First commit of Igor Lokhtine's quenching routine.
[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;
1d5b1b20 68//...Switch off decay of pi0, K0S, Lambda, Sigma+-, Xi0-, Omega-.
69 SetMDCY(Pycomp(111) ,1,0);
70 SetMDCY(Pycomp(310) ,1,0);
71 SetMDCY(Pycomp(3122),1,0);
72 SetMDCY(Pycomp(3112),1,0);
73 SetMDCY(Pycomp(3212),1,0);
74 SetMDCY(Pycomp(3222),1,0);
75 SetMDCY(Pycomp(3312),1,0);
76 SetMDCY(Pycomp(3322),1,0);
77 SetMDCY(Pycomp(3334),1,0);
78 // select structure function
8d2cd130 79 SetMSTP(52,2);
80 SetMSTP(51,strucfunc);
81//
82// Pythia initialisation for selected processes//
83//
84// Make MSEL clean
85//
86 for (Int_t i=1; i<= 200; i++) {
87 SetMSUB(i,0);
88 }
89// select charm production
90 switch (process)
91 {
92 case kPyCharm:
93 SetMSEL(4);
94//
95// heavy quark masses
96
97 SetPMAS(4,1,1.2);
98 SetMSTU(16,2);
99//
100// primordial pT
101 SetMSTP(91,1);
102 SetPARP(91,1.);
103 SetPARP(93,5.);
104//
105 break;
106 case kPyBeauty:
107 SetMSEL(5);
108 SetPMAS(5,1,4.75);
109 SetMSTU(16,2);
110 break;
111 case kPyJpsi:
112 SetMSEL(0);
113// gg->J/Psi g
114 SetMSUB(86,1);
115 break;
116 case kPyJpsiChi:
117 SetMSEL(0);
118// gg->J/Psi g
119 SetMSUB(86,1);
120// gg-> chi_0c g
121 SetMSUB(87,1);
122// gg-> chi_1c g
123 SetMSUB(88,1);
124// gg-> chi_2c g
125 SetMSUB(89,1);
126 break;
127 case kPyCharmUnforced:
128 SetMSEL(0);
129// gq->qg
130 SetMSUB(28,1);
131// gg->qq
132 SetMSUB(53,1);
133// gg->gg
134 SetMSUB(68,1);
135 break;
136 case kPyBeautyUnforced:
137 SetMSEL(0);
138// gq->qg
139 SetMSUB(28,1);
140// gg->qq
141 SetMSUB(53,1);
142// gg->gg
143 SetMSUB(68,1);
144 break;
145 case kPyMb:
146// Minimum Bias pp-Collisions
147//
148//
149// select Pythia min. bias model
150 SetMSEL(0);
511db649 151 SetMSUB(92,1); // single diffraction AB-->XB
152 SetMSUB(93,1); // single diffraction AB-->AX
153 SetMSUB(94,1); // double diffraction
154 SetMSUB(95,1); // low pt production
155
156//
157// ATLAS Tuning
158//
c01c4118 159
160 SetMSTP(51, kCTEQ5L); // CTEQ5L pdf
511db649 161 SetMSTP(81,1); // Multiple Interactions ON
162 SetMSTP(82,4); // Double Gaussian Model
163
164 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
165 SetPARP(89,1000.); // [GeV] Ref. energy
166 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
167 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
168 SetPARP(84,0.5); // Core radius
169 SetPARP(85,0.33); // Regulates gluon prod. mechanism
170 SetPARP(86,0.66); // Regulates gluon prod. mechanism
171 SetPARP(67,1); // Regulates Initial State Radiation
172 break;
8d2cd130 173 case kPyMbNonDiffr:
174// Minimum Bias pp-Collisions
175//
176//
177// select Pythia min. bias model
178 SetMSEL(0);
511db649 179 SetMSUB(95,1); // low pt production
0f482ae4 180
181//
182// ATLAS Tuning
183//
511db649 184
d682afd1 185 SetMSTP(51,kCTEQ5L); // CTEQ5L pdf
511db649 186 SetMSTP(81,1); // Multiple Interactions ON
187 SetMSTP(82,4); // Double Gaussian Model
188
189 SetPARP(82,1.8); // [GeV] PT_min at Ref. energy
190 SetPARP(89,1000.); // [GeV] Ref. energy
191 SetPARP(90,0.16); // 2*epsilon (exponent in power law)
192 SetPARP(83,0.5); // Core density in proton matter distribution (def.value)
193 SetPARP(84,0.5); // Core radius
194 SetPARP(85,0.33); // Regulates gluon prod. mechanism
195 SetPARP(86,0.66); // Regulates gluon prod. mechanism
196 SetPARP(67,1); // Regulates Initial State Radiation
8d2cd130 197 break;
198 case kPyJets:
199//
200// QCD Jets
201//
202 SetMSEL(1);
203 break;
204 case kPyDirectGamma:
205 SetMSEL(10);
206 break;
adf4d898 207 case kPyCharmPbPbMNR:
208 case kPyD0PbPbMNR:
8d2cd130 209 // Tuning of Pythia parameters aimed to get a resonable agreement
210 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
211 // c-cbar single inclusive and double differential distributions.
