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():
84 // Default Constructor
88 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
89 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
90 for (i = 0; i < 4; i++) fZQuench[i] = 0;
92 if (!AliPythiaRndm::GetPythiaRandom())
93 AliPythiaRndm::SetPythiaRandom(GetRandom());
95 fQuenchingWeights = 0;
98 AliPythia6::AliPythia6(const AliPythia6& pythia):
115 for (i = 0; i < 501; i++) fDefMDCY[i] = 0;
116 for (i = 0; i < 2001; i++) fDefMDME[i] = 0;
117 for (i = 0; i < 4; i++) fZQuench[i] = 0;
121 void AliPythia6::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc, Int_t /*tune*/)
123 // Initialise the process to generate
124 if (!AliPythiaRndm::GetPythiaRandom())
125 AliPythiaRndm::SetPythiaRandom(GetRandom());
129 fStrucFunc = strucfunc;
130 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
131 SetMDCY(Pycomp(111) ,1,0);
132 SetMDCY(Pycomp(310) ,1,0);
133 SetMDCY(Pycomp(3122),1,0);
134 SetMDCY(Pycomp(3112),1,0);
135 SetMDCY(Pycomp(3212),1,0);
136 SetMDCY(Pycomp(3222),1,0);
137 SetMDCY(Pycomp(3312),1,0);
138 SetMDCY(Pycomp(3322),1,0);
139 SetMDCY(Pycomp(3334),1,0);
140 // Select structure function
142 SetMSTP(51,AliStructFuncType::PDFsetIndex(strucfunc));
143 // Particles produced in string fragmentation point directly to either of the two endpoints
144 // of the string (depending in the side they were generated from).
148 // Pythia initialisation for selected processes//
152 for (Int_t i=1; i<= 200; i++) {
155 // select charm production
158 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
159 // Multiple interactions on.
161 // Double Gaussian matter distribution.
167 // Reference energy for pT0 and energy rescaling pace.
170 // String drawing almost completely minimizes string length.
173 // ISR and FSR activity.
179 case kPyOldUEQ2ordered2:
180 // Old underlying events with Q2 ordered QCD processes
181 // Multiple interactions on.
183 // Double Gaussian matter distribution.
189 // Reference energy for pT0 and energy rescaling pace.
191 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
192 // String drawing almost completely minimizes string length.
195 // ISR and FSR activity.
202 // Old production mechanism: Old Popcorn
205 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
207 // (D=1)see can be used to form baryons (BARYON JUNCTION)
213 // heavy quark masses
243 case kPyCharmUnforced:
252 case kPyBeautyUnforced:
262 // Minimum Bias pp-Collisions
265 // select Pythia min. bias model
267 SetMSUB(92,1); // single diffraction AB-->XB
268 SetMSUB(93,1); // single diffraction AB-->AX
269 SetMSUB(94,1); // double diffraction
270 SetMSUB(95,1); // low pt production
274 case kPyMbAtlasTuneMC09:
275 // Minimum Bias pp-Collisions
278 // select Pythia min. bias model
280 SetMSUB(92,1); // single diffraction AB-->XB
281 SetMSUB(93,1); // single diffraction AB-->AX
282 SetMSUB(94,1); // double diffraction
283 SetMSUB(95,1); // low pt production
288 case kPyMbWithDirectPhoton:
289 // Minimum Bias pp-Collisions with direct photon processes added
292 // select Pythia min. bias model
294 SetMSUB(92,1); // single diffraction AB-->XB
295 SetMSUB(93,1); // single diffraction AB-->AX
296 SetMSUB(94,1); // double diffraction
297 SetMSUB(95,1); // low pt production
310 // Minimum Bias pp-Collisions
313 // select Pythia min. bias model
315 SetMSUB(92,1); // single diffraction AB-->XB
316 SetMSUB(93,1); // single diffraction AB-->AX
317 SetMSUB(94,1); // double diffraction
318 SetMSUB(95,1); // low pt production
322 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
323 // -> Pythia 6.3 or above is needed
326 SetMSUB(92,1); // single diffraction AB-->XB
327 SetMSUB(93,1); // single diffraction AB-->AX
328 SetMSUB(94,1); // double diffraction
329 SetMSUB(95,1); // low pt production
330 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll));
334 SetMSTP(81,1); // Multiple Interactions ON
335 SetMSTP(82,4); // Double Gaussian Model
338 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
339 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
340 SetPARP(84,0.5); // Core radius
341 SetPARP(85,0.9); // Regulates gluon prod. mechanism
342 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
346 // Minimum Bias pp-Collisions
349 // select Pythia min. bias model
351 SetMSUB(95,1); // low pt production
358 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
