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 "AliFastGlauber.h"
22 #include "AliQuenchingWeights.h"
24 #include "PyquenCommon.h"
29 # define pyclus pyclus_
30 # define pycell pycell_
31 # define pyshow pyshow_
32 # define pyrobo pyrobo_
33 # define pyquen pyquen_
34 # define pyevnw pyevnw_
37 # define pyclus PYCLUS
38 # define pycell PYCELL
39 # define pyrobo PYROBO
40 # define pyquen PYQUEN
41 # define pyevnw PYEVNW
42 # define type_of_call _stdcall
45 extern "C" void type_of_call pyclus(Int_t & );
46 extern "C" void type_of_call pycell(Int_t & );
47 extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
48 extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
49 extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
50 extern "C" void type_of_call pyevnw(){;}
52 //_____________________________________________________________________________
54 AliPythia* AliPythia::fgAliPythia=NULL;
56 AliPythia::AliPythia():
67 // Default Constructor
70 if (!AliPythiaRndm::GetPythiaRandom())
71 AliPythiaRndm::SetPythiaRandom(GetRandom());
73 fQuenchingWeights = 0;
76 AliPythia::AliPythia(const AliPythia& pythia):
93 void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
95 // Initialise the process to generate
96 if (!AliPythiaRndm::GetPythiaRandom())
97 AliPythiaRndm::SetPythiaRandom(GetRandom());
101 fStrucFunc = strucfunc;
102 //...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
103 SetMDCY(Pycomp(111) ,1,0); // pi0
104 SetMDCY(Pycomp(310) ,1,0); // K0S
105 SetMDCY(Pycomp(3122),1,0); // kLambda
106 SetMDCY(Pycomp(3112),1,0); // sigma -
107 SetMDCY(Pycomp(3212),1,0); // sigma 0
108 SetMDCY(Pycomp(3222),1,0); // sigma +
109 SetMDCY(Pycomp(3312),1,0); // xi -
110 SetMDCY(Pycomp(3322),1,0); // xi 0
111 SetMDCY(Pycomp(3334),1,0); // omega-
112 // Select structure function
114 SetMSTP(51, AliStructFuncType::PDFsetIndex(strucfunc));
115 // Particles produced in string fragmentation point directly to either of the two endpoints
116 // of the string (depending in the side they were generated from).
120 // Pythia initialisation for selected processes//
124 for (Int_t i=1; i<= 200; i++) {
127 // select charm production
130 case kPyOldUEQ2ordered: //Old underlying events with Q2 ordered QCD processes
131 // Multiple interactions on.
133 // Double Gaussian matter distribution.
139 // Reference energy for pT0 and energy rescaling pace.
142 // String drawing almost completely minimizes string length.
145 // ISR and FSR activity.
151 case kPyOldUEQ2ordered2:
152 // Old underlying events with Q2 ordered QCD processes
153 // Multiple interactions on.
155 // Double Gaussian matter distribution.
161 // Reference energy for pT0 and energy rescaling pace.
163 SetPARP(90,0.16); // here is the difference with kPyOldUEQ2ordered
164 // String drawing almost completely minimizes string length.
167 // ISR and FSR activity.
174 // Old production mechanism: Old Popcorn
177 // (D=2) Like MSTJ(12)=2 but added prod ofthe 1er rank baryon
179 // (D=1)see can be used to form baryons (BARYON JUNCTION)
185 // heavy quark masses
215 case kPyCharmUnforced:
224 case kPyBeautyUnforced:
234 // Minimum Bias pp-Collisions
237 // select Pythia min. bias model
239 SetMSUB(92,1); // single diffraction AB-->XB
240 SetMSUB(93,1); // single diffraction AB-->AX
241 SetMSUB(94,1); // double diffraction
242 SetMSUB(95,1); // low pt production
247 // Minimum Bias pp-Collisions
250 // select Pythia min. bias model
252 SetMSUB(92,1); // single diffraction AB-->XB
253 SetMSUB(93,1); // single diffraction AB-->AX
254 SetMSUB(94,1); // double diffraction
255 SetMSUB(95,1); // low pt production
259 // Les Houches Working Group 05 Minimum Bias pp-Collisions: hep-ph/0604120
260 // -> Pythia 6.3 or above is needed
263 SetMSUB(92,1); // single diffraction AB-->XB
264 SetMSUB(93,1); // single diffraction AB-->AX
265 SetMSUB(94,1); // double diffraction
266 SetMSUB(95,1); // low pt production
268 SetMSTP(51,AliStructFuncType::PDFsetIndex(kCTEQ6ll)); // CTEQ6ll pdf
272 SetMSTP(81,1); // Multiple Interactions ON
273 SetMSTP(82,4); // Double Gaussian Model
276 SetPARP(82,2.3); // [GeV] PT_min at Ref. energy
277 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
278 SetPARP(84,0.5); // Core radius
279 SetPARP(85,0.9); // Regulates gluon prod. mechanism
280 SetPARP(90,0.2); // 2*epsilon (exponent in power law)
284 // Minimum Bias pp-Collisions
287 // select Pythia min. bias model
289 SetMSUB(95,1); // low pt production
296 SetMSTP(91,1);// Width (1=gaussian) primordial kT dist. inside hadrons
297 SetPARP(91,1.); // <kT^2> = PARP(91,1.)^2
