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 **************************************************************************/
18 #include "AliPythia.h"
19 #include "AliPythiaRndm.h"
20 #include "../FASTSIM/AliFastGlauber.h"
21 #include "../FASTSIM/AliQuenchingWeights.h"
27 # define pyclus pyclus_
28 # define pycell pycell_
29 # define pyshow pyshow_
30 # define pyrobo pyrobo_
31 # define pyquen pyquen_
32 # define pyevnw pyevnw_
35 # define pyclus PYCLUS
36 # define pycell PYCELL
37 # define pyrobo PYROBO
38 # define pyquen PYQUEN
39 # define pyevnw PYEVNW
40 # define type_of_call _stdcall
43 extern "C" void type_of_call pyclus(Int_t & );
44 extern "C" void type_of_call pycell(Int_t & );
45 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
46 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
47 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
48 extern "C" void type_of_call pyevnw(){;}
50 //_____________________________________________________________________________
52 AliPythia* AliPythia::fgAliPythia=NULL;
54 AliPythia::AliPythia()
56 // Default Constructor
59 if (!AliPythiaRndm::GetPythiaRandom())
60 AliPythiaRndm::SetPythiaRandom(GetRandom());
62 fQuenchingWeights = 0;
65 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
67 // Initialise the process to generate
68 if (!AliPythiaRndm::GetPythiaRandom())
69 AliPythiaRndm::SetPythiaRandom(GetRandom());
73 fStrucFunc = strucfunc;
74 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
75 SetMDCY(Pycomp(111) ,1,0);
76 SetMDCY(Pycomp(310) ,1,0);
77 SetMDCY(Pycomp(3122),1,0);
78 SetMDCY(Pycomp(3112),1,0);
79 SetMDCY(Pycomp(3212),1,0);
80 SetMDCY(Pycomp(3222),1,0);
81 SetMDCY(Pycomp(3312),1,0);
82 SetMDCY(Pycomp(3322),1,0);
83 SetMDCY(Pycomp(3334),1,0);
84 // select structure function
86 SetMSTP(51,strucfunc);
88 // Pythia initialisation for selected processes//
92 for (Int_t i=1; i<= 200; i++) {
95 // select charm production
98 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
99 // Multiple interactions on.
101 // Double Gaussian matter distribution.
107 // Reference energy for pT0 and energy rescaling pace.
110 // String drawing almost completely minimizes string length.
113 // ISR and FSR activity.
119 case kPyOldUEQ2ordered2:
120 // Old underlying events with Q2 ordered QCD processes
121 // Multiple interactions on.
123 // Double Gaussian matter distribution.
129 // Reference energy for pT0 and energy rescaling pace.
131 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
132 // String drawing almost completely minimizes string length.
135 // ISR and FSR activity.
142 // Old production mechanism: Old Popcorn
145 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
147 // (D=1)see can be used to form baryons (BARYON JUNCTION)
149 SetMSTP(51,kCTEQ5L);// CTEQ 5L ! CTEQ5L pdf
150 SetMSTP(81,1); // Multiple Interactions ON
151 SetMSTP(82,4); // Double Gaussian Model
152 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
153 SetPARP(89,1000.); // [GeV] Ref. energy
154 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
155 SetPARP(83,0.5); // Core density in proton matter dist. (def.value)
156 SetPARP(84,0.5); // Core radius
157 SetPARP(85,0.33); // Regulates gluon prod. mechanism
158 SetPARP(86,0.66); // Regulates gluon prod. mechanism
159 SetPARP(67,1); // Regulate gluon prod. mechanism
163 // heavy quark masses
195 case kPyCharmUnforced:
204 case kPyBeautyUnforced:
214 // Minimum Bias pp-Collisions
217 // select Pythia min. bias model
219 SetMSUB(92,1); // single diffraction AB-->XB
220 SetMSUB(93,1); // single diffraction AB-->AX
221 SetMSUB(94,1); // double diffraction
222 SetMSUB(95,1); // low pt production
228 SetMSTP(51, kCTEQ5L); // CTEQ5L pdf
229 SetMSTP(81,1); // Multiple Interactions ON
230 SetMSTP(82,4); // Double Gaussian Model
232 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
233 SetPARP(89,1000.); // [GeV] Ref. energy
234 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
235 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
236 SetPARP(84,0.5); // Core radius
237 SetPARP(85,0.33); // Regulates gluon prod. mechanism
238 SetPARP(86,0.66); // Regulates gluon prod. mechanism
239 SetPARP(67,1); // Regulates Initial State Radiation
242 // Minimum Bias pp-Collisions
245 // select Pythia min. bias model
247 SetMSUB(95,1); // low pt production
253 SetMSTP(51,kCTEQ5L); // CTEQ5L pdf
254 SetMSTP(81,1); // Multiple Interactions ON
255 SetMSTP(82,4); // Double Gaussian Model
257 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
258 SetPARP(89,1000.); // [GeV] Ref. energy
259 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
260 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
261 SetPARP(84,0.5); // Core radius
262 SetPARP(85,0.33); // Regulates gluon prod. mechanism
263 SetPARP(86,0.66); // Regulates gluon prod. mechanism
264 SetPARP(67,1); // Regulates Initial State Radiation
271 // Pythia Tune A (CDF)
273 SetPARP(67,4.); // Regulates Initial State Radiation
274 SetMSTP(82,4); // Double Gaussian Model
275 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
276 SetPARP(84,0.4); // Core radius
277 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
278 SetPARP(86,0.95); // Regulates gluon prod. mechanism
279 SetPARP(89,1800.); // [GeV] Ref. energy
280 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
285 case kPyCharmPbPbMNR:
287 case kPyDPlusPbPbMNR:
288 // Tuning of Pythia parameters aimed to get a resonable agreement
289 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
290 // c-cbar single inclusive and double differential distributions.
