxs += fPyjets->P[0][i];
1283 pys += fPyjets->P[1][i];
1284 pzs += fPyjets->P[2][i];
1285 es -= fPyjets->P[3][i];
1287 if (TMath::Abs(pxs) > 1.e-2 ||
1288 TMath::Abs(pys) > 1.e-2 ||
1289 TMath::Abs(pzs) > 1.e-1) {
1290 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1291 // Fatal("Quench()", "4-Momentum non-conservation");
1294 } // end quenching loop (systems)
1296 for (Int_t i = 0; i < numpart; i++)
1298 imo = fPyjets->K[2][i];
1300 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1307 void AliPythia6::Pyquen(Double_t a, Int_t ibf, Double_t b)
1309 // Igor Lokthine's quenching routine
1310 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1315 void AliPythia6::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1317 // Set the parameters for the PYQUEN package.
1318 // See comments in PyquenCommon.h
1324 PYQPAR.iengl = iengl;
1325 PYQPAR.iangl = iangl;
1328 void AliPythia6::LoadEvent(AliStack* stack, Int_t flag, Int_t reHadr)
1331 // Load event into Pythia Common Block
1334 Int_t npart = stack -> GetNprimary();
1338 GetPyjets()->N = npart;
1340 n0 = GetPyjets()->N;
1341 GetPyjets()->N = n0 + npart;
1345 for (Int_t part = 0; part < npart; part++) {
1346 TParticle *mPart = stack->Particle(part);
1348 Int_t kf = mPart->GetPdgCode();
1349 Int_t ks = mPart->GetStatusCode();
1350 Int_t idf = mPart->GetFirstDaughter();
1351 Int_t idl = mPart->GetLastDaughter();
1354 if (ks == 11 || ks == 12) {
1361 Float_t px = mPart->Px();
1362 Float_t py = mPart->Py();
1363 Float_t pz = mPart->Pz();
1364 Float_t e = mPart->Energy();
1365 Float_t m = mPart->GetCalcMass();
1368 (GetPyjets())->P[0][part+n0] = px;
1369 (GetPyjets())->P[1][part+n0] = py;
1370 (GetPyjets())->P[2][part+n0] = pz;
1371 (GetPyjets())->P[3][part+n0] = e;
1372 (GetPyjets())->P[4][part+n0] = m;
1374 (GetPyjets())->K[1][part+n0] = kf;
1375 (GetPyjets())->K[0][part+n0] = ks;
1376 (GetPyjets())->K[3][part+n0] = idf + 1;
1377 (GetPyjets())->K[4][part+n0] = idl + 1;
1378 (GetPyjets())->K[2][part+n0] = mPart->GetFirstMother() + 1;
1383 void AliPythia6::Pyevnw()
1385 // New multiple interaction scenario
1389 void AliPythia6::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1391 // Return event specific quenching parameters
1394 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1398 void AliPythia6::ConfigHeavyFlavor()
1401 // Default configuration for Heavy Flavor production
1403 // All QCD processes
1407 // No multiple interactions
1411 // Initial/final parton shower on (Pythia default)
1415 // 2nd order alpha_s
1423 void AliPythia6::AtlasTuning()
1426 // Configuration for the ATLAS tuning
1427 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ5L));
1428 SetMSTP(81,1); // Multiple Interactions ON
1429 SetMSTP(82,4); // Double Gaussian Model
1430 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1431 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1432 SetPARP(89,1000.); // [GeV] Ref. energy
1433 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1434 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1435 SetPARP(84,0.5); // Core radius
1436 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1437 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1438 SetPARP(67,1); // Regulates Initial State Radiation
1441 void AliPythia6::AtlasTuningMC09()
1444 // Configuration for the ATLAS tuning
1445 printf("ATLAS New TUNE MC09\n");
1446 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1447 SetMSTP(82, 4); // Double Gaussian Model
1448 SetMSTP(52, 2); // External PDF
1449 SetMSTP(51, 20650); // MRST LO*
1452 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1453 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1454 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1455 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1457 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1458 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1459 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1460 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1461 SetPARP(84, 0.7); // Core radius
1462 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1463 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1466 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1468 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1469 SetPARP(89,1800.); // [GeV] Ref. energy
1472 void AliPythia6::SetPtHardRange(Float_t ptmin, Float_t ptmax)
1474 // Set the pt hard range
1479 void AliPythia6::SetYHardRange(Float_t ymin, Float_t ymax)
1481 // Set the y hard range
1487 void AliPythia6::SetFragmentation(Int_t flag)
1489 // Switch fragmentation on/off
1493 void AliPythia6::SetInitialAndFinalStateRadiation(Int_t flag1, Int_t flag2)
1495 // initial state radiation
1497 // final state radiation
1501 void AliPythia6::SetIntrinsicKt(Float_t kt)
1503 // Set the inreinsic kt
1507 SetPARP(93, 4. * kt);
1513 void AliPythia6::SwitchHFOff()
1515 // Switch off heavy flavor
1516 // Maximum number of quark flavours used in pdf
1518 // Maximum number of flavors that can be used in showers
1522 void AliPythia6::SetPycellParameters(Float_t etamax, Int_t neta, Int_t nphi,
1523 Float_t thresh, Float_t etseed, Float_t minet, Float_t r)
1525 // Set pycell parameters
1526 SetPARU(51, etamax);
1529 SetPARU(58, thresh);
1530 SetPARU(52, etseed);
1536 void AliPythia6::ModifiedSplitting()
1538 // Modified splitting probability as a model for quenching
1540 SetMSTJ(41, 1); // QCD radiation only
1541 SetMSTJ(42, 2); // angular ordering
1542 SetMSTJ(44, 2); // option to run alpha_s
1543 SetMSTJ(47, 0); // No correction back to hard scattering element
1544 SetMSTJ(50, 0); // No coherence in first branching
1545 SetPARJ(82, 1.); // Cut off for parton showers
1548 void AliPythia6::SwitchHadronisationOff()
1550 // Switch off hadronisarion
1554 void AliPythia6::SwitchHadronisationOn()
1556 // Switch on hadronisarion
1561 void AliPythia6::GetXandQ(Float_t& x1, Float_t& x2, Float_t& q)
1563 // Get x1, x2 and Q for this event
1570 Float_t AliPythia6::GetXSection()
1572 // Get the total cross-section
1573 return (GetPARI(1));
1576 Float_t AliPythia6::GetPtHard()
1578 // Get the pT hard for this event
1582 Int_t AliPythia6::ProcessCode()
1584 // Get the subprocess code
1588 void AliPythia6::PrintStatistics()
1590 // End of run statistics
1594 void AliPythia6::EventListing()
1596 // End of run statistics
1600 AliPythia6& AliPythia6::operator=(const AliPythia6& rhs)
1602 // Assignment operator
1607 void AliPythia6::Copy(TObject&) const
1612 Fatal("Copy","Not implemented!\n");