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_
33 # define pyclus PYCLUS
34 # define pycell PYCELL
35 # define pyrobo PYROBO
36 # define type_of_call _stdcall
39 extern "C" void type_of_call pyclus(Int_t & );
40 extern "C" void type_of_call pycell(Int_t & );
41 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
42 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
44 //_____________________________________________________________________________
46 AliPythia* AliPythia::fgAliPythia=NULL;
48 AliPythia::AliPythia()
50 // Default Constructor
53 if (!AliPythiaRndm::GetPythiaRandom())
54 AliPythiaRndm::SetPythiaRandom(GetRandom());
56 fQuenchingWeights = 0;
59 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
61 // Initialise the process to generate
62 if (!AliPythiaRndm::GetPythiaRandom())
63 AliPythiaRndm::SetPythiaRandom(GetRandom());
67 fStrucFunc = strucfunc;
69 SetMDCY(Pycomp(111),1,0);
70 // select structure function
72 SetMSTP(51,strucfunc);
74 // Pythia initialisation for selected processes//
78 for (Int_t i=1; i<= 200; i++) {
81 // select charm production
119 case kPyCharmUnforced:
128 case kPyBeautyUnforced:
138 // Minimum Bias pp-Collisions
141 // select Pythia min. bias model
143 SetMSUB(92,1); // single diffraction AB-->XB
144 SetMSUB(93,1); // single diffraction AB-->AX
145 SetMSUB(94,1); // double diffraction
146 SetMSUB(95,1); // low pt production
151 SetMSTP(51,7); // CTEQ5L pdf
152 SetMSTP(81,1); // Multiple Interactions ON
153 SetMSTP(82,4); // Double Gaussian Model
155 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
156 SetPARP(89,1000.); // [GeV] Ref. energy
157 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
158 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
159 SetPARP(84,0.5); // Core radius
160 SetPARP(85,0.33); // Regulates gluon prod. mechanism
161 SetPARP(86,0.66); // Regulates gluon prod. mechanism
162 SetPARP(67,1); // Regulates Initial State Radiation
165 // Minimum Bias pp-Collisions
168 // select Pythia min. bias model
170 SetMSUB(95,1); // low pt production
176 SetMSTP(51,7); // CTEQ5L pdf
177 SetMSTP(81,1); // Multiple Interactions ON
178 SetMSTP(82,4); // Double Gaussian Model
180 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
181 SetPARP(89,1000.); // [GeV] Ref. energy
182 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
183 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
184 SetPARP(84,0.5); // Core radius
185 SetPARP(85,0.33); // Regulates gluon prod. mechanism
186 SetPARP(86,0.66); // Regulates gluon prod. mechanism
187 SetPARP(67,1); // Regulates Initial State Radiation
198 case kPyCharmPbPbMNR:
200 // Tuning of Pythia parameters aimed to get a resonable agreement
201 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
202 // c-cbar single inclusive and double differential distributions.
203 // This parameter settings are meant to work with Pb-Pb collisions
204 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
205 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
206 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
211 // No multiple interactions
216 // Initial/final parton shower on (Pythia default)
236 case kPyDPlusPbPbMNR:
237 // Tuning of Pythia parameters aimed to get a resonable agreement
238 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
239 // c-cbar single inclusive and double differential distributions.
240 // This parameter settings are meant to work with Pb-Pb collisions
241 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
242 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
243 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
248 // No multiple interactions
253 // Initial/final parton shower on (Pythia default)
275 // Tuning of Pythia parameters aimed to get a resonable agreement
276 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
277 // c-cbar single inclusive and double differential distributions.
278 // This parameter settings are meant to work with p-Pb collisions
279 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
280 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
281 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
286 // No multiple interactions
291 // Initial/final parton shower on (Pythia default)
312 // Tuning of Pythia parameters aimed to get a resonable agreement
313 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
314 // c-cbar single inclusive and double differential distributions.
315 // This parameter settings are meant to work with p-Pb collisions
316 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
317 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
318 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
323 // No multiple interactions
328 // Initial/final parton shower on (Pythia default)
350 // Tuning of Pythia parameters aimed to get a resonable agreement
351 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
352 // c-cbar single inclusive and double differential distributions.
