2 /**************************************************************************
3 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
5 * Author: The ALICE Off-line Project. *
6 * Contributors are mentioned in the code where appropriate. *
8 * Permission to use, copy, modify and distribute this software and its *
9 * documentation strictly for non-commercial purposes is hereby granted *
10 * without fee, provided that the above copyright notice appears in all *
11 * copies and that both the copyright notice and this permission notice *
12 * appear in the supporting documentation. The authors make no claims *
13 * about the suitability of this software for any purpose. It is *
14 * provided "as is" without express or implied warranty. *
15 **************************************************************************/
19 #include "AliPythia.h"
20 #include "AliPythiaRndm.h"
21 #include "AliFastGlauber.h"
22 #include "AliQuenchingWeights.h"
24 #include "PyquenCommon.h"
29 # define pyclus pyclus_
30 # define pycell pycell_
31 # define pyshow pyshow_
32 # define pyrobo pyrobo_
33 # define pyquen pyquen_
34 # define pyevnw pyevnw_
37 # define pyclus PYCLUS
38 # define pycell PYCELL
39 # define pyrobo PYROBO
40 # define pyquen PYQUEN
41 # define pyevnw PYEVNW
42 # define type_of_call _stdcall
45 extern "C" void type_of_call pyclus(Int_t & );
46 extern "C" void type_of_call pycell(Int_t & );
47 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
48 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
49 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
50 extern "C" void type_of_call pyevnw(){;}
52 //_____________________________________________________________________________
54 AliPythia* AliPythia::fgAliPythia=NULL;
56 AliPythia::AliPythia():
67 // Default Constructor
70 if (!AliPythiaRndm::GetPythiaRandom())
71 AliPythiaRndm::SetPythiaRandom(GetRandom());
73 fQuenchingWeights = 0;
76 AliPythia::AliPythia(const AliPythia& pythia):
93 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
95 // Initialise the process to generate
96 if (!AliPythiaRndm::GetPythiaRandom())
97 AliPythiaRndm::SetPythiaRandom(GetRandom());
101 fStrucFunc = strucfunc;
102 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
103 SetMDCY(Pycomp(111) ,1,0); // pi0
104 SetMDCY(Pycomp(310) ,1,0); // K0S
105 SetMDCY(Pycomp(3122),1,0); // kLambda
106 SetMDCY(Pycomp(3112),1,0); // sigma -
107 SetMDCY(Pycomp(3212),1,0); // sigma 0
108 SetMDCY(Pycomp(3222),1,0); // sigma +
109 SetMDCY(Pycomp(3312),1,0); // xi -
110 SetMDCY(Pycomp(3322),1,0); // xi 0
111 SetMDCY(Pycomp(3334),1,0); // omega-
112 // Select structure function
114 SetMSTP(51, AliStructFuncType::PDFsetIndex(strucfunc));
115 // Particles produced in string fragmentation point directly to either of the two endpoints
116 // of the string (depending in the side they were generated from).
120 // Pythia initialisation for selected processes//
124 for (Int_t i=1; i<= 200; i++) {
127 // select charm production
130 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
131 // Multiple interactions on.
133 // Double Gaussian matter distribution.
139 // Reference energy for pT0 and energy rescaling pace.
142 // String drawing almost completely minimizes string length.
145 // ISR and FSR activity.
151 case kPyOldUEQ2ordered2:
152 // Old underlying events with Q2 ordered QCD processes
153 // Multiple interactions on.
155 // Double Gaussian matter distribution.
161 // Reference energy for pT0 and energy rescaling pace.
163 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
164 // String drawing almost completely minimizes string length.
167 // ISR and FSR activity.
