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
613 //Inclusive production of Z
617 // Initial/final parton shower on (Pythia default)
618 // With parton showers on we are generating "Z inclusive process"
619 SetMSTP(61,1); //Initial QCD & QED showers on
620 SetMSTP(71,1); //Final QCD & QED showers on
622 case kPyMBRSingleDiffraction:
623 case kPyMBRDoubleDiffraction:
624 case kPyMBRCentralDiffraction:
629 // For the case of jet production the following parameter setting
630 // limits the transverse momentum of secondary scatterings, due
631 // to multiple parton interactions, to be less than that of the
632 // primary interaction (see POWHEG Dijet paper arXiv:1012.3380
633 // [hep-ph] sec. 4.1 and also the PYTHIA Manual).
635 // maximum number of errors before pythia aborts (def=10)
637 // number of warnings printed on the shell
643 // number of warnings printed on the shell
649 SetMSTP(41,1); // all resonance decays switched on
650 if (process == kPyJetsPWHG || process == kPyCharmPWHG || process == kPyBeautyPWHG || process == kPyWPWHG) {
651 Initialize("USER","","",0.);
653 Initialize("CMS",fProjectile,fTarget,fEcms);
657 Int_t AliPythia6::CheckedLuComp(Int_t kf)
659 // Check Lund particle code (for debugging)
664 void AliPythia6::SetNuclei(Int_t a1, Int_t a2)
666 // Treat protons as inside nuclei with mass numbers a1 and a2
667 // The MSTP array in the PYPARS common block is used to enable and
668 // select the nuclear structure functions.
669 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
670 // =1: internal PYTHIA acording to MSTP(51)
671 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
672 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
673 // MSTP(192) : Mass number of nucleus side 1
674 // MSTP(193) : Mass number of nucleus side 2
681 AliPythia6* AliPythia6::Instance()
683 // Set random number generator
687 fgAliPythia = new AliPythia6();
692 void AliPythia6::PrintParticles()
694 // Print list of particl properties
696 char* name = new char[16];
697 for (Int_t kf=0; kf<1000000; kf++) {
698 for (Int_t c = 1; c > -2; c-=2) {
699 Int_t kc = Pycomp(c*kf);
701 Float_t mass = GetPMAS(kc,1);
702 Float_t width = GetPMAS(kc,2);
703 Float_t tau = GetPMAS(kc,4);
709 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
710 c*kf, name, mass, width, tau);
714 printf("\n Number of particles %d \n \n", np);
717 void AliPythia6::ResetDecayTable()
719 // Set default values for pythia decay switches
721 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
722 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
725 void AliPythia6::SetDecayTable()
727 // Set default values for pythia decay switches
730 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
731 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
734 void AliPythia6::Pyjoin(Int_t& npart, Int_t *ipart)
736 // Call Pythia join alogorithm to set up a string between
737 // npart partons, given by indices in array ipart[npart]
739 pyjoin(npart, ipart);
742 void AliPythia6::Pyshowq(Int_t ip1, Int_t ip2, Double_t qmax)
744 // Call qPythia showering
746 pyshowq(ip1, ip2, qmax);
749 void AliPythia6::Qpygin0()
751 //position of the hard scattering in the nuclear overlapping area.
756 void AliPythia6::Pyclus(Int_t& njet)
758 // Call Pythia clustering algorithm
763 void AliPythia6::Pycell(Int_t& njet)
765 // Call Pythia jet reconstruction algorithm
770 void AliPythia6::GetJet(Int_t i, Float_t& px, Float_t& py, Float_t& pz, Float_t& e)
774 px = GetPyjets()->P[0][n+i];
775 py = GetPyjets()->P[1][n+i];
776 pz = GetPyjets()->P[2][n+i];
777 e = GetPyjets()->P[3][n+i];
780 void AliPythia6::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
782 // Call Pythia showering
784 pyshow(ip1, ip2, qmax);
787 void AliPythia6::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
789 pyrobo(imi, ima, the, phi, bex, bey, bez);
794 void AliPythia6::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
797 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
798 // (2) The nuclear geometry using the Glauber Model
801 fGlauber = AliFastGlauber::Instance();
803 fGlauber->SetCentralityClass(cMin, cMax);
805 fQuenchingWeights = new AliQuenchingWeights();
806 fQuenchingWeights->InitMult();
807 fQuenchingWeights->SetK(k);
808 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
815 void AliPythia6::Quench()
819 // Simple Jet Quenching routine:
820 // =============================
821 // The jet formed by all final state partons radiated by the parton created
822 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
823 // the initial parton reference frame:
824 // (E + p_z)new = (1-z) (E + p_z)old
829 // The lost momentum is first balanced by one gluon with virtuality > 0.