291 // This parameter settings are meant to work with Pb-Pb collisions
292 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
293 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
294 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
306 // Tuning of Pythia parameters aimed to get a resonable agreement
307 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
308 // c-cbar single inclusive and double differential distributions.
309 // This parameter settings are meant to work with p-Pb collisions
310 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
311 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
312 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
325 // Tuning of Pythia parameters aimed to get a resonable agreement
326 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
327 // c-cbar single inclusive and double differential distributions.
328 // This parameter settings are meant to work with pp collisions
329 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
330 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
331 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
341 case kPyBeautyPbPbMNR:
342 // Tuning of Pythia parameters aimed to get a resonable agreement
343 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
344 // b-bbar single inclusive and double differential distributions.
345 // This parameter settings are meant to work with Pb-Pb collisions
346 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
347 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
348 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
360 case kPyBeautypPbMNR:
361 // Tuning of Pythia parameters aimed to get a resonable agreement
362 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
363 // b-bbar single inclusive and double differential distributions.
364 // This parameter settings are meant to work with p-Pb collisions
365 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
366 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
367 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
380 // Tuning of Pythia parameters aimed to get a resonable agreement
381 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
382 // b-bbar single inclusive and double differential distributions.
383 // This parameter settings are meant to work with pp collisions
384 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
385 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
386 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
403 //Inclusive production of W+/-
409 // //f fbar -> gamma W+
416 // Initial/final parton shower on (Pythia default)
417 // With parton showers on we are generating "W inclusive process"
418 SetMSTP(61,1); //Initial QCD & QED showers on
419 SetMSTP(71,1); //Final QCD & QED showers on
425 //Inclusive production of Z
430 // // f fbar -> g Z/gamma
432 // // f fbar -> gamma Z/gamma
434 // // f g -> f Z/gamma
436 // // f gamma -> f Z/gamma
439 //only Z included, not gamma
442 // Initial/final parton shower on (Pythia default)
443 // With parton showers on we are generating "Z inclusive process"
444 SetMSTP(61,1); //Initial QCD & QED showers on
445 SetMSTP(71,1); //Final QCD & QED showers on
452 SetMSTP(41,1); // all resonance decays switched on
454 Initialize("CMS","p","p",fEcms);
458 Int_t AliPythia::CheckedLuComp(Int_t kf)
460 // Check Lund particle code (for debugging)
462 printf("\n Lucomp kf,kc %d %d",kf,kc);
466 void AliPythia::SetNuclei(Int_t a1, Int_t a2)
468 // Treat protons as inside nuclei with mass numbers a1 and a2
469 // The MSTP array in the PYPARS common block is used to enable and
470 // select the nuclear structure functions.
