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Muonic decay of W added. (Zaida Conesa del Valle)
[u/mrichter/AliRoot.git] / PYTHIA6 / AliPythia.cxx
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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_
992f2843 31# define pyquen pyquen_
8d2cd130 32# define type_of_call
33#else
34# define pyclus PYCLUS
35# define pycell PYCELL
452af8c7 36# define pyrobo PYROBO
992f2843 37# define pyquen PYQUEN
8d2cd130 38# define type_of_call _stdcall
39#endif
40
41extern "C" void type_of_call pyclus(Int_t & );
42extern "C" void type_of_call pycell(Int_t & );
452af8c7 43extern "C" void type_of_call pyshow(Int_t &, Int_t &, Double_t &);
44extern "C" void type_of_call pyrobo(Int_t &, Int_t &, Double_t &, Double_t &, Double_t &, Double_t &, Double_t &);
992f2843 45extern "C" void type_of_call pyquen(Double_t &, Int_t &, Double_t &);
8d2cd130 46
47//_____________________________________________________________________________
48
49AliPythia* AliPythia::fgAliPythia=NULL;
50
51AliPythia::AliPythia()
52{
53// Default Constructor
54//
55// Set random number
7cdba479 56 if (!AliPythiaRndm::GetPythiaRandom())
57 AliPythiaRndm::SetPythiaRandom(GetRandom());
0f482ae4 58 fGlauber = 0;
59 fQuenchingWeights = 0;
8d2cd130 60}
61
62void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc)
63{
64// Initialise the process to generate
7cdba479 65 if (!AliPythiaRndm::GetPythiaRandom())
66 AliPythiaRndm::SetPythiaRandom(GetRandom());
8d2cd130 67
68 fProcess = process;
69 fEcms = energy;
70 fStrucFunc = strucfunc;
1d5b1b20 71//...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
72 SetMDCY(Pycomp(111) ,1,0);
73 SetMDCY(Pycomp(310) ,1,0);
74 SetMDCY(Pycomp(3122),1,0);
75 SetMDCY(Pycomp(3112),1,0);
76 SetMDCY(Pycomp(3212),1,0);
77 SetMDCY(Pycomp(3222),1,0);
78 SetMDCY(Pycomp(3312),1,0);
79 SetMDCY(Pycomp(3322),1,0);
80 SetMDCY(Pycomp(3334),1,0);
81 // select structure function
8d2cd130 82 SetMSTP(52,2);
83 SetMSTP(51,strucfunc);
84//
85// Pythia initialisation for selected processes//
86//
87// Make MSEL clean
88//
89 for (Int_t i=1; i<= 200; i++) {
90 SetMSUB(i,0);
91 }
92// select charm production
93 switch (process)
94 {
95 case kPyCharm:
96 SetMSEL(4);
97//
98// heavy quark masses
99
100 SetPMAS(4,1,1.2);
101 SetMSTU(16,2);
102//
103// primordial pT
104 SetMSTP(91,1);
105 SetPARP(91,1.);
106 SetPARP(93,5.);
107//
108 break;
109 case kPyBeauty:
110 SetMSEL(5);
111 SetPMAS(5,1,4.75);
112 SetMSTU(16,2);
113 break;
114 case kPyJpsi:
115 SetMSEL(0);
116// gg->J/Psi g
117 SetMSUB(86,1);
118 break;
119 case kPyJpsiChi:
120 SetMSEL(0);
121// gg->J/Psi g
122 SetMSUB(86,1);
123// gg-> chi_0c g
124 SetMSUB(87,1);
125// gg-> chi_1c g
126 SetMSUB(88,1);
127// gg-> chi_2c g
128 SetMSUB(89,1);
129 break;
130 case kPyCharmUnforced:
131 SetMSEL(0);
132// gq->qg
133 SetMSUB(28,1);
134// gg->qq
135 SetMSUB(53,1);
136// gg->gg
137 SetMSUB(68,1);
138 break;
139 case kPyBeautyUnforced:
140 SetMSEL(0);
141// gq->qg
142 SetMSUB(28,1);
143// gg->qq
144 SetMSUB(53,1);
145// gg->gg
146 SetMSUB(68,1);
147 break;
148 case kPyMb:
149// Minimum Bias pp-Collisions
150//
151//
152// select Pythia min. bias model
153 SetMSEL(0);
511db649 154 SetMSUB(92,1); // single diffraction AB-->XB
155 SetMSUB(93,1); // single diffraction AB-->AX
156 SetMSUB(94,1); // double diffraction
157 SetMSUB(95,1); // low pt production
158
159//
160// ATLAS Tuning
161//
c01c4118 162
163 SetMSTP(51, kCTEQ5L); // CTEQ5L pdf
511db649 164 SetMSTP(81,1); // Multiple Interactions ON
165 SetMSTP(82,4); // Double Gaussian Model
166
167 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
168 SetPARP(89,1000.); // [GeV] Ref. energy
169 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
170 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
171 SetPARP(84,0.5); // Core radius
172 SetPARP(85,0.33); // Regulates gluon prod. mechanism
173 SetPARP(86,0.66); // Regulates gluon prod. mechanism
174 SetPARP(67,1); // Regulates Initial State Radiation
175 break;
8d2cd130 176 case kPyMbNonDiffr:
177// Minimum Bias pp-Collisions
178//
179//
180// select Pythia min. bias model
