2 /**************************************************************************
3 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
5 * Author: The ALICE Off-line Project. *
6 * Contributors are mentioned in the code where appropriate. *
8 * Permission to use, copy, modify and distribute this software and its *
9 * documentation strictly for non-commercial purposes is hereby granted *
10 * without fee, provided that the above copyright notice appears in all *
11 * copies and that both the copyright notice and this permission notice *
12 * appear in the supporting documentation. The authors make no claims *
13 * about the suitability of this software for any purpose. It is *
14 * provided "as is" without express or implied warranty. *
15 **************************************************************************/
19 #include "AliPythia.h"
20 #include "AliPythiaRndm.h"
21 #include "../FASTSIM/AliFastGlauber.h"
22 #include "../FASTSIM/AliQuenchingWeights.h"
28 # define pyclus pyclus_
29 # define pycell pycell_
30 # define pyshow pyshow_
31 # define pyrobo pyrobo_
32 # define pyquen pyquen_
33 # define pyevnw pyevnw_
36 # define pyclus PYCLUS
37 # define pycell PYCELL
38 # define pyrobo PYROBO
39 # define pyquen PYQUEN
40 # define pyevnw PYEVNW
41 # define type_of_call _stdcall
44 extern "C" void type_of_call pyclus(Int_t & );
45 extern "C" void type_of_call pycell(Int_t & );
46 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
47 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
48 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
49 extern "C" void type_of_call pyevnw(){;}
51 //_____________________________________________________________________________
53 AliPythia* AliPythia::fgAliPythia=NULL;
55 AliPythia::AliPythia():
66 // Default Constructor
69 if (!AliPythiaRndm::GetPythiaRandom())
70 AliPythiaRndm::SetPythiaRandom(GetRandom());
72 fQuenchingWeights = 0;
75 AliPythia::AliPythia(const AliPythia& pythia):
92 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
94 // Initialise the process to generate
95 if (!AliPythiaRndm::GetPythiaRandom())
96 AliPythiaRndm::SetPythiaRandom(GetRandom());
100 fStrucFunc = strucfunc;
101 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
102 SetMDCY(Pycomp(111) ,1,0);
103 SetMDCY(Pycomp(310) ,1,0);
104 SetMDCY(Pycomp(3122),1,0);
105 SetMDCY(Pycomp(3112),1,0);
106 SetMDCY(Pycomp(3212),1,0);
107 SetMDCY(Pycomp(3222),1,0);
108 SetMDCY(Pycomp(3312),1,0);
109 SetMDCY(Pycomp(3322),1,0);
110 SetMDCY(Pycomp(3334),1,0);
111 // Select structure function
113 SetMSTP(51,strucfunc);
114 // Particles produced in string fragmentation point directly to either of the two endpoints
115 // of the string (depending in the side they were generated from).
119 // Pythia initialisation for selected processes//
123 for (Int_t i=1; i<= 200; i++) {
126 // select charm production
129 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
130 // Multiple interactions on.
132 // Double Gaussian matter distribution.
138 // Reference energy for pT0 and energy rescaling pace.
141 // String drawing almost completely minimizes string length.
144 // ISR and FSR activity.
150 case kPyOldUEQ2ordered2:
151 // Old underlying events with Q2 ordered QCD processes
152 // Multiple interactions on.
154 // Double Gaussian matter distribution.
160 // Reference energy for pT0 and energy rescaling pace.
162 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
163 // String drawing almost completely minimizes string length.
166 // ISR and FSR activity.