471 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
472 // =1: internal PYTHIA acording to MSTP(51)
473 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
474 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
475 // MSTP(192) : Mass number of nucleus side 1
476 // MSTP(193) : Mass number of nucleus side 2
483 AliPythia* AliPythia::Instance()
485 // Set random number generator
489 fgAliPythia = new AliPythia();
494 void AliPythia::PrintParticles()
496 // Print list of particl properties
498 char* name = new char[16];
499 for (Int_t kf=0; kf<1000000; kf++) {
500 for (Int_t c = 1; c > -2; c-=2) {
501 Int_t kc = Pycomp(c*kf);
503 Float_t mass = GetPMAS(kc,1);
504 Float_t width = GetPMAS(kc,2);
505 Float_t tau = GetPMAS(kc,4);
511 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
512 c*kf, name, mass, width, tau);
516 printf("\n Number of particles %d \n \n", np);
519 void AliPythia::ResetDecayTable()
521 // Set default values for pythia decay switches
523 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
524 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
527 void AliPythia::SetDecayTable()
529 // Set default values for pythia decay switches
532 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
533 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
536 void AliPythia::Pyclus(Int_t& njet)
538 // Call Pythia clustering algorithm
543 void AliPythia::Pycell(Int_t& njet)
545 // Call Pythia jet reconstruction algorithm
550 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
552 // Call Pythia jet reconstruction algorithm
554 pyshow(ip1, ip2, qmax);
557 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
559 pyrobo(imi, ima, the, phi, bex, bey, bez);
564 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod)
567 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
568 // (2) The nuclear geometry using the Glauber Model
572 fGlauber = new AliFastGlauber();
574 fGlauber->SetCentralityClass(cMin, cMax);
576 fQuenchingWeights = new AliQuenchingWeights();
577 fQuenchingWeights->InitMult();
578 fQuenchingWeights->SetK(k);
579 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
583 void AliPythia::Quench()
587 // Simple Jet Quenching routine:
588 // =============================
589 // The jet formed by all final state partons radiated by the parton created
590 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
591 // the initial parton reference frame:
592 // (E + p_z)new = (1-z) (E + p_z)old
597 // The lost momentum is first balanced by one gluon with virtuality > 0.
598 // Subsequently the gluon splits to yield two gluons with E = p.
602 static Float_t eMean = 0.;
603 static Int_t icall = 0;
608 Int_t klast[4] = {-1, -1, -1, -1};
610 Int_t numpart = fPyjets->N;
611 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
612 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
620 // Sore information about Primary partons
623 // 0, 1 partons from hard scattering
624 // 2, 3 partons from initial state radiation
626 for (Int_t i = 2; i <= 7; i++) {
628 // Skip gluons that participate in hard scattering
629 if (i == 4 || i == 5) continue;
630 // Gluons from hard Scattering
631 if (i == 6 || i == 7) {
633 pxq[j] = fPyjets->P[0][i];
634 pyq[j] = fPyjets->P[1][i];
635 pzq[j] = fPyjets->P[2][i];
636 eq[j] = fPyjets->P[3][i];
637 mq[j] = fPyjets->P[4][i];
639 // Gluons from initial state radiation
641 // Obtain 4-momentum vector from difference between original parton and parton after gluon
642 // radiation. Energy is calculated independently because initial state radition does not
643 // conserve strictly momentum and energy for each partonic system independently.
645 // Not very clean. Should be improved !
649 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
650 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
651 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
652 mq[j] = fPyjets->P[4][i];
653 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
656 // Calculate some kinematic variables
658 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
659 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
660 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
661 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
662 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
663 qPdg[j] = fPyjets->K[1][i];
669 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
671 for (Int_t j = 0; j < 4; j++) {
673 // Quench only central jets and with E > 10.
677 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
678 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
680 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
683 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
689 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
690 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
692 // Fractional energy loss
693 fZQuench[j] = eloss / eq[j];
695 // Avoid complete loss
697 if (fZQuench[j] == 1.) fZQuench[j] = 0.95;
699 // Some debug printing
702 // 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",
703 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
705 // fZQuench[j] = 0.8;
706 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
709 quenched[j] = (fZQuench[j] > 0.01);
714 Double_t pNew[1000][4];
721 for (Int_t isys = 0; isys < 4; isys++) {
722 // Skip to next system if not quenched.