830 // Subsequently the gluon splits to yield two gluons with E = p.
834 static Float_t eMean = 0.;
835 static Int_t icall = 0;
840 Int_t klast[4] = {-1, -1, -1, -1};
842 Int_t numpart = fPyjets->N;
843 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
844 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
846 Double_t wjtKick[4] = {0., 0., 0., 0.};
852 // Sore information about Primary partons
855 // 0, 1 partons from hard scattering
856 // 2, 3 partons from initial state radiation
858 for (Int_t i = 2; i <= 7; i++) {
860 // Skip gluons that participate in hard scattering
861 if (i == 4 || i == 5) continue;
862 // Gluons from hard Scattering
863 if (i == 6 || i == 7) {
865 pxq[j] = fPyjets->P[0][i];
866 pyq[j] = fPyjets->P[1][i];
867 pzq[j] = fPyjets->P[2][i];
868 eq[j] = fPyjets->P[3][i];
869 mq[j] = fPyjets->P[4][i];
871 // Gluons from initial state radiation
873 // Obtain 4-momentum vector from difference between original parton and parton after gluon
874 // radiation. Energy is calculated independently because initial state radition does not
875 // conserve strictly momentum and energy for each partonic system independently.
877 // Not very clean. Should be improved !
881 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
882 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
883 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
884 mq[j] = fPyjets->P[4][i];
885 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
888 // Calculate some kinematic variables
890 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
891 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
892 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
893 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
894 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
895 qPdg[j] = fPyjets->K[1][i];
901 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
903 for (Int_t j = 0; j < 4; j++) {
905 // Quench only central jets and with E > 10.
909 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
910 // Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
911 Double_t eloss = fQuenchingWeights->GetELossRandomK(itype, int0[j], int1[j], eq[j]);
913 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
916 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
922 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
923 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
925 // Fractional energy loss
926 fZQuench[j] = eloss / eq[j];
928 // Avoid complete loss
930 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
932 // Some debug printing
935 // 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",
936 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
938 // fZQuench[j] = 0.8;
939 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
942 quenched[j] = (fZQuench[j] > 0.01);
947 Double_t pNew[1000][4];
954 for (Int_t isys = 0; isys < 4; isys++) {
955 // Skip to next system if not quenched.
