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_
34 # define pyclus PYCLUS
35 # define pycell PYCELL
36 # define pyrobo PYROBO
37 # define pyquen PYQUEN
38 # define type_of_call _stdcall
41 extern "C" void type_of_call pyclus(Int_t & );
42 extern "C" void type_of_call pycell(Int_t & );
43 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
44 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
45 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
47 //_____________________________________________________________________________
49 AliPythia* AliPythia::fgAliPythia=NULL;
51 AliPythia::AliPythia()
53 // Default Constructor
56 if (!AliPythiaRndm::GetPythiaRandom())
57 AliPythiaRndm::SetPythiaRandom(GetRandom());
59 fQuenchingWeights = 0;
62 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
64 // Initialise the process to generate
65 if (!AliPythiaRndm::GetPythiaRandom())
66 AliPythiaRndm::SetPythiaRandom(GetRandom());
70 fStrucFunc = strucfunc;
71 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
72 SetMDCY(Pycomp(111) ,1,0);
73 SetMDCY(Pycomp(310) ,1,0);
74 SetMDCY(Pycomp(3122),1,0);
75 SetMDCY(Pycomp(3112),1,0);
76 SetMDCY(Pycomp(3212),1,0);
77 SetMDCY(Pycomp(3222),1,0);
78 SetMDCY(Pycomp(3312),1,0);
79 SetMDCY(Pycomp(3322),1,0);
80 SetMDCY(Pycomp(3334),1,0);
81 // select structure function
83 SetMSTP(51,strucfunc);
85 // Pythia initialisation for selected processes//
89 for (Int_t i=1; i<= 200; i++) {
92 // select charm production
130 case kPyCharmUnforced:
139 case kPyBeautyUnforced:
149 // Minimum Bias pp-Collisions
152 // select Pythia min. bias model
154 SetMSUB(92,1); // single diffraction AB-->XB
155 SetMSUB(93,1); // single diffraction AB-->AX
156 SetMSUB(94,1); // double diffraction
157 SetMSUB(95,1); // low pt production
163 SetMSTP(51, kCTEQ5L); // CTEQ5L pdf
164 SetMSTP(81,1); // Multiple Interactions ON
165 SetMSTP(82,4); // Double Gaussian Model
167 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
168 SetPARP(89,1000.); // [GeV] Ref. energy
169 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
170 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
171 SetPARP(84,0.5); // Core radius
172 SetPARP(85,0.33); // Regulates gluon prod. mechanism
173 SetPARP(86,0.66); // Regulates gluon prod. mechanism
174 SetPARP(67,1); // Regulates Initial State Radiation
177 // Minimum Bias pp-Collisions
180 // select Pythia min. bias model
182 SetMSUB(95,1); // low pt production
188 SetMSTP(51,kCTEQ5L); // CTEQ5L pdf
189 SetMSTP(81,1); // Multiple Interactions ON
190 SetMSTP(82,4); // Double Gaussian Model
192 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
193 SetPARP(89,1000.); // [GeV] Ref. energy
194 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
195 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
196 SetPARP(84,0.5); // Core radius
197 SetPARP(85,0.33); // Regulates gluon prod. mechanism
198 SetPARP(86,0.66); // Regulates gluon prod. mechanism
199 SetPARP(67,1); // Regulates Initial State Radiation
210 case kPyCharmPbPbMNR:
212 // Tuning of Pythia parameters aimed to get a resonable agreement
213 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
214 // c-cbar single inclusive and double differential distributions.
215 // This parameter settings are meant to work with Pb-Pb collisions
216 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
217 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
218 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
223 // No multiple interactions
228 // Initial/final parton shower on (Pythia default)
248 case kPyDPlusPbPbMNR:
249 // Tuning of Pythia parameters aimed to get a resonable agreement
250 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
251 // c-cbar single inclusive and double differential distributions.
252 // This parameter settings are meant to work with Pb-Pb collisions
253 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
254 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
255 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
260 // No multiple interactions
265 // Initial/final parton shower on (Pythia default)
287 // Tuning of Pythia parameters aimed to get a resonable agreement
288 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
289 // c-cbar single inclusive and double differential distributions.
