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
152 SetMSTP(51, kCTEQ5L); // CTEQ5L pdf
153 SetMSTP(81,1); // Multiple Interactions ON
154 SetMSTP(82,4); // Double Gaussian Model
156 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
157 SetPARP(89,1000.); // [GeV] Ref. energy
158 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
159 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
160 SetPARP(84,0.5); // Core radius
161 SetPARP(85,0.33); // Regulates gluon prod. mechanism
162 SetPARP(86,0.66); // Regulates gluon prod. mechanism
163 SetPARP(67,1); // Regulates Initial State Radiation
166 // Minimum Bias pp-Collisions
169 // select Pythia min. bias model
171 SetMSUB(95,1); // low pt production
177 SetMSTP(51,7); // CTEQ5L pdf
178 SetMSTP(81,1); // Multiple Interactions ON
179 SetMSTP(82,4); // Double Gaussian Model
181 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
182 SetPARP(89,1000.); // [GeV] Ref. energy
183 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
184 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
185 SetPARP(84,0.5); // Core radius
186 SetPARP(85,0.33); // Regulates gluon prod. mechanism
187 SetPARP(86,0.66); // Regulates gluon prod. mechanism
188 SetPARP(67,1); // Regulates Initial State Radiation
199 case kPyCharmPbPbMNR:
201 // Tuning of Pythia parameters aimed to get a resonable agreement
202 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
203 // c-cbar single inclusive and double differential distributions.
204 // This parameter settings are meant to work with Pb-Pb collisions
205 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
206 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
207 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
212 // No multiple interactions
217 // Initial/final parton shower on (Pythia default)
237 case kPyDPlusPbPbMNR:
238 // Tuning of Pythia parameters aimed to get a resonable agreement
239 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
240 // c-cbar single inclusive and double differential distributions.
241 // This parameter settings are meant to work with Pb-Pb collisions
242 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
243 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
244 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
249 // No multiple interactions
254 // Initial/final parton shower on (Pythia default)
276 // Tuning of Pythia parameters aimed to get a resonable agreement
277 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
278 // c-cbar single inclusive and double differential distributions.
279 // This parameter settings are meant to work with p-Pb collisions
280 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
281 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
282 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
287 // No multiple interactions
292 // Initial/final parton shower on (Pythia default)
313 // Tuning of Pythia parameters aimed to get a resonable agreement
314 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
315 // c-cbar single inclusive and double differential distributions.
316 // This parameter settings are meant to work with p-Pb collisions
317 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
318 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
319 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
324 // No multiple interactions
329 // Initial/final parton shower on (Pythia default)
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 pp 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.
362 // No multiple interactions
367 // Initial/final parton shower on (Pythia default)
388 // Tuning of Pythia parameters aimed to get a resonable agreement
389 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
390 // c-cbar single inclusive and double differential distributions.
391 // This parameter settings are meant to work with pp collisions
392 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
393 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
394 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
399 // No multiple interactions
404 // Initial/final parton shower on (Pythia default)
424 case kPyBeautyPbPbMNR:
425 // Tuning of Pythia parameters aimed to get a resonable agreement
426 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
427 // b-bbar single inclusive and double differential distributions.
428 // This parameter settings are meant to work with Pb-Pb collisions
429 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
430 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
431 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
436 // No multiple interactions
441 // Initial/final parton shower on (Pythia default)
463 case kPyBeautypPbMNR:
464 // Tuning of Pythia parameters aimed to get a resonable agreement
465 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
466 // b-bbar single inclusive and double differential distributions.
467 // This parameter settings are meant to work with p-Pb collisions
468 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
469 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
470 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
475 // No multiple interactions
480 // Initial/final parton shower on (Pythia default)
503 // Tuning of Pythia parameters aimed to get a resonable agreement
504 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
505 // b-bbar single inclusive and double differential distributions.