181 SetMSEL(0);
511db649 182 SetMSUB(95,1); // low pt production
0f482ae4 183
184//
185// ATLAS Tuning
186//
511db649 187
d682afd1 188 SetMSTP(51,kCTEQ5L); // CTEQ5L pdf
511db649 189 SetMSTP(81,1); // Multiple Interactions ON
190 SetMSTP(82,4); // Double Gaussian Model
191
192 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
193 SetPARP(89,1000.); // [GeV] Ref. energy
194 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
195 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
196 SetPARP(84,0.5); // Core radius
197 SetPARP(85,0.33); // Regulates gluon prod. mechanism
198 SetPARP(86,0.66); // Regulates gluon prod. mechanism
199 SetPARP(67,1); // Regulates Initial State Radiation
8d2cd130 200 break;
201 case kPyJets:
202//
203// QCD Jets
204//
205 SetMSEL(1);
206 break;
207 case kPyDirectGamma:
208 SetMSEL(10);
209 break;
adf4d898 210 case kPyCharmPbPbMNR:
211 case kPyD0PbPbMNR:
8d2cd130 212 // Tuning of Pythia parameters aimed to get a resonable agreement
213 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
214 // c-cbar single inclusive and double differential distributions.
215 // This parameter settings are meant to work with Pb-Pb collisions
adf4d898 216 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
8d2cd130 217 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
218 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
219
220 // All QCD processes
221 SetMSEL(1);
222
223 // No multiple interactions
224 SetMSTP(81,0);
225 SetPARP(81,0.0);
226 SetPARP(82,0.0);
227
228 // Initial/final parton shower on (Pythia default)
229 SetMSTP(61,1);
230 SetMSTP(71,1);
231
232 // 2nd order alpha_s
233 SetMSTP(2,2);
234
235 // QCD scales
236 SetMSTP(32,2);
237 SetPARP(34,1.0);
238
adf4d898 239 // Intrinsic <kT>
8d2cd130 240 SetMSTP(91,1);
241 SetPARP(91,1.304);
242 SetPARP(93,6.52);
243
244 // Set c-quark mass
245 SetPMAS(4,1,1.2);
246
90d7b703 247 break;
248 case kPyDPlusPbPbMNR:
249 // Tuning of Pythia parameters aimed to get a resonable agreement
250 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
251 // c-cbar single inclusive and double differential distributions.
252 // This parameter settings are meant to work with Pb-Pb collisions
253 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
254 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
255 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
256
257 // All QCD processes
258 SetMSEL(1);
259
260 // No multiple interactions
261 SetMSTP(81,0);
262 SetPARP(81,0.0);
263 SetPARP(82,0.0);
264
265 // Initial/final parton shower on (Pythia default)
266 SetMSTP(61,1);
267 SetMSTP(71,1);
268
269 // 2nd order alpha_s
270 SetMSTP(2,2);
271
272 // QCD scales
273 SetMSTP(32,2);
274 SetPARP(34,1.0);
275
276 // Intrinsic <kT>
277 SetMSTP(91,1);
278 SetPARP(91,1.304);
279 SetPARP(93,6.52);
280
281 // Set c-quark mass
282 SetPMAS(4,1,1.2);
283
8d2cd130 284 break;
adf4d898 285 case kPyCharmpPbMNR:
286 case kPyD0pPbMNR:
287 // Tuning of Pythia parameters aimed to get a resonable agreement
288 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
289 // c-cbar single inclusive and double differential distributions.
290 // This parameter settings are meant to work with p-Pb collisions
291 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
292 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
293 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
294
295 // All QCD processes
296 SetMSEL(1);
297
298 // No multiple interactions
299 SetMSTP(81,0);
300 SetPARP(81,0.0);
301 SetPARP(82,0.0);
302
303 // Initial/final parton shower on (Pythia default)
304 SetMSTP(61,1);
305 SetMSTP(71,1);
306
307 // 2nd order alpha_s
308 SetMSTP(2,2);
309
310 // QCD scales
311 SetMSTP(32,2);
312 SetPARP(34,1.0);
313
314 // Intrinsic <kT>
315 SetMSTP(91,1);
316 SetPARP(91,1.16);
317 SetPARP(93,5.8);
318
319 // Set c-quark mass
320 SetPMAS(4,1,1.2);
321
90d7b703 322 break;
323 case kPyDPluspPbMNR:
324 // Tuning of Pythia parameters aimed to get a resonable agreement
325 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
326 // c-cbar single inclusive and double differential distributions.