290 // This parameter settings are meant to work with p-Pb collisions
291 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
292 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
293 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
298 // No multiple interactions
303 // Initial/final parton shower on (Pythia default)
324 // Tuning of Pythia parameters aimed to get a resonable agreement
325 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
326 // c-cbar single inclusive and double differential distributions.
327 // This parameter settings are meant to work with p-Pb collisions
328 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
329 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
330 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
335 // No multiple interactions
340 // Initial/final parton shower on (Pythia default)
362 // Tuning of Pythia parameters aimed to get a resonable agreement
363 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
364 // c-cbar single inclusive and double differential distributions.
365 // This parameter settings are meant to work with pp collisions
366 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
367 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
368 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
373 // No multiple interactions
378 // Initial/final parton shower on (Pythia default)
399 // Tuning of Pythia parameters aimed to get a resonable agreement
400 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
401 // c-cbar single inclusive and double differential distributions.
402 // This parameter settings are meant to work with pp collisions
403 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
404 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
405 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
410 // No multiple interactions
415 // Initial/final parton shower on (Pythia default)
435 case kPyBeautyPbPbMNR:
436 // Tuning of Pythia parameters aimed to get a resonable agreement
437 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
438 // b-bbar single inclusive and double differential distributions.
439 // This parameter settings are meant to work with Pb-Pb collisions
440 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
441 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
442 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
447 // No multiple interactions
452 // Initial/final parton shower on (Pythia default)
474 case kPyBeautypPbMNR:
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 p-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.
486 // No multiple interactions
491 // Initial/final parton shower on (Pythia default)
514 // Tuning of Pythia parameters aimed to get a resonable agreement
515 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
516 // b-bbar single inclusive and double differential distributions.
517 // This parameter settings are meant to work with pp collisions
518 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
519 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
520 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
525 // No multiple interactions
530 // Initial/final parton shower on (Pythia default)
555 //Inclusive production of W+/-
561 // //f fbar -> gamma W+
568 // Initial/final parton shower on (Pythia default)
569 // With parton showers on we are generating "W inclusive process"
570 SetMSTP(61,1); //Initial QCD & QED showers on
571 SetMSTP(71,1); //Final QCD & QED showers on
577 SetMSTP(41,1); // all resonance decays switched on
579 Initialize("CMS","p","p",fEcms);
583 Int_t AliPythia::CheckedLuComp(Int_t kf)
585 // Check Lund particle code (for debugging)
587 printf("\n Lucomp kf,kc %d %d",kf,kc);
591 void AliPythia::SetNuclei(Int_t a1, Int_t a2)
593 // Treat protons as inside nuclei with mass numbers a1 and a2
594 // The MSTP array in the PYPARS common block is used to enable and
595 // select the nuclear structure functions.
596 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
597 // =1: internal PYTHIA acording to MSTP(51)
598 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
599 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
600 // MSTP(192) : Mass number of nucleus side 1
601 // MSTP(193) : Mass number of nucleus side 2
608 AliPythia* AliPythia::Instance()
610 // Set random number generator
614 fgAliPythia = new AliPythia();
619 void AliPythia::PrintParticles()
621 // Print list of particl properties
623 char* name = new char[16];
624 for (Int_t kf=0; kf<1000000; kf++) {
625 for (Int_t c = 1; c > -2; c-=2) {
626 Int_t kc = Pycomp(c*kf);
628 Float_t mass = GetPMAS(kc,1);
629 Float_t width = GetPMAS(kc,2);
630 Float_t tau = GetPMAS(kc,4);
636 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
637 c*kf, name, mass, width, tau);
641 printf("\n Number of particles %d \n \n", np);
644 void AliPythia::ResetDecayTable()
646 // Set default values for pythia decay switches
648 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
649 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
652 void AliPythia::SetDecayTable()
654 // Set default values for pythia decay switches
657 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
658 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
661 void AliPythia::Pyclus(Int_t& njet)
663 // Call Pythia clustering algorithm
668 void AliPythia::Pycell(Int_t& njet)
670 // Call Pythia jet reconstruction algorithm
675 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
677 // Call Pythia jet reconstruction algorithm
679 pyshow(ip1, ip2, qmax);
682 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
684 pyrobo(imi, ima, the, phi, bex, bey, bez);
689 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod)
692 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
693 // (2) The nuclear geometry using the Glauber Model
697 fGlauber = new AliFastGlauber();
699 fGlauber->SetCentralityClass(cMin, cMax);
701 fQuenchingWeights = new AliQuenchingWeights();
702 fQuenchingWeights->InitMult();
703 fQuenchingWeights->SetK(k);
704 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
708 void AliPythia::Quench()
712 // Simple Jet Quenching routine:
713 // =============================
714 // The jet formed by all final state partons radiated by the parton created
715 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
716 // the initial parton reference frame:
717 // (E + p_z)new = (1-z) (E + p_z)old
722 // The lost momentum is first balanced by one gluon with virtuality > 0.
