New quenching algorithm.
[u/mrichter/AliRoot.git] / PYTHIA6 / AliPythia.cxx
CommitLineData
8d2cd130 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
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 **************************************************************************/
15
7cdba479 16/* $Id$ */
8d2cd130 17
18#include "AliPythia.h"
7cdba479 19#include "AliPythiaRndm.h"
0f482ae4 20#include "../FASTSIM/AliFastGlauber.h"
21#include "../FASTSIM/AliQuenchingWeights.h"
22#include "TVector3.h"
8d2cd130 23
24ClassImp(AliPythia)
25
26#ifndef WIN32
27# define pyclus pyclus_
28# define pycell pycell_
452af8c7 29# define pyshow pyshow_
30# define pyrobo pyrobo_
8d2cd130 31# define type_of_call
32#else
33# define pyclus PYCLUS
34# define pycell PYCELL
452af8c7 35# define pyrobo PYROBO
8d2cd130 36# define type_of_call _stdcall
37#endif
38
39extern "C" void type_of_call pyclus(Int_t & );
40extern "C" void type_of_call pycell(Int_t & );
452af8c7 41extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
42extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
8d2cd130 43
44//_____________________________________________________________________________
45
46AliPythia* AliPythia::fgAliPythia=NULL;
47
48AliPythia::AliPythia()
49{
50// Default Constructor
51//
52// Set random number
7cdba479 53 if (!AliPythiaRndm::GetPythiaRandom())
54 AliPythiaRndm::SetPythiaRandom(GetRandom());
0f482ae4 55 fGlauber = 0;
56 fQuenchingWeights = 0;
8d2cd130 57}
58
59void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
60{
61// Initialise the process to generate
7cdba479 62 if (!AliPythiaRndm::GetPythiaRandom())
63 AliPythiaRndm::SetPythiaRandom(GetRandom());
8d2cd130 64
65 fProcess = process;
66 fEcms = energy;
67 fStrucFunc = strucfunc;
68// don't decay p0
69 SetMDCY(Pycomp(111),1,0);
70// select structure function
71 SetMSTP(52,2);
72 SetMSTP(51,strucfunc);
73//
74// Pythia initialisation for selected processes//
75//
76// Make MSEL clean
77//
78 for (Int_t i=1; i<= 200; i++) {
79 SetMSUB(i,0);
80 }
81// select charm production
82 switch (process)
83 {
84 case kPyCharm:
85 SetMSEL(4);
86//
87// heavy quark masses
88
89 SetPMAS(4,1,1.2);
90 SetMSTU(16,2);
91//
92// primordial pT
93 SetMSTP(91,1);
94 SetPARP(91,1.);
95 SetPARP(93,5.);
96//
97 break;
98 case kPyBeauty:
99 SetMSEL(5);
100 SetPMAS(5,1,4.75);
101 SetMSTU(16,2);
102 break;
103 case kPyJpsi:
104 SetMSEL(0);
105// gg->J/Psi g
106 SetMSUB(86,1);
107 break;
108 case kPyJpsiChi:
109 SetMSEL(0);
110// gg->J/Psi g
111 SetMSUB(86,1);
112// gg-> chi_0c g
113 SetMSUB(87,1);
114// gg-> chi_1c g
115 SetMSUB(88,1);
116// gg-> chi_2c g
117 SetMSUB(89,1);
118 break;
119 case kPyCharmUnforced:
120 SetMSEL(0);
121// gq->qg
122 SetMSUB(28,1);
123// gg->qq
124 SetMSUB(53,1);
125// gg->gg
126 SetMSUB(68,1);
127 break;
128 case kPyBeautyUnforced:
129 SetMSEL(0);
130// gq->qg
131 SetMSUB(28,1);
132// gg->qq
133 SetMSUB(53,1);
134// gg->gg
135 SetMSUB(68,1);
136 break;
137 case kPyMb:
138// Minimum Bias pp-Collisions
139//
140//
141// select Pythia min. bias model
142 SetMSEL(0);
511db649 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
147
148//
149// ATLAS Tuning
150//
0f482ae4 151 SetMSTP(51,7); // CTEQ5L pdf
511db649 152 SetMSTP(81,1); // Multiple Interactions ON
153 SetMSTP(82,4); // Double Gaussian Model
154
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
163 break;
8d2cd130 164 case kPyMbNonDiffr:
165// Minimum Bias pp-Collisions
166//
167//
168// select Pythia min. bias model
169 SetMSEL(0);
511db649 170 SetMSUB(95,1); // low pt production
0f482ae4 171
172//
173// ATLAS Tuning
174//
511db649 175
0f482ae4 176 SetMSTP(51,7); // CTEQ5L pdf