298 SetPARP(93,5.); // Upper cut-off
300 SetPMAS(4,1,1.2); // Charm quark mass
301 SetPMAS(5,1,4.78); // Beauty quark mass
302 SetPARP(71,4.); // Defaut value
311 // Pythia Tune A (CDF)
313 SetPARP(67,2.5); // Regulates Initial State Radiation (value from best fit to D0 dijet analysis)
314 SetMSTP(82,4); // Double Gaussian Model
315 SetPARP(82,2.0); // [GeV] PT_min at Ref. energy
316 SetPARP(84,0.4); // Core radius
317 SetPARP(85,0.90) ; // Regulates gluon prod. mechanism
318 SetPARP(86,0.95); // Regulates gluon prod. mechanism
319 SetPARP(89,1800.); // [GeV] Ref. energy
320 SetPARP(90,0.25); // 2*epsilon (exponent in power law)
325 case kPyCharmPbPbMNR:
327 case kPyDPlusPbPbMNR:
328 case kPyDPlusStrangePbPbMNR:
329 // Tuning of Pythia parameters aimed to get a resonable agreement
330 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
331 // c-cbar single inclusive and double differential distributions.
332 // This parameter settings are meant to work with Pb-Pb collisions
333 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
334 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
335 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
347 case kPyDPlusStrangepPbMNR:
348 // Tuning of Pythia parameters aimed to get a resonable agreement
349 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
350 // c-cbar single inclusive and double differential distributions.
351 // This parameter settings are meant to work with p-Pb collisions
352 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
353 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
354 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
367 case kPyDPlusStrangeppMNR:
368 // Tuning of Pythia parameters aimed to get a resonable agreement
369 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
370 // c-cbar single inclusive and double differential distributions.
371 // This parameter settings are meant to work with pp collisions
372 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
373 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
374 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
384 case kPyCharmppMNRwmi:
385 // Tuning of Pythia parameters aimed to get a resonable agreement
386 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
387 // c-cbar single inclusive and double differential distributions.
388 // This parameter settings are meant to work with pp collisions
389 // and with kCTEQ5L PDFs.
390 // Added multiple interactions according to ATLAS tune settings.
391 // To get a "reasonable" agreement with MNR results, events have to be
392 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
394 // To get a "perfect" agreement with MNR results, events have to be
395 // generated in four ptHard bins with the following relative
411 case kPyBeautyPbPbMNR:
412 // Tuning of Pythia parameters aimed to get a resonable agreement
413 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
414 // b-bbar single inclusive and double differential distributions.
415 // This parameter settings are meant to work with Pb-Pb collisions
416 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
417 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
418 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
430 case kPyBeautypPbMNR:
431 // Tuning of Pythia parameters aimed to get a resonable agreement
432 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
433 // b-bbar single inclusive and double differential distributions.
434 // This parameter settings are meant to work with p-Pb collisions
435 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
436 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
437 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
450 // Tuning of Pythia parameters aimed to get a resonable agreement
451 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
452 // b-bbar single inclusive and double differential distributions.
453 // This parameter settings are meant to work with pp collisions
454 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
455 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
456 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
470 case kPyBeautyppMNRwmi:
471 // Tuning of Pythia parameters aimed to get a resonable agreement
472 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
473 // b-bbar single inclusive and double differential distributions.
474 // This parameter settings are meant to work with pp collisions
475 // and with kCTEQ5L PDFs.
476 // Added multiple interactions according to ATLAS tune settings.