723 // Subsequently the gluon splits to yield two gluons with E = p.
727 static Float_t eMean = 0.;
728 static Int_t icall = 0;
733 Int_t klast[4] = {-1, -1, -1, -1};
735 Int_t numpart = fPyjets->N;
736 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
737 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
745 // Sore information about Primary partons
748 // 0, 1 partons from hard scattering
749 // 2, 3 partons from initial state radiation
751 for (Int_t i = 2; i <= 7; i++) {
753 // Skip gluons that participate in hard scattering
754 if (i == 4 || i == 5) continue;
755 // Gluons from hard Scattering
756 if (i == 6 || i == 7) {
758 pxq[j] = fPyjets->P[0][i];
759 pyq[j] = fPyjets->P[1][i];
760 pzq[j] = fPyjets->P[2][i];
761 eq[j] = fPyjets->P[3][i];
762 mq[j] = fPyjets->P[4][i];
764 // Gluons from initial state radiation
766 // Obtain 4-momentum vector from difference between original parton and parton after gluon
767 // radiation. Energy is calculated independently because initial state radition does not
768 // conserve strictly momentum and energy for each partonic system independently.
770 // Not very clean. Should be improved !
774 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
775 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
776 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
777 mq[j] = fPyjets->P[4][i];
778 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
781 // Calculate some kinematic variables
783 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
784 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
785 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
786 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
787 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
788 qPdg[j] = fPyjets->K[1][i];
794 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
796 for (Int_t j = 0; j < 4; j++) {
798 // Quench only central jets and with E > 10.
802 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
803 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
805 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
808 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
814 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
815 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
817 // Fractional energy loss
818 fZQuench[j] = eloss / eq[j];
820 // Avoid complete loss
822 if (fZQuench[j] == 1.) fZQuench[j] = 0.95;
824 // Some debug printing
827 // 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",
828 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
830 // fZQuench[j] = 0.8;
831 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
834 quenched[j] = (fZQuench[j] > 0.01);
839 Double_t pNew[1000][4];
846 for (Int_t isys = 0; isys < 4; isys++) {
847 // Skip to next system if not quenched.
848 if (!quenched[isys]) continue;
850 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
851 if (nGluon[isys] > 6) nGluon[isys] = 6;
852 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
853 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
859 Double_t pg[4] = {0., 0., 0., 0.};
862 // Loop on radiation events
864 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
867 for (Int_t k = 0; k < 4; k++)
874 for (Int_t i = 0; i < numpart; i++)
876 imo = fPyjets->K[2][i];
877 kst = fPyjets->K[0][i];
878 pdg = fPyjets->K[1][i];
882 // Quarks and gluons only
883 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
884 // Particles from hard scattering only
886 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
887 Int_t imom = imo % 1000;
888 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
889 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
892 // Skip comment lines
893 if (kst != 1 && kst != 2) continue;
896 px = fPyjets->P[0][i];
897 py = fPyjets->P[1][i];
898 pz = fPyjets->P[2][i];
899 e = fPyjets->P[3][i];
900 m = fPyjets->P[4][i];
901 pt = TMath::Sqrt(px * px + py * py);
902 p = TMath::Sqrt(px * px + py * py + pz * pz);
903 phi = TMath::Pi() + TMath::ATan2(-py, -px);
904 theta = TMath::ATan2(pt, pz);
907 // Save 4-momentum sum for balancing
918 // Fractional energy loss
919 Double_t z = zquench[index];
922 // Don't fully quench radiated gluons
925 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
930 // printf("z: %d %f\n", imo, z);
937 // Transform into frame in which initial parton is along z-axis
939 TVector3 v(px, py, pz);
940 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
941 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
943 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
944 Double_t mt2 = jt * jt + m * m;
947 // Kinematic limit on z
949 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
951 // Change light-cone kinematics rel. to initial parton
953 Double_t eppzOld = e + pl;
954 Double_t empzOld = e - pl;
956 Double_t eppzNew = (1. - z) * eppzOld;
957 Double_t empzNew = empzOld - mt2 * z / eppzOld;
958 Double_t eNew = 0.5 * (eppzNew + empzNew);
959 Double_t plNew = 0.5 * (eppzNew - empzNew);
963 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
964 Double_t mt2New = eppzNew * empzNew;
965 if (mt2New < 1.e-8) mt2New = 0.;
967 if (m * m > mt2New) {
969 // This should not happen
971 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
974 jtNew = TMath::Sqrt(mt2New - m * m);
977 // If pT is to small (probably a leading massive particle) we scale only the energy
978 // This can cause negative masses of the radiated gluon
979 // Let's hope for the best ...