327 // This parameter settings are meant to work with p-Pb collisions
328 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
329 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
330 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
331
332 // All QCD processes
333 SetMSEL(1);
334
335 // No multiple interactions
336 SetMSTP(81,0);
337 SetPARP(81,0.0);
338 SetPARP(82,0.0);
339
340 // Initial/final parton shower on (Pythia default)
341 SetMSTP(61,1);
342 SetMSTP(71,1);
343
344 // 2nd order alpha_s
345 SetMSTP(2,2);
346
347 // QCD scales
348 SetMSTP(32,2);
349 SetPARP(34,1.0);
350
351 // Intrinsic <kT>
352 SetMSTP(91,1);
353 SetPARP(91,1.16);
354 SetPARP(93,5.8);
355
356 // Set c-quark mass
357 SetPMAS(4,1,1.2);
358
adf4d898 359 break;
360 case kPyCharmppMNR:
361 case kPyD0ppMNR:
362 // Tuning of Pythia parameters aimed to get a resonable agreement
363 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
364 // c-cbar single inclusive and double differential distributions.
365 // This parameter settings are meant to work with pp collisions
366 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
367 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
368 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
369
370 // All QCD processes
371 SetMSEL(1);
372
373 // No multiple interactions
374 SetMSTP(81,0);
375 SetPARP(81,0.0);
376 SetPARP(82,0.0);
377
378 // Initial/final parton shower on (Pythia default)
379 SetMSTP(61,1);
380 SetMSTP(71,1);
381
382 // 2nd order alpha_s
383 SetMSTP(2,2);
384
385 // QCD scales
386 SetMSTP(32,2);
387 SetPARP(34,1.0);
388
389 // Intrinsic <kT^2>
390 SetMSTP(91,1);
391 SetPARP(91,1.);
392 SetPARP(93,5.);
393
394 // Set c-quark mass
395 SetPMAS(4,1,1.2);
396
90d7b703 397 break;
398 case kPyDPlusppMNR:
399 // Tuning of Pythia parameters aimed to get a resonable agreement
400 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
401 // c-cbar single inclusive and double differential distributions.
402 // This parameter settings are meant to work with pp collisions
403 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
404 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
405 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
406
407 // All QCD processes
408 SetMSEL(1);
409
410 // No multiple interactions
411 SetMSTP(81,0);
412 SetPARP(81,0.0);
413 SetPARP(82,0.0);
414
415 // Initial/final parton shower on (Pythia default)
416 SetMSTP(61,1);
417 SetMSTP(71,1);
418
419 // 2nd order alpha_s
420 SetMSTP(2,2);
421
422 // QCD scales
423 SetMSTP(32,2);
424 SetPARP(34,1.0);
425
426 // Intrinsic <kT^2>
427 SetMSTP(91,1);
428 SetPARP(91,1.);
429 SetPARP(93,5.);
430
431 // Set c-quark mass
432 SetPMAS(4,1,1.2);
433
adf4d898 434 break;
435 case kPyBeautyPbPbMNR:
8d2cd130 436 // Tuning of Pythia parameters aimed to get a resonable agreement
437 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
438 // b-bbar single inclusive and double differential distributions.
439 // This parameter settings are meant to work with Pb-Pb collisions
440 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
441 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
442 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
443
444 // All QCD processes
445 SetMSEL(1);
446
447 // No multiple interactions
448 SetMSTP(81,0);
449 SetPARP(81,0.0);
450 SetPARP(82,0.0);
451
452 // Initial/final parton shower on (Pythia default)
453 SetMSTP(61,1);
454 SetMSTP(71,1);
455
456 // 2nd order alpha_s
457 SetMSTP(2,2);
458
459 // QCD scales
460 SetMSTP(32,2);
461 SetPARP(34,1.0);
462 SetPARP(67,1.0);
463 SetPARP(71,1.0);
464
adf4d898 465 // Intrinsic <kT>
8d2cd130 466 SetMSTP(91,1);
467 SetPARP(91,2.035);
468 SetPARP(93,10.17);
469
470 // Set b-quark mass
471 SetPMAS(5,1,4.75);
472
adf4d898 473 break;
474 case kPyBeautypPbMNR:
475 // Tuning of Pythia parameters aimed to get a resonable agreement
476 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
477 // b-bbar single inclusive and double differential distributions.
478 // This parameter settings are meant to work with p-Pb collisions
479 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
480 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
481 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
482
483 // All QCD processes
484 SetMSEL(1);
485
486 // No multiple interactions
487 SetMSTP(81,0);
488 SetPARP(81,0.0);
489 SetPARP(82,0.0);
490
491 // Initial/final parton shower on (Pythia default)
492 SetMSTP(61,1);
493 SetMSTP(71,1);
494
495 // 2nd order alpha_s
496 SetMSTP(2,2);
497
498 // QCD scales
499 SetMSTP(32,2);
500 SetPARP(34,1.0);
501 SetPARP(67,1.0);
502 SetPARP(71,1.0);
503
504 // Intrinsic <kT>
505 SetMSTP(91,1);
506 SetPARP(91,1.60);
507 SetPARP(93,8.00);
508
509 // Set b-quark mass
510 SetPMAS(5,1,4.75);
511
512 break;
513 case kPyBeautyppMNR:
514 // Tuning of Pythia parameters aimed to get a resonable agreement
515 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
516 // b-bbar single inclusive and double differential distributions.