956 if (!quenched[isys]) continue;
958 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
959 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
960 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
961 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
967 Double_t pg[4] = {0., 0., 0., 0.};
970 // Loop on radiation events
972 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
975 for (Int_t k = 0; k < 4; k++)
982 for (Int_t i = 0; i < numpart; i++)
984 imo = fPyjets->K[2][i];
985 kst = fPyjets->K[0][i];
986 pdg = fPyjets->K[1][i];
990 // Quarks and gluons only
991 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
992 // Particles from hard scattering only
994 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
995 Int_t imom = imo % 1000;
996 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
997 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
1000 // Skip comment lines
1001 if (kst != 1 && kst != 2) continue;
1004 px = fPyjets->P[0][i];
1005 py = fPyjets->P[1][i];
1006 pz = fPyjets->P[2][i];
1007 e = fPyjets->P[3][i];
1008 m = fPyjets->P[4][i];
1009 pt = TMath::Sqrt(px * px + py * py);
1010 p = TMath::Sqrt(px * px + py * py + pz * pz);
1011 phi = TMath::Pi() + TMath::ATan2(-py, -px);
1012 theta = TMath::ATan2(pt, pz);
1015 // Save 4-momentum sum for balancing
1026 // Fractional energy loss
1027 Double_t z = zquench[index];
1030 // Don't fully quench radiated gluons
1033 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
1038 // printf("z: %d %f\n", imo, z);
1045 // Transform into frame in which initial parton is along z-axis
1047 TVector3 v(px, py, pz);
1048 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
1049 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
1051 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
1052 Double_t mt2 = jt * jt + m * m;
1055 // Kinematic limit on z
1057 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
1059 // Change light-cone kinematics rel. to initial parton
1061 Double_t eppzOld = e + pl;
1062 Double_t empzOld = e - pl;
1064 Double_t eppzNew = (1. - z) * eppzOld;
1065 Double_t empzNew = empzOld - mt2 * z / eppzOld;
1066 Double_t eNew = 0.5 * (eppzNew + empzNew);
1067 Double_t plNew = 0.5 * (eppzNew - empzNew);
1071 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
1072 Double_t mt2New = eppzNew * empzNew;
1073 if (mt2New < 1.e-8) mt2New = 0.;
1075 if (m * m > mt2New) {
1077 // This should not happen
1079 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
1082 jtNew = TMath::Sqrt(mt2New - m * m);
1085 // If pT is to small (probably a leading massive particle) we scale only the energy
1086 // This can cause negative masses of the radiated gluon
1087 // Let's hope for the best ...
1089 eNew = TMath::Sqrt(plNew * plNew + mt2);
1093 // Calculate new px, py
1099 pxNew = jtNew / jt * pxs;
1100 pyNew = jtNew / jt * pys;
1103 // Double_t dpx = pxs - pxNew;
1104 // Double_t dpy = pys - pyNew;
1105 // Double_t dpz = pl - plNew;
1106 // Double_t de = e - eNew;
1107 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1108 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1109 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1113 TVector3 w(pxNew, pyNew, plNew);
1114 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1115 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1117 p1[index][0] += pxNew;
1118 p1[index][1] += pyNew;
1119 p1[index][2] += plNew;
1120 p1[index][3] += eNew;
1122 // Updated 4-momentum vectors
1124 pNew[icount][0] = pxNew;
1125 pNew[icount][1] = pyNew;
1126 pNew[icount][2] = plNew;
1127 pNew[icount][3] = eNew;
1132 // Check if there was phase-space for quenching
1135 if (icount == 0) quenched[isys] = kFALSE;
1136 if (!quenched[isys]) break;
1138 for (Int_t j = 0; j < 4; j++)
1140 p2[isys][j] = p0[isys][j] - p1[isys][j];
1142 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];
1143 if (p2[isys][4] > 0.) {
1144 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1147 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1148 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]);
1149 if (p2[isys][4] < -0.01) {
1150 printf("Negative mass squared !\n");
1151 // Here we have to put the gluon back to mass shell
1152 // This will lead to a small energy imbalance
1154 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1163 printf("zHeavy lowered to %f\n", zHeavy);
1164 if (zHeavy < 0.01) {
1165 printf("No success ! \n");
1167 quenched[isys] = kFALSE;
1171 } // iteration on z (while)
1173 // Update event record
1174 for (Int_t k = 0; k < icount; k++) {
1175 // 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] );
1176 fPyjets->P[0][kNew[k]] = pNew[k][0];
1177 fPyjets->P[1][kNew[k]] = pNew[k][1];
1178 fPyjets->P[2][kNew[k]] = pNew[k][2];
1179 fPyjets->P[3][kNew[k]] = pNew[k][3];
1186 if (!quenched[isys]) continue;
1188 // Last parton from shower i
1189 Int_t in = klast[isys];
1191 // Continue if no parton in shower i selected
1192 if (in == -1) continue;
1194 // If this is the second initial parton and it is behind the first move pointer by previous ish
1195 if (isys == 1 && klast[1] > klast[0]) in += ish;
1200 // How many additional gluons will be generated
1202 if (p2[isys][4] > 0.05) ish = 2;
1204 // Position of gluons
1206 if (iglu == 0) igMin = iGlu;
1209 (fPyjets->N) += ish;
1212 fPyjets->P[0][iGlu] = p2[isys][0];
1213 fPyjets->P[1][iGlu] = p2[isys][1];
1214 fPyjets->P[2][iGlu] = p2[isys][2];
1215 fPyjets->P[3][iGlu] = p2[isys][3];
1216 fPyjets->P[4][iGlu] = p2[isys][4];
1218 fPyjets->K[0][iGlu] = 1;
1219 if (iglu == nGluon[isys] - 1) 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 pg[0] += p2[isys][0];
1226 pg[1] += p2[isys][1];
1227 pg[2] += p2[isys][2];
1228 pg[3] += p2[isys][3];
1231 // Split gluon in rest frame.