511db649 177 SetMSTP(81,1); // Multiple Interactions ON
178 SetMSTP(82,4); // Double Gaussian Model
179
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
8d2cd130 188 break;
189 case kPyJets:
190//
191// QCD Jets
192//
193 SetMSEL(1);
194 break;
195 case kPyDirectGamma:
196 SetMSEL(10);
197 break;
adf4d898 198 case kPyCharmPbPbMNR:
199 case kPyD0PbPbMNR:
8d2cd130 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
adf4d898 204 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
8d2cd130 205 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
206 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
207
208 // All QCD processes
209 SetMSEL(1);
210
211 // No multiple interactions
212 SetMSTP(81,0);
213 SetPARP(81,0.0);
214 SetPARP(82,0.0);
215
216 // Initial/final parton shower on (Pythia default)
217 SetMSTP(61,1);
218 SetMSTP(71,1);
219
220 // 2nd order alpha_s
221 SetMSTP(2,2);
222
223 // QCD scales
224 SetMSTP(32,2);
225 SetPARP(34,1.0);
226
adf4d898 227 // Intrinsic <kT>
8d2cd130 228 SetMSTP(91,1);
229 SetPARP(91,1.304);
230 SetPARP(93,6.52);
231
232 // Set c-quark mass
233 SetPMAS(4,1,1.2);
234
235 break;
adf4d898 236 case kPyCharmpPbMNR:
237 case kPyD0pPbMNR:
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 p-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.
245
246 // All QCD processes
247 SetMSEL(1);
248
249 // No multiple interactions
250 SetMSTP(81,0);
251 SetPARP(81,0.0);
252 SetPARP(82,0.0);
253
254 // Initial/final parton shower on (Pythia default)
255 SetMSTP(61,1);
256 SetMSTP(71,1);
257
258 // 2nd order alpha_s
259 SetMSTP(2,2);
260
261 // QCD scales
262 SetMSTP(32,2);
263 SetPARP(34,1.0);
264
265 // Intrinsic <kT>
266 SetMSTP(91,1);
267 SetPARP(91,1.16);
268 SetPARP(93,5.8);
269
270 // Set c-quark mass
271 SetPMAS(4,1,1.2);
272
273 break;
274 case kPyCharmppMNR:
275 case kPyD0ppMNR:
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 pp 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.
283
284 // All QCD processes
285 SetMSEL(1);
286
287 // No multiple interactions
288 SetMSTP(81,0);
289 SetPARP(81,0.0);
290 SetPARP(82,0.0);
291
292 // Initial/final parton shower on (Pythia default)
293 SetMSTP(61,1);
294 SetMSTP(71,1);
295
296 // 2nd order alpha_s
297 SetMSTP(2,2);
298
299 // QCD scales
300 SetMSTP(32,2);
301 SetPARP(34,1.0);
302
303 // Intrinsic <kT^2>
304 SetMSTP(91,1);
305 SetPARP(91,1.);
306 SetPARP(93,5.);
307
308 // Set c-quark mass
309 SetPMAS(4,1,1.2);
310
311 break;
312 case kPyBeautyPbPbMNR:
8d2cd130 313 // Tuning of Pythia parameters aimed to get a resonable agreement
314 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
315 // b-bbar single inclusive and double differential distributions.
316 // This parameter settings are meant to work with Pb-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 2.75GeV. Example in ConfigBeautyPPR.C.
320
321 // All QCD processes
322 SetMSEL(1);
323
324 // No multiple interactions
325 SetMSTP(81,0);
326 SetPARP(81,0.0);
327 SetPARP(82,0.0);
328
329 // Initial/final parton shower on (Pythia default)
330 SetMSTP(61,1);
331 SetMSTP(71,1);
332
333 // 2nd order alpha_s
334 SetMSTP(2,2);
335
336 // QCD scales
337 SetMSTP(32,2);
338 SetPARP(34,1.0);
339 SetPARP(67,1.0);
340 SetPARP(71,1.0);
341
adf4d898 342 // Intrinsic <kT>
8d2cd130 343 SetMSTP(91,1);
344 SetPARP(91,2.035);
345 SetPARP(93,10.17);
346
347 // Set b-quark mass
348 SetPMAS(5,1,4.75);
349
350 break;
adf4d898 351 case kPyBeautypPbMNR:
352 // Tuning of Pythia parameters aimed to get a resonable agreement
353 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
354 // b-bbar single inclusive and double differential distributions.