353 // This parameter settings are meant to work with pp collisions
354 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
355 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
356 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
361 // No multiple interactions
366 // Initial/final parton shower on (Pythia default)
387 // Tuning of Pythia parameters aimed to get a resonable agreement
388 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
389 // c-cbar single inclusive and double differential distributions.
390 // This parameter settings are meant to work with pp collisions
391 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
392 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
393 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
398 // No multiple interactions
403 // Initial/final parton shower on (Pythia default)
423 case kPyBeautyPbPbMNR:
424 // Tuning of Pythia parameters aimed to get a resonable agreement
425 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
426 // b-bbar single inclusive and double differential distributions.
427 // This parameter settings are meant to work with Pb-Pb collisions
428 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
429 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
430 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
435 // No multiple interactions
440 // Initial/final parton shower on (Pythia default)
462 case kPyBeautypPbMNR:
463 // Tuning of Pythia parameters aimed to get a resonable agreement
464 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
465 // b-bbar single inclusive and double differential distributions.
466 // This parameter settings are meant to work with p-Pb collisions
467 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
468 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
469 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
474 // No multiple interactions
479 // Initial/final parton shower on (Pythia default)
502 // Tuning of Pythia parameters aimed to get a resonable agreement
503 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
504 // b-bbar single inclusive and double differential distributions.
505 // This parameter settings are meant to work with pp collisions
506 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
507 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
508 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
513 // No multiple interactions
518 // Initial/final parton shower on (Pythia default)
543 SetMSTP(41,1); // all resonance decays switched on
545 Initialize("CMS","p","p",fEcms);
549 Int_t AliPythia::CheckedLuComp(Int_t kf)
551 // Check Lund particle code (for debugging)
553 printf("\n Lucomp kf,kc %d %d",kf,kc);
557 void AliPythia::SetNuclei(Int_t a1, Int_t a2)
559 // Treat protons as inside nuclei with mass numbers a1 and a2
560 // The MSTP array in the PYPARS common block is used to enable and
561 // select the nuclear structure functions.
562 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
563 // =1: internal PYTHIA acording to MSTP(51)
564 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
565 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
566 // MSTP(192) : Mass number of nucleus side 1
567 // MSTP(193) : Mass number of nucleus side 2
574 AliPythia* AliPythia::Instance()
576 // Set random number generator
580 fgAliPythia = new AliPythia();
585 void AliPythia::PrintParticles()
587 // Print list of particl properties
589 char* name = new char[16];
590 for (Int_t kf=0; kf<1000000; kf++) {
591 for (Int_t c = 1; c > -2; c-=2) {
592 Int_t kc = Pycomp(c*kf);
594 Float_t mass = GetPMAS(kc,1);
595 Float_t width = GetPMAS(kc,2);
596 Float_t tau = GetPMAS(kc,4);
602 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
603 c*kf, name, mass, width, tau);
607 printf("\n Number of particles %d \n \n", np);
610 void AliPythia::ResetDecayTable()
612 // Set default values for pythia decay switches
614 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
615 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
618 void AliPythia::SetDecayTable()
620 // Set default values for pythia decay switches
623 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
624 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
627 void AliPythia::Pyclus(Int_t& njet)
629 // Call Pythia clustering algorithm
634 void AliPythia::Pycell(Int_t& njet)
636 // Call Pythia jet reconstruction algorithm
641 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
643 // Call Pythia jet reconstruction algorithm
645 pyshow(ip1, ip2, qmax);
648 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
650 pyrobo(imi, ima, the, phi, bex, bey, bez);
655 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t qTransport, Float_t maxLength, Int_t iECMethod)
658 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
659 // (2) The nuclear geometry using the Glauber Model
663 fGlauber = new AliFastGlauber();
665 fGlauber->SetCentralityClass(cMin, cMax);
667 fQuenchingWeights = new AliQuenchingWeights();
668 fQuenchingWeights->InitMult();
669 fQuenchingWeights->SetQTransport(qTransport);
670 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
671 fQuenchingWeights->SetLengthMax(Int_t(maxLength));
672 fQuenchingWeights->SampleEnergyLoss();
677 void AliPythia::Quench()
681 // Simple Jet Quenching routine:
682 // =============================
683 // The jet formed by all final state partons radiated by the parton created
684 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
685 // the initial parton reference frame:
686 // (E + p_z)new = (1-z) (E + p_z)old
691 // The lost momentum is first balanced by one gluon with virtuality > 0.