174 // Old production mechanism: Old Popcorn
177 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
179 // (D=1)see can be used to form baryons (BARYON JUNCTION)
185 // heavy quark masses
215 case kPyCharmUnforced:
224 case kPyBeautyUnforced:
234 // Minimum Bias pp-Collisions
237 // select Pythia min. bias model
239 SetMSUB(92,1); // single diffraction AB-->XB
240 SetMSUB(93,1); // single diffraction AB-->AX
241 SetMSUB(94,1); // double diffraction
242 SetMSUB(95,1); // low pt production
247 case kPyMbWithDirectPhoton:
248 // Minimum Bias pp-Collisions with direct photon processes added
251 // select Pythia min. bias model
253 SetMSUB(92,1); // single diffraction AB-->XB
254 SetMSUB(93,1); // single diffraction AB-->AX
255 SetMSUB(94,1); // double diffraction
256 SetMSUB(95,1); // low pt production
269 // Minimum Bias pp-Collisions
272 // select Pythia min. bias model
274 SetMSUB(92,1); // single diffraction AB-->XB
275 SetMSUB(93,1); // single diffraction AB-->AX
276 SetMSUB(94,1); // double diffraction
277 SetMSUB(95,1); // low pt production
281 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
282 // -> Pythia 6.3 or above is needed
285 SetMSUB(92,1); // single diffraction AB-->XB
286 SetMSUB(93,1); // single diffraction AB-->AX
287 SetMSUB(94,1); // double diffraction
288 SetMSUB(95,1); // low pt production
290 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll)); // CTEQ6ll pdf
294 SetMSTP(81,1); // Multiple Interactions ON
295 SetMSTP(82,4); // Double Gaussian Model
298 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
299 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
300 SetPARP(84,0.5); // Core radius
301 SetPARP(85,0.9); // Regulates gluon prod. mechanism
302 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
306 // Minimum Bias pp-Collisions
309 // select Pythia min. bias model
311 SetMSUB(95,1); // low pt production
318 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
319 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
320 SetPARP(93,5.); // Upper cut-off
322 SetPMAS(4,1,1.2); // Charm quark mass
323 SetPMAS(5,1,4.78); // Beauty quark mass
324 SetPARP(71,4.); // Defaut value
333 // Pythia Tune A (CDF)
335 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
336 SetMSTP(82,4); // Double Gaussian Model
337 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
338 SetPARP(84,0.4); // Core radius
339 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
340 SetPARP(86,0.95); // Regulates gluon prod. mechanism
341 SetPARP(89,1800.); // [GeV] Ref. energy
342 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
347 case kPyCharmPbPbMNR:
349 case kPyDPlusPbPbMNR:
350 case kPyDPlusStrangePbPbMNR:
351 // Tuning of Pythia parameters aimed to get a resonable agreement
352 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
353 // c-cbar single inclusive and double differential distributions.
354 // This parameter settings are meant to work with Pb-Pb collisions
355 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
356 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
357 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
369 case kPyDPlusStrangepPbMNR:
370 // Tuning of Pythia parameters aimed to get a resonable agreement
371 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
372 // c-cbar single inclusive and double differential distributions.
373 // This parameter settings are meant to work with p-Pb collisions
374 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
375 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
376 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
389 case kPyDPlusStrangeppMNR:
390 // Tuning of Pythia parameters aimed to get a resonable agreement
391 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
392 // c-cbar single inclusive and double differential distributions.
393 // This parameter settings are meant to work with pp collisions
394 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
395 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
396 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
406 case kPyCharmppMNRwmi:
407 // Tuning of Pythia parameters aimed to get a resonable agreement
408 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
409 // c-cbar single inclusive and double differential distributions.
410 // This parameter settings are meant to work with pp collisions
411 // and with kCTEQ5L PDFs.
412 // Added multiple interactions according to ATLAS tune settings.
413 // To get a "reasonable" agreement with MNR results, events have to be
414 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
416 // To get a "perfect" agreement with MNR results, events have to be
417 // generated in four ptHard bins with the following relative
433 case kPyBeautyPbPbMNR:
434 // Tuning of Pythia parameters aimed to get a resonable agreement
435 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
436 // b-bbar single inclusive and double differential distributions.
437 // This parameter settings are meant to work with Pb-Pb collisions
438 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
439 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
440 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
452 case kPyBeautypPbMNR:
453 // Tuning of Pythia parameters aimed to get a resonable agreement
454 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
455 // b-bbar single inclusive and double differential distributions.
456 // This parameter settings are meant to work with p-Pb collisions
457 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
458 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
459 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
472 // Tuning of Pythia parameters aimed to get a resonable agreement
473 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
474 // b-bbar single inclusive and double differential distributions.
475 // This parameter settings are meant to work with pp collisions
476 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
477 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
478 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
492 case kPyBeautyppMNRwmi:
493 // Tuning of Pythia parameters aimed to get a resonable agreement
494 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
495 // b-bbar single inclusive and double differential distributions.
496 // This parameter settings are meant to work with pp collisions
497 // and with kCTEQ5L PDFs.