355 // This parameter settings are meant to work with p-Pb collisions
356 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
357 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
358 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
359
360 // All QCD processes
361 SetMSEL(1);
362
363 // No multiple interactions
364 SetMSTP(81,0);
365 SetPARP(81,0.0);
366 SetPARP(82,0.0);
367
368 // Initial/final parton shower on (Pythia default)
369 SetMSTP(61,1);
370 SetMSTP(71,1);
371
372 // 2nd order alpha_s
373 SetMSTP(2,2);
374
375 // QCD scales
376 SetMSTP(32,2);
377 SetPARP(34,1.0);
378 SetPARP(67,1.0);
379 SetPARP(71,1.0);
380
381 // Intrinsic <kT>
382 SetMSTP(91,1);
383 SetPARP(91,1.60);
384 SetPARP(93,8.00);
385
386 // Set b-quark mass
387 SetPMAS(5,1,4.75);
388
389 break;
390 case kPyBeautyppMNR:
391 // Tuning of Pythia parameters aimed to get a resonable agreement
392 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
393 // b-bbar single inclusive and double differential distributions.
394 // This parameter settings are meant to work with pp collisions
395 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
396 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
397 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
398
399 // All QCD processes
400 SetMSEL(1);
401
402 // No multiple interactions
403 SetMSTP(81,0);
404 SetPARP(81,0.0);
405 SetPARP(82,0.0);
406
407 // Initial/final parton shower on (Pythia default)
408 SetMSTP(61,1);
409 SetMSTP(71,1);
410
411 // 2nd order alpha_s
412 SetMSTP(2,2);
413
414 // QCD scales
415 SetMSTP(32,2);
416 SetPARP(34,1.0);
417 SetPARP(67,1.0);
418 SetPARP(71,1.0);
419
420 // Intrinsic <kT>
421 SetMSTP(91,1);
422 SetPARP(91,1.);
423 SetPARP(93,5.);
424
425 // Set b-quark mass
426 SetPMAS(5,1,4.75);
427
428 break;
8d2cd130 429 }
430//
431// Initialize PYTHIA
432 SetMSTP(41,1); // all resonance decays switched on
433
434 Initialize("CMS","p","p",fEcms);
435
436}
437
438Int_t AliPythia::CheckedLuComp(Int_t kf)
439{
440// Check Lund particle code (for debugging)
441 Int_t kc=Pycomp(kf);
442 printf("\n Lucomp kf,kc %d %d",kf,kc);
443 return kc;
444}
445
446void AliPythia::SetNuclei(Int_t a1, Int_t a2)
447{
448// Treat protons as inside nuclei with mass numbers a1 and a2
449// The MSTP array in the PYPARS common block is used to enable and
450// select the nuclear structure functions.
451// MSTP(52) : (D=1) choice of proton and nuclear structure-function library
452// =1: internal PYTHIA acording to MSTP(51)
453// =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
454// If the following mass number both not equal zero, nuclear corrections of the stf are used.