173 // Old production mechanism: Old Popcorn
176 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
178 // (D=1)see can be used to form baryons (BARYON JUNCTION)
184 // heavy quark masses
214 case kPyCharmUnforced:
223 case kPyBeautyUnforced:
233 // Minimum Bias pp-Collisions
236 // select Pythia min. bias model
238 SetMSUB(92,1); // single diffraction AB-->XB
239 SetMSUB(93,1); // single diffraction AB-->AX
240 SetMSUB(94,1); // double diffraction
241 SetMSUB(95,1); // low pt production
246 // Minimum Bias pp-Collisions
249 // select Pythia min. bias model
251 SetMSUB(92,1); // single diffraction AB-->XB
252 SetMSUB(93,1); // single diffraction AB-->AX
253 SetMSUB(94,1); // double diffraction
254 SetMSUB(95,1); // low pt production
258 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
259 // -> Pythia 6.3 or above is needed
262 SetMSUB(92,1); // single diffraction AB-->XB
263 SetMSUB(93,1); // single diffraction AB-->AX
264 SetMSUB(94,1); // double diffraction
265 SetMSUB(95,1); // low pt production
267 SetMSTP(51,kCTEQ6ll); // CTEQ6ll pdf
271 SetMSTP(81,1); // Multiple Interactions ON
272 SetMSTP(82,4); // Double Gaussian Model
275 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
276 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
277 SetPARP(84,0.5); // Core radius
278 SetPARP(85,0.9); // Regulates gluon prod. mechanism
279 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
283 // Minimum Bias pp-Collisions
286 // select Pythia min. bias model
288 SetMSUB(95,1); // low pt production
295 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
296 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
297 SetPARP(93,5.); // Upper cut-off
299 SetPMAS(4,1,1.2); // Charm quark mass
300 SetPMAS(5,1,4.78); // Beauty quark mass
301 SetPARP(71,4.); // Defaut value
310 // Pythia Tune A (CDF)
312 SetPARP(67,4.); // Regulates Initial State Radiation
313 SetMSTP(82,4); // Double Gaussian Model
314 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
315 SetPARP(84,0.4); // Core radius
316 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
317 SetPARP(86,0.95); // Regulates gluon prod. mechanism
318 SetPARP(89,1800.); // [GeV] Ref. energy
319 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
324 case kPyCharmPbPbMNR:
326 case kPyDPlusPbPbMNR:
327 case kPyDPlusStrangePbPbMNR:
328 // Tuning of Pythia parameters aimed to get a resonable agreement
329 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
330 // c-cbar single inclusive and double differential distributions.
331 // This parameter settings are meant to work with Pb-Pb collisions
332 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
333 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
334 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
346 case kPyDPlusStrangepPbMNR:
347 // Tuning of Pythia parameters aimed to get a resonable agreement
348 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
349 // c-cbar single inclusive and double differential distributions.
350 // This parameter settings are meant to work with p-Pb collisions
351 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
352 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
353 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
366 case kPyDPlusStrangeppMNR:
367 // Tuning of Pythia parameters aimed to get a resonable agreement
368 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
369 // c-cbar single inclusive and double differential distributions.
370 // This parameter settings are meant to work with pp collisions
371 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
372 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
373 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
383 case kPyCharmppMNRwmi:
384 // Tuning of Pythia parameters aimed to get a resonable agreement
385 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
386 // c-cbar single inclusive and double differential distributions.
387 // This parameter settings are meant to work with pp collisions
388 // and with kCTEQ5L PDFs.
389 // Added multiple interactions according to ATLAS tune settings.
390 // To get a "reasonable" agreement with MNR results, events have to be
391 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
393 // To get a "perfect" agreement with MNR results, events have to be
394 // generated in four ptHard bins with the following relative
410 case kPyBeautyPbPbMNR:
411 // Tuning of Pythia parameters aimed to get a resonable agreement
412 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
413 // b-bbar single inclusive and double differential distributions.
414 // This parameter settings are meant to work with Pb-Pb collisions
415 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
416 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
417 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
429 case kPyBeautypPbMNR:
430 // Tuning of Pythia parameters aimed to get a resonable agreement
431 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
432 // b-bbar single inclusive and double differential distributions.
433 // This parameter settings are meant to work with p-Pb collisions
434 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
435 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
436 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
449 // Tuning of Pythia parameters aimed to get a resonable agreement
450 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
451 // b-bbar single inclusive and double differential distributions.
452 // This parameter settings are meant to work with pp collisions
453 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
454 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
455 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
469 case kPyBeautyppMNRwmi:
470 // Tuning of Pythia parameters aimed to get a resonable agreement
471 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
472 // b-bbar single inclusive and double differential distributions.
473 // This parameter settings are meant to work with pp collisions
474 // and with kCTEQ5L PDFs.
475 // Added multiple interactions according to ATLAS tune settings.