212 // This parameter settings are meant to work with Pb-Pb collisions
adf4d898 213 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
8d2cd130 214 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
215 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
216
217 // All QCD processes
218 SetMSEL(1);
219
220 // No multiple interactions
221 SetMSTP(81,0);
222 SetPARP(81,0.0);
223 SetPARP(82,0.0);
224
225 // Initial/final parton shower on (Pythia default)
226 SetMSTP(61,1);
227 SetMSTP(71,1);
228
229 // 2nd order alpha_s
230 SetMSTP(2,2);
231
232 // QCD scales
233 SetMSTP(32,2);
234 SetPARP(34,1.0);
235
adf4d898 236 // Intrinsic <kT>
8d2cd130 237 SetMSTP(91,1);
238 SetPARP(91,1.304);
239 SetPARP(93,6.52);
240
241 // Set c-quark mass
242 SetPMAS(4,1,1.2);
243
90d7b703 244 break;
245 case kPyDPlusPbPbMNR:
246 // Tuning of Pythia parameters aimed to get a resonable agreement
247 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
248 // c-cbar single inclusive and double differential distributions.
249 // This parameter settings are meant to work with Pb-Pb collisions
250 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
251 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
252 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
253
254 // All QCD processes
255 SetMSEL(1);
256
257 // No multiple interactions
258 SetMSTP(81,0);
259 SetPARP(81,0.0);
260 SetPARP(82,0.0);
261
262 // Initial/final parton shower on (Pythia default)
263 SetMSTP(61,1);
264 SetMSTP(71,1);
265
266 // 2nd order alpha_s
267 SetMSTP(2,2);
268
269 // QCD scales
270 SetMSTP(32,2);
271 SetPARP(34,1.0);
272
273 // Intrinsic <kT>
274 SetMSTP(91,1);
275 SetPARP(91,1.304);
276 SetPARP(93,6.52);
277
278 // Set c-quark mass
279 SetPMAS(4,1,1.2);
280
8d2cd130 281 break;
adf4d898 282 case kPyCharmpPbMNR:
283 case kPyD0pPbMNR:
284 // Tuning of Pythia parameters aimed to get a resonable agreement
285 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
286 // c-cbar single inclusive and double differential distributions.
287 // This parameter settings are meant to work with p-Pb collisions
288 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
289 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
290 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
291
292 // All QCD processes
293 SetMSEL(1);
294
295 // No multiple interactions
296 SetMSTP(81,0);
297 SetPARP(81,0.0);
298 SetPARP(82,0.0);
299
300 // Initial/final parton shower on (Pythia default)
301 SetMSTP(61,1);
302 SetMSTP(71,1);
303
304 // 2nd order alpha_s
305 SetMSTP(2,2);
306
307 // QCD scales
308 SetMSTP(32,2);
309 SetPARP(34,1.0);
310
311 // Intrinsic <kT>
312 SetMSTP(91,1);
313 SetPARP(91,1.16);
314 SetPARP(93,5.8);
315
316 // Set c-quark mass
317 SetPMAS(4,1,1.2);
318
90d7b703 319 break;
320 case kPyDPluspPbMNR:
321 // Tuning of Pythia parameters aimed to get a resonable agreement
322 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
323 // c-cbar single inclusive and double differential distributions.
324 // This parameter settings are meant to work with p-Pb collisions
325 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
326 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
327 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
328
329 // All QCD processes
330 SetMSEL(1);
331
332 // No multiple interactions
333 SetMSTP(81,0);
334 SetPARP(81,0.0);
335 SetPARP(82,0.0);
336
337 // Initial/final parton shower on (Pythia default)
338 SetMSTP(61,1);
339 SetMSTP(71,1);
340
341 // 2nd order alpha_s
342 SetMSTP(2,2);
343
344 // QCD scales
345 SetMSTP(32,2);
346 SetPARP(34,1.0);
347
348 // Intrinsic <kT>
349 SetMSTP(91,1);
350 SetPARP(91,1.16);
351 SetPARP(93,5.8);
352
353 // Set c-quark mass
354 SetPMAS(4,1,1.2);
355
adf4d898 356 break;
357 case kPyCharmppMNR:
358 case kPyD0ppMNR:
359 // Tuning of Pythia parameters aimed to get a resonable agreement
360 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
361 // c-cbar single inclusive and double differential distributions.