455// MSTP(192) : Mass number of nucleus side 1
456// MSTP(193) : Mass number of nucleus side 2
457 SetMSTP(52,2);
458 SetMSTP(192, a1);
459 SetMSTP(193, a2);
460}
461
462
463AliPythia* AliPythia::Instance()
464{
465// Set random number generator
466 if (fgAliPythia) {
467 return fgAliPythia;
468 } else {
469 fgAliPythia = new AliPythia();
470 return fgAliPythia;
471 }
472}
473
474void AliPythia::PrintParticles()
475{
476// Print list of particl properties
477 Int_t np = 0;
c31f1d37 478 char* name = new char[16];
8d2cd130 479 for (Int_t kf=0; kf<1000000; kf++) {
480 for (Int_t c = 1; c > -2; c-=2) {
8d2cd130 481 Int_t kc = Pycomp(c*kf);
482 if (kc) {
483 Float_t mass = GetPMAS(kc,1);
484 Float_t width = GetPMAS(kc,2);
485 Float_t tau = GetPMAS(kc,4);
c31f1d37 486
8d2cd130 487 Pyname(kf,name);
488
489 np++;
490
491 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
492 c*kf, name, mass, width, tau);
493 }
494 }
495 }
496 printf("\n Number of particles %d \n \n", np);
497}
498
499void AliPythia::ResetDecayTable()
500{
501// Set default values for pythia decay switches
502 Int_t i;
503 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
504 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
505}
506
507void AliPythia::SetDecayTable()
508{
509// Set default values for pythia decay switches
510//
511 Int_t i;
512 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
513 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
514}
515
516void AliPythia::Pyclus(Int_t& njet)
517{
518// Call Pythia clustering algorithm
519//
520 pyclus(njet);
521}
522
523void AliPythia::Pycell(Int_t& njet)
524{
525// Call Pythia jet reconstruction algorithm
526//
527 pycell(njet);
528}
529
452af8c7 530void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
531{
532// Call Pythia jet reconstruction algorithm
533//
534 Int_t numpart = fPyjets->N;
535 for (Int_t i = 0; i < numpart; i++)
536 {
537 if (fPyjets->K[2][i] == 7) ip1 = i+1;
538 if (fPyjets->K[2][i] == 8) ip2 = i+1;
539 }
540
541
542 qmax = 2. * GetVINT(51);
543 printf("Pyshow %d %d %f", ip1, ip2, qmax);
544
545 pyshow(ip1, ip2, qmax);
546}
547
548void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
549{
550 pyrobo(imi, ima, the, phi, bex, bey, bez);
551}
552
553
554
0f482ae4 555void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t qTransport, Float_t maxLength, Int_t iECMethod)
556{
557// Initializes
558// (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
559// (2) The nuclear geometry using the Glauber Model
560//
561
562
563 fGlauber = new AliFastGlauber();
564 fGlauber->Init(2);
565 fGlauber->SetCentralityClass(cMin, cMax);
566
567 fQuenchingWeights = new AliQuenchingWeights();
568 fQuenchingWeights->InitMult();
569 fQuenchingWeights->SetQTransport(qTransport);
570 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
571 fQuenchingWeights->SetLengthMax(Int_t(maxLength));
572 fQuenchingWeights->SampleEnergyLoss();
573
574}
575
576
452af8c7 577void AliPythia::Quench()
578{
579//
580//
581// Simple Jet Quenching routine:
582// =============================
583// The jet formed by all final state partons radiated by the parton created
0f482ae4 584// in the hard collisions is quenched by a factor (1-z) using light cone variables in
585// the initial parton reference frame:
452af8c7 586// (E + p_z)new = (1-z) (E + p_z)old
587//
0f482ae4 588//
589//
590//
452af8c7 591// The lost momentum is first balanced by one gluon with virtuality > 0.
592// Subsequently the gluon splits to yield two gluons with E = p.
593//
0f482ae4 594//
595//
596 const Int_t kGluons = 1;
597
598 Double_t p0[2][5];
599 Double_t p1[2][5];
600 Double_t p2[2][5];