517 // This parameter settings are meant to work with pp collisions
518 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
519 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
520 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
521
522 // All QCD processes
523 SetMSEL(1);
524
525 // No multiple interactions
526 SetMSTP(81,0);
527 SetPARP(81,0.0);
528 SetPARP(82,0.0);
529
530 // Initial/final parton shower on (Pythia default)
531 SetMSTP(61,1);
532 SetMSTP(71,1);
533
534 // 2nd order alpha_s
535 SetMSTP(2,2);
536
537 // QCD scales
538 SetMSTP(32,2);
539 SetPARP(34,1.0);
540 SetPARP(67,1.0);
541 SetPARP(71,1.0);
542
543 // Intrinsic <kT>
544 SetMSTP(91,1);
545 SetPARP(91,1.);
546 SetPARP(93,5.);
547
548 // Set b-quark mass
549 SetPMAS(5,1,4.75);
550
8d2cd130 551 break;
552 }
553//
554// Initialize PYTHIA
555 SetMSTP(41,1); // all resonance decays switched on
556
557 Initialize("CMS","p","p",fEcms);
558
559}
560
561Int_t AliPythia::CheckedLuComp(Int_t kf)
562{
563// Check Lund particle code (for debugging)
564 Int_t kc=Pycomp(kf);
565 printf("\n Lucomp kf,kc %d %d",kf,kc);
566 return kc;
567}
568
569void AliPythia::SetNuclei(Int_t a1, Int_t a2)
570{
571// Treat protons as inside nuclei with mass numbers a1 and a2
572// The MSTP array in the PYPARS common block is used to enable and
573// select the nuclear structure functions.
574// MSTP(52) : (D=1) choice of proton and nuclear structure-function library
575// =1: internal PYTHIA acording to MSTP(51)
576// =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
577// If the following mass number both not equal zero, nuclear corrections of the stf are used.
578// MSTP(192) : Mass number of nucleus side 1
579// MSTP(193) : Mass number of nucleus side 2
580 SetMSTP(52,2);
581 SetMSTP(192, a1);
582 SetMSTP(193, a2);
583}
584
585
586AliPythia* AliPythia::Instance()
587{
588// Set random number generator
589 if (fgAliPythia) {
590 return fgAliPythia;
591 } else {
592 fgAliPythia = new AliPythia();
593 return fgAliPythia;
594 }
595}
596
597void AliPythia::PrintParticles()
598{
599// Print list of particl properties
600 Int_t np = 0;
c31f1d37 601 char* name = new char[16];
8d2cd130 602 for (Int_t kf=0; kf<1000000; kf++) {
603 for (Int_t c = 1; c > -2; c-=2) {
8d2cd130 604 Int_t kc = Pycomp(c*kf);
605 if (kc) {
606 Float_t mass = GetPMAS(kc,1);
607 Float_t width = GetPMAS(kc,2);
608 Float_t tau = GetPMAS(kc,4);
c31f1d37 609
8d2cd130 610 Pyname(kf,name);
611
612 np++;
613
614 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
615 c*kf, name, mass, width, tau);
616 }
617 }
618 }
619 printf("\n Number of particles %d \n \n", np);
620}
621
622void AliPythia::ResetDecayTable()
623{
624// Set default values for pythia decay switches
625 Int_t i;
626 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
627 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
628}
629
630void AliPythia::SetDecayTable()
631{
632// Set default values for pythia decay switches
633//
634 Int_t i;
635 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
636 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
637}
638
639void AliPythia::Pyclus(Int_t& njet)
640{
641// Call Pythia clustering algorithm
642//
643 pyclus(njet);
644}
645
646void AliPythia::Pycell(Int_t& njet)
647{
648// Call Pythia jet reconstruction algorithm
649//
650 pycell(njet);
651}
652
452af8c7 653void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
654{
655// Call Pythia jet reconstruction algorithm
656//
452af8c7 657 pyshow(ip1, ip2, qmax);
658}
659
660void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
661{
662 pyrobo(imi, ima, the, phi, bex, bey, bez);
663}
664
665
666
86b6ad68 667void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod)
0f482ae4 668{
669// Initializes
670// (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
671// (2) The nuclear geometry using the Glauber Model
672//
673
674
675 fGlauber = new AliFastGlauber();
676 fGlauber->Init(2);
677 fGlauber->SetCentralityClass(cMin, cMax);
678
679 fQuenchingWeights = new AliQuenchingWeights();
680 fQuenchingWeights->InitMult();
86b6ad68 681 fQuenchingWeights->SetK(k);
0f482ae4 682 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
0f482ae4 683}
684
685
452af8c7 686void AliPythia::Quench()
687{
688//
689//
690// Simple Jet Quenching routine:
691// =============================
692// The jet formed by all final state partons radiated by the parton created
0f482ae4 693// in the hard collisions is quenched by a factor (1-z) using light cone variables in
694// the initial parton reference frame:
452af8c7 695// (E + p_z)new = (1-z) (E + p_z)old
696//
0f482ae4 697//
698//
699//
452af8c7 700// The lost momentum is first balanced by one gluon with virtuality > 0.