476 // To get a "reasonable" agreement with MNR results, events have to be
477 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
479 // To get a "perfect" agreement with MNR results, events have to be
480 // generated in four ptHard bins with the following relative
503 //Inclusive production of W+/-
509 // //f fbar -> gamma W+
516 // Initial/final parton shower on (Pythia default)
517 // With parton showers on we are generating "W inclusive process"
518 SetMSTP(61,1); //Initial QCD & QED showers on
519 SetMSTP(71,1); //Final QCD & QED showers on
525 //Inclusive production of Z
530 // // f fbar -> g Z/gamma
532 // // f fbar -> gamma Z/gamma
534 // // f g -> f Z/gamma
536 // // f gamma -> f Z/gamma
539 //only Z included, not gamma
542 // Initial/final parton shower on (Pythia default)
543 // With parton showers on we are generating "Z inclusive process"
544 SetMSTP(61,1); //Initial QCD & QED showers on
545 SetMSTP(71,1); //Final QCD & QED showers on
552 SetMSTP(41,1); // all resonance decays switched on
554 Initialize("CMS","p","p",fEcms);
558 Int_t AliPythia::CheckedLuComp(Int_t kf)
560 // Check Lund particle code (for debugging)
562 printf("\n Lucomp kf,kc %d %d",kf,kc);
566 void AliPythia::SetNuclei(Int_t a1, Int_t a2)
568 // Treat protons as inside nuclei with mass numbers a1 and a2
569 // The MSTP array in the PYPARS common block is used to enable and
570 // select the nuclear structure functions.
571 // MSTP(52) : (D=1) choice of proton and nuclear structure-function library
572 // =1: internal PYTHIA acording to MSTP(51)
573 // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
574 // If the following mass number both not equal zero, nuclear corrections of the stf are used.
575 // MSTP(192) : Mass number of nucleus side 1
576 // MSTP(193) : Mass number of nucleus side 2
583 AliPythia* AliPythia::Instance()
585 // Set random number generator
589 fgAliPythia = new AliPythia();
594 void AliPythia::PrintParticles()
596 // Print list of particl properties
598 char* name = new char[16];
599 for (Int_t kf=0; kf<1000000; kf++) {
600 for (Int_t c = 1; c > -2; c-=2) {
601 Int_t kc = Pycomp(c*kf);
603 Float_t mass = GetPMAS(kc,1);
604 Float_t width = GetPMAS(kc,2);
605 Float_t tau = GetPMAS(kc,4);
611 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
612 c*kf, name, mass, width, tau);
616 printf("\n Number of particles %d \n \n", np);
619 void AliPythia::ResetDecayTable()
621 // Set default values for pythia decay switches
623 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
624 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
627 void AliPythia::SetDecayTable()
629 // Set default values for pythia decay switches
632 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
633 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
636 void AliPythia::Pyclus(Int_t& njet)
638 // Call Pythia clustering algorithm
643 void AliPythia::Pycell(Int_t& njet)
645 // Call Pythia jet reconstruction algorithm
650 void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
652 // Call Pythia jet reconstruction algorithm
654 pyshow(ip1, ip2, qmax);
657 void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
659 pyrobo(imi, ima, the, phi, bex, bey, bez);
664 void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod, Float_t zmax, Int_t ngmax)
667 // (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
668 // (2) The nuclear geometry using the Glauber Model
671 fGlauber = new AliFastGlauber();
673 fGlauber->SetCentralityClass(cMin, cMax);
675 fQuenchingWeights = new AliQuenchingWeights();
676 fQuenchingWeights->InitMult();
677 fQuenchingWeights->SetK(k);
678 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
685 void AliPythia::Quench()
689 // Simple Jet Quenching routine:
690 // =============================
691 // The jet formed by all final state partons radiated by the parton created
692 // in the hard collisions is quenched by a factor (1-z) using light cone variables in
693 // the initial parton reference frame:
694 // (E + p_z)new = (1-z) (E + p_z)old
699 // The lost momentum is first balanced by one gluon with virtuality > 0.
700 // Subsequently the gluon splits to yield two gluons with E = p.