981 eNew = TMath::Sqrt(plNew * plNew + mt2);
985 // Calculate new px, py
987 Double_t pxNew = jtNew / jt * pxs;
988 Double_t pyNew = jtNew / jt * pys;
990 // Double_t dpx = pxs - pxNew;
991 // Double_t dpy = pys - pyNew;
992 // Double_t dpz = pl - plNew;
993 // Double_t de = e - eNew;
994 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
995 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
996 // printf("New mass (2) %e %e \n", pxNew, pyNew);
1000 TVector3 w(pxNew, pyNew, plNew);
1001 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
1002 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
1004 p1[index][0] += pxNew;
1005 p1[index][1] += pyNew;
1006 p1[index][2] += plNew;
1007 p1[index][3] += eNew;
1009 // Updated 4-momentum vectors
1011 pNew[icount][0] = pxNew;
1012 pNew[icount][1] = pyNew;
1013 pNew[icount][2] = plNew;
1014 pNew[icount][3] = eNew;
1019 // Check if there was phase-space for quenching
1022 if (icount == 0) quenched[isys] = kFALSE;
1023 if (!quenched[isys]) break;
1025 for (Int_t j = 0; j < 4; j++)
1027 p2[isys][j] = p0[isys][j] - p1[isys][j];
1029 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];
1030 if (p2[isys][4] > 0.) {
1031 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1034 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1035 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]);
1036 if (p2[isys][4] < -0.01) {
1037 printf("Negative mass squared !\n");
1038 // Here we have to put the gluon back to mass shell
1039 // This will lead to a small energy imbalance
1041 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1050 printf("zHeavy lowered to %f\n", zHeavy);
1051 if (zHeavy < 0.01) {
1052 printf("No success ! \n");
1054 quenched[isys] = kFALSE;
1058 } // iteration on z (while)
1060 // Update event record
1061 for (Int_t k = 0; k < icount; k++) {
1062 // 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] );
1063 fPyjets->P[0][kNew[k]] = pNew[k][0];
1064 fPyjets->P[1][kNew[k]] = pNew[k][1];
1065 fPyjets->P[2][kNew[k]] = pNew[k][2];
1066 fPyjets->P[3][kNew[k]] = pNew[k][3];
1073 if (!quenched[isys]) continue;
1075 // Last parton from shower i
1076 Int_t in = klast[isys];
1078 // Continue if no parton in shower i selected
1079 if (in == -1) continue;
1081 // If this is the second initial parton and it is behind the first move pointer by previous ish
1082 if (isys == 1 && klast[1] > klast[0]) in += ish;
1087 // How many additional gluons will be generated
1089 if (p2[isys][4] > 0.05) ish = 2;
1091 // Position of gluons
1093 if (iglu == 0) igMin = iGlu;
1096 (fPyjets->N) += ish;
1099 fPyjets->P[0][iGlu] = p2[isys][0];
1100 fPyjets->P[1][iGlu] = p2[isys][1];
1101 fPyjets->P[2][iGlu] = p2[isys][2];
1102 fPyjets->P[3][iGlu] = p2[isys][3];
1103 fPyjets->P[4][iGlu] = p2[isys][4];
1105 fPyjets->K[0][iGlu] = 1;
1106 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1107 fPyjets->K[1][iGlu] = 21;
1108 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1109 fPyjets->K[3][iGlu] = -1;
1110 fPyjets->K[4][iGlu] = -1;
1112 pg[0] += p2[isys][0];
1113 pg[1] += p2[isys][1];
1114 pg[2] += p2[isys][2];
1115 pg[3] += p2[isys][3];
1118 // Split gluon in rest frame.