359 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
360 SetPARP(93,5.); // Upper cut-off
362 SetPMAS(4,1,1.2); // Charm quark mass
363 SetPMAS(5,1,4.78); // Beauty quark mass
364 SetPARP(71,4.); // Defaut value
373 // Pythia Tune A (CDF)
375 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
376 SetMSTP(82,4); // Double Gaussian Model
377 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
378 SetPARP(84,0.4); // Core radius
379 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
380 SetPARP(86,0.95); // Regulates gluon prod. mechanism
381 SetPARP(89,1800.); // [GeV] Ref. energy
382 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
387 case kPyCharmPbPbMNR:
389 case kPyDPlusPbPbMNR:
390 case kPyDPlusStrangePbPbMNR:
391 // Tuning of Pythia parameters aimed to get a resonable agreement
392 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
393 // c-cbar single inclusive and double differential distributions.
394 // This parameter settings are meant to work with Pb-Pb collisions
395 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
396 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
397 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
409 case kPyDPlusStrangepPbMNR:
410 // Tuning of Pythia parameters aimed to get a resonable agreement
411 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
412 // c-cbar single inclusive and double differential distributions.
413 // This parameter settings are meant to work with p-Pb collisions
414 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
415 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
416 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
429 case kPyDPlusStrangeppMNR:
430 case kPyLambdacppMNR:
431 // Tuning of Pythia parameters aimed to get a resonable agreement
432 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
433 // c-cbar single inclusive and double differential distributions.
434 // This parameter settings are meant to work with pp collisions
435 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
436 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
437 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
447 case kPyCharmppMNRwmi:
448 // Tuning of Pythia parameters aimed to get a resonable agreement
449 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
450 // c-cbar single inclusive and double differential distributions.
451 // This parameter settings are meant to work with pp collisions
452 // and with kCTEQ5L PDFs.
453 // Added multiple interactions according to ATLAS tune settings.
454 // To get a "reasonable" agreement with MNR results, events have to be
455 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
457 // To get a "perfect" agreement with MNR results, events have to be
458 // generated in four ptHard bins with the following relative
474 case kPyBeautyPbPbMNR:
475 // Tuning of Pythia parameters aimed to get a resonable agreement
476 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
477 // b-bbar single inclusive and double differential distributions.
478 // This parameter settings are meant to work with Pb-Pb collisions
479 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
480 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
481 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
493 case kPyBeautypPbMNR:
494 // Tuning of Pythia parameters aimed to get a resonable agreement
495 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
496 // b-bbar single inclusive and double differential distributions.
497 // This parameter settings are meant to work with p-Pb collisions
498 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
499 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
500 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
513 // Tuning of Pythia parameters aimed to get a resonable agreement
514 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
515 // b-bbar single inclusive and double differential distributions.
516 // This parameter settings are meant to work with pp collisions
517 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
518 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
519 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
534 case kPyBeautyppMNRwmi:
535 // Tuning of Pythia parameters aimed to get a resonable agreement
536 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
537 // b-bbar single inclusive and double differential distributions.