362 // This parameter settings are meant to work with pp collisions
363 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
364 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
365 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
366
367 // All QCD processes
368 SetMSEL(1);
369
370 // No multiple interactions
371 SetMSTP(81,0);
372 SetPARP(81,0.0);
373 SetPARP(82,0.0);
374
375 // Initial/final parton shower on (Pythia default)
376 SetMSTP(61,1);
377 SetMSTP(71,1);
378
379 // 2nd order alpha_s
380 SetMSTP(2,2);
381
382 // QCD scales
383 SetMSTP(32,2);
384 SetPARP(34,1.0);
385
386 // Intrinsic <kT^2>
387 SetMSTP(91,1);
388 SetPARP(91,1.);
389 SetPARP(93,5.);
390
391 // Set c-quark mass
392 SetPMAS(4,1,1.2);
393
90d7b703 394 break;
395 case kPyDPlusppMNR:
396 // Tuning of Pythia parameters aimed to get a resonable agreement
397 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
398 // c-cbar single inclusive and double differential distributions.
399 // This parameter settings are meant to work with pp collisions
400 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
401 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
402 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
403
404 // All QCD processes
405 SetMSEL(1);
406
407 // No multiple interactions
408 SetMSTP(81,0);
409 SetPARP(81,0.0);
410 SetPARP(82,0.0);
411
412 // Initial/final parton shower on (Pythia default)
413 SetMSTP(61,1);
414 SetMSTP(71,1);
415
416 // 2nd order alpha_s
417 SetMSTP(2,2);
418
419 // QCD scales
420 SetMSTP(32,2);
421 SetPARP(34,1.0);
422
423 // Intrinsic <kT^2>
424 SetMSTP(91,1);
425 SetPARP(91,1.);
426 SetPARP(93,5.);
427
428 // Set c-quark mass
429 SetPMAS(4,1,1.2);
430
adf4d898 431 break;
432 case kPyBeautyPbPbMNR:
8d2cd130 433 // Tuning of Pythia parameters aimed to get a resonable agreement
434 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
435 // b-bbar single inclusive and double differential distributions.
436 // This parameter settings are meant to work with Pb-Pb collisions
437 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
438 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
439 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
440
441 // All QCD processes
442 SetMSEL(1);
443
444 // No multiple interactions
445 SetMSTP(81,0);
446 SetPARP(81,0.0);
447 SetPARP(82,0.0);
448
449 // Initial/final parton shower on (Pythia default)
450 SetMSTP(61,1);
451 SetMSTP(71,1);
452
453 // 2nd order alpha_s
454 SetMSTP(2,2);
455
456 // QCD scales
457 SetMSTP(32,2);
458 SetPARP(34,1.0);
459 SetPARP(67,1.0);
460 SetPARP(71,1.0);
461
adf4d898 462 // Intrinsic <kT>
8d2cd130 463 SetMSTP(91,1);
464 SetPARP(91,2.035);
465 SetPARP(93,10.17);
466
467 // Set b-quark mass
468 SetPMAS(5,1,4.75);
469
adf4d898 470 break;
471 case kPyBeautypPbMNR:
472 // Tuning of Pythia parameters aimed to get a resonable agreement
473 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
474 // b-bbar single inclusive and double differential distributions.
475 // This parameter settings are meant to work with p-Pb collisions
476 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
477 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
478 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
479
480 // All QCD processes
481 SetMSEL(1);
482
483 // No multiple interactions
484 SetMSTP(81,0);
485 SetPARP(81,0.0);
486 SetPARP(82,0.0);
487
488 // Initial/final parton shower on (Pythia default)
489 SetMSTP(61,1);
490 SetMSTP(71,1);
491
492 // 2nd order alpha_s
493 SetMSTP(2,2);
494
495 // QCD scales
496 SetMSTP(32,2);
497 SetPARP(34,1.0);
498 SetPARP(67,1.0);
499 SetPARP(71,1.0);
500
501 // Intrinsic <kT>
502 SetMSTP(91,1);
503 SetPARP(91,1.60);
504 SetPARP(93,8.00);
505
506 // Set b-quark mass
507 SetPMAS(5,1,4.75);
508
509 break;
510 case kPyBeautyppMNR:
511 // Tuning of Pythia parameters aimed to get a resonable agreement
512 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
513 // b-bbar single inclusive and double differential distributions.