1120 Double_t bx = p2[isys][0] / p2[isys][3];
1121 Double_t by = p2[isys][1] / p2[isys][3];
1122 Double_t bz = p2[isys][2] / p2[isys][3];
1123 Double_t pst = p2[isys][4] / 2.;
1125 // Isotropic decay ????
1126 Double_t cost = 2. * gRandom->Rndm() - 1.;
1127 Double_t sint = TMath::Sqrt(1. - cost * cost);
1128 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1130 Double_t pz1 = pst * cost;
1131 Double_t pz2 = -pst * cost;
1132 Double_t pt1 = pst * sint;
1133 Double_t pt2 = -pst * sint;
1134 Double_t px1 = pt1 * TMath::Cos(phi);
1135 Double_t py1 = pt1 * TMath::Sin(phi);
1136 Double_t px2 = pt2 * TMath::Cos(phi);
1137 Double_t py2 = pt2 * TMath::Sin(phi);
1139 fPyjets->P[0][iGlu] = px1;
1140 fPyjets->P[1][iGlu] = py1;
1141 fPyjets->P[2][iGlu] = pz1;
1142 fPyjets->P[3][iGlu] = pst;
1143 fPyjets->P[4][iGlu] = 0.;
1145 fPyjets->K[0][iGlu] = 1 ;
1146 fPyjets->K[1][iGlu] = 21;
1147 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1148 fPyjets->K[3][iGlu] = -1;
1149 fPyjets->K[4][iGlu] = -1;
1151 fPyjets->P[0][iGlu+1] = px2;
1152 fPyjets->P[1][iGlu+1] = py2;
1153 fPyjets->P[2][iGlu+1] = pz2;
1154 fPyjets->P[3][iGlu+1] = pst;
1155 fPyjets->P[4][iGlu+1] = 0.;
1157 fPyjets->K[0][iGlu+1] = 1;
1158 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1159 fPyjets->K[1][iGlu+1] = 21;
1160 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1161 fPyjets->K[3][iGlu+1] = -1;
1162 fPyjets->K[4][iGlu+1] = -1;
1168 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1171 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1172 Double_t px, py, pz;
1173 px = fPyjets->P[0][ig];
1174 py = fPyjets->P[1][ig];
1175 pz = fPyjets->P[2][ig];
1176 TVector3 v(px, py, pz);
1177 v.RotateZ(-phiq[isys]);
1178 v.RotateY(-thetaq[isys]);
1179 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1180 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1181 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1182 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1183 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1184 pxs += jtKick * TMath::Cos(phiKick);
1185 pys += jtKick * TMath::Sin(phiKick);
1186 TVector3 w(pxs, pys, pzs);
1187 w.RotateY(thetaq[isys]);
1188 w.RotateZ(phiq[isys]);
1189 fPyjets->P[0][ig] = w.X();
1190 fPyjets->P[1][ig] = w.Y();
1191 fPyjets->P[2][ig] = w.Z();
1192 fPyjets->P[2][ig] = w.Mag();
1198 // Check energy conservation
1202 Double_t es = 14000.;
1204 for (Int_t i = 0; i < numpart; i++)
1206 kst = fPyjets->K[0][i];
1207 if (kst != 1 && kst != 2) continue;
1208 pxs += fPyjets->P[0][i];
1209 pys += fPyjets->P[1][i];
1210 pzs += fPyjets->P[2][i];
1211 es -= fPyjets->P[3][i];
1213 if (TMath::Abs(pxs) > 1.e-2 ||
1214 TMath::Abs(pys) > 1.e-2 ||
1215 TMath::Abs(pzs) > 1.e-1) {
1216 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1217 // Fatal("Quench()", "4-Momentum non-conservation");
1220 } // end quenching loop (systems)
1222 for (Int_t i = 0; i < numpart; i++)
1224 imo = fPyjets->K[2][i];
1226 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1233 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1235 // Igor Lokthine's quenching routine
1239 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1241 // Return event specific quenching parameters
1244 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];