1233 Double_t bx = p2[isys][0] / p2[isys][3];
1234 Double_t by = p2[isys][1] / p2[isys][3];
1235 Double_t bz = p2[isys][2] / p2[isys][3];
1236 Double_t pst = p2[isys][4] / 2.;
1238 // Isotropic decay ????
1239 Double_t cost = 2. * gRandom->Rndm() - 1.;
1240 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1241 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1243 Double_t pz1 = pst * cost;
1244 Double_t pz2 = -pst * cost;
1245 Double_t pt1 = pst * sint;
1246 Double_t pt2 = -pst * sint;
1247 Double_t px1 = pt1 * TMath::Cos(phis);
1248 Double_t py1 = pt1 * TMath::Sin(phis);
1249 Double_t px2 = pt2 * TMath::Cos(phis);
1250 Double_t py2 = pt2 * TMath::Sin(phis);
1252 fPyjets->P[0][iGlu] = px1;
1253 fPyjets->P[1][iGlu] = py1;
1254 fPyjets->P[2][iGlu] = pz1;
1255 fPyjets->P[3][iGlu] = pst;
1256 fPyjets->P[4][iGlu] = 0.;
1258 fPyjets->K[0][iGlu] = 1 ;
1259 fPyjets->K[1][iGlu] = 21;
1260 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1261 fPyjets->K[3][iGlu] = -1;
1262 fPyjets->K[4][iGlu] = -1;
1264 fPyjets->P[0][iGlu+1] = px2;
1265 fPyjets->P[1][iGlu+1] = py2;
1266 fPyjets->P[2][iGlu+1] = pz2;
1267 fPyjets->P[3][iGlu+1] = pst;
1268 fPyjets->P[4][iGlu+1] = 0.;
1270 fPyjets->K[0][iGlu+1] = 1;
1271 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1272 fPyjets->K[1][iGlu+1] = 21;
1273 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1274 fPyjets->K[3][iGlu+1] = -1;
1275 fPyjets->K[4][iGlu+1] = -1;
1281 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1284 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1285 Double_t px, py, pz;
1286 px = fPyjets->P[0][ig];
1287 py = fPyjets->P[1][ig];
1288 pz = fPyjets->P[2][ig];
1289 TVector3 v(px, py, pz);
1290 v.RotateZ(-phiq[isys]);
1291 v.RotateY(-thetaq[isys]);
1292 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1293 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1294 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1295 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1296 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1297 pxs += jtKick * TMath::Cos(phiKick);
1298 pys += jtKick * TMath::Sin(phiKick);
1299 TVector3 w(pxs, pys, pzs);
1300 w.RotateY(thetaq[isys]);
1301 w.RotateZ(phiq[isys]);
1302 fPyjets->P[0][ig] = w.X();
1303 fPyjets->P[1][ig] = w.Y();
1304 fPyjets->P[2][ig] = w.Z();
1305 fPyjets->P[2][ig] = w.Mag();
1311 // Check energy conservation
1315 Double_t es = 14000.;
1317 for (Int_t i = 0; i < numpart; i++)
1319 kst = fPyjets->K[0][i];
1320 if (kst != 1 && kst != 2) continue;
1321 pxs += fPyjets->P[0][i];
1322 pys += fPyjets->P[1][i];
1323 pzs += fPyjets->P[2][i];
1324 es -= fPyjets->P[3][i];
1326 if (TMath::Abs(pxs) > 1.e-2 ||
1327 TMath::Abs(pys) > 1.e-2 ||
1328 TMath::Abs(pzs) > 1.e-1) {
1329 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1330 // Fatal("Quench()", "4-Momentum non-conservation");
1333 } // end quenching loop (systems)
1335 for (Int_t i = 0; i < numpart; i++)
1337 imo = fPyjets->K[2][i];
1339 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1346 void AliPythia6::Pyquen(Double_t a, Int_t ibf, Double_t b)
1348 // Igor Lokthine's quenching routine
1349 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1354 void AliPythia6::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1356 // Set the parameters for the PYQUEN package.