538 // This parameter settings are meant to work with pp collisions
539 // and with kCTEQ5L PDFs.
540 // Added multiple interactions according to ATLAS tune settings.
541 // To get a "reasonable" agreement with MNR results, events have to be
542 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
544 // To get a "perfect" agreement with MNR results, events have to be
545 // generated in four ptHard bins with the following relative
568 //Inclusive production of W+/-
574 // //f fbar -> gamma W+
581 // Initial/final parton shower on (Pythia default)
582 // With parton showers on we are generating "W inclusive process"
583 SetMSTP(61,1); //Initial QCD & QED showers on
584 SetMSTP(71,1); //Final QCD & QED showers on
590 //Inclusive production of Z
595 // // f fbar -> g Z/gamma
597 // // f fbar -> gamma Z/gamma
599 // // f g -> f Z/gamma
601 // // f gamma -> f Z/gamma
604 //only Z included, not gamma
607 // Initial/final parton shower on (Pythia default)
608 // With parton showers on we are generating "Z inclusive process"
609 SetMSTP(61,1); //Initial QCD & QED showers on
610 SetMSTP(71,1); //Final QCD & QED showers on
612 case kPyMBRSingleDiffraction:
613 case kPyMBRDoubleDiffraction:
614 case kPyMBRCentralDiffraction:
620 SetMSTP(41,1); // all resonance decays switched on
621 Initialize("CMS",fProjectile,fTarget,fEcms);
625 Int_t AliPythia6::CheckedLuComp(Int_t kf)
627 // Check Lund particle code (for debugging)
632 void AliPythia6::SetNuclei(Int_t a1, Int_t a2)
634 // Treat protons as inside nuclei with mass numbers a1 and a2
635 // The MSTP array in the PYPARS common block is used to enable and
636 // select the nuclear structure functions.
637 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
638 // =1: internal PYTHIA acording to MSTP(51)
639 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
640 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
641 // MSTP(192) : Mass number of nucleus side 1
642 // MSTP(193) : Mass number of nucleus side 2
649 AliPythia6* AliPythia6::Instance()
651 // Set random number generator
655 fgAliPythia = new AliPythia6();
660 void AliPythia6::PrintParticles()
662 // Print list of particl properties
664 char* name = new char[16];
665 for (Int_t kf=0; kf<1000000; kf++) {
666 for (Int_t c = 1; c > -2; c-=2) {
667 Int_t kc = Pycomp(c*kf);
669 Float_t mass = GetPMAS(kc,1);
670 Float_t width = GetPMAS(kc,2);
671 Float_t tau = GetPMAS(kc,4);
677 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
678 c*kf, name, mass, width, tau);
682 printf("\n Number of particles %d \n \n", np);
685 void AliPythia6::ResetDecayTable()
687 // Set default values for pythia decay switches
689 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
690 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
693 void AliPythia6::SetDecayTable()
695 // Set default values for pythia decay switches
698 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
699 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
702 void AliPythia6::Pyjoin(Int_t& npart, Int_t *ipart)
704 // Call Pythia join alogorithm to set up a string between
705 // npart partons, given by indices in array ipart[npart]
707 pyjoin(npart, ipart);
710 void AliPythia6::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
712 // Call qPythia showering
714 pyshowq(ip1, ip2, qmax);
717 void AliPythia6::Qpygin0()
719 //position of the hard scattering in the nuclear overlapping area.