506 // This parameter settings are meant to work with pp collisions
507 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
508 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
509 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
514 // No multiple interactions
519 // Initial/final parton shower on (Pythia default)
544 SetMSTP(41,1); // all resonance decays switched on
546 Initialize("CMS","p","p",fEcms);
550 Int_t AliPythia::CheckedLuComp(Int_t kf)
552 // Check Lund particle code (for debugging)
554 printf("\n Lucomp kf,kc %d %d",kf,kc);
558 void AliPythia::SetNuclei(Int_t a1, Int_t a2)
560 // Treat protons as inside nuclei with mass numbers a1 and a2
561 // The MSTP array in the PYPARS common block is used to enable and
562 // select the nuclear structure functions.
563 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
564 // =1: internal PYTHIA acording to MSTP(51)
565 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
566 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
567 // MSTP(192) : Mass number of nucleus side 1
568 // MSTP(193) : Mass number of nucleus side 2
575 AliPythia* AliPythia::Instance()
577 // Set random number generator
581 fgAliPythia = new AliPythia();
586 void AliPythia::PrintParticles()
588 // Print list of particl properties
590 char* name = new char[16];
591 for (Int_t kf=0; kf<1000000; kf++) {
592 for (Int_t c = 1; c > -2; c-=2) {
593 Int_t kc = Pycomp(c*kf);
595 Float_t mass = GetPMAS(kc,1);
596 Float_t width = GetPMAS(kc,2);
597 Float_t tau = GetPMAS(kc,4);
603 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
604 c*kf, name, mass, width, tau);
608 printf("\n Number of particles %d \n \n", np);
611 void AliPythia::ResetDecayTable()
613 // Set default values for pythia decay switches
615 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
616 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
619 void AliPythia::SetDecayTable()
621 // Set default values for pythia decay switches
624 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
625 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
628 void AliPythia::Pyclus(Int_t& njet)
630 // Call Pythia clustering algorithm
635 void AliPythia::Pycell(Int_t& njet)
637 // Call Pythia jet reconstruction algorithm
642 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
644 // Call Pythia jet reconstruction algorithm
646 pyshow(ip1, ip2, qmax);
649 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
651 pyrobo(imi, ima, the, phi, bex, bey, bez);
656 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t qTransport, Float_t maxLength, Int_t iECMethod)
659 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
660 // (2) The nuclear geometry using the Glauber Model
664 fGlauber = new AliFastGlauber();
666 fGlauber->SetCentralityClass(cMin, cMax);
668 fQuenchingWeights = new AliQuenchingWeights();
669 fQuenchingWeights->InitMult();
670 fQuenchingWeights->SetQTransport(qTransport);
671 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
672 fQuenchingWeights->SetLengthMax(Int_t(maxLength));
673 fQuenchingWeights->SampleEnergyLoss();
678 void AliPythia::Quench()
682 // Simple Jet Quenching routine:
683 // =============================
684 // The jet formed by all final state partons radiated by the parton created
685 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
686 // the initial parton reference frame:
687 // (E + p_z)new = (1-z) (E + p_z)old
692 // The lost momentum is first balanced by one gluon with virtuality > 0.
693 // Subsequently the gluon splits to yield two gluons with E = p.
697 static Float_t eMean = 0.;
698 static Int_t icall = 0;
703 Int_t klast[4] = {-1, -1, -1, -1};
705 Int_t numpart = fPyjets->N;
706 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0.;
707 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
710 Double_t zInitial[4], wjtKick[4];
715 // Sore information about Primary partons
718 // 0, 1 partons from hard scattering
719 // 2, 3 partons from initial state radiation
721 for (Int_t i = 2; i <= 7; i++) {
723 // Skip gluons that participate in hard scattering
724 if (i == 4 || i == 5) continue;
725 // Gluons from hard Scattering
726 if (i == 6 || i == 7) {
728 pxq[j] = fPyjets->P[0][i];
729 pyq[j] = fPyjets->P[1][i];
730 pzq[j] = fPyjets->P[2][i];
731 eq[j] = fPyjets->P[3][i];
732 mq[j] = fPyjets->P[4][i];
734 // Gluons from initial state radiation
736 // Obtain 4-momentum vector from difference between original parton and parton after gluon
737 // radiation. Energy is calculated independently because initial state radition does not
738 // conserve strictly momentum and energy for each partonic system independently.