701// Subsequently the gluon splits to yield two gluons with E = p.
702//
0f482ae4 703//
704//
4e383037 705 static Float_t eMean = 0.;
706 static Int_t icall = 0;
0f482ae4 707
c2c598a3 708 Double_t p0[4][5];
709 Double_t p1[4][5];
710 Double_t p2[4][5];
711 Int_t klast[4] = {-1, -1, -1, -1};
452af8c7 712
713 Int_t numpart = fPyjets->N;
86b6ad68 714 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
c2c598a3 715 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
716 Bool_t quenched[4];
b280c4cc 717 Double_t wjtKick[4];
c2c598a3 718 Int_t nGluon[4];
86b6ad68 719 Int_t qPdg[4];
0f482ae4 720 Int_t imo, kst, pdg;
b280c4cc 721
511db649 722//
c2c598a3 723// Sore information about Primary partons
724//
725// j =
726// 0, 1 partons from hard scattering
727// 2, 3 partons from initial state radiation
728//
729 for (Int_t i = 2; i <= 7; i++) {
730 Int_t j = 0;
731 // Skip gluons that participate in hard scattering
732 if (i == 4 || i == 5) continue;
733 // Gluons from hard Scattering
734 if (i == 6 || i == 7) {
735 j = i - 6;
736 pxq[j] = fPyjets->P[0][i];
737 pyq[j] = fPyjets->P[1][i];
738 pzq[j] = fPyjets->P[2][i];
739 eq[j] = fPyjets->P[3][i];
740 mq[j] = fPyjets->P[4][i];
741 } else {
742 // Gluons from initial state radiation
743 //
744 // Obtain 4-momentum vector from difference between original parton and parton after gluon
745 // radiation. Energy is calculated independently because initial state radition does not
746 // conserve strictly momentum and energy for each partonic system independently.
747 //
748 // Not very clean. Should be improved !
749 //
750 //
751 j = i;
752 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
753 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
754 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
755 mq[j] = fPyjets->P[4][i];
756 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
757 }
758//
759// Calculate some kinematic variables
511db649 760//
4e383037 761 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
0f482ae4 762 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
763 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
764 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
765 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
86b6ad68 766 qPdg[j] = fPyjets->K[1][i];
767 }
768
769 Double_t int0[4];
770 Double_t int1[4];
86b6ad68 771
b280c4cc 772 fGlauber->GetI0I1ForPythiaAndXY(4, phiq, int0, int1, fXJet, fYJet, 15.);
773
86b6ad68 774 for (Int_t j = 0; j < 4; j++) {
c2c598a3 775 //
776 // Quench only central jets and with E > 10.
777 //
86b6ad68 778
779
780 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
781 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
782
c2c598a3 783 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
b280c4cc 784 fZQuench[j] = 0.;
0f482ae4 785 } else {
c2c598a3 786 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
4e383037 787 icall ++;
788 eMean += eloss;
789 }
0f482ae4 790 //
791 // Extra pt
86b6ad68 792 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
793 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
0f482ae4 794 //
795 // Fractional energy loss
b280c4cc 796 fZQuench[j] = eloss / eq[j];
0f482ae4 797 //
798 // Avoid complete loss
799 //
b280c4cc 800 if (fZQuench[j] == 1.) fZQuench[j] = 0.95;
0f482ae4 801 //
802 // Some debug printing
86b6ad68 803
804
bf9bb016 805// 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",
806// j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
4e383037 807
b280c4cc 808// fZQuench[j] = 0.8;
809// while (fZQuench[j] >= 0.95) fZQuench[j] = gRandom->Exp(0.2);
0f482ae4 810 }
4e383037 811
b280c4cc 812 quenched[j] = (fZQuench[j] > 0.01);
4e383037 813 } // primary partons
c2c598a3 814
b280c4cc 815
816
6e90ad26 817 Double_t pNew[1000][4];
818 Int_t kNew[1000];
819 Int_t icount = 0;
b280c4cc 820 Double_t zquench[4];
821
6e90ad26 822//
4e383037 823// System Loop
c2c598a3 824 for (Int_t isys = 0; isys < 4; isys++) {
6e90ad26 825// Skip to next system if not quenched.