724 void AliPythia6::Pyclus(Int_t& njet)
726 // Call Pythia clustering algorithm
731 void AliPythia6::Pycell(Int_t& njet)
733 // Call Pythia jet reconstruction algorithm
738 void AliPythia6::GetJet(Int_t i, Float_t& px, Float_t& py, Float_t& pz, Float_t& e)
742 px = GetPyjets()->P[0][n+i];
743 py = GetPyjets()->P[1][n+i];
744 pz = GetPyjets()->P[2][n+i];
745 e = GetPyjets()->P[3][n+i];
748 void AliPythia6::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
750 // Call Pythia showering
752 pyshow(ip1, ip2, qmax);
755 void AliPythia6::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
757 pyrobo(imi, ima, the, phi, bex, bey, bez);
762 void AliPythia6::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
765 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
766 // (2) The nuclear geometry using the Glauber Model
769 fGlauber = AliFastGlauber::Instance();
771 fGlauber->SetCentralityClass(cMin, cMax);
773 fQuenchingWeights = new AliQuenchingWeights();
774 fQuenchingWeights->InitMult();
775 fQuenchingWeights->SetK(k);
776 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
783 void AliPythia6::Quench()
787 // Simple Jet Quenching routine:
788 // =============================
789 // The jet formed by all final state partons radiated by the parton created
790 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
791 // the initial parton reference frame:
792 // (E + p_z)new = (1-z) (E + p_z)old
797 // The lost momentum is first balanced by one gluon with virtuality > 0.
798 // Subsequently the gluon splits to yield two gluons with E = p.
802 static Float_t eMean = 0.;
803 static Int_t icall = 0;
808 Int_t klast[4] = {-1, -1, -1, -1};
810 Int_t numpart = fPyjets->N;
811 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
812 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
814 Double_t wjtKick[4] = {0., 0., 0., 0.};
820 // Sore information about Primary partons
823 // 0, 1 partons from hard scattering
824 // 2, 3 partons from initial state radiation
826 for (Int_t i = 2; i <= 7; i++) {
828 // Skip gluons that participate in hard scattering
829 if (i == 4 || i == 5) continue;
830 // Gluons from hard Scattering
831 if (i == 6 || i == 7) {
833 pxq[j] = fPyjets->P[0][i];
834 pyq[j] = fPyjets->P[1][i];
835 pzq[j] = fPyjets->P[2][i];
836 eq[j] = fPyjets->P[3][i];
837 mq[j] = fPyjets->P[4][i];
839 // Gluons from initial state radiation
841 // Obtain 4-momentum vector from difference between original parton and parton after gluon
842 // radiation. Energy is calculated independently because initial state radition does not
843 // conserve strictly momentum and energy for each partonic system independently.
845 // Not very clean. Should be improved !
849 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
850 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
851 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
852 mq[j] = fPyjets->P[4][i];
853 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
856 // Calculate some kinematic variables
858 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
859 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
860 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
861 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
862 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
863 qPdg[j] = fPyjets->K[1][i];
869 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
871 for (Int_t j = 0; j < 4; j++) {
873 // Quench only central jets and with E > 10.
877 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
878 // Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
879 Double_t eloss = fQuenchingWeights->GetELossRandomK(itype, int0[j], int1[j], eq[j]);
881 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
884 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
890 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
891 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
893 // Fractional energy loss
894 fZQuench[j] = eloss / eq[j];
896 // Avoid complete loss
898 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
900 // Some debug printing
903 // 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",
904 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
906 // fZQuench[j] = 0.8;
907 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
910 quenched[j] = (fZQuench[j] > 0.01);
915 Double_t pNew[1000][4];
922 for (Int_t isys = 0; isys < 4; isys++) {
923 // Skip to next system if not quenched.