740 // Not very clean. Should be improved !
744 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
745 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
746 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
747 mq[j] = fPyjets->P[4][i];
748 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
751 // Calculate some kinematic variables
753 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
754 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
755 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
756 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
757 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
760 // Quench only central jets and with E > 10.
762 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
765 pdg = fPyjets->K[1][i];
766 // Get length in nucleus
768 fGlauber->GetLengthsForPythia(1, &phi, &l, -1.);
770 // Energy loss for given length and parton type
771 Int_t itype = (pdg == 21) ? 2 : 1;
773 Double_t eloss = fQuenchingWeights->GetELossRandom(itype, l, eq[j]);
774 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
782 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->GetQTransport());
784 // Fractional energy loss
785 zInitial[j] = eloss / eq[j];
787 // Avoid complete loss
789 if (zInitial[j] == 1.) zInitial[j] = 0.95;
791 // Some debug printing
792 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",
793 j, itype, eq[j], phi, l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
795 // zInitial[j] = 0.8;
796 // while (zInitial[j] >= 0.95) zInitial[j] = gRandom->Exp(0.2);
799 quenched[j] = (zInitial[j] > 0.01);
802 Double_t pNew[1000][4];
807 for (Int_t isys = 0; isys < 4; isys++) {
808 // Skip to next system if not quenched.
809 if (!quenched[isys]) continue;
811 nGluon[isys] = 1 + Int_t(zInitial[isys] / (1. - zInitial[isys]));
812 if (nGluon[isys] > 6) nGluon[isys] = 6;
813 zInitial[isys] = 1. - TMath::Power(1. - zInitial[isys], 1./Double_t(nGluon[isys]));
814 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
820 Double_t pg[4] = {0., 0., 0., 0.};
823 // Loop on radiation events
825 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
828 for (Int_t k = 0; k < 4; k++)
835 for (Int_t i = 0; i < numpart; i++)
837 imo = fPyjets->K[2][i];
838 kst = fPyjets->K[0][i];
839 pdg = fPyjets->K[1][i];
843 // Quarks and gluons only
844 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
845 // Particles from hard scattering only
847 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
848 Int_t imom = imo % 1000;
849 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
850 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
853 // Skip comment lines
854 if (kst != 1 && kst != 2) continue;
857 px = fPyjets->P[0][i];
858 py = fPyjets->P[1][i];
859 pz = fPyjets->P[2][i];
860 e = fPyjets->P[3][i];
861 m = fPyjets->P[4][i];
862 pt = TMath::Sqrt(px * px + py * py);
863 p = TMath::Sqrt(px * px + py * py + pz * pz);
864 phi = TMath::Pi() + TMath::ATan2(-py, -px);
865 theta = TMath::ATan2(pt, pz);
868 // Save 4-momentum sum for balancing
879 // Fractional energy loss
880 Double_t z = zInitial[index];
883 // Don't fully quench radiated gluons
886 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
891 // printf("z: %d %f\n", imo, z);
898 // Transform into frame in which initial parton is along z-axis
900 TVector3 v(px, py, pz);
901 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
902 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
904 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
905 Double_t mt2 = jt * jt + m * m;
908 // Kinematic limit on z
910 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
912 // Change light-cone kinematics rel. to initial parton
914 Double_t eppzOld = e + pl;
915 Double_t empzOld = e - pl;
917 Double_t eppzNew = (1. - z) * eppzOld;
918 Double_t empzNew = empzOld - mt2 * z / eppzOld;
919 Double_t eNew = 0.5 * (eppzNew + empzNew);
920 Double_t plNew = 0.5 * (eppzNew - empzNew);
924 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
925 Double_t mt2New = eppzNew * empzNew;
926 if (mt2New < 1.e-8) mt2New = 0.;
928 if (m * m > mt2New) {
930 // This should not happen
932 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
935 jtNew = TMath::Sqrt(mt2New - m * m);
938 // If pT is to small (probably a leading massive particle) we scale only the energy
939 // This can cause negative masses of the radiated gluon
940 // Let's hope for the best ...