452af8c7 601 Int_t klast[2] = {-1, -1};
602 Int_t kglu[2];
452af8c7 603
604 Int_t numpart = fPyjets->N;
0f482ae4 605 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0.;
606 Double_t pxq[2], pyq[2], pzq[2], eq[2], yq[2], mq[2], pq[2], phiq[2], thetaq[2], ptq[2];
607 Bool_t quenched[2];
608 Double_t phi;
609 Double_t zInitial[2], wjtKick[2];
610 Int_t imo, kst, pdg;
511db649 611//
0f482ae4 612// Primary partons
511db649 613//
0f482ae4 614
615 for (Int_t i = 6; i <= 7; i++) {
616 Int_t j = i - 6;
452af8c7 617
0f482ae4 618 pxq[j] = fPyjets->P[0][i];
619 pyq[j] = fPyjets->P[1][i];
620 pzq[j] = fPyjets->P[2][i];
621 eq[j] = fPyjets->P[3][i];
622 mq[j] = fPyjets->P[4][i];
623 yq[j] = 0.5 * TMath::Log((e + pz + 1.e-14) / (e - pz + 1.e-14));
624 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
625 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
626 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
627 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
628 phi = phiq[j];
629
630 // Quench only central jets
631 if (TMath::Abs(yq[j]) > 2.5) {
632 zInitial[j] = 0.;
633 } else {
634 pdg = fPyjets->K[1][i];
635
636 // Get length in nucleus
637 Double_t l;
638 fGlauber->GetLengthsForPythia(1, &phi, &l, -1.);
639 //
640 // Energy loss for given length and parton typr
641 Int_t itype = (pdg == 21) ? 2 : 1;
642 Double_t eloss = fQuenchingWeights->GetELossRandom(itype, l, eq[j]);
643 //
644 // Extra pt
645 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->GetQTransport());
646 //
647 // Fractional energy loss
648 zInitial[j] = eloss / eq[j];
649 //
650 // Avoid complete loss
651 //
652 if (zInitial[j] == 1.) zInitial[j] = 0.95;
653 //
654 // Some debug printing
655 printf("Initial parton # %3d, Type %3d Energy %10.3f Phi %10.3f Length %10.3f Loss %10.3f Kick %10.3f\n",
656 j, itype, eq[j], phi, l, eloss, wjtKick[j]);
657 }
658
659 quenched[j] = (zInitial[j] > 0.01);
452af8c7 660
661 }
0f482ae4 662
663//
664// Radiated partons
665//
666 zInitial[0] = 1. - TMath::Power(1. - zInitial[0], 1./Double_t(kGluons));
667 zInitial[1] = 1. - TMath::Power(1. - zInitial[1], 1./Double_t(kGluons));
668 wjtKick[0] = wjtKick[0] / TMath::Sqrt(Double_t(kGluons));
669 wjtKick[1] = wjtKick[1] / TMath::Sqrt(Double_t(kGluons));
670// this->Pylist(1);
452af8c7 671
0f482ae4 672 for (Int_t iglu = 0; iglu < kGluons; iglu++) {
673 for (Int_t k = 0; k < 4; k++)
452af8c7 674 {
0f482ae4 675 p0[0][k] = 0.; p0[1][k] = 0.;
676 p1[0][k] = 0.; p1[1][k] = 0.;
677 p2[0][k] = 0.; p2[1][k] = 0.;
452af8c7 678 }
0f482ae4 679
680 Int_t nq[2] = {0, 0};
681
682 for (Int_t i = 0; i < numpart; i++)
452af8c7 683 {
0f482ae4 684 imo = fPyjets->K[2][i];
685 kst = fPyjets->K[0][i];
686 pdg = fPyjets->K[1][i];
687
688
689
690// Quarks and gluons only
691 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
692// Particles from hard scattering only
693 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
694 if (imo != 7 && imo != 8 && imo != 1007 && imo != 1008) continue;
695
696// Skip comment lines
697 if (kst != 1 && kst != 2) continue;
698//
699// Parton kinematic
700 px = fPyjets->P[0][i];
701 py = fPyjets->P[1][i];
702 pz = fPyjets->P[2][i];
703 e = fPyjets->P[3][i];
704 m = fPyjets->P[4][i];
705 pt = TMath::Sqrt(px * px + py * py);
706 p = TMath::Sqrt(px * px + py * py + pz * pz);
707 phi = TMath::Pi() + TMath::ATan2(-py, -px);
708 theta = TMath::ATan2(pt, pz);
709
710//
711// Save 4-momentum sum for balancing
712 Int_t index = imo - 7;
713 if (index >= 1000) index -= 1000;
714
715 p0[index][0] += px;
716 p0[index][1] += py;
717 p0[index][2] += pz;
718 p0[index][3] += e;
719
720// Don't quench radiated gluons