924 if (!quenched[isys]) continue;
926 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
927 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
928 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
929 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
935 Double_t pg[4] = {0., 0., 0., 0.};
938 // Loop on radiation events
940 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
943 for (Int_t k = 0; k < 4; k++)
950 for (Int_t i = 0; i < numpart; i++)
952 imo = fPyjets->K[2][i];
953 kst = fPyjets->K[0][i];
954 pdg = fPyjets->K[1][i];
958 // Quarks and gluons only
959 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
960 // Particles from hard scattering only
962 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
963 Int_t imom = imo % 1000;
964 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
965 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
968 // Skip comment lines
969 if (kst != 1 && kst != 2) continue;
972 px = fPyjets->P[0][i];
973 py = fPyjets->P[1][i];
974 pz = fPyjets->P[2][i];
975 e = fPyjets->P[3][i];
976 m = fPyjets->P[4][i];
977 pt = TMath::Sqrt(px * px + py * py);
978 p = TMath::Sqrt(px * px + py * py + pz * pz);
979 phi = TMath::Pi() + TMath::ATan2(-py, -px);
980 theta = TMath::ATan2(pt, pz);
983 // Save 4-momentum sum for balancing
994 // Fractional energy loss
995 Double_t z = zquench[index];
998 // Don't fully quench radiated gluons
1001 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1006 // printf("z: %d %f\n", imo, z);
1013 // Transform into frame in which initial parton is along z-axis
1015 TVector3 v(px, py, pz);
1016 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1017 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1019 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1020 Double_t mt2 = jt * jt + m * m;
1023 // Kinematic limit on z
1025 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1027 // Change light-cone kinematics rel. to initial parton
1029 Double_t eppzOld = e + pl;
1030 Double_t empzOld = e - pl;
1032 Double_t eppzNew = (1. - z) * eppzOld;
1033 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1034 Double_t eNew = 0.5 * (eppzNew + empzNew);
1035 Double_t plNew = 0.5 * (eppzNew - empzNew);
1039 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1040 Double_t mt2New = eppzNew * empzNew;
1041 if (mt2New < 1.e-8) mt2New = 0.;
1043 if (m * m > mt2New) {
1045 // This should not happen
1047 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1050 jtNew = TMath::Sqrt(mt2New - m * m);
1053 // If pT is to small (probably a leading massive particle) we scale only the energy
1054 // This can cause negative masses of the radiated gluon
1055 // Let's hope for the best ...
1057 eNew = TMath::Sqrt(plNew * plNew + mt2);
1061 // Calculate new px, py
1067 pxNew = jtNew / jt * pxs;
1068 pyNew = jtNew / jt * pys;
1071 // Double_t dpx = pxs - pxNew;
1072 // Double_t dpy = pys - pyNew;
1073 // Double_t dpz = pl - plNew;
1074 // Double_t de = e - eNew;
1075 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1076 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1077 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1081 TVector3 w(pxNew, pyNew, plNew);
1082 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1083 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1085 p1[index][0] += pxNew;
1086 p1[index][1] += pyNew;
1087 p1[index][2] += plNew;
1088 p1[index][3] += eNew;
1090 // Updated 4-momentum vectors
1092 pNew[icount][0] = pxNew;
1093 pNew[icount][1] = pyNew;
1094 pNew[icount][2] = plNew;
1095 pNew[icount][3] = eNew;
1100 // Check if there was phase-space for quenching
1103 if (icount == 0) quenched[isys] = kFALSE;
1104 if (!quenched[isys]) break;
1106 for (Int_t j = 0; j < 4; j++)