942 eNew = TMath::Sqrt(plNew * plNew + mt2);
946 // Calculate new px, py
948 Double_t pxNew = jtNew / jt * pxs;
949 Double_t pyNew = jtNew / jt * pys;
951 // Double_t dpx = pxs - pxNew;
952 // Double_t dpy = pys - pyNew;
953 // Double_t dpz = pl - plNew;
954 // Double_t de = e - eNew;
955 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
956 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
957 // printf("New mass (2) %e %e \n", pxNew, pyNew);
961 TVector3 w(pxNew, pyNew, plNew);
962 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
963 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
965 p1[index][0] += pxNew;
966 p1[index][1] += pyNew;
967 p1[index][2] += plNew;
968 p1[index][3] += eNew;
970 // Updated 4-momentum vectors
972 pNew[icount][0] = pxNew;
973 pNew[icount][1] = pyNew;
974 pNew[icount][2] = plNew;
975 pNew[icount][3] = eNew;
980 // Check if there was phase-space for quenching
983 if (icount == 0) quenched[isys] = kFALSE;
984 if (!quenched[isys]) break;
986 for (Int_t j = 0; j < 4; j++)
988 p2[isys][j] = p0[isys][j] - p1[isys][j];
990 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];
991 if (p2[isys][4] > 0.) {
992 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
995 printf("Warning negative mass squared in system %d %f ! \n", isys, zInitial[isys]);
996 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]);
997 if (p2[isys][4] < -0.01) {
998 printf("Negative mass squared !\n");
999 // Here we have to put the gluon back to mass shell
1000 // This will lead to a small energy imbalance
1002 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1011 printf("zHeavy lowered to %f\n", zHeavy);
1012 if (zHeavy < 0.01) {
1013 printf("No success ! \n");
1015 quenched[isys] = kFALSE;
1019 } // iteration on z (while)
1021 // Update event record
1022 for (Int_t k = 0; k < icount; k++) {
1023 // 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] );
1024 fPyjets->P[0][kNew[k]] = pNew[k][0];
1025 fPyjets->P[1][kNew[k]] = pNew[k][1];
1026 fPyjets->P[2][kNew[k]] = pNew[k][2];
1027 fPyjets->P[3][kNew[k]] = pNew[k][3];
1034 if (!quenched[isys]) continue;
1036 // Last parton from shower i
1037 Int_t in = klast[isys];
1039 // Continue if no parton in shower i selected
1040 if (in == -1) continue;
1042 // If this is the second initial parton and it is behind the first move pointer by previous ish
1043 if (isys == 1 && klast[1] > klast[0]) in += ish;
1048 // How many additional gluons will be generated
1050 if (p2[isys][4] > 0.05) ish = 2;
1052 // Position of gluons
1054 if (iglu == 0) igMin = iGlu;
1057 (fPyjets->N) += ish;
1060 fPyjets->P[0][iGlu] = p2[isys][0];
1061 fPyjets->P[1][iGlu] = p2[isys][1];
1062 fPyjets->P[2][iGlu] = p2[isys][2];
1063 fPyjets->P[3][iGlu] = p2[isys][3];
1064 fPyjets->P[4][iGlu] = p2[isys][4];
1066 fPyjets->K[0][iGlu] = 1;
1067 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1068 fPyjets->K[1][iGlu] = 21;
1069 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1070 fPyjets->K[3][iGlu] = -1;
1071 fPyjets->K[4][iGlu] = -1;
1073 pg[0] += p2[isys][0];
1074 pg[1] += p2[isys][1];
1075 pg[2] += p2[isys][2];
1076 pg[3] += p2[isys][3];
1079 // Split gluon in rest frame.