721//
722 if (imo == 1007 || imo == 1008) {
723 p1[index][0] += px;
724 p1[index][1] += py;
725 p1[index][2] += pz;
726 p1[index][3] += e;
727 continue;
728 }
729
730//
452af8c7 731
0f482ae4 732 klast[index] = i;
733//
734// Fractional energy loss
735 Double_t z = zInitial[index];
736 if (!quenched[index]) continue;
452af8c7 737 //
452af8c7 738 //
0f482ae4 739 // Transform into frame in which initial parton is along z-axis
740 //
741 TVector3 v(px, py, pz);
742 v.RotateZ(-phiq[index]);
743 v.RotateY(-thetaq[index]);
744 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
745 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
746 Double_t mt2 = jt * jt + m * m;
747 Double_t mt = TMath::Sqrt(mt2);
748 Double_t zmin = 0.;
749 Double_t zmax = 1.;
750 //
751 // z**2 mt**2 - pt**2 + pt'**2 > 0
752 // z**2 mt**2 + mt'**2 + m**2 - pt**2
753 // z**2 mt**2 + (1-z)**2 mt**2 + m**2 - pt**2
754 // mt**2(z**2 + 1 + z**2 - 2z) + m**2 - pt**2
755 // mt**2(2z**2 + 1 - 2z) + m**2 - pt**2 > 0
756 // mt**2(2z**2 + 1 - 2z) + 2 m**2 - mt**2 > 0
757 // mt**2(2z**2 - 2z) + 2 m**2 > 0
758 // z mt**2 (1 - z) - m**2 < 0
759 // z**2 - z + 1/4 > 1/4 - m**2/mt**2
760 // (z-1/2)**2 > 1/4 - m**2/mt**2
761 // |z-1/2| > sqrt(1/4 - m**2/mt**2)
762 //
763 // m/mt < 1/2
764 // mt > 2m
765 //
766 if (mt < 2. * m) {
767 printf("No phase space for quenching !: mt (%e) < 2 m (%e) \n", mt, m);
768 p1[index][0] += px;
769 p1[index][1] += py;
770 p1[index][2] += pz;
771 p1[index][3] += e;
772 continue;
773 } else {
774 zmin = 0.5 - TMath::Sqrt(0.25 - m * m / mt2);
775 if (z < zmin) {
776 printf("No phase space for quenching ??: z (%e) < zmin (%e) \n", z, zmin);
777// z = zmin * 1.01;
778
779 p1[index][0] += px;
780 p1[index][1] += py;
781 p1[index][2] += pz;
782 p1[index][3] += e;
783 continue;
784
785 }
786 }
787 //
788 // Kinematic limit on z
789 //
790
791 if (m > 0.) {
792 zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
793 if (z > zmax) {
794 printf("We have to put z to the kinematic limit %e %e \n", z, zmax);
795 z = 0.9999 * zmax;
796 } // z > zmax
797 if (z < 0.01) {
798//
799// If z is too small, there is no phase space for quenching
800//
801 printf("No phase space for quenching ! %e \n", z);
802
803 p1[index][0] += px;
804 p1[index][1] += py;
805 p1[index][2] += pz;
806 p1[index][3] += e;
807 continue;
808 }
809 } // massive particles
810
811 //
812 // Change light-cone kinematics rel. to initial parton
813 //
814 Double_t eppzOld = e + pl;
815 Double_t empzOld = e - pl;
816
817 Double_t eppzNew = (1. - z) * eppzOld;
818 Double_t empzNew = empzOld - mt2 * z / eppzOld;
819 Double_t eNew0 = 0.5 * (eppzNew + empzNew);
820 Double_t pzNew0 = 0.5 * (eppzNew - empzNew);
821
822 Double_t ptNew;
823 //
824 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
825 Double_t mt2New = eppzNew * empzNew;
826 if (mt2New < 1.e-8) mt2New = 0.;
827
828 if (m * m > mt2New) {
829 //
830 // This should not happen
831 //
832 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
833 ptNew = 0;
834 } else {
835 ptNew = TMath::Sqrt(mt2New - m * m);
836 }
837
838
839 //
840 // Calculate new px, py
841 //
842 Double_t pxNew0 = ptNew / jt * pxs;
843 Double_t pyNew0 = ptNew / jt * pys;
452af8c7 844/*
0f482ae4 845 Double_t dpx = pxs - pxNew0;
846 Double_t dpy = pys - pyNew0;
847 Double_t dpz = pl - pzNew0;
848 Double_t de = e - eNew0;
849 Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
452af8c7 850*/
0f482ae4 851 //
852 // Rotate back
853 //
854 TVector3 w(pxNew0, pyNew0, pzNew0);
855 w.RotateY(thetaq[index]);
856 w.RotateZ(phiq[index]);
857 pxNew0 = w.X(); pyNew0 = w.Y(); pzNew0 = w.Z();
858
859