1108 p2[isys][j] = p0[isys][j] - p1[isys][j];
1110 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];
1111 if (p2[isys][4] > 0.) {
1112 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1115 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1116 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]);
1117 if (p2[isys][4] < -0.01) {
1118 printf("Negative mass squared !\n");
1119 // Here we have to put the gluon back to mass shell
1120 // This will lead to a small energy imbalance
1122 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1131 printf("zHeavy lowered to %f\n", zHeavy);
1132 if (zHeavy < 0.01) {
1133 printf("No success ! \n");
1135 quenched[isys] = kFALSE;
1139 } // iteration on z (while)
1141 // Update event record
1142 for (Int_t k = 0; k < icount; k++) {
1143 // 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] );
1144 fPyjets->P[0][kNew[k]] = pNew[k][0];
1145 fPyjets->P[1][kNew[k]] = pNew[k][1];
1146 fPyjets->P[2][kNew[k]] = pNew[k][2];
1147 fPyjets->P[3][kNew[k]] = pNew[k][3];
1154 if (!quenched[isys]) continue;
1156 // Last parton from shower i
1157 Int_t in = klast[isys];
1159 // Continue if no parton in shower i selected
1160 if (in == -1) continue;
1162 // If this is the second initial parton and it is behind the first move pointer by previous ish
1163 if (isys == 1 && klast[1] > klast[0]) in += ish;
1168 // How many additional gluons will be generated
1170 if (p2[isys][4] > 0.05) ish = 2;
1172 // Position of gluons
1174 if (iglu == 0) igMin = iGlu;
1177 (fPyjets->N) += ish;
1180 fPyjets->P[0][iGlu] = p2[isys][0];
1181 fPyjets->P[1][iGlu] = p2[isys][1];
1182 fPyjets->P[2][iGlu] = p2[isys][2];
1183 fPyjets->P[3][iGlu] = p2[isys][3];
1184 fPyjets->P[4][iGlu] = p2[isys][4];
1186 fPyjets->K[0][iGlu] = 1;
1187 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1188 fPyjets->K[1][iGlu] = 21;
1189 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1190 fPyjets->K[3][iGlu] = -1;
1191 fPyjets->K[4][iGlu] = -1;
1193 pg[0] += p2[isys][0];
1194 pg[1] += p2[isys][1];
1195 pg[2] += p2[isys][2];
1196 pg[3] += p2[isys][3];
1199 // Split gluon in rest frame.
1201 Double_t bx = p2[isys][0] / p2[isys][3];
1202 Double_t by = p2[isys][1] / p2[isys][3];
1203 Double_t bz = p2[isys][2] / p2[isys][3];
1204 Double_t pst = p2[isys][4] / 2.;
1206 // Isotropic decay ????
1207 Double_t cost = 2. * gRandom->Rndm() - 1.;
1208 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1209 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1211 Double_t pz1 = pst * cost;
1212 Double_t pz2 = -pst * cost;
1213 Double_t pt1 = pst * sint;
1214 Double_t pt2 = -pst * sint;
1215 Double_t px1 = pt1 * TMath::Cos(phis);
1216 Double_t py1 = pt1 * TMath::Sin(phis);
1217 Double_t px2 = pt2 * TMath::Cos(phis);
1218 Double_t py2 = pt2 * TMath::Sin(phis);
1220 fPyjets->P[0][iGlu] = px1;
1221 fPyjets->P[1][iGlu] = py1;
1222 fPyjets->P[2][iGlu] = pz1;
1223 fPyjets->P[3][iGlu] = pst;
1224 fPyjets->P[4][iGlu] = 0.;
1226 fPyjets->K[0][iGlu] = 1 ;
1227 fPyjets->K[1][iGlu] = 21;
1228 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1229 fPyjets->K[3][iGlu] = -1;
1230 fPyjets->K[4][iGlu] = -1;
1232 fPyjets->P[0][iGlu+1] = px2;
1233 fPyjets->P[1][iGlu+1] = py2;
1234 fPyjets->P[2][iGlu+1] = pz2;
1235 fPyjets->P[3][iGlu+1] = pst;
1236 fPyjets->P[4][iGlu+1] = 0.;
1238 fPyjets->K[0][iGlu+1] = 1;
1239 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1240 fPyjets->K[1][iGlu+1] = 21;
1241 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1242 fPyjets->K[3][iGlu+1] = -1;
1243 fPyjets->K[4][iGlu+1] = -1;
1249 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1252 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1253 Double_t px, py, pz;
1254 px = fPyjets->P[0][ig];