1081 Double_t bx = p2[isys][0] / p2[isys][3];
1082 Double_t by = p2[isys][1] / p2[isys][3];
1083 Double_t bz = p2[isys][2] / p2[isys][3];
1084 Double_t pst = p2[isys][4] / 2.;
1086 // Isotropic decay ????
1087 Double_t cost = 2. * gRandom->Rndm() - 1.;
1088 Double_t sint = TMath::Sqrt(1. - cost * cost);
1089 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1091 Double_t pz1 = pst * cost;
1092 Double_t pz2 = -pst * cost;
1093 Double_t pt1 = pst * sint;
1094 Double_t pt2 = -pst * sint;
1095 Double_t px1 = pt1 * TMath::Cos(phi);
1096 Double_t py1 = pt1 * TMath::Sin(phi);
1097 Double_t px2 = pt2 * TMath::Cos(phi);
1098 Double_t py2 = pt2 * TMath::Sin(phi);
1100 fPyjets->P[0][iGlu] = px1;
1101 fPyjets->P[1][iGlu] = py1;
1102 fPyjets->P[2][iGlu] = pz1;
1103 fPyjets->P[3][iGlu] = pst;
1104 fPyjets->P[4][iGlu] = 0.;
1106 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 fPyjets->P[0][iGlu+1] = px2;
1113 fPyjets->P[1][iGlu+1] = py2;
1114 fPyjets->P[2][iGlu+1] = pz2;
1115 fPyjets->P[3][iGlu+1] = pst;
1116 fPyjets->P[4][iGlu+1] = 0.;
1118 fPyjets->K[0][iGlu+1] = 1;
1119 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1120 fPyjets->K[1][iGlu+1] = 21;
1121 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1122 fPyjets->K[3][iGlu+1] = -1;
1123 fPyjets->K[4][iGlu+1] = -1;
1129 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1132 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1133 Double_t px, py, pz;
1134 px = fPyjets->P[0][ig];
1135 py = fPyjets->P[1][ig];
1136 pz = fPyjets->P[2][ig];
1137 TVector3 v(px, py, pz);
1138 v.RotateZ(-phiq[isys]);
1139 v.RotateY(-thetaq[isys]);
1140 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1141 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1142 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1143 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1144 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1145 pxs += jtKick * TMath::Cos(phiKick);
1146 pys += jtKick * TMath::Sin(phiKick);
1147 TVector3 w(pxs, pys, pzs);
1148 w.RotateY(thetaq[isys]);
1149 w.RotateZ(phiq[isys]);
1150 fPyjets->P[0][ig] = w.X();
1151 fPyjets->P[1][ig] = w.Y();
1152 fPyjets->P[2][ig] = w.Z();
1153 fPyjets->P[2][ig] = w.Mag();
1159 // Check energy conservation
1163 Double_t es = 14000.;
1165 for (Int_t i = 0; i < numpart; i++)
1167 kst = fPyjets->K[0][i];
1168 if (kst != 1 && kst != 2) continue;
1169 pxs += fPyjets->P[0][i];
1170 pys += fPyjets->P[1][i];
1171 pzs += fPyjets->P[2][i];
1172 es -= fPyjets->P[3][i];
1174 if (TMath::Abs(pxs) > 1.e-2 ||
1175 TMath::Abs(pys) > 1.e-2 ||
1176 TMath::Abs(pzs) > 1.e-1) {
1177 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1178 // Fatal("Quench()", "4-Momentum non-conservation");
1181 } // end quenching loop (systems)
1183 for (Int_t i = 0; i < numpart; i++)
1185 imo = fPyjets->K[2][i];
1187 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;