704 static Float_t eMean = 0.;
705 static Int_t icall = 0;
710 Int_t klast[4] = {-1, -1, -1, -1};
712 Int_t numpart = fPyjets->N;
713 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
714 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
722 // Sore information about Primary partons
725 // 0, 1 partons from hard scattering
726 // 2, 3 partons from initial state radiation
728 for (Int_t i = 2; i <= 7; i++) {
730 // Skip gluons that participate in hard scattering
731 if (i == 4 || i == 5) continue;
732 // Gluons from hard Scattering
733 if (i == 6 || i == 7) {
735 pxq[j] = fPyjets->P[0][i];
736 pyq[j] = fPyjets->P[1][i];
737 pzq[j] = fPyjets->P[2][i];
738 eq[j] = fPyjets->P[3][i];
739 mq[j] = fPyjets->P[4][i];
741 // Gluons from initial state radiation
743 // Obtain 4-momentum vector from difference between original parton and parton after gluon
744 // radiation. Energy is calculated independently because initial state radition does not
745 // conserve strictly momentum and energy for each partonic system independently.
747 // Not very clean. Should be improved !
751 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
752 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
753 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
754 mq[j] = fPyjets->P[4][i];
755 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
758 // Calculate some kinematic variables
760 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
761 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
762 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
763 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
764 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
765 qPdg[j] = fPyjets->K[1][i];
771 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
773 for (Int_t j = 0; j < 4; j++) {
775 // Quench only central jets and with E > 10.
779 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
780 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
782 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
785 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
791 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
792 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
794 // Fractional energy loss
795 fZQuench[j] = eloss / eq[j];
797 // Avoid complete loss
799 if (fZQuench[j] == 1.) fZQuench[j] = fZmax;
801 // Some debug printing
804 // 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",
805 // j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
807 // fZQuench[j] = 0.8;
808 // while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
811 quenched[j] = (fZQuench[j] > 0.01);
816 Double_t pNew[1000][4];
823 for (Int_t isys = 0; isys < 4; isys++) {
824 // Skip to next system if not quenched.
825 if (!quenched[isys]) continue;
827 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
828 if (nGluon[isys] > fNGmax) nGluon[isys] = fNGmax;
829 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
830 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
836 Double_t pg[4] = {0., 0., 0., 0.};
839 // Loop on radiation events
841 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
844 for (Int_t k = 0; k < 4; k++)
851 for (Int_t i = 0; i < numpart; i++)
853 imo = fPyjets->K[2][i];
854 kst = fPyjets->K[0][i];
855 pdg = fPyjets->K[1][i];
859 // Quarks and gluons only
860 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
861 // Particles from hard scattering only
863 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
864 Int_t imom = imo % 1000;
865 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
866 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
869 // Skip comment lines
870 if (kst != 1 && kst != 2) continue;
873 px = fPyjets->P[0][i];
874 py = fPyjets->P[1][i];
875 pz = fPyjets->P[2][i];
876 e = fPyjets->P[3][i];
877 m = fPyjets->P[4][i];
878 pt = TMath::Sqrt(px * px + py * py);
879 p = TMath::Sqrt(px * px + py * py + pz * pz);
880 phi = TMath::Pi() + TMath::ATan2(-py, -px);
881 theta = TMath::ATan2(pt, pz);
884 // Save 4-momentum sum for balancing
895 // Fractional energy loss
896 Double_t z = zquench[index];
899 // Don't fully quench radiated gluons
902 // This small factor makes sure that the gluons are not too close in phase space to avoid recombination
907 // printf("z: %d %f\n", imo, z);
914 // Transform into frame in which initial parton is along z-axis
916 TVector3 v(px, py, pz);
917 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
918 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
920 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
921 Double_t mt2 = jt * jt + m * m;
924 // Kinematic limit on z
926 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
928 // Change light-cone kinematics rel. to initial parton
930 Double_t eppzOld = e + pl;
931 Double_t empzOld = e - pl;
933 Double_t eppzNew = (1. - z) * eppzOld;
934 Double_t empzNew = empzOld - mt2 * z / eppzOld;
935 Double_t eNew = 0.5 * (eppzNew + empzNew);
936 Double_t plNew = 0.5 * (eppzNew - empzNew);
940 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
941 Double_t mt2New = eppzNew * empzNew;
942 if (mt2New < 1.e-8) mt2New = 0.;
944 if (m * m > mt2New) {
946 // This should not happen
948 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
951 jtNew = TMath::Sqrt(mt2New - m * m);
954 // If pT is to small (probably a leading massive particle) we scale only the energy
955 // This can cause negative masses of the radiated gluon
956 // Let's hope for the best ...