1357 // See comments in PyquenCommon.h
1363 PYQPAR.iengl = iengl;
1364 PYQPAR.iangl = iangl;
1367 void AliPythia6::LoadEvent(AliStack* stack, Int_t flag, Int_t reHadr)
1370 // Load event into Pythia Common Block
1373 Int_t npart = stack -> GetNprimary();
1377 GetPyjets()->N = npart;
1379 n0 = GetPyjets()->N;
1380 GetPyjets()->N = n0 + npart;
1384 for (Int_t part = 0; part < npart; part++) {
1385 TParticle *mPart = stack->Particle(part);
1387 Int_t kf = mPart->GetPdgCode();
1388 Int_t ks = mPart->GetStatusCode();
1389 Int_t idf = mPart->GetFirstDaughter();
1390 Int_t idl = mPart->GetLastDaughter();
1393 if (ks == 11 || ks == 12) {
1400 Float_t px = mPart->Px();
1401 Float_t py = mPart->Py();
1402 Float_t pz = mPart->Pz();
1403 Float_t e = mPart->Energy();
1404 Float_t m = mPart->GetCalcMass();
1407 (GetPyjets())->P[0][part+n0] = px;
1408 (GetPyjets())->P[1][part+n0] = py;
1409 (GetPyjets())->P[2][part+n0] = pz;
1410 (GetPyjets())->P[3][part+n0] = e;
1411 (GetPyjets())->P[4][part+n0] = m;
1413 (GetPyjets())->K[1][part+n0] = kf;
1414 (GetPyjets())->K[0][part+n0] = ks;
1415 (GetPyjets())->K[3][part+n0] = idf + 1;
1416 (GetPyjets())->K[4][part+n0] = idl + 1;
1417 (GetPyjets())->K[2][part+n0] = mPart->GetFirstMother() + 1;
1422 void AliPythia6::Pyevnw()
1424 // New multiple interaction scenario
1428 void AliPythia6::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1430 // Return event specific quenching parameters
1433 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1437 void AliPythia6::ConfigHeavyFlavor()
1440 // Default configuration for Heavy Flavor production
1442 // All QCD processes
1446 // No multiple interactions
1450 // Initial/final parton shower on (Pythia default)
1454 // 2nd order alpha_s
1462 void AliPythia6::AtlasTuning()
1465 // Configuration for the ATLAS tuning
1466 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ5L));
1467 SetMSTP(81,1); // Multiple Interactions ON
1468 SetMSTP(82,4); // Double Gaussian Model
1469 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1470 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1471 SetPARP(89,1000.); // [GeV] Ref. energy
1472 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1473 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1474 SetPARP(84,0.5); // Core radius
1475 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1476 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1477 SetPARP(67,1); // Regulates Initial State Radiation
1480 void AliPythia6::AtlasTuningMC09()
1483 // Configuration for the ATLAS tuning
1484 printf("ATLAS New TUNE MC09\n");
1485 SetMSTP(81,21); // treatment for MI, ISR, FSR and beam remnants: MI on, new model
1486 SetMSTP(82, 4); // Double Gaussian Model
1487 SetMSTP(52, 2); // External PDF
1488 SetMSTP(51, 20650); // MRST LO*
1491 SetMSTP(70, 0); // (was 2: def manual 1, def code 0) virtuality scale for ISR
1492 SetMSTP(72, 1); // (was 0: def 1) maximum scale for FSR
1493 SetMSTP(88, 1); // (was 0: def 1) strategy for qq junction to di-quark or baryon in beam remnant