477 // To get a "reasonable" agreement with MNR results, events have to be
478 // generated with the minimum ptHard (AliGenPythia::SetPtHard)
480 // To get a "perfect" agreement with MNR results, events have to be
481 // generated in four ptHard bins with the following relative
504 //Inclusive production of W+/-
510 // //f fbar -> gamma W+
517 // Initial/final parton shower on (Pythia default)
518 // With parton showers on we are generating "W inclusive process"
519 SetMSTP(61,1); //Initial QCD & QED showers on
520 SetMSTP(71,1); //Final QCD & QED showers on
526 //Inclusive production of Z
531 // // f fbar -> g Z/gamma
533 // // f fbar -> gamma Z/gamma
535 // // f g -> f Z/gamma
537 // // f gamma -> f Z/gamma
540 //only Z included, not gamma
543 // Initial/final parton shower on (Pythia default)
544 // With parton showers on we are generating "Z inclusive process"
545 SetMSTP(61,1); //Initial QCD & QED showers on
546 SetMSTP(71,1); //Final QCD & QED showers on
553 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
968 pxNew = jtNew / jt * pxs;
969 pyNew = jtNew / jt * pys;
971 // Double_t dpx = pxs - pxNew;
972 // Double_t dpy = pys - pyNew;
973 // Double_t dpz = pl - plNew;
974 // Double_t de = e - eNew;
975 // Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
976 // printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
977 // printf("New mass (2) %e %e \n", pxNew, pyNew);
981 TVector3 w(pxNew, pyNew, plNew);
982 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
983 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
985 p1[index][0] += pxNew;
986 p1[index][1] += pyNew;
987 p1[index][2] += plNew;
988 p1[index][3] += eNew;
990 // Updated 4-momentum vectors
992 pNew[icount][0] = pxNew;
993 pNew[icount][1] = pyNew;
994 pNew[icount][2] = plNew;
995 pNew[icount][3] = eNew;
1000 // Check if there was phase-space for quenching
1003 if (icount == 0) quenched[isys] = kFALSE;
1004 if (!quenched[isys]) break;
1006 for (Int_t j = 0; j < 4; j++)
1008 p2[isys][j] = p0[isys][j] - p1[isys][j];
1010 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];
1011 if (p2[isys][4] > 0.) {
1012 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1015 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
1016 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]);
1017 if (p2[isys][4] < -0.01) {
1018 printf("Negative mass squared !\n");
1019 // Here we have to put the gluon back to mass shell
1020 // This will lead to a small energy imbalance
1022 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1031 printf("zHeavy lowered to %f\n", zHeavy);
1032 if (zHeavy < 0.01) {
1033 printf("No success ! \n");
1035 quenched[isys] = kFALSE;
1039 } // iteration on z (while)
1041 // Update event record
1042 for (Int_t k = 0; k < icount; k++) {
1043 // 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] );
1044 fPyjets->P[0][kNew[k]] = pNew[k][0];
1045 fPyjets->P[1][kNew[k]] = pNew[k][1];
1046 fPyjets->P[2][kNew[k]] = pNew[k][2];
1047 fPyjets->P[3][kNew[k]] = pNew[k][3];
1054 if (!quenched[isys]) continue;
1056 // Last parton from shower i
1057 Int_t in = klast[isys];
1059 // Continue if no parton in shower i selected
1060 if (in == -1) continue;
1062 // If this is the second initial parton and it is behind the first move pointer by previous ish
1063 if (isys == 1 && klast[1] > klast[0]) in += ish;
1068 // How many additional gluons will be generated
1070 if (p2[isys][4] > 0.05) ish = 2;
1072 // Position of gluons
1074 if (iglu == 0) igMin = iGlu;
1077 (fPyjets->N) += ish;
1080 fPyjets->P[0][iGlu] = p2[isys][0];
1081 fPyjets->P[1][iGlu] = p2[isys][1];
1082 fPyjets->P[2][iGlu] = p2[isys][2];
1083 fPyjets->P[3][iGlu] = p2[isys][3];
1084 fPyjets->P[4][iGlu] = p2[isys][4];
1086 fPyjets->K[0][iGlu] = 1;
1087 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
1088 fPyjets->K[1][iGlu] = 21;
1089 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1090 fPyjets->K[3][iGlu] = -1;
1091 fPyjets->K[4][iGlu] = -1;
1093 pg[0] += p2[isys][0];
1094 pg[1] += p2[isys][1];
1095 pg[2] += p2[isys][2];
1096 pg[3] += p2[isys][3];
1099 // Split gluon in rest frame.
1101 Double_t bx = p2[isys][0] / p2[isys][3];
1102 Double_t by = p2[isys][1] / p2[isys][3];
1103 Double_t bz = p2[isys][2] / p2[isys][3];
1104 Double_t pst = p2[isys][4] / 2.;
1106 // Isotropic decay ????