4e383037 826 if (!quenched[isys]) continue;
827
b280c4cc 828 nGluon[isys] = 1 + Int_t(fZQuench[isys] / (1. - fZQuench[isys]));
4e383037 829 if (nGluon[isys] > 6) nGluon[isys] = 6;
b280c4cc 830 zquench[isys] = 1. - TMath::Power(1. - fZQuench[isys], 1./Double_t(nGluon[isys]));
4e383037 831 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
0f482ae4 832
4e383037 833
834
835 Int_t igMin = -1;
836 Int_t igMax = -1;
837 Double_t pg[4] = {0., 0., 0., 0.};
838
839//
840// Loop on radiation events
841
842 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
6e90ad26 843 while (1) {
844 icount = 0;
845 for (Int_t k = 0; k < 4; k++)
846 {
847 p0[isys][k] = 0.;
848 p1[isys][k] = 0.;
849 p2[isys][k] = 0.;
850 }
851// Loop over partons
852 for (Int_t i = 0; i < numpart; i++)
853 {
854 imo = fPyjets->K[2][i];
855 kst = fPyjets->K[0][i];
856 pdg = fPyjets->K[1][i];
857
858
859
0f482ae4 860// Quarks and gluons only
6e90ad26 861 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
0f482ae4 862// Particles from hard scattering only
c2c598a3 863
6e90ad26 864 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
c2c598a3 865 Int_t imom = imo % 1000;
866 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
867 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
868
6e90ad26 869
0f482ae4 870// Skip comment lines
6e90ad26 871 if (kst != 1 && kst != 2) continue;
0f482ae4 872//
873// Parton kinematic
6e90ad26 874 px = fPyjets->P[0][i];
875 py = fPyjets->P[1][i];
876 pz = fPyjets->P[2][i];
877 e = fPyjets->P[3][i];
878 m = fPyjets->P[4][i];
879 pt = TMath::Sqrt(px * px + py * py);
880 p = TMath::Sqrt(px * px + py * py + pz * pz);
881 phi = TMath::Pi() + TMath::ATan2(-py, -px);
882 theta = TMath::ATan2(pt, pz);
883
0f482ae4 884//
c2c598a3 885// Save 4-momentum sum for balancing
886 Int_t index = isys;
6e90ad26 887
888 p0[index][0] += px;
889 p0[index][1] += py;
890 p0[index][2] += pz;
891 p0[index][3] += e;
6e90ad26 892
893 klast[index] = i;
894
0f482ae4 895//
896// Fractional energy loss
b280c4cc 897 Double_t z = zquench[index];
4e383037 898
c2c598a3 899
4e383037 900// Don't fully quench radiated gluons
901//
902 if (imo > 1000) {
903// This small factor makes sure that the gluons are not too close in phase space to avoid recombination
904//
905
c2c598a3 906 z = 0.02;
4e383037 907 }
c2c598a3 908// printf("z: %d %f\n", imo, z);
909
4e383037 910
911//
6e90ad26 912
913 //
914 //
915 // Transform into frame in which initial parton is along z-axis
916 //
917 TVector3 v(px, py, pz);
918 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
919 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
920
921 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
922 Double_t mt2 = jt * jt + m * m;
923 Double_t zmax = 1.;
924 //
925 // Kinematic limit on z
926 //
4e383037 927 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
6e90ad26 928 //
929 // Change light-cone kinematics rel. to initial parton
930 //
931 Double_t eppzOld = e + pl;
932 Double_t empzOld = e - pl;
933
934 Double_t eppzNew = (1. - z) * eppzOld;
935 Double_t empzNew = empzOld - mt2 * z / eppzOld;
936 Double_t eNew = 0.5 * (eppzNew + empzNew);
937 Double_t plNew = 0.5 * (eppzNew - empzNew);
938
939 Double_t jtNew;
940 //
941 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
942 Double_t mt2New = eppzNew * empzNew;
943 if (mt2New < 1.e-8) mt2New = 0.;
4e383037 944 if (z < zmax) {
945 if (m * m > mt2New) {
946 //
947 // This should not happen
948 //
949 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
950 jtNew = 0;
951 } else {
952 jtNew = TMath::Sqrt(mt2New - m * m);
953 }
6e90ad26 954 } else {
4e383037 955 // If pT is to small (probably a leading massive particle) we scale only the energy
956 // This can cause negative masses of the radiated gluon
957 // Let's hope for the best ...