723 if (!quenched[isys]) continue;
725 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
726 if (nGluon[isys] > 6) nGluon[isys] = 6;
727 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
728 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
734 Double_t pg[4] = {0., 0., 0., 0.};
737 // Loop on radiation events
739 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
742 for (Int_t k = 0; k < 4; k++)
749 for (Int_t i = 0; i < numpart; i++)
751 imo = fPyjets->K[2][i];
752 kst = fPyjets->K[0][i];
753 pdg = fPyjets->K[1][i];
757 // Quarks and gluons only
758 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
759 // Particles from hard scattering only
761 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
762 Int_t imom = imo % 1000;
763 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
764 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
767 // Skip comment lines
768 if (kst != 1 && kst != 2) continue;
771 px = fPyjets->P[0][i];
772 py = fPyjets->P[1][i];
773 pz = fPyjets->P[2][i];
774 e = fPyjets->P[3][i];
775 m = fPyjets->P[4][i];
776 pt = TMath::Sqrt(px * px + py * py);
777 p = TMath::Sqrt(px * px + py * py + pz * pz);
778 phi = TMath::Pi() + TMath::ATan2(-py, -px);
779 theta = TMath::ATan2(pt, pz);
782 // Save 4-momentum sum for balancing
793 // Fractional energy loss
794 Double_t z = zquench[index];
797 // Don't fully quench radiated gluons
800 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
805 // printf("z: %d %f\n", imo, z);
812 // Transform into frame in which initial parton is along z-axis
814 TVector3 v(px, py, pz);
815 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
816 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
818 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
819 Double_t mt2 = jt * jt + m * m;
822 // Kinematic limit on z
824 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
826 // Change light-cone kinematics rel. to initial parton
828 Double_t eppzOld = e + pl;
829 Double_t empzOld = e - pl;
831 Double_t eppzNew = (1. - z) * eppzOld;
832 Double_t empzNew = empzOld - mt2 * z / eppzOld;
833 Double_t eNew = 0.5 * (eppzNew + empzNew);
834 Double_t plNew = 0.5 * (eppzNew - empzNew);
838 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
839 Double_t mt2New = eppzNew * empzNew;
840 if (mt2New < 1.e-8) mt2New = 0.;
842 if (m * m > mt2New) {
844 // This should not happen
846 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
849 jtNew = TMath::Sqrt(mt2New - m * m);
852 // If pT is to small (probably a leading massive particle) we scale only the energy
853 // This can cause negative masses of the radiated gluon
854 // Let's hope for the best ...
856 eNew = TMath::Sqrt(plNew * plNew + mt2);
860 // Calculate new px, py
862 Double_t pxNew = jtNew / jt * pxs;
863 Double_t pyNew = jtNew / jt * pys;
865 // Double_t dpx = pxs - pxNew;
866 // Double_t dpy = pys - pyNew;
867 // Double_t dpz = pl - plNew;
868 // Double_t de = e - eNew;
869 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
870 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
871 // printf("New mass (2) %e %e \n", pxNew, pyNew);
875 TVector3 w(pxNew, pyNew, plNew);
876 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
877 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
879 p1[index][0] += pxNew;
880 p1[index][1] += pyNew;
881 p1[index][2] += plNew;
882 p1[index][3] += eNew;
884 // Updated 4-momentum vectors
886 pNew[icount][0] = pxNew;
887 pNew[icount][1] = pyNew;
888 pNew[icount][2] = plNew;
889 pNew[icount][3] = eNew;
894 // Check if there was phase-space for quenching
897 if (icount == 0) quenched[isys] = kFALSE;
898 if (!quenched[isys]) break;
900 for (Int_t j = 0; j < 4; j++)
902 p2[isys][j] = p0[isys][j] - p1[isys][j];
904 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];
905 if (p2[isys][4] > 0.) {
906 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
909 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
910 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]);
911 if (p2[isys][4] < -0.01) {
912 printf("Negative mass squared !\n");
913 // Here we have to put the gluon back to mass shell
914 // This will lead to a small energy imbalance
916 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
925 printf("zHeavy lowered to %f\n", zHeavy);
927 printf("No success ! \n");
929 quenched[isys] = kFALSE;
933 } // iteration on z (while)
935 // Update event record
936 for (Int_t k = 0; k < icount; k++) {
937 // 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] );
938 fPyjets->P[0][kNew[k]] = pNew[k][0];
939 fPyjets->P[1][kNew[k]] = pNew[k][1];
940 fPyjets->P[2][kNew[k]] = pNew[k][2];
941 fPyjets->P[3][kNew[k]] = pNew[k][3];
948 if (!quenched[isys]) continue;
950 // Last parton from shower i
951 Int_t in = klast[isys];
953 // Continue if no parton in shower i selected
954 if (in == -1) continue;
956 // If this is the second initial parton and it is behind the first move pointer by previous ish
957 if (isys == 1 && klast[1] > klast[0]) in += ish;
962 // How many additional gluons will be generated
964 if (p2[isys][4] > 0.05) ish = 2;
966 // Position of gluons
968 if (iglu == 0) igMin = iGlu;
974 fPyjets->P[0][iGlu] = p2[isys][0];
975 fPyjets->P[1][iGlu] = p2[isys][1];
976 fPyjets->P[2][iGlu] = p2[isys][2];
977 fPyjets->P[3][iGlu] = p2[isys][3];
978 fPyjets->P[4][iGlu] = p2[isys][4];
980 fPyjets->K[0][iGlu] = 1;
981 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
982 fPyjets->K[1][iGlu] = 21;
983 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
984 fPyjets->K[3][iGlu] = -1;
985 fPyjets->K[4][iGlu] = -1;
987 pg[0] += p2[isys][0];
988 pg[1] += p2[isys][1];
989 pg[2] += p2[isys][2];
990 pg[3] += p2[isys][3];
993 // Split gluon in rest frame.