498 // Added multiple interactions according to ATLAS tune settings.
499 // To get a "reasonable" agreement with MNR results, events have to be
500 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
502 // To get a "perfect" agreement with MNR results, events have to be
503 // generated in four ptHard bins with the following relative
526 //Inclusive production of W+/-
532 // //f fbar -> gamma W+
539 // Initial/final parton shower on (Pythia default)
540 // With parton showers on we are generating "W inclusive process"
541 SetMSTP(61,1); //Initial QCD & QED showers on
542 SetMSTP(71,1); //Final QCD & QED showers on
548 //Inclusive production of Z
553 // // f fbar -> g Z/gamma
555 // // f fbar -> gamma Z/gamma
557 // // f g -> f Z/gamma
559 // // f gamma -> f Z/gamma
562 //only Z included, not gamma
565 // Initial/final parton shower on (Pythia default)
566 // With parton showers on we are generating "Z inclusive process"
567 SetMSTP(61,1); //Initial QCD & QED showers on
568 SetMSTP(71,1); //Final QCD & QED showers on
575 SetMSTP(41,1); // all resonance decays switched on
576 Initialize("CMS","p","p",fEcms);
580 Int_t AliPythia::CheckedLuComp(Int_t kf)
582 // Check Lund particle code (for debugging)
584 printf("\n Lucomp kf,kc %d %d",kf,kc);
588 void AliPythia::SetNuclei(Int_t a1, Int_t a2, Int_t pdf)
590 // Treat protons as inside nuclei with mass numbers a1 and a2
591 // The MSTP array in the PYPARS common block is used to enable and
592 // select the nuclear structure functions.
593 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
594 // =1: internal PYTHIA acording to MSTP(51)
595 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
596 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
597 // MSTP(192) : Mass number of nucleus side 1
598 // MSTP(193) : Mass number of nucleus side 2
599 // MSTP(194) : Nuclear structure function: 0: EKS98 1:EPS08
607 AliPythia* AliPythia::Instance()
609 // Set random number generator
613 fgAliPythia = new AliPythia();
618 void AliPythia::PrintParticles()
620 // Print list of particl properties
622 char* name = new char[16];
623 for (Int_t kf=0; kf<1000000; kf++) {
624 for (Int_t c = 1; c > -2; c-=2) {
625 Int_t kc = Pycomp(c*kf);
627 Float_t mass = GetPMAS(kc,1);
628 Float_t width = GetPMAS(kc,2);
629 Float_t tau = GetPMAS(kc,4);
635 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
636 c*kf, name, mass, width, tau);
640 printf("\n Number of particles %d \n \n", np);
643 void AliPythia::ResetDecayTable()
645 // Set default values for pythia decay switches
647 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
648 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
651 void AliPythia::SetDecayTable()
653 // Set default values for pythia decay switches
656 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
657 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
660 void AliPythia::Pyclus(Int_t& njet)
662 // Call Pythia clustering algorithm
667 void AliPythia::Pycell(Int_t& njet)
669 // Call Pythia jet reconstruction algorithm
674 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
676 // Call Pythia jet reconstruction algorithm
678 pyshow(ip1, ip2, qmax);
681 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
683 pyrobo(imi, ima, the, phi, bex, bey, bez);
688 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
691 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
692 // (2) The nuclear geometry using the Glauber Model
695 fGlauber = AliFastGlauber::Instance();
697 fGlauber->SetCentralityClass(cMin, cMax);
699 fQuenchingWeights = new AliQuenchingWeights();
700 fQuenchingWeights->InitMult();
701 fQuenchingWeights->SetK(k);
702 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
709 void AliPythia::Quench()
713 // Simple Jet Quenching routine:
714 // =============================
715 // The jet formed by all final state partons radiated by the parton created
716 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
717 // the initial parton reference frame:
718 // (E + p_z)new = (1-z) (E + p_z)old
723 // The lost momentum is first balanced by one gluon with virtuality > 0.
724 // Subsequently the gluon splits to yield two gluons with E = p.