958 jtNew = jt;
959 eNew = TMath::Sqrt(plNew * plNew + mt2);
960
6e90ad26 961 }
6e90ad26 962 //
963 // Calculate new px, py
964 //
965 Double_t pxNew = jtNew / jt * pxs;
966 Double_t pyNew = jtNew / jt * pys;
967
968// Double_t dpx = pxs - pxNew;
969// Double_t dpy = pys - pyNew;
970// Double_t dpz = pl - plNew;
971// Double_t de = e - eNew;
972// Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
973// printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
974// printf("New mass (2) %e %e \n", pxNew, pyNew);
975 //
976 // Rotate back
977 //
978 TVector3 w(pxNew, pyNew, plNew);
979 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
980 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
981
982 p1[index][0] += pxNew;
983 p1[index][1] += pyNew;
984 p1[index][2] += plNew;
985 p1[index][3] += eNew;
986 //
987 // Updated 4-momentum vectors
988 //
989 pNew[icount][0] = pxNew;
990 pNew[icount][1] = pyNew;
991 pNew[icount][2] = plNew;
992 pNew[icount][3] = eNew;
993 kNew[icount] = i;
994 icount++;
995 } // parton loop
0f482ae4 996 //
6e90ad26 997 // Check if there was phase-space for quenching
0f482ae4 998 //
0f482ae4 999
6e90ad26 1000 if (icount == 0) quenched[isys] = kFALSE;
1001 if (!quenched[isys]) break;
1002
1003 for (Int_t j = 0; j < 4; j++)
1004 {
1005 p2[isys][j] = p0[isys][j] - p1[isys][j];
1006 }
1007 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];
6e90ad26 1008 if (p2[isys][4] > 0.) {
1009 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1010 break;
1011 } else {
b280c4cc 1012 printf("Warning negative mass squared in system %d %f ! \n", isys, zquench[isys]);
4e383037 1013 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]);
6e90ad26 1014 if (p2[isys][4] < -0.01) {
4e383037 1015 printf("Negative mass squared !\n");
1016 // Here we have to put the gluon back to mass shell
1017 // This will lead to a small energy imbalance
1018 p2[isys][4] = 0.;
1019 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1020 break;
6e90ad26 1021 } else {
1022 p2[isys][4] = 0.;
1023 break;
1024 }
1025 }
6e90ad26 1026 /*
6e90ad26 1027 zHeavy *= 0.98;
1028 printf("zHeavy lowered to %f\n", zHeavy);
1029 if (zHeavy < 0.01) {
1030 printf("No success ! \n");
1031 icount = 0;
1032 quenched[isys] = kFALSE;
1033 break;
1034 }
4e383037 1035 */
1036 } // iteration on z (while)
1037
6e90ad26 1038// Update event record
1039 for (Int_t k = 0; k < icount; k++) {
1040// 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] );
1041 fPyjets->P[0][kNew[k]] = pNew[k][0];
1042 fPyjets->P[1][kNew[k]] = pNew[k][1];
1043 fPyjets->P[2][kNew[k]] = pNew[k][2];
1044 fPyjets->P[3][kNew[k]] = pNew[k][3];
0f482ae4 1045 }
4e383037 1046 //
1047 // Add the gluons
1048 //
1049 Int_t ish = 0;
1837e95c 1050 Int_t iGlu;
4e383037 1051 if (!quenched[isys]) continue;
0f482ae4 1052//
1053// Last parton from shower i
4e383037 1054 Int_t in = klast[isys];
0f482ae4 1055//
1056// Continue if no parton in shower i selected
1057 if (in == -1) continue;
1058//
1059// If this is the second initial parton and it is behind the first move pointer by previous ish
4e383037 1060 if (isys == 1 && klast[1] > klast[0]) in += ish;
0f482ae4 1061//
1062// Starting index
452af8c7 1063
4e383037 1064// jmin = in - 1;
0f482ae4 1065// How many additional gluons will be generated
1066 ish = 1;
4e383037 1067 if (p2[isys][4] > 0.05) ish = 2;
0f482ae4 1068//
1069// Position of gluons
4e383037 1070 iGlu = numpart;
1071 if (iglu == 0) igMin = iGlu;
1072 igMax = iGlu;
0f482ae4 1073 numpart += ish;
1074 (fPyjets->N) += ish;
4e383037 1075
0f482ae4 1076 if (ish == 1) {
4e383037 1077 fPyjets->P[0][iGlu] = p2[isys][0];
1078 fPyjets->P[1][iGlu] = p2[isys][1];
1079 fPyjets->P[2][iGlu] = p2[isys][2];
1080 fPyjets->P[3][iGlu] = p2[isys][3];
1081 fPyjets->P[4][iGlu] = p2[isys][4];
0f482ae4 1082
4e383037 1083 fPyjets->K[0][iGlu] = 1;
1084 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
0f482ae4 1085 fPyjets->K[1][iGlu] = 21;
4e383037 1086 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
0f482ae4 1087 fPyjets->K[3][iGlu] = -1;
1088 fPyjets->K[4][iGlu] = -1;
4e383037 1089
1090 pg[0] += p2[isys][0];
1091 pg[1] += p2[isys][1];
1092 pg[2] += p2[isys][2];
1093 pg[3] += p2[isys][3];
0f482ae4 1094 } else {
1095 //
1096 // Split gluon in rest frame.
1097 //
4e383037 1098 Double_t bx = p2[isys][0] / p2[isys][3];
1099 Double_t by = p2[isys][1] / p2[isys][3];
1100 Double_t bz = p2[isys][2] / p2[isys][3];
1101 Double_t pst = p2[isys][4] / 2.;
0f482ae4 1102 //
1103 // Isotropic decay ????