958 eNew = TMath::Sqrt(plNew * plNew + mt2);
962 // Calculate new px, py
964 Double_t pxNew = jtNew / jt * pxs;
965 Double_t pyNew = jtNew / jt * pys;
967 // Double_t dpx = pxs - pxNew;
968 // Double_t dpy = pys - pyNew;
969 // Double_t dpz = pl - plNew;
970 // Double_t de = e - eNew;
971 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
972 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
973 // printf("New mass (2) %e %e \n", pxNew, pyNew);
977 TVector3 w(pxNew, pyNew, plNew);
978 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
979 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
981 p1[index][0] += pxNew;
982 p1[index][1] += pyNew;
983 p1[index][2] += plNew;
984 p1[index][3] += eNew;
986 // Updated 4-momentum vectors
988 pNew[icount][0] = pxNew;
989 pNew[icount][1] = pyNew;
990 pNew[icount][2] = plNew;
991 pNew[icount][3] = eNew;
996 // Check if there was phase-space for quenching
999 if (icount == 0) quenched[isys] = kFALSE;
1000 if (!quenched[isys]) break;
1002 for (Int_t j = 0; j < 4; j++)
1004 p2[isys][j] = p0[isys][j] - p1[isys][j];
1006 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];
1007 if (p2[isys][4] > 0.) {
1008 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1011 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1012 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]);
1013 if (p2[isys][4] < -0.01) {
1014 printf("Negative mass squared !\n");
1015 // Here we have to put the gluon back to mass shell
1016 // This will lead to a small energy imbalance
1018 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1027 printf("zHeavy lowered to %f\n", zHeavy);
1028 if (zHeavy < 0.01) {
1029 printf("No success ! \n");
1031 quenched[isys] = kFALSE;
1035 } // iteration on z (while)
1037 // Update event record
1038 for (Int_t k = 0; k < icount; k++) {
1039 // 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] );
1040 fPyjets->P[0][kNew[k]] = pNew[k][0];
1041 fPyjets->P[1][kNew[k]] = pNew[k][1];
1042 fPyjets->P[2][kNew[k]] = pNew[k][2];
1043 fPyjets->P[3][kNew[k]] = pNew[k][3];
1050 if (!quenched[isys]) continue;
1052 // Last parton from shower i
1053 Int_t in = klast[isys];
1055 // Continue if no parton in shower i selected
1056 if (in == -1) continue;
1058 // If this is the second initial parton and it is behind the first move pointer by previous ish
1059 if (isys == 1 && klast[1] > klast[0]) in += ish;
1064 // How many additional gluons will be generated
1066 if (p2[isys][4] > 0.05) ish = 2;
1068 // Position of gluons
1070 if (iglu == 0) igMin = iGlu;
1073 (fPyjets->N) += ish;
1076 fPyjets->P[0][iGlu] = p2[isys][0];
1077 fPyjets->P[1][iGlu] = p2[isys][1];
1078 fPyjets->P[2][iGlu] = p2[isys][2];
1079 fPyjets->P[3][iGlu] = p2[isys][3];
1080 fPyjets->P[4][iGlu] = p2[isys][4];
1082 fPyjets->K[0][iGlu] = 1;
1083 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1084 fPyjets->K[1][iGlu] = 21;
1085 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1086 fPyjets->K[3][iGlu] = -1;
1087 fPyjets->K[4][iGlu] = -1;
1089 pg[0] += p2[isys][0];
1090 pg[1] += p2[isys][1];
1091 pg[2] += p2[isys][2];
1092 pg[3] += p2[isys][3];
1095 // Split gluon in rest frame.
1097 Double_t bx = p2[isys][0] / p2[isys][3];
1098 Double_t by = p2[isys][1] / p2[isys][3];
1099 Double_t bz = p2[isys][2] / p2[isys][3];
1100 Double_t pst = p2[isys][4] / 2.;
1102 // Isotropic decay ????