1107 Double_t cost = 2. * gRandom->Rndm() - 1.;
1108 Double_t sint = TMath::Sqrt(1. - cost * cost);
1109 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1111 Double_t pz1 = pst * cost;
1112 Double_t pz2 = -pst * cost;
1113 Double_t pt1 = pst * sint;
1114 Double_t pt2 = -pst * sint;
1115 Double_t px1 = pt1 * TMath::Cos(phi);
1116 Double_t py1 = pt1 * TMath::Sin(phi);
1117 Double_t px2 = pt2 * TMath::Cos(phi);
1118 Double_t py2 = pt2 * TMath::Sin(phi);
1120 fPyjets->P[0][iGlu] = px1;
1121 fPyjets->P[1][iGlu] = py1;
1122 fPyjets->P[2][iGlu] = pz1;
1123 fPyjets->P[3][iGlu] = pst;
1124 fPyjets->P[4][iGlu] = 0.;
1126 fPyjets->K[0][iGlu] = 1 ;
1127 fPyjets->K[1][iGlu] = 21;
1128 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
1129 fPyjets->K[3][iGlu] = -1;
1130 fPyjets->K[4][iGlu] = -1;
1132 fPyjets->P[0][iGlu+1] = px2;
1133 fPyjets->P[1][iGlu+1] = py2;
1134 fPyjets->P[2][iGlu+1] = pz2;
1135 fPyjets->P[3][iGlu+1] = pst;
1136 fPyjets->P[4][iGlu+1] = 0.;
1138 fPyjets->K[0][iGlu+1] = 1;
1139 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
1140 fPyjets->K[1][iGlu+1] = 21;
1141 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
1142 fPyjets->K[3][iGlu+1] = -1;
1143 fPyjets->K[4][iGlu+1] = -1;
1149 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1152 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1153 Double_t px, py, pz;
1154 px = fPyjets->P[0][ig];
1155 py = fPyjets->P[1][ig];
1156 pz = fPyjets->P[2][ig];
1157 TVector3 v(px, py, pz);
1158 v.RotateZ(-phiq[isys]);
1159 v.RotateY(-thetaq[isys]);
1160 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1161 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1162 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1163 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1164 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1165 pxs += jtKick * TMath::Cos(phiKick);
1166 pys += jtKick * TMath::Sin(phiKick);
1167 TVector3 w(pxs, pys, pzs);
1168 w.RotateY(thetaq[isys]);
1169 w.RotateZ(phiq[isys]);
1170 fPyjets->P[0][ig] = w.X();
1171 fPyjets->P[1][ig] = w.Y();
1172 fPyjets->P[2][ig] = w.Z();
1173 fPyjets->P[2][ig] = w.Mag();
1179 // Check energy conservation
1183 Double_t es = 14000.;
1185 for (Int_t i = 0; i < numpart; i++)
1187 kst = fPyjets->K[0][i];
1188 if (kst != 1 && kst != 2) continue;
1189 pxs += fPyjets->P[0][i];
1190 pys += fPyjets->P[1][i];
1191 pzs += fPyjets->P[2][i];
1192 es -= fPyjets->P[3][i];
1194 if (TMath::Abs(pxs) > 1.e-2 ||
1195 TMath::Abs(pys) > 1.e-2 ||
1196 TMath::Abs(pzs) > 1.e-1) {
1197 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1198 // Fatal("Quench()", "4-Momentum non-conservation");
1201 } // end quenching loop (systems)
1203 for (Int_t i = 0; i < numpart; i++)
1205 imo = fPyjets->K[2][i];
1207 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1214 void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1216 // Igor Lokthine's quenching routine
1217 // http://lokhtin.web.cern.ch/lokhtin/pyquen/pyquen.txt
1222 void AliPythia::SetPyquenParameters(Double_t t0, Double_t tau0, Int_t nf, Int_t iengl, Int_t iangl)
1224 // Set the parameters for the PYQUEN package.
1225 // See comments in PyquenCommon.h
1231 PYQPAR.iengl = iengl;
1232 PYQPAR.iangl = iangl;
1236 void AliPythia::Pyevnw()
1238 // New multiple interaction scenario
1242 void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1244 // Return event specific quenching parameters
1247 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1251 void AliPythia::ConfigHeavyFlavor()
1254 // Default configuration for Heavy Flavor production
1256 // All QCD processes
1260 // No multiple interactions
1264 // Initial/final parton shower on (Pythia default)
1268 // 2nd order alpha_s
1276 void AliPythia::AtlasTuning()
1279 // Configuration for the ATLAS tuning
1280 SetMSTP(51, AliStructFuncType::PDFsetIndex(kCTEQ5L)); // CTEQ5L pdf
1281 SetMSTP(81,1); // Multiple Interactions ON
1282 SetMSTP(82,4); // Double Gaussian Model
1283 SetPARP(81,1.9); // Min. pt for multiple interactions (default in 6.2-14)
1284 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
1285 SetPARP(89,1000.); // [GeV] Ref. energy
1286 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
1287 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
1288 SetPARP(84,0.5); // Core radius
1289 SetPARP(85,0.33); // Regulates gluon prod. mechanism
1290 SetPARP(86,0.66); // Regulates gluon prod. mechanism
1291 SetPARP(67,1); // Regulates Initial State Radiation
1294 AliPythia& AliPythia::operator=(const AliPythia& rhs)
1296 // Assignment operator
1301 void AliPythia::Copy(TObject&) const
1306 Fatal("Copy","Not implemented!\n");