728 static Float_t eMean = 0.;
729 static Int_t icall = 0;
734 Int_t klast[4] = {-1, -1, -1, -1};
736 Int_t numpart = fPyjets->N;
737 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
738 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
746 // Sore information about Primary partons
749 // 0, 1 partons from hard scattering
750 // 2, 3 partons from initial state radiation
752 for (Int_t i = 2; i <= 7; i++) {
754 // Skip gluons that participate in hard scattering
755 if (i == 4 || i == 5) continue;
756 // Gluons from hard Scattering
757 if (i == 6 || i == 7) {
759 pxq[j] = fPyjets->P[0][i];
760 pyq[j] = fPyjets->P[1][i];
761 pzq[j] = fPyjets->P[2][i];
762 eq[j] = fPyjets->P[3][i];
763 mq[j] = fPyjets->P[4][i];
765 // Gluons from initial state radiation
767 // Obtain 4-momentum vector from difference between original parton and parton after gluon
768 // radiation. Energy is calculated independently because initial state radition does not
769 // conserve strictly momentum and energy for each partonic system independently.
771 // Not very clean. Should be improved !
775 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
776 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
777 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
778 mq[j] = fPyjets->P[4][i];
779 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
782 // Calculate some kinematic variables
784 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
785 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
786 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
787 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
788 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
789 qPdg[j] = fPyjets->K[1][i];
795 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
797 for (Int_t j = 0; j < 4; j++) {
799 // Quench only central jets and with E > 10.
803 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
804 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
806 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
809 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
815 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
816 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
818 // Fractional energy loss
819 fZQuench[j] = eloss / eq[j];
821 // Avoid complete loss
823 if (fZQuench[j] > fZmax) fZQuench[j] = fZmax;
825 // Some debug printing
828 // 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",
829 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
831 // fZQuench[j] = 0.8;
832 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
835 quenched[j] = (fZQuench[j] > 0.01);
840 Double_t pNew[1000][4];
847 for (Int_t isys = 0; isys < 4; isys++) {
848 // Skip to next system if not quenched.
849 if (!quenched[isys]) continue;
851 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
852 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
853 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
854 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
860 Double_t pg[4] = {0., 0., 0., 0.};
863 // Loop on radiation events
865 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
868 for (Int_t k = 0; k < 4; k++)
875 for (Int_t i = 0; i < numpart; i++)
877 imo = fPyjets->K[2][i];
878 kst = fPyjets->K[0][i];
879 pdg = fPyjets->K[1][i];
883 // Quarks and gluons only
884 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
885 // Particles from hard scattering only
887 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
888 Int_t imom = imo % 1000;
889 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
890 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
893 // Skip comment lines
894 if (kst != 1 && kst != 2) continue;
897 px = fPyjets->P[0][i];
898 py = fPyjets->P[1][i];
899 pz = fPyjets->P[2][i];
900 e = fPyjets->P[3][i];
901 m = fPyjets->P[4][i];
902 pt = TMath::Sqrt(px * px + py * py);
903 p = TMath::Sqrt(px * px + py * py + pz * pz);
904 phi = TMath::Pi() + TMath::ATan2(-py, -px);
905 theta = TMath::ATan2(pt, pz);
908 // Save 4-momentum sum for balancing
919 // Fractional energy loss
920 Double_t z = zquench[index];
923 // Don't fully quench radiated gluons
926 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
931 // printf("z: %d %f\n", imo, z);
938 // Transform into frame in which initial parton is along z-axis
940 TVector3 v(px, py, pz);
941 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
942 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
944 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
945 Double_t mt2 = jt * jt + m * m;
948 // Kinematic limit on z
950 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
952 // Change light-cone kinematics rel. to initial parton
954 Double_t eppzOld = e + pl;
955 Double_t empzOld = e - pl;
957 Double_t eppzNew = (1. - z) * eppzOld;
958 Double_t empzNew = empzOld - mt2 * z / eppzOld;
959 Double_t eNew = 0.5 * (eppzNew + empzNew);
960 Double_t plNew = 0.5 * (eppzNew - empzNew);
964 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
965 Double_t mt2New = eppzNew * empzNew;
966 if (mt2New < 1.e-8) mt2New = 0.;
968 if (m * m > mt2New) {
970 // This should not happen
972 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
975 jtNew = TMath::Sqrt(mt2New - m * m);
978 // If pT is to small (probably a leading massive particle) we scale only the energy
979 // This can cause negative masses of the radiated gluon
980 // Let's hope for the best ...