1494 SetMSTP(90, 0); // (was 1: def 0) strategy of compensate the primordial kT
1496 SetPARP(78, 0.3); // the amount of color reconnection in the final state
1497 SetPARP(80, 0.1); // probability of color partons kicked out from beam remnant
1498 SetPARP(82, 2.3); // [GeV] PT_min at Ref. energy
1499 SetPARP(83, 0.8); // Core density in proton matter distribution (def.value)
1500 SetPARP(84, 0.7); // Core radius
1501 SetPARP(90, 0.25); // 2*epsilon (exponent in power law)
1502 SetPARJ(81, 0.29); // (was 0.14: def 0.29) Labmda value in running alpha_s for parton showers
1505 SetPARJ(41, 0.3); // a and b parameters of the symmm. Lund FF
1507 SetPARJ(46, 0.75); // mod. of the Lund FF for heavy end-point quarks
1508 SetPARP(89,1800.); // [GeV] Ref. energy
1511 void AliPythia6::SetPtHardRange(Float_t ptmin, Float_t ptmax)
1513 // Set the pt hard range
1518 void AliPythia6::SetYHardRange(Float_t ymin, Float_t ymax)
1520 // Set the y hard range
1526 void AliPythia6::SetFragmentation(Int_t flag)
1528 // Switch fragmentation on/off
1532 void AliPythia6::SetInitialAndFinalStateRadiation(Int_t flag1, Int_t flag2)
1534 // initial state radiation
1536 // final state radiation
1540 void AliPythia6::SetIntrinsicKt(Float_t kt)
1542 // Set the inreinsic kt
1546 SetPARP(93, 4. * kt);
1552 void AliPythia6::SwitchHFOff()
1554 // Switch off heavy flavor
1555 // Maximum number of quark flavours used in pdf
1557 // Maximum number of flavors that can be used in showers
1561 void AliPythia6::SetPycellParameters(Float_t etamax, Int_t neta, Int_t nphi,
1562 Float_t thresh, Float_t etseed, Float_t minet, Float_t r)
1564 // Set pycell parameters
1565 SetPARU(51, etamax);
1568 SetPARU(58, thresh);
1569 SetPARU(52, etseed);
1575 void AliPythia6::ModifiedSplitting()
1577 // Modified splitting probability as a model for quenching
1579 SetMSTJ(41, 1); // QCD radiation only
1580 SetMSTJ(42, 2); // angular ordering
1581 SetMSTJ(44, 2); // option to run alpha_s
1582 SetMSTJ(47, 0); // No correction back to hard scattering element
1583 SetMSTJ(50, 0); // No coherence in first branching
1584 SetPARJ(82, 1.); // Cut off for parton showers
1587 void AliPythia6::SwitchHadronisationOff()
1589 // Switch off hadronisarion
1593 void AliPythia6::SwitchHadronisationOn()
1595 // Switch on hadronisarion
1600 void AliPythia6::GetXandQ(Float_t& x1, Float_t& x2, Float_t& q)
1602 // Get x1, x2 and Q for this event
1609 Float_t AliPythia6::GetXSection()
1611 // Get the total cross-section
1612 return (GetPARI(1));
1615 Float_t AliPythia6::GetPtHard()
1617 // Get the pT hard for this event
1621 Int_t AliPythia6::ProcessCode()
1623 // Get the subprocess code
1627 void AliPythia6::PrintStatistics()
1629 // End of run statistics
1633 void AliPythia6::EventListing()
1635 // End of run statistics
1639 AliPythia6& AliPythia6::operator=(const AliPythia6& rhs)
1641 // Assignment operator
1646 void AliPythia6::Copy(TObject&) const
1651 Fatal("Copy","Not implemented!\n");