514 // This parameter settings are meant to work with pp collisions
515 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
516 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
517 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
518
519 // All QCD processes
520 SetMSEL(1);
521
522 // No multiple interactions
523 SetMSTP(81,0);
524 SetPARP(81,0.0);
525 SetPARP(82,0.0);
526
527 // Initial/final parton shower on (Pythia default)
528 SetMSTP(61,1);
529 SetMSTP(71,1);
530
531 // 2nd order alpha_s
532 SetMSTP(2,2);
533
534 // QCD scales
535 SetMSTP(32,2);
536 SetPARP(34,1.0);
537 SetPARP(67,1.0);
538 SetPARP(71,1.0);
539
540 // Intrinsic <kT>
541 SetMSTP(91,1);
542 SetPARP(91,1.);
543 SetPARP(93,5.);
544
545 // Set b-quark mass
546 SetPMAS(5,1,4.75);
547
8d2cd130 548 break;
549 }
550//
551// Initialize PYTHIA
552 SetMSTP(41,1); // all resonance decays switched on
553
554 Initialize("CMS","p","p",fEcms);
555
556}
557
558Int_t AliPythia::CheckedLuComp(Int_t kf)
559{
560// Check Lund particle code (for debugging)
561 Int_t kc=Pycomp(kf);
562 printf("\n Lucomp kf,kc %d %d",kf,kc);
563 return kc;
564}
565
566void AliPythia::SetNuclei(Int_t a1, Int_t a2)
567{
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
577 SetMSTP(52,2);
578 SetMSTP(192, a1);
579 SetMSTP(193, a2);
580}
581
582
583AliPythia* AliPythia::Instance()
584{
585// Set random number generator
586 if (fgAliPythia) {
587 return fgAliPythia;
588 } else {
589 fgAliPythia = new AliPythia();
590 return fgAliPythia;
591 }
592}
593
594void AliPythia::PrintParticles()
595{
596// Print list of particl properties
597 Int_t np = 0;
c31f1d37 598 char* name = new char[16];
8d2cd130 599 for (Int_t kf=0; kf<1000000; kf++) {
600 for (Int_t c = 1; c > -2; c-=2) {
8d2cd130 601 Int_t kc = Pycomp(c*kf);
602 if (kc) {
603 Float_t mass = GetPMAS(kc,1);
604 Float_t width = GetPMAS(kc,2);
605 Float_t tau = GetPMAS(kc,4);
c31f1d37 606
8d2cd130 607 Pyname(kf,name);
608
609 np++;
610
611 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
612 c*kf, name, mass, width, tau);
613 }
614 }
615 }
616 printf("\n Number of particles %d \n \n", np);
617}
618
619void AliPythia::ResetDecayTable()
620{
621// Set default values for pythia decay switches
622 Int_t i;
623 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
624 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
625}
626
627void AliPythia::SetDecayTable()
628{
629// Set default values for pythia decay switches
630//
631 Int_t i;
632 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
633 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
634}
635
636void AliPythia::Pyclus(Int_t& njet)
637{
638// Call Pythia clustering algorithm
639//
640 pyclus(njet);
641}
642
643void AliPythia::Pycell(Int_t& njet)
644{
645// Call Pythia jet reconstruction algorithm
646//
647 pycell(njet);
648}
649
452af8c7 650void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
651{
652// Call Pythia jet reconstruction algorithm
653//
452af8c7 654 pyshow(ip1, ip2, qmax);
655}
656
657void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
658{
659 pyrobo(imi, ima, the, phi, bex, bey, bez);
660}
661
662
663
86b6ad68 664void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t k, Int_t iECMethod)
0f482ae4 665{
666// Initializes
667// (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
668// (2) The nuclear geometry using the Glauber Model
669//
670
671
672 fGlauber = new AliFastGlauber();
673 fGlauber->Init(2);
674 fGlauber->SetCentralityClass(cMin, cMax);
675
676 fQuenchingWeights = new AliQuenchingWeights();
677 fQuenchingWeights->InitMult();
86b6ad68 678 fQuenchingWeights->SetK(k);
0f482ae4 679 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
0f482ae4 680}
681
682
452af8c7 683void AliPythia::Quench()
684{
685//
686//
687// Simple Jet Quenching routine:
688// =============================
689// The jet formed by all final state partons radiated by the parton created
0f482ae4 690// in the hard collisions is quenched by a factor (1-z) using light cone variables in
691// the initial parton reference frame:
452af8c7 692// (E + p_z)new = (1-z) (E + p_z)old
693//
0f482ae4 694//
695//
696//
452af8c7 697// The lost momentum is first balanced by one gluon with virtuality > 0.