982 eNew = TMath::Sqrt(plNew * plNew + mt2);
986 // Calculate new px, py
992 pxNew = jtNew / jt * pxs;
993 pyNew = jtNew / jt * pys;
995 // Double_t dpx = pxs - pxNew;
996 // Double_t dpy = pys - pyNew;
997 // Double_t dpz = pl - plNew;
998 // Double_t de = e - eNew;
999 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
1000 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
1001 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1005 TVector3 w(pxNew, pyNew, plNew);
1006 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1007 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1009 p1[index][0] += pxNew;
1010 p1[index][1] += pyNew;
1011 p1[index][2] += plNew;
1012 p1[index][3] += eNew;
1014 // Updated 4-momentum vectors
1016 pNew[icount][0] = pxNew;
1017 pNew[icount][1] = pyNew;
1018 pNew[icount][2] = plNew;
1019 pNew[icount][3] = eNew;
1024 // Check if there was phase-space for quenching
1027 if (icount == 0) quenched[isys] = kFALSE;
1028 if (!quenched[isys]) break;
1030 for (Int_t j = 0; j < 4; j++)
1032 p2[isys][j] = p0[isys][j] - p1[isys][j];
1034 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];
1035 if (p2[isys][4] > 0.) {
1036 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1039 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1040 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]);
1041 if (p2[isys][4] < -0.01) {
1042 printf("Negative mass squared !\n");
1043 // Here we have to put the gluon back to mass shell
1044 // This will lead to a small energy imbalance
1046 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1055 printf("zHeavy lowered to %f\n", zHeavy);
1056 if (zHeavy < 0.01) {
1057 printf("No success ! \n");
1059 quenched[isys] = kFALSE;
1063 } // iteration on z (while)
1065 // Update event record
1066 for (Int_t k = 0; k < icount; k++) {
1067 // 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] );
1068 fPyjets->P[0][kNew[k]] = pNew[k][0];
1069 fPyjets->P[1][kNew[k]] = pNew[k][1];
1070 fPyjets->P[2][kNew[k]] = pNew[k][2];
1071 fPyjets->P[3][kNew[k]] = pNew[k][3];
1078 if (!quenched[isys]) continue;
1080 // Last parton from shower i
1081 Int_t in = klast[isys];
1083 // Continue if no parton in shower i selected
1084 if (in == -1) continue;
1086 // If this is the second initial parton and it is behind the first move pointer by previous ish
1087 if (isys == 1 && klast[1] > klast[0]) in += ish;
1092 // How many additional gluons will be generated
1094 if (p2[isys][4] > 0.05) ish = 2;
1096 // Position of gluons
1098 if (iglu == 0) igMin = iGlu;
1101 (fPyjets->N) += ish;
1104 fPyjets->P[0][iGlu] = p2[isys][0];
1105 fPyjets->P[1][iGlu] = p2[isys][1];
1106 fPyjets->P[2][iGlu] = p2[isys][2];
1107 fPyjets->P[3][iGlu] = p2[isys][3];
1108 fPyjets->P[4][iGlu] = p2[isys][4];
1110 fPyjets->K[0][iGlu] = 1;
1111 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1112 fPyjets->K[1][iGlu] = 21;
1113 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1114 fPyjets->K[3][iGlu] = -1;
1115 fPyjets->K[4][iGlu] = -1;
1117 pg[0] += p2[isys][0];
1118 pg[1] += p2[isys][1];
1119 pg[2] += p2[isys][2];
1120 pg[3] += p2[isys][3];
1123 // Split gluon in rest frame.
1125 Double_t bx = p2[isys][0] / p2[isys][3];
1126 Double_t by = p2[isys][1] / p2[isys][3];
1127 Double_t bz = p2[isys][2] / p2[isys][3];
1128 Double_t pst = p2[isys][4] / 2.;
1130 // Isotropic decay ????