692 // Subsequently the gluon splits to yield two gluons with E = p.
696 static Float_t eMean = 0.;
697 static Int_t icall = 0;
702 Int_t klast[2] = {-1, -1};
704 Int_t numpart = fPyjets->N;
705 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0.;
706 Double_t pxq[2], pyq[2], pzq[2], eq[2], yq[2], mq[2], pq[2], phiq[2], thetaq[2], ptq[2];
709 Double_t zInitial[2], wjtKick[2];
719 for (Int_t i = 6; i <= 7; i++) {
722 pxq[j] = fPyjets->P[0][i];
723 pyq[j] = fPyjets->P[1][i];
724 pzq[j] = fPyjets->P[2][i];
725 eq[j] = fPyjets->P[3][i];
726 mq[j] = fPyjets->P[4][i];
727 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
728 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
729 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
730 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
731 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
734 // Quench only central jets
735 if (TMath::Abs(yq[j]) > 2.5) {
738 pdg = fPyjets->K[1][i];
740 // Get length in nucleus
742 fGlauber->GetLengthsForPythia(1, &phi, &l, -1.);
744 // Energy loss for given length and parton typr
745 Int_t itype = (pdg == 21) ? 2 : 1;
747 Double_t eloss = fQuenchingWeights->GetELossRandom(itype, l, eq[j]);
748 if (eq[j] > 80. && TMath::Abs(yq[j]) < 0.5) {
756 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->GetQTransport());
758 // Fractional energy loss
759 zInitial[j] = eloss / eq[j];
761 // Avoid complete loss
763 if (zInitial[j] == 1.) zInitial[j] = 0.95;
765 // Some debug printing
766 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",
767 j, itype, eq[j], phi, l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
770 while (zInitial[j] >= 0.95) zInitial[j] = gRandom->Exp(0.2);
773 quenched[j] = (zInitial[j] > 0.01);
776 Double_t pNew[1000][4];
781 for (Int_t isys = 0; isys < 2; isys++) {
782 // Skip to next system if not quenched.
783 if (!quenched[isys]) continue;
785 nGluon[isys] = 1 + Int_t(zInitial[isys] / (1. - zInitial[isys]));
786 if (nGluon[isys] > 6) nGluon[isys] = 6;
787 zInitial[isys] = 1. - TMath::Power(1. - zInitial[isys], 1./Double_t(nGluon[isys]));
788 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
794 Double_t pg[4] = {0., 0., 0., 0.};
797 // Loop on radiation events
799 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
800 Double_t zHeavy = zInitial[isys];
805 for (Int_t k = 0; k < 4; k++)
812 for (Int_t i = 0; i < numpart; i++)
814 imo = fPyjets->K[2][i];
815 kst = fPyjets->K[0][i];
816 pdg = fPyjets->K[1][i];
820 // Quarks and gluons only
821 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
822 // Particles from hard scattering only
823 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
824 if (imo != (isys + 7) && (imo % 1000) != (isys + 7)) continue;
826 // Skip comment lines
827 if (kst != 1 && kst != 2) continue;
830 px = fPyjets->P[0][i];
831 py = fPyjets->P[1][i];
832 pz = fPyjets->P[2][i];
833 e = fPyjets->P[3][i];
834 m = fPyjets->P[4][i];
835 pt = TMath::Sqrt(px * px + py * py);
836 p = TMath::Sqrt(px * px + py * py + pz * pz);
837 phi = TMath::Pi() + TMath::ATan2(-py, -px);
838 theta = TMath::ATan2(pt, pz);
841 // Save 4-momentum sum for balancing
842 Int_t index = imo - 7;
843 if (index >= 1000) index = imo % 1000 - 7;
853 // Fractional energy loss
854 Double_t z = zInitial[index];
856 // Don't fully quench radiated gluons
859 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
867 if (m > 0.) z = zHeavy;
871 // Transform into frame in which initial parton is along z-axis
873 TVector3 v(px, py, pz);
874 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
875 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
877 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
878 Double_t mt2 = jt * jt + m * m;
881 // Kinematic limit on z
883 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
885 // Change light-cone kinematics rel. to initial parton
887 Double_t eppzOld = e + pl;
888 Double_t empzOld = e - pl;
890 Double_t eppzNew = (1. - z) * eppzOld;
891 Double_t empzNew = empzOld - mt2 * z / eppzOld;
892 Double_t eNew = 0.5 * (eppzNew + empzNew);
893 Double_t plNew = 0.5 * (eppzNew - empzNew);
897 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
898 Double_t mt2New = eppzNew * empzNew;
899 if (mt2New < 1.e-8) mt2New = 0.;
901 if (m * m > mt2New) {
903 // This should not happen
905 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
908 jtNew = TMath::Sqrt(mt2New - m * m);
911 // If pT is to small (probably a leading massive particle) we scale only the energy
912 // This can cause negative masses of the radiated gluon
913 // Let's hope for the best ...