860 p1[index][0] += pxNew0;
861 p1[index][1] += pyNew0;
862 p1[index][2] += pzNew0;
863 p1[index][3] += eNew0;
864 //
865 // Update event record
866 //
867 fPyjets->P[0][i] = pxNew0;
868 fPyjets->P[1][i] = pyNew0;
869 fPyjets->P[2][i] = pzNew0;
870 fPyjets->P[3][i] = eNew0;
871 nq[index]++;
872
452af8c7 873 }
452af8c7 874
0f482ae4 875 //
876 // Gluons
877 //
452af8c7 878
0f482ae4 879 for (Int_t k = 0; k < 2; k++)
452af8c7 880 {
452af8c7 881 //
0f482ae4 882 // Check if there was phase-space for quenching
452af8c7 883 //
0f482ae4 884 if (nq[k] == 0) quenched[k] = kFALSE;
452af8c7 885
0f482ae4 886 if (!quenched[k]) continue;
452af8c7 887
0f482ae4 888 for (Int_t j = 0; j < 4; j++)
889 {
890 p2[k][j] = p0[k][j] - p1[k][j];
891 }
892 p2[k][4] = p2[k][3] * p2[k][3] - p2[k][0] * p2[k][0] - p2[k][1] * p2[k][1] - p2[k][2] * p2[k][2];
893
894 if (p2[k][4] > 0.) {
895 p2[k][4] = TMath::Sqrt(p2[k][4]);
896 } else {
897 printf("Warning negative mass squared in system %d %f ! \n", k, zInitial[k]);
898 printf("Kinematics %10.3e %10.3e %10.3e %10.3e %10.3e \n", p2[k][0], p2[k][1], p2[k][2], p2[k][3], p2[k][4]);
899 if (p2[k][4] < -0.1) Fatal("Boost", "Negative mass squared !");
900 p2[k][4] = 0.;
901 }
902 //
903 // jt-kick
904 //
905 /*
906 TVector3 v(p2[k][0], p2[k][1], p2[k][2]);
907 v.RotateZ(-phiq[k]);
908 v.RotateY(-thetaq[k]);
909 Double_t px = v.X(); Double_t py = v.Y(); Double_t pz = v.Z();
910 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
911 Double_t jtKick = wjtKick[k] * TMath::Sqrt(-TMath::Log(r));
912 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
913 px += jtKick * TMath::Cos(phiKick);
914 py += jtKick * TMath::Sin(phiKick);
915 TVector3 w(px, py, pz);
916 w.RotateY(thetaq[k]);
917 w.RotateZ(phiq[k]);
918 p2[k][0] = w.X(); p2[k][1] = w.Y(); p2[k][2] = w.Z();
919 p2[k][3] = TMath::Sqrt(p2[k][0] * p2[k][0] + p2[k][1] * p2[k][1] + p2[k][2] * p2[k][2] + p2[k][4] * p2[k][4]);
920 */
921 }
922
923 //
924 // Add the gluons
925 //
926
927 Int_t ish = 0;
928 for (Int_t i = 0; i < 2; i++) {
929 Int_t jmin, jmax, iGlu, iNew;
930 if (!quenched[i]) continue;
931//
932// Last parton from shower i
933 Int_t in = klast[i];
934//
935// Continue if no parton in shower i selected
936 if (in == -1) continue;
937//
938// If this is the second initial parton and it is behind the first move pointer by previous ish
939 if (i == 1 && klast[1] > klast[0]) in += ish;
940//
941// Starting index
452af8c7 942
0f482ae4 943 jmin = in - 1;
944// How many additional gluons will be generated
945 ish = 1;
946 if (p2[i][4] > 0.05) ish = 2;
947//
948// Position of gluons
949 iGlu = in;
950 iNew = in + ish;
951 jmax = numpart + ish - 1;
452af8c7 952
0f482ae4 953 if (fPyjets->K[0][in-1] == 1 || fPyjets->K[0][in-1] == 21 || fPyjets->K[0][in-1] == 11) {
954 jmin = in;
955 iGlu = in + 1;
956 iNew = in;
957 }
452af8c7 958
0f482ae4 959 kglu[i] = iGlu;
960//
961// Shift stack
962//
963 for (Int_t j = jmax; j > jmin; j--)
964 {
965 for (Int_t k = 0; k < 5; k++) {
966 fPyjets->K[k][j] = fPyjets->K[k][j-ish];
967 fPyjets->P[k][j] = fPyjets->P[k][j-ish];
968 fPyjets->V[k][j] = fPyjets->V[k][j-ish];
969 }
970 } // end shifting
452af8c7 971
0f482ae4 972 numpart += ish;
973 (fPyjets->N) += ish;
974
975 if (ish == 1) {
976 fPyjets->P[0][iGlu] = p2[i][0];
977 fPyjets->P[1][iGlu] = p2[i][1];
978 fPyjets->P[2][iGlu] = p2[i][2];
979 fPyjets->P[3][iGlu] = p2[i][3];
980 fPyjets->P[4][iGlu] = p2[i][4];
981
982 fPyjets->K[0][iGlu] = 2;
983 fPyjets->K[1][iGlu] = 21;
984 fPyjets->K[2][iGlu] = fPyjets->K[2][iNew] + 1000;
985 fPyjets->K[3][iGlu] = -1;
986 fPyjets->K[4][iGlu] = -1;
987 } else {
988 //
989 // Split gluon in rest frame.