698// Subsequently the gluon splits to yield two gluons with E = p.
699//
0f482ae4 700//
701//
4e383037 702 static Float_t eMean = 0.;
703 static Int_t icall = 0;
0f482ae4 704
c2c598a3 705 Double_t p0[4][5];
706 Double_t p1[4][5];
707 Double_t p2[4][5];
708 Int_t klast[4] = {-1, -1, -1, -1};
452af8c7 709
710 Int_t numpart = fPyjets->N;
86b6ad68 711 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0., phi = 0.;
c2c598a3 712 Double_t pxq[4], pyq[4], pzq[4], eq[4], yq[4], mq[4], pq[4], phiq[4], thetaq[4], ptq[4];
713 Bool_t quenched[4];
c2c598a3 714 Double_t zInitial[4], wjtKick[4];
715 Int_t nGluon[4];
86b6ad68 716 Int_t qPdg[4];
0f482ae4 717 Int_t imo, kst, pdg;
511db649 718//
c2c598a3 719// Sore information about Primary partons
720//
721// j =
722// 0, 1 partons from hard scattering
723// 2, 3 partons from initial state radiation
724//
725 for (Int_t i = 2; i <= 7; i++) {
726 Int_t j = 0;
727 // Skip gluons that participate in hard scattering
728 if (i == 4 || i == 5) continue;
729 // Gluons from hard Scattering
730 if (i == 6 || i == 7) {
731 j = i - 6;
732 pxq[j] = fPyjets->P[0][i];
733 pyq[j] = fPyjets->P[1][i];
734 pzq[j] = fPyjets->P[2][i];
735 eq[j] = fPyjets->P[3][i];
736 mq[j] = fPyjets->P[4][i];
737 } else {
738 // Gluons from initial state radiation
739 //
740 // Obtain 4-momentum vector from difference between original parton and parton after gluon
741 // radiation. Energy is calculated independently because initial state radition does not
742 // conserve strictly momentum and energy for each partonic system independently.
743 //
744 // Not very clean. Should be improved !
745 //
746 //
747 j = i;
748 pxq[j] = fPyjets->P[0][i] - fPyjets->P[0][i+2];
749 pyq[j] = fPyjets->P[1][i] - fPyjets->P[1][i+2];
750 pzq[j] = fPyjets->P[2][i] - fPyjets->P[2][i+2];
751 mq[j] = fPyjets->P[4][i];
752 eq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j] + mq[j] * mq[j]);
753 }
754//
755// Calculate some kinematic variables
511db649 756//
4e383037 757 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
0f482ae4 758 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
759 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
760 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
761 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
86b6ad68 762 qPdg[j] = fPyjets->K[1][i];
763 }
764
765 Double_t int0[4];
766 Double_t int1[4];
767
768 fGlauber->GetI0I1ForPythia(4, phiq, int0, int1, 15.);
769
770 for (Int_t j = 0; j < 4; j++) {
c2c598a3 771 //
772 // Quench only central jets and with E > 10.
773 //
86b6ad68 774
775
776 Int_t itype = (qPdg[j] == 21) ? 2 : 1;
777 Double_t eloss = fQuenchingWeights->GetELossRandomKFast(itype, int0[j], int1[j], eq[j]);
778
c2c598a3 779 if (TMath::Abs(yq[j]) > 2.5 || eq[j] < 10.) {
0f482ae4 780 zInitial[j] = 0.;
781 } else {
c2c598a3 782 if (eq[j] > 40. && TMath::Abs(yq[j]) < 0.5) {
4e383037 783 icall ++;
784 eMean += eloss;
785 }
0f482ae4 786 //
787 // Extra pt
86b6ad68 788 Double_t l = fQuenchingWeights->CalcLk(int0[j], int1[j]);
789 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->CalcQk(int0[j], int1[j]));
0f482ae4 790 //
791 // Fractional energy loss
792 zInitial[j] = eloss / eq[j];
793 //
794 // Avoid complete loss
795 //
796 if (zInitial[j] == 1.) zInitial[j] = 0.95;
797 //
798 // Some debug printing
86b6ad68 799
800
bf9bb016 801// 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",
802// j, itype, eq[j], phiq[j], l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
4e383037 803
c2c598a3 804// zInitial[j] = 0.8;
805// while (zInitial[j] >= 0.95) zInitial[j] = gRandom->Exp(0.2);
0f482ae4 806 }
4e383037 807
0f482ae4 808 quenched[j] = (zInitial[j] > 0.01);
4e383037 809 } // primary partons
c2c598a3 810
6e90ad26 811 Double_t pNew[1000][4];
812 Int_t kNew[1000];
813 Int_t icount = 0;
814//
4e383037 815// System Loop
c2c598a3 816 for (Int_t isys = 0; isys < 4; isys++) {
6e90ad26 817// Skip to next system if not quenched.