1255 py = fPyjets->P[1][ig];
1256 pz = fPyjets->P[2][ig];
1257 TVector3 v(px, py, pz);
1258 v.RotateZ(-phiq[isys]);
1259 v.RotateY(-thetaq[isys]);
1260 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1261 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1262 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1263 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1264 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1265 pxs += jtKick * TMath::Cos(phiKick);
1266 pys += jtKick * TMath::Sin(phiKick);
1267 TVector3 w(pxs, pys, pzs);
1268 w.RotateY(thetaq[isys]);
1269 w.RotateZ(phiq[isys]);
1270 fPyjets->P[0][ig] = w.X();
1271 fPyjets->P[1][ig] = w.Y();
1272 fPyjets->P[2][ig] = w.Z();
1273 fPyjets->P[2][ig] = w.Mag();
1279 // Check energy conservation
1283 Double_t es = 14000.;
1285 for (Int_t i = 0; i < numpart; i++)
1287 kst = fPyjets->K[0][i];
1288 if (kst != 1 && kst != 2) continue;
1289 pxs += fPyjets->P[0][i];
1290 pys += fPyjets->P[1][i];
1291 pzs += fPyjets->P[2][i];
1292 es -= fPyjets->P[3][i];
1294 if (TMath::Abs(pxs) > 1.e-2 ||
1295 TMath::Abs(pys) > 1.e-2 ||
1296 TMath::Abs(pzs) > 1.e-1) {
1297 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1298 // Fatal("Quench()", "4-Momentum non-conservation");
1301 } // end quenching loop (systems)
1303 for (Int_t i = 0; i < numpart; i++)
1305 imo = fPyjets->K[2][i];
1307 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1314 void AliPythia6::Pyquen(Double_t a, Int_t ibf, Double_t b)
1316 // Igor Lokthine's quenching routine
1317 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1322 void AliPythia6::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1324 // Set the parameters for the PYQUEN package.
1325 // See comments in PyquenCommon.h
1331 PYQPAR.iengl = iengl;
1332 PYQPAR.iangl = iangl;
1335 void AliPythia6::LoadEvent(AliStack* stack, Int_t flag, Int_t reHadr)
1338 // Load event into Pythia Common Block
1341 Int_t npart = stack -> GetNprimary();
1345 GetPyjets()->N = npart;
1347 n0 = GetPyjets()->N;
1348 GetPyjets()->N = n0 + npart;
1352 for (Int_t part = 0; part < npart; part++) {
1353 TParticle *mPart = stack->Particle(part);
1355 Int_t kf = mPart->GetPdgCode();
1356 Int_t ks = mPart->GetStatusCode();
1357 Int_t idf = mPart->GetFirstDaughter();
1358 Int_t idl = mPart->GetLastDaughter();
1361 if (ks == 11 || ks == 12) {
1368 Float_t px = mPart->Px();
1369 Float_t py = mPart->Py();
1370 Float_t pz = mPart->Pz();
1371 Float_t e = mPart->Energy();
1372 Float_t m = mPart->GetCalcMass();
1375 (GetPyjets())->P[0][part+n0] = px;
1376 (GetPyjets())->P[1][part+n0] = py;
1377 (GetPyjets())->P[2][part+n0] = pz;
1378 (GetPyjets())->P[3][part+n0] = e;
1379 (GetPyjets())->P[4][part+n0] = m;
1381 (GetPyjets())->K[1][part+n0] = kf;
1382 (GetPyjets())->K[0][part+n0] = ks;
1383 (GetPyjets())->K[3][part+n0] = idf + 1;
1384 (GetPyjets())->K[4][part+n0] = idl + 1;
1385 (GetPyjets())->K[2][part+n0] = mPart->GetFirstMother() + 1;
1390 void AliPythia6::Pyevnw()
1392 // New multiple interaction scenario
1396 void AliPythia6::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1398 // Return event specific quenching parameters
1401 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1405 void AliPythia6::ConfigHeavyFlavor()
1408 // Default configuration for Heavy Flavor production
1410 // All QCD processes
1414 // No multiple interactions
1418 // Initial/final parton shower on (Pythia default)
1422 // 2nd order alpha_s
1430 void AliPythia6::AtlasTuning()
1433 // Configuration for the ATLAS tuning
1434 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ5L));
1435 SetMSTP(81,1); // Multiple Interactions ON
1436 SetMSTP(82,4); // Double Gaussian Model