915 eNew = TMath::Sqrt(plNew * plNew + mt2);
919 // Calculate new px, py
921 Double_t pxNew = jtNew / jt * pxs;
922 Double_t pyNew = jtNew / jt * pys;
924 // Double_t dpx = pxs - pxNew;
925 // Double_t dpy = pys - pyNew;
926 // Double_t dpz = pl - plNew;
927 // Double_t de = e - eNew;
928 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
929 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
930 // printf("New mass (2) %e %e \n", pxNew, pyNew);
934 TVector3 w(pxNew, pyNew, plNew);
935 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
936 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
938 p1[index][0] += pxNew;
939 p1[index][1] += pyNew;
940 p1[index][2] += plNew;
941 p1[index][3] += eNew;
943 // Updated 4-momentum vectors
945 pNew[icount][0] = pxNew;
946 pNew[icount][1] = pyNew;
947 pNew[icount][2] = plNew;
948 pNew[icount][3] = eNew;
953 // Check if there was phase-space for quenching
956 if (icount == 0) quenched[isys] = kFALSE;
957 if (!quenched[isys]) break;
959 for (Int_t j = 0; j < 4; j++)
961 p2[isys][j] = p0[isys][j] - p1[isys][j];
963 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];
964 if (p2[isys][4] > 0.) {
965 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
968 printf("Warning negative mass squared in system %d %f ! \n", isys, zInitial[isys]);
969 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]);
970 if (p2[isys][4] < -0.01) {
971 printf("Negative mass squared !\n");
972 // Here we have to put the gluon back to mass shell
973 // This will lead to a small energy imbalance
975 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
984 printf("zHeavy lowered to %f\n", zHeavy);
986 printf("No success ! \n");
988 quenched[isys] = kFALSE;
992 } // iteration on z (while)
994 // Update event record
995 for (Int_t k = 0; k < icount; k++) {
996 // 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] );
997 fPyjets->P[0][kNew[k]] = pNew[k][0];
998 fPyjets->P[1][kNew[k]] = pNew[k][1];
999 fPyjets->P[2][kNew[k]] = pNew[k][2];
1000 fPyjets->P[3][kNew[k]] = pNew[k][3];
1007 if (!quenched[isys]) continue;
1009 // Last parton from shower i
1010 Int_t in = klast[isys];
1012 // Continue if no parton in shower i selected
1013 if (in == -1) continue;
1015 // If this is the second initial parton and it is behind the first move pointer by previous ish
1016 if (isys == 1 && klast[1] > klast[0]) in += ish;
1021 // How many additional gluons will be generated
1023 if (p2[isys][4] > 0.05) ish = 2;
1025 // Position of gluons
1027 if (iglu == 0) igMin = iGlu;
1030 (fPyjets->N) += ish;
1033 fPyjets->P[0][iGlu] = p2[isys][0];
1034 fPyjets->P[1][iGlu] = p2[isys][1];
1035 fPyjets->P[2][iGlu] = p2[isys][2];
1036 fPyjets->P[3][iGlu] = p2[isys][3];
1037 fPyjets->P[4][iGlu] = p2[isys][4];
1039 fPyjets->K[0][iGlu] = 1;
1040 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1041 fPyjets->K[1][iGlu] = 21;
1042 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1043 fPyjets->K[3][iGlu] = -1;
1044 fPyjets->K[4][iGlu] = -1;
1046 pg[0] += p2[isys][0];
1047 pg[1] += p2[isys][1];
1048 pg[2] += p2[isys][2];
1049 pg[3] += p2[isys][3];
1052 // Split gluon in rest frame.