4e383037 818 if (!quenched[isys]) continue;
819
820 nGluon[isys] = 1 + Int_t(zInitial[isys] / (1. - zInitial[isys]));
821 if (nGluon[isys] > 6) nGluon[isys] = 6;
822 zInitial[isys] = 1. - TMath::Power(1. - zInitial[isys], 1./Double_t(nGluon[isys]));
823 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
0f482ae4 824
4e383037 825
826
827 Int_t igMin = -1;
828 Int_t igMax = -1;
829 Double_t pg[4] = {0., 0., 0., 0.};
830
831//
832// Loop on radiation events
833
834 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
6e90ad26 835 while (1) {
836 icount = 0;
837 for (Int_t k = 0; k < 4; k++)
838 {
839 p0[isys][k] = 0.;
840 p1[isys][k] = 0.;
841 p2[isys][k] = 0.;
842 }
843// Loop over partons
844 for (Int_t i = 0; i < numpart; i++)
845 {
846 imo = fPyjets->K[2][i];
847 kst = fPyjets->K[0][i];
848 pdg = fPyjets->K[1][i];
849
850
851
0f482ae4 852// Quarks and gluons only
6e90ad26 853 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
0f482ae4 854// Particles from hard scattering only
c2c598a3 855
6e90ad26 856 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
c2c598a3 857 Int_t imom = imo % 1000;
858 if ((isys == 0 || isys == 1) && ((imom != (isys + 7)))) continue;
859 if ((isys == 2 || isys == 3) && ((imom != (isys + 1)))) continue;
860
6e90ad26 861
0f482ae4 862// Skip comment lines
6e90ad26 863 if (kst != 1 && kst != 2) continue;
0f482ae4 864//
865// Parton kinematic
6e90ad26 866 px = fPyjets->P[0][i];
867 py = fPyjets->P[1][i];
868 pz = fPyjets->P[2][i];
869 e = fPyjets->P[3][i];
870 m = fPyjets->P[4][i];
871 pt = TMath::Sqrt(px * px + py * py);
872 p = TMath::Sqrt(px * px + py * py + pz * pz);
873 phi = TMath::Pi() + TMath::ATan2(-py, -px);
874 theta = TMath::ATan2(pt, pz);
875
0f482ae4 876//
c2c598a3 877// Save 4-momentum sum for balancing
878 Int_t index = isys;
6e90ad26 879
880 p0[index][0] += px;
881 p0[index][1] += py;
882 p0[index][2] += pz;
883 p0[index][3] += e;
6e90ad26 884
885 klast[index] = i;
886
0f482ae4 887//
888// Fractional energy loss
6e90ad26 889 Double_t z = zInitial[index];
4e383037 890
c2c598a3 891
4e383037 892// Don't fully quench radiated gluons
893//
894 if (imo > 1000) {
895// This small factor makes sure that the gluons are not too close in phase space to avoid recombination
896//
897
c2c598a3 898 z = 0.02;
4e383037 899 }
c2c598a3 900// printf("z: %d %f\n", imo, z);
901
4e383037 902
903//
6e90ad26 904
905 //
906 //
907 // Transform into frame in which initial parton is along z-axis
908 //
909 TVector3 v(px, py, pz);
910 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
911 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
912
913 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
914 Double_t mt2 = jt * jt + m * m;
915 Double_t zmax = 1.;
916 //
917 // Kinematic limit on z
918 //
4e383037 919 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
6e90ad26 920 //
921 // Change light-cone kinematics rel. to initial parton
922 //
923 Double_t eppzOld = e + pl;
924 Double_t empzOld = e - pl;
925
926 Double_t eppzNew = (1. - z) * eppzOld;
927 Double_t empzNew = empzOld - mt2 * z / eppzOld;
928 Double_t eNew = 0.5 * (eppzNew + empzNew);
929 Double_t plNew = 0.5 * (eppzNew - empzNew);
930
931 Double_t jtNew;
932 //
933 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
934 Double_t mt2New = eppzNew * empzNew;
935 if (mt2New < 1.e-8) mt2New = 0.;
4e383037 936 if (z < zmax) {
937 if (m * m > mt2New) {
938 //
939 // This should not happen
940 //
941 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
942 jtNew = 0;
943 } else {
944 jtNew = TMath::Sqrt(mt2New - m * m);
945 }
6e90ad26 946 } else {
4e383037 947 // If pT is to small (probably a leading massive particle) we scale only the energy
948 // This can cause negative masses of the radiated gluon
949 // Let's hope for the best ...