1103 Double_t cost = 2. * gRandom->Rndm() - 1.;
1104 Double_t sint = TMath::Sqrt(1. - cost * cost);
1105 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1107 Double_t pz1 = pst * cost;
1108 Double_t pz2 = -pst * cost;
1109 Double_t pt1 = pst * sint;
1110 Double_t pt2 = -pst * sint;
1111 Double_t px1 = pt1 * TMath::Cos(phi);
1112 Double_t py1 = pt1 * TMath::Sin(phi);
1113 Double_t px2 = pt2 * TMath::Cos(phi);
1114 Double_t py2 = pt2 * TMath::Sin(phi);
1116 fPyjets->P[0][iGlu] = px1;
1117 fPyjets->P[1][iGlu] = py1;
1118 fPyjets->P[2][iGlu] = pz1;
1119 fPyjets->P[3][iGlu] = pst;
1120 fPyjets->P[4][iGlu] = 0.;
1122 fPyjets->K[0][iGlu] = 1 ;
1123 fPyjets->K[1][iGlu] = 21;
1124 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1125 fPyjets->K[3][iGlu] = -1;
1126 fPyjets->K[4][iGlu] = -1;
1128 fPyjets->P[0][iGlu+1] = px2;
1129 fPyjets->P[1][iGlu+1] = py2;
1130 fPyjets->P[2][iGlu+1] = pz2;
1131 fPyjets->P[3][iGlu+1] = pst;
1132 fPyjets->P[4][iGlu+1] = 0.;
1134 fPyjets->K[0][iGlu+1] = 1;
1135 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1136 fPyjets->K[1][iGlu+1] = 21;
1137 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1138 fPyjets->K[3][iGlu+1] = -1;
1139 fPyjets->K[4][iGlu+1] = -1;
1145 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1148 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1149 Double_t px, py, pz;
1150 px = fPyjets->P[0][ig];
1151 py = fPyjets->P[1][ig];
1152 pz = fPyjets->P[2][ig];
1153 TVector3 v(px, py, pz);
1154 v.RotateZ(-phiq[isys]);
1155 v.RotateY(-thetaq[isys]);
1156 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1157 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1158 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1159 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1160 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1161 pxs += jtKick * TMath::Cos(phiKick);
1162 pys += jtKick * TMath::Sin(phiKick);
1163 TVector3 w(pxs, pys, pzs);
1164 w.RotateY(thetaq[isys]);
1165 w.RotateZ(phiq[isys]);
1166 fPyjets->P[0][ig] = w.X();
1167 fPyjets->P[1][ig] = w.Y();
1168 fPyjets->P[2][ig] = w.Z();
1169 fPyjets->P[2][ig] = w.Mag();
1175 // Check energy conservation
1179 Double_t es = 14000.;
1181 for (Int_t i = 0; i < numpart; i++)
1183 kst = fPyjets->K[0][i];
1184 if (kst != 1 && kst != 2) continue;
1185 pxs += fPyjets->P[0][i];
1186 pys += fPyjets->P[1][i];
1187 pzs += fPyjets->P[2][i];
1188 es -= fPyjets->P[3][i];
1190 if (TMath::Abs(pxs) > 1.e-2 ||
1191 TMath::Abs(pys) > 1.e-2 ||
1192 TMath::Abs(pzs) > 1.e-1) {
1193 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1194 // Fatal("Quench()", "4-Momentum non-conservation");
1197 } // end quenching loop (systems)
1199 for (Int_t i = 0; i < numpart; i++)
1201 imo = fPyjets->K[2][i];
1203 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1210 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1212 // Igor Lokthine's quenching routine
1216 void AliPythia::Pyevnw()
1218 // New multiple interaction scenario
1222 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1224 // Return event specific quenching parameters
1227 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1231 void AliPythia::ConfigHeavyFlavor()
1234 // Default configuration for Heavy Flavor production
1236 // All QCD processes
1240 // No multiple interactions
1244 // Initial/final parton shower on (Pythia default)
1248 // 2nd order alpha_s
1256 void AliPythia::AtlasTuning()
1259 // Configuration for the ATLAS tuning
1260 SetMSTP(51, kCTEQ5L); // CTEQ5L pdf
1261 SetMSTP(81,1); // Multiple Interactions ON
1262 SetMSTP(82,4); // Double Gaussian Model
1263 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1264 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1265 SetPARP(89,1000.); // [GeV] Ref. energy
1266 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1267 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1268 SetPARP(84,0.5); // Core radius
1269 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1270 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1271 SetPARP(67,1); // Regulates Initial State Radiation
1274 AliPythia& AliPythia::operator=(const AliPythia& rhs)
1276 // Assignment operator
1281 void AliPythia::Copy(TObject&) const
1286 Fatal("Copy","Not implemented!\n");