1104 Double_t cost = 2. * gRandom->Rndm() - 1.;
1105 Double_t sint = TMath::Sqrt(1. - cost * cost);
1106 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1107
1108 Double_t pz1 = pst * cost;
1109 Double_t pz2 = -pst * cost;
1110 Double_t pt1 = pst * sint;
1111 Double_t pt2 = -pst * sint;
1112 Double_t px1 = pt1 * TMath::Cos(phi);
1113 Double_t py1 = pt1 * TMath::Sin(phi);
1114 Double_t px2 = pt2 * TMath::Cos(phi);
1115 Double_t py2 = pt2 * TMath::Sin(phi);
1116
1117 fPyjets->P[0][iGlu] = px1;
1118 fPyjets->P[1][iGlu] = py1;
1119 fPyjets->P[2][iGlu] = pz1;
1120 fPyjets->P[3][iGlu] = pst;
1121 fPyjets->P[4][iGlu] = 0.;
1122
4e383037 1123 fPyjets->K[0][iGlu] = 1 ;
0f482ae4 1124 fPyjets->K[1][iGlu] = 21;
4e383037 1125 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
0f482ae4 1126 fPyjets->K[3][iGlu] = -1;
1127 fPyjets->K[4][iGlu] = -1;
1128
1129 fPyjets->P[0][iGlu+1] = px2;
1130 fPyjets->P[1][iGlu+1] = py2;
1131 fPyjets->P[2][iGlu+1] = pz2;
1132 fPyjets->P[3][iGlu+1] = pst;
1133 fPyjets->P[4][iGlu+1] = 0.;
1134
4e383037 1135 fPyjets->K[0][iGlu+1] = 1;
1136 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
0f482ae4 1137 fPyjets->K[1][iGlu+1] = 21;
4e383037 1138 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
0f482ae4 1139 fPyjets->K[3][iGlu+1] = -1;
1140 fPyjets->K[4][iGlu+1] = -1;
1141 SetMSTU(1,0);
1142 SetMSTU(2,0);
1143 //
1144 // Boost back
1145 //
1146 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1147 }
4e383037 1148/*
1149 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1150 Double_t px, py, pz;
1151 px = fPyjets->P[0][ig];
1152 py = fPyjets->P[1][ig];
1153 pz = fPyjets->P[2][ig];
1154 TVector3 v(px, py, pz);
1155 v.RotateZ(-phiq[isys]);
1156 v.RotateY(-thetaq[isys]);
1157 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1158 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1159 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1160 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1161 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1162 pxs += jtKick * TMath::Cos(phiKick);
1163 pys += jtKick * TMath::Sin(phiKick);
1164 TVector3 w(pxs, pys, pzs);
1165 w.RotateY(thetaq[isys]);
1166 w.RotateZ(phiq[isys]);
1167 fPyjets->P[0][ig] = w.X();
1168 fPyjets->P[1][ig] = w.Y();
1169 fPyjets->P[2][ig] = w.Z();
1170 fPyjets->P[2][ig] = w.Mag();
1171 }
1172*/
1173 } // kGluon
1174
6e90ad26 1175
4e383037 1176 // Check energy conservation
0f482ae4 1177 Double_t pxs = 0.;
1178 Double_t pys = 0.;
1179 Double_t pzs = 0.;
1180 Double_t es = 14000.;
1181
1182 for (Int_t i = 0; i < numpart; i++)
1183 {
1184 kst = fPyjets->K[0][i];
1185 if (kst != 1 && kst != 2) continue;
1186 pxs += fPyjets->P[0][i];
1187 pys += fPyjets->P[1][i];
1188 pzs += fPyjets->P[2][i];
1189 es -= fPyjets->P[3][i];
1190 }
1191 if (TMath::Abs(pxs) > 1.e-2 ||
1192 TMath::Abs(pys) > 1.e-2 ||
1193 TMath::Abs(pzs) > 1.e-1) {
1194 printf("%e %e %e %e\n", pxs, pys, pzs, es);
4e383037 1195// Fatal("Quench()", "4-Momentum non-conservation");
452af8c7 1196 }
4e383037 1197
1198 } // end quenching loop (systems)
6e90ad26 1199// Clean-up
0f482ae4 1200 for (Int_t i = 0; i < numpart; i++)
1201 {
4e383037 1202 imo = fPyjets->K[2][i];
1203 if (imo > 1000) {
1204 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1205 }
0f482ae4 1206 }
4e383037 1207// this->Pylist(1);
0f482ae4 1208} // end quench
90d7b703 1209
992f2843 1210
1211void AliPythia::Pyquen(Double_t a, Int_t ibf, Double_t b)
1212{
1213 // Igor Lokthine's quenching routine
1214 pyquen(a, ibf, b);
1215}
b280c4cc 1216
1217void AliPythia::GetQuenchingParameters(Double_t& xp, Double_t& yp, Double_t z[4])
1218{
1219 // Return event specific quenching parameters
1220 xp = fXJet;
1221 yp = fYJet;
1222 for (Int_t i = 0; i < 4; i++) z[i] = fZQuench[i];
1223
1224}
1225