950 jtNew = jt;
951 eNew = TMath::Sqrt(plNew * plNew + mt2);
952
6e90ad26 953 }
6e90ad26 954 //
955 // Calculate new px, py
956 //
957 Double_t pxNew = jtNew / jt * pxs;
958 Double_t pyNew = jtNew / jt * pys;
959
960// Double_t dpx = pxs - pxNew;
961// Double_t dpy = pys - pyNew;
962// Double_t dpz = pl - plNew;
963// Double_t de = e - eNew;
964// Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
965// printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
966// printf("New mass (2) %e %e \n", pxNew, pyNew);
967 //
968 // Rotate back
969 //
970 TVector3 w(pxNew, pyNew, plNew);
971 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
972 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
973
974 p1[index][0] += pxNew;
975 p1[index][1] += pyNew;
976 p1[index][2] += plNew;
977 p1[index][3] += eNew;
978 //
979 // Updated 4-momentum vectors
980 //
981 pNew[icount][0] = pxNew;
982 pNew[icount][1] = pyNew;
983 pNew[icount][2] = plNew;
984 pNew[icount][3] = eNew;
985 kNew[icount] = i;
986 icount++;
987 } // parton loop
0f482ae4 988 //
6e90ad26 989 // Check if there was phase-space for quenching
0f482ae4 990 //
0f482ae4 991
6e90ad26 992 if (icount == 0) quenched[isys] = kFALSE;
993 if (!quenched[isys]) break;
994
995 for (Int_t j = 0; j < 4; j++)
996 {
997 p2[isys][j] = p0[isys][j] - p1[isys][j];
998 }
999 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 1000 if (p2[isys][4] > 0.) {
1001 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
1002 break;
1003 } else {
1004 printf("Warning negative mass squared in system %d %f ! \n", isys, zInitial[isys]);
4e383037 1005 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 1006 if (p2[isys][4] < -0.01) {
4e383037 1007 printf("Negative mass squared !\n");
1008 // Here we have to put the gluon back to mass shell
1009 // This will lead to a small energy imbalance
1010 p2[isys][4] = 0.;
1011 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
1012 break;
6e90ad26 1013 } else {
1014 p2[isys][4] = 0.;
1015 break;
1016 }
1017 }
6e90ad26 1018 /*
6e90ad26 1019 zHeavy *= 0.98;
1020 printf("zHeavy lowered to %f\n", zHeavy);
1021 if (zHeavy < 0.01) {
1022 printf("No success ! \n");
1023 icount = 0;
1024 quenched[isys] = kFALSE;
1025 break;
1026 }
4e383037 1027 */
1028 } // iteration on z (while)
1029
6e90ad26 1030// Update event record
1031 for (Int_t k = 0; k < icount; k++) {
1032// 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] );
1033 fPyjets->P[0][kNew[k]] = pNew[k][0];
1034 fPyjets->P[1][kNew[k]] = pNew[k][1];
1035 fPyjets->P[2][kNew[k]] = pNew[k][2];
1036 fPyjets->P[3][kNew[k]] = pNew[k][3];
0f482ae4 1037 }
4e383037 1038 //
1039 // Add the gluons
1040 //
1041 Int_t ish = 0;
1837e95c 1042 Int_t iGlu;
4e383037 1043 if (!quenched[isys]) continue;
0f482ae4 1044//
1045// Last parton from shower i
4e383037 1046 Int_t in = klast[isys];
0f482ae4 1047//
1048// Continue if no parton in shower i selected
1049 if (in == -1) continue;
1050//
1051// If this is the second initial parton and it is behind the first move pointer by previous ish
4e383037 1052 if (isys == 1 && klast[1] > klast[0]) in += ish;
0f482ae4 1053//
1054// Starting index
452af8c7 1055
4e383037 1056// jmin = in - 1;
0f482ae4 1057// How many additional gluons will be generated
1058 ish = 1;
4e383037 1059 if (p2[isys][4] > 0.05) ish = 2;
0f482ae4 1060//
1061// Position of gluons
4e383037 1062 iGlu = numpart;
1063 if (iglu == 0) igMin = iGlu;
1064 igMax = iGlu;
0f482ae4 1065 numpart += ish;
1066 (fPyjets->N) += ish;
4e383037 1067
0f482ae4 1068 if (ish == 1) {
4e383037 1069 fPyjets->P[0][iGlu] = p2[isys][0];
1070 fPyjets->P[1][iGlu] = p2[isys][1];
1071 fPyjets->P[2][iGlu] = p2[isys][2];
1072 fPyjets->P[3][iGlu] = p2[isys][3];
1073 fPyjets->P[4][iGlu] = p2[isys][4];
0f482ae4 1074
4e383037 1075 fPyjets->K[0][iGlu] = 1;
1076 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
0f482ae4 1077 fPyjets->K[1][iGlu] = 21;
4e383037 1078 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
0f482ae4 1079 fPyjets->K[3][iGlu] = -1;
1080 fPyjets->K[4][iGlu] = -1;
4e383037 1081
1082 pg[0] += p2[isys][0];
1083 pg[1] += p2[isys][1];
1084 pg[2] += p2[isys][2];
1085 pg[3] += p2[isys][3];
0f482ae4 1086 } else {
1087 //
1088 // Split gluon in rest frame.