995 Double_t bx = p2[isys][0] / p2[isys][3];
996 Double_t by = p2[isys][1] / p2[isys][3];
997 Double_t bz = p2[isys][2] / p2[isys][3];
998 Double_t pst = p2[isys][4] / 2.;
1000 // Isotropic decay ????
1001 Double_t cost = 2. * gRandom->Rndm() - 1.;
1002 Double_t sint = TMath::Sqrt(1. - cost * cost);
1003 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1005 Double_t pz1 = pst * cost;
1006 Double_t pz2 = -pst * cost;
1007 Double_t pt1 = pst * sint;
1008 Double_t pt2 = -pst * sint;
1009 Double_t px1 = pt1 * TMath::Cos(phi);
1010 Double_t py1 = pt1 * TMath::Sin(phi);
1011 Double_t px2 = pt2 * TMath::Cos(phi);
1012 Double_t py2 = pt2 * TMath::Sin(phi);
1014 fPyjets->P[0][iGlu] = px1;
1015 fPyjets->P[1][iGlu] = py1;
1016 fPyjets->P[2][iGlu] = pz1;
1017 fPyjets->P[3][iGlu] = pst;
1018 fPyjets->P[4][iGlu] = 0.;
1020 fPyjets->K[0][iGlu] = 1 ;
1021 fPyjets->K[1][iGlu] = 21;
1022 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1023 fPyjets->K[3][iGlu] = -1;
1024 fPyjets->K[4][iGlu] = -1;
1026 fPyjets->P[0][iGlu+1] = px2;
1027 fPyjets->P[1][iGlu+1] = py2;
1028 fPyjets->P[2][iGlu+1] = pz2;
1029 fPyjets->P[3][iGlu+1] = pst;
1030 fPyjets->P[4][iGlu+1] = 0.;
1032 fPyjets->K[0][iGlu+1] = 1;
1033 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1034 fPyjets->K[1][iGlu+1] = 21;
1035 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1036 fPyjets->K[3][iGlu+1] = -1;
1037 fPyjets->K[4][iGlu+1] = -1;
1043 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1046 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1047 Double_t px, py, pz;
1048 px = fPyjets->P[0][ig];
1049 py = fPyjets->P[1][ig];
1050 pz = fPyjets->P[2][ig];
1051 TVector3 v(px, py, pz);
1052 v.RotateZ(-phiq[isys]);
1053 v.RotateY(-thetaq[isys]);
1054 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1055 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1056 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1057 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1058 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1059 pxs += jtKick * TMath::Cos(phiKick);
1060 pys += jtKick * TMath::Sin(phiKick);
1061 TVector3 w(pxs, pys, pzs);
1062 w.RotateY(thetaq[isys]);
1063 w.RotateZ(phiq[isys]);
1064 fPyjets->P[0][ig] = w.X();
1065 fPyjets->P[1][ig] = w.Y();
1066 fPyjets->P[2][ig] = w.Z();
1067 fPyjets->P[2][ig] = w.Mag();
1073 // Check energy conservation
1077 Double_t es = 14000.;
1079 for (Int_t i = 0; i < numpart; i++)
1081 kst = fPyjets->K[0][i];
1082 if (kst != 1 && kst != 2) continue;
1083 pxs += fPyjets->P[0][i];
1084 pys += fPyjets->P[1][i];
1085 pzs += fPyjets->P[2][i];
1086 es -= fPyjets->P[3][i];
1088 if (TMath::Abs(pxs) > 1.e-2 ||
1089 TMath::Abs(pys) > 1.e-2 ||
1090 TMath::Abs(pzs) > 1.e-1) {
1091 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1092 // Fatal("Quench()", "4-Momentum non-conservation");
1095 } // end quenching loop (systems)
1097 for (Int_t i = 0; i < numpart; i++)
1099 imo = fPyjets->K[2][i];
1101 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1108 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1110 // Igor Lokthine's quenching routine
1114 void AliPythia::Pyevnw()
1116 // New multiple interaction scenario
1120 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1122 // Return event specific quenching parameters
1125 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1129 void AliPythia::ConfigHeavyFlavor()
1132 // Default configuration for Heavy Flavor production
1134 // All QCD processes
1138 // No multiple interactions
1143 // Initial/final parton shower on (Pythia default)
1147 // 2nd order alpha_s