1437 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1438 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1439 SetPARP(89,1000.); // [GeV] Ref. energy
1440 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1441 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1442 SetPARP(84,0.5); // Core radius
1443 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1444 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1445 SetPARP(67,1); // Regulates Initial State Radiation
1448 void AliPythia6::AtlasTuningMC09()
1451 // Configuration for the ATLAS tuning
1452 printf("ATLAS New TUNE MC09\n");
1453 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1454 SetMSTP(82, 4); // Double Gaussian Model
1455 SetMSTP(52, 2); // External PDF
1456 SetMSTP(51, 20650); // MRST LO*
1459 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1460 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1461 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1462 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1464 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1465 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1466 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1467 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1468 SetPARP(84, 0.7); // Core radius
1469 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1470 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1473 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1475 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1476 SetPARP(89,1800.); // [GeV] Ref. energy
1479 void AliPythia6::SetPtHardRange(Float_t ptmin, Float_t ptmax)
1481 // Set the pt hard range
1486 void AliPythia6::SetYHardRange(Float_t ymin, Float_t ymax)
1488 // Set the y hard range
1494 void AliPythia6::SetFragmentation(Int_t flag)
1496 // Switch fragmentation on/off
1500 void AliPythia6::SetInitialAndFinalStateRadiation(Int_t flag1, Int_t flag2)
1502 // initial state radiation
1504 // final state radiation
1508 void AliPythia6::SetIntrinsicKt(Float_t kt)
1510 // Set the inreinsic kt
1514 SetPARP(93, 4. * kt);
1520 void AliPythia6::SwitchHFOff()
1522 // Switch off heavy flavor
1523 // Maximum number of quark flavours used in pdf
1525 // Maximum number of flavors that can be used in showers
1529 void AliPythia6::SetPycellParameters(Float_t etamax, Int_t neta, Int_t nphi,
1530 Float_t thresh, Float_t etseed, Float_t minet, Float_t r)
1532 // Set pycell parameters
1533 SetPARU(51, etamax);
1536 SetPARU(58, thresh);
1537 SetPARU(52, etseed);
1543 void AliPythia6::ModifiedSplitting()
1545 // Modified splitting probability as a model for quenching
1547 SetMSTJ(41, 1); // QCD radiation only
1548 SetMSTJ(42, 2); // angular ordering
1549 SetMSTJ(44, 2); // option to run alpha_s
1550 SetMSTJ(47, 0); // No correction back to hard scattering element
1551 SetMSTJ(50, 0); // No coherence in first branching
1552 SetPARJ(82, 1.); // Cut off for parton showers
1555 void AliPythia6::SwitchHadronisationOff()
1557 // Switch off hadronisarion
1561 void AliPythia6::SwitchHadronisationOn()
1563 // Switch on hadronisarion
1568 void AliPythia6::GetXandQ(Float_t& x1, Float_t& x2, Float_t& q)
1570 // Get x1, x2 and Q for this event
1577 Float_t AliPythia6::GetXSection()
1579 // Get the total cross-section
1580 return (GetPARI(1));
1583 Float_t AliPythia6::GetPtHard()
1585 // Get the pT hard for this event
1589 Int_t AliPythia6::ProcessCode()
1591 // Get the subprocess code
1595 void AliPythia6::PrintStatistics()
1597 // End of run statistics
1601 void AliPythia6::EventListing()
1603 // End of run statistics
1607 AliPythia6& AliPythia6::operator=(const AliPythia6& rhs)
1609 // Assignment operator
1614 void AliPythia6::Copy(TObject&) const
1619 Fatal("Copy","Not implemented!\n");