990 //
991 Double_t bx = p2[i][0] / p2[i][3];
992 Double_t by = p2[i][1] / p2[i][3];
993 Double_t bz = p2[i][2] / p2[i][3];
994 Double_t pst = p2[i][4] / 2.;
995 //
996 // Isotropic decay ????
997 Double_t cost = 2. * gRandom->Rndm() - 1.;
998 Double_t sint = TMath::Sqrt(1. - cost * cost);
999 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1000
1001 Double_t pz1 = pst * cost;
1002 Double_t pz2 = -pst * cost;
1003 Double_t pt1 = pst * sint;
1004 Double_t pt2 = -pst * sint;
1005 Double_t px1 = pt1 * TMath::Cos(phi);
1006 Double_t py1 = pt1 * TMath::Sin(phi);
1007 Double_t px2 = pt2 * TMath::Cos(phi);
1008 Double_t py2 = pt2 * TMath::Sin(phi);
1009
1010 fPyjets->P[0][iGlu] = px1;
1011 fPyjets->P[1][iGlu] = py1;
1012 fPyjets->P[2][iGlu] = pz1;
1013 fPyjets->P[3][iGlu] = pst;
1014 fPyjets->P[4][iGlu] = 0.;
1015
1016 fPyjets->K[0][iGlu] = 2;
1017 fPyjets->K[1][iGlu] = 21;
1018 fPyjets->K[2][iGlu] = fPyjets->K[2][iNew] + 1000;
1019 fPyjets->K[3][iGlu] = -1;
1020 fPyjets->K[4][iGlu] = -1;
1021
1022 fPyjets->P[0][iGlu+1] = px2;
1023 fPyjets->P[1][iGlu+1] = py2;
1024 fPyjets->P[2][iGlu+1] = pz2;
1025 fPyjets->P[3][iGlu+1] = pst;
1026 fPyjets->P[4][iGlu+1] = 0.;
1027
1028 fPyjets->K[0][iGlu+1] = 2;
1029 fPyjets->K[1][iGlu+1] = 21;
1030 fPyjets->K[2][iGlu+1] = fPyjets->K[2][iNew] + 1000;
1031 fPyjets->K[3][iGlu+1] = -1;
1032 fPyjets->K[4][iGlu+1] = -1;
1033 SetMSTU(1,0);
1034 SetMSTU(2,0);
1035 //
1036 // Boost back
1037 //
1038 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1039 }
1040 } // end adding gluons
1041 //
1042 // Check energy conservation
1043 Double_t pxs = 0.;
1044 Double_t pys = 0.;
1045 Double_t pzs = 0.;
1046 Double_t es = 14000.;
1047
1048 for (Int_t i = 0; i < numpart; i++)
1049 {
1050 kst = fPyjets->K[0][i];
1051 if (kst != 1 && kst != 2) continue;
1052 pxs += fPyjets->P[0][i];
1053 pys += fPyjets->P[1][i];
1054 pzs += fPyjets->P[2][i];
1055 es -= fPyjets->P[3][i];
1056 }
1057 if (TMath::Abs(pxs) > 1.e-2 ||
1058 TMath::Abs(pys) > 1.e-2 ||
1059 TMath::Abs(pzs) > 1.e-1) {
1060 printf("%e %e %e %e\n", pxs, pys, pzs, es);
1061 this->Pylist(1);
1062 Fatal("Quench()", "4-Momentum non-conservation");
452af8c7 1063 }
452af8c7 1064
0f482ae4 1065 } // end quenchin loop
1066 // Clean-up
1067 for (Int_t i = 0; i < numpart; i++)
1068 {
1069 imo = fPyjets->K[2][i];
1070 if (imo > 1000) fPyjets->K[2][i] -= 1000;
1071 }
1072
1073} // end quench