1131 Double_t cost = 2. * gRandom->Rndm() - 1.;
1132 Double_t sint = TMath::Sqrt((1.-cost)*(1.+cost));
1133 Double_t phis = 2. * TMath::Pi() * gRandom->Rndm();
1135 Double_t pz1 = pst * cost;
1136 Double_t pz2 = -pst * cost;
1137 Double_t pt1 = pst * sint;
1138 Double_t pt2 = -pst * sint;
1139 Double_t px1 = pt1 * TMath::Cos(phis);
1140 Double_t py1 = pt1 * TMath::Sin(phis);
1141 Double_t px2 = pt2 * TMath::Cos(phis);
1142 Double_t py2 = pt2 * TMath::Sin(phis);
1144 fPyjets->P[0][iGlu] = px1;
1145 fPyjets->P[1][iGlu] = py1;
1146 fPyjets->P[2][iGlu] = pz1;
1147 fPyjets->P[3][iGlu] = pst;
1148 fPyjets->P[4][iGlu] = 0.;
1150 fPyjets->K[0][iGlu] = 1 ;
1151 fPyjets->K[1][iGlu] = 21;
1152 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1153 fPyjets->K[3][iGlu] = -1;
1154 fPyjets->K[4][iGlu] = -1;
1156 fPyjets->P[0][iGlu+1] = px2;
1157 fPyjets->P[1][iGlu+1] = py2;
1158 fPyjets->P[2][iGlu+1] = pz2;
1159 fPyjets->P[3][iGlu+1] = pst;
1160 fPyjets->P[4][iGlu+1] = 0.;
1162 fPyjets->K[0][iGlu+1] = 1;
1163 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1164 fPyjets->K[1][iGlu+1] = 21;
1165 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1166 fPyjets->K[3][iGlu+1] = -1;
1167 fPyjets->K[4][iGlu+1] = -1;
1173 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1176 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1177 Double_t px, py, pz;
1178 px = fPyjets->P[0][ig];
1179 py = fPyjets->P[1][ig];
1180 pz = fPyjets->P[2][ig];
1181 TVector3 v(px, py, pz);
1182 v.RotateZ(-phiq[isys]);
1183 v.RotateY(-thetaq[isys]);
1184 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1185 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1186 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1187 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1188 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1189 pxs += jtKick * TMath::Cos(phiKick);
1190 pys += jtKick * TMath::Sin(phiKick);
1191 TVector3 w(pxs, pys, pzs);
1192 w.RotateY(thetaq[isys]);
1193 w.RotateZ(phiq[isys]);
1194 fPyjets->P[0][ig] = w.X();
1195 fPyjets->P[1][ig] = w.Y();
1196 fPyjets->P[2][ig] = w.Z();
1197 fPyjets->P[2][ig] = w.Mag();
1203 // Check energy conservation
1207 Double_t es = 14000.;
1209 for (Int_t i = 0; i < numpart; i++)
1211 kst = fPyjets->K[0][i];
1212 if (kst != 1 && kst != 2) continue;
1213 pxs += fPyjets->P[0][i];
1214 pys += fPyjets->P[1][i];
1215 pzs += fPyjets->P[2][i];
1216 es -= fPyjets->P[3][i];
1218 if (TMath::Abs(pxs) > 1.e-2 ||
1219 TMath::Abs(pys) > 1.e-2 ||
1220 TMath::Abs(pzs) > 1.e-1) {
1221 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1222 // Fatal("Quench()", "4-Momentum non-conservation");
1225 } // end quenching loop (systems)
1227 for (Int_t i = 0; i < numpart; i++)
1229 imo = fPyjets->K[2][i];
1231 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1238 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1240 // Igor Lokthine's quenching routine
1241 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1246 void AliPythia::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1248 // Set the parameters for the PYQUEN package.
1249 // See comments in PyquenCommon.h
1255 PYQPAR.iengl = iengl;
1256 PYQPAR.iangl = iangl;
1260 void AliPythia::Pyevnw()
1262 // New multiple interaction scenario
1266 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1268 // Return event specific quenching parameters
1271 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1275 void AliPythia::ConfigHeavyFlavor()
1278 // Default configuration for Heavy Flavor production
1280 // All QCD processes
1284 // No multiple interactions
1288 // Initial/final parton shower on (Pythia default)
1292 // 2nd order alpha_s
1300 void AliPythia::AtlasTuning()
1303 // Configuration for the ATLAS tuning
1304 SetMSTP(51, AliStructFuncType::PDFsetIndex(kCTEQ5L)); // CTEQ5L pdf
1305 SetMSTP(81,1); // Multiple Interactions ON
1306 SetMSTP(82,4); // Double Gaussian Model
1307 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1308 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1309 SetPARP(89,1000.); // [GeV] Ref. energy
1310 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1311 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1312 SetPARP(84,0.5); // Core radius
1313 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1314 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1315 SetPARP(67,1); // Regulates Initial State Radiation
1318 AliPythia& AliPythia::operator=(const AliPythia& rhs)
1320 // Assignment operator
1325 void AliPythia::Copy(TObject&) const
1330 Fatal("Copy","Not implemented!\n");