1054 Double_t bx = p2[isys][0] / p2[isys][3];
1055 Double_t by = p2[isys][1] / p2[isys][3];
1056 Double_t bz = p2[isys][2] / p2[isys][3];
1057 Double_t pst = p2[isys][4] / 2.;
1059 // Isotropic decay ????
1060 Double_t cost = 2. * gRandom->Rndm() - 1.;
1061 Double_t sint = TMath::Sqrt(1. - cost * cost);
1062 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1064 Double_t pz1 = pst * cost;
1065 Double_t pz2 = -pst * cost;
1066 Double_t pt1 = pst * sint;
1067 Double_t pt2 = -pst * sint;
1068 Double_t px1 = pt1 * TMath::Cos(phi);
1069 Double_t py1 = pt1 * TMath::Sin(phi);
1070 Double_t px2 = pt2 * TMath::Cos(phi);
1071 Double_t py2 = pt2 * TMath::Sin(phi);
1073 fPyjets->P[0][iGlu] = px1;
1074 fPyjets->P[1][iGlu] = py1;
1075 fPyjets->P[2][iGlu] = pz1;
1076 fPyjets->P[3][iGlu] = pst;
1077 fPyjets->P[4][iGlu] = 0.;
1079 fPyjets->K[0][iGlu] = 1 ;
1080 fPyjets->K[1][iGlu] = 21;
1081 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1082 fPyjets->K[3][iGlu] = -1;
1083 fPyjets->K[4][iGlu] = -1;
1085 fPyjets->P[0][iGlu+1] = px2;
1086 fPyjets->P[1][iGlu+1] = py2;
1087 fPyjets->P[2][iGlu+1] = pz2;
1088 fPyjets->P[3][iGlu+1] = pst;
1089 fPyjets->P[4][iGlu+1] = 0.;
1091 fPyjets->K[0][iGlu+1] = 1;
1092 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1093 fPyjets->K[1][iGlu+1] = 21;
1094 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1095 fPyjets->K[3][iGlu+1] = -1;
1096 fPyjets->K[4][iGlu+1] = -1;
1102 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1105 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1106 Double_t px, py, pz;
1107 px = fPyjets->P[0][ig];
1108 py = fPyjets->P[1][ig];
1109 pz = fPyjets->P[2][ig];
1110 TVector3 v(px, py, pz);
1111 v.RotateZ(-phiq[isys]);
1112 v.RotateY(-thetaq[isys]);
1113 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1114 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1115 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1116 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1117 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1118 pxs += jtKick * TMath::Cos(phiKick);
1119 pys += jtKick * TMath::Sin(phiKick);
1120 TVector3 w(pxs, pys, pzs);
1121 w.RotateY(thetaq[isys]);
1122 w.RotateZ(phiq[isys]);
1123 fPyjets->P[0][ig] = w.X();
1124 fPyjets->P[1][ig] = w.Y();
1125 fPyjets->P[2][ig] = w.Z();
1126 fPyjets->P[2][ig] = w.Mag();
1132 // Check energy conservation
1136 Double_t es = 14000.;
1138 for (Int_t i = 0; i < numpart; i++)
1140 kst = fPyjets->K[0][i];
1141 if (kst != 1 && kst != 2) continue;
1142 pxs += fPyjets->P[0][i];
1143 pys += fPyjets->P[1][i];
1144 pzs += fPyjets->P[2][i];
1145 es -= fPyjets->P[3][i];
1147 if (TMath::Abs(pxs) > 1.e-2 ||
1148 TMath::Abs(pys) > 1.e-2 ||
1149 TMath::Abs(pzs) > 1.e-1) {
1150 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1151 // Fatal("Quench()", "4-Momentum non-conservation");
1154 } // end quenching loop (systems)
1156 for (Int_t i = 0; i < numpart; i++)
1158 imo = fPyjets->K[2][i];
1160 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;