1089 //
4e383037 1090 Double_t bx = p2[isys][0] / p2[isys][3];
1091 Double_t by = p2[isys][1] / p2[isys][3];
1092 Double_t bz = p2[isys][2] / p2[isys][3];
1093 Double_t pst = p2[isys][4] / 2.;
0f482ae4 1094 //
1095 // Isotropic decay ????
1096 Double_t cost = 2. * gRandom->Rndm() - 1.;
1097 Double_t sint = TMath::Sqrt(1. - cost * cost);
1098 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1099
1100 Double_t pz1 = pst * cost;
1101 Double_t pz2 = -pst * cost;
1102 Double_t pt1 = pst * sint;
1103 Double_t pt2 = -pst * sint;
1104 Double_t px1 = pt1 * TMath::Cos(phi);
1105 Double_t py1 = pt1 * TMath::Sin(phi);
1106 Double_t px2 = pt2 * TMath::Cos(phi);
1107 Double_t py2 = pt2 * TMath::Sin(phi);
1108
1109 fPyjets->P[0][iGlu] = px1;
1110 fPyjets->P[1][iGlu] = py1;
1111 fPyjets->P[2][iGlu] = pz1;
1112 fPyjets->P[3][iGlu] = pst;
1113 fPyjets->P[4][iGlu] = 0.;
1114
4e383037 1115 fPyjets->K[0][iGlu] = 1 ;
0f482ae4 1116 fPyjets->K[1][iGlu] = 21;
4e383037 1117 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
0f482ae4 1118 fPyjets->K[3][iGlu] = -1;
1119 fPyjets->K[4][iGlu] = -1;
1120
1121 fPyjets->P[0][iGlu+1] = px2;
1122 fPyjets->P[1][iGlu+1] = py2;
1123 fPyjets->P[2][iGlu+1] = pz2;
1124 fPyjets->P[3][iGlu+1] = pst;
1125 fPyjets->P[4][iGlu+1] = 0.;
1126
4e383037 1127 fPyjets->K[0][iGlu+1] = 1;
1128 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
0f482ae4 1129 fPyjets->K[1][iGlu+1] = 21;
4e383037 1130 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
0f482ae4 1131 fPyjets->K[3][iGlu+1] = -1;
1132 fPyjets->K[4][iGlu+1] = -1;
1133 SetMSTU(1,0);
1134 SetMSTU(2,0);
1135 //
1136 // Boost back
1137 //
1138 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1139 }
4e383037 1140/*
1141 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1142 Double_t px, py, pz;
1143 px = fPyjets->P[0][ig];
1144 py = fPyjets->P[1][ig];
1145 pz = fPyjets->P[2][ig];
1146 TVector3 v(px, py, pz);
1147 v.RotateZ(-phiq[isys]);
1148 v.RotateY(-thetaq[isys]);
1149 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1150 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1151 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1152 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1153 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1154 pxs += jtKick * TMath::Cos(phiKick);
1155 pys += jtKick * TMath::Sin(phiKick);
1156 TVector3 w(pxs, pys, pzs);
1157 w.RotateY(thetaq[isys]);
1158 w.RotateZ(phiq[isys]);
1159 fPyjets->P[0][ig] = w.X();
1160 fPyjets->P[1][ig] = w.Y();
1161 fPyjets->P[2][ig] = w.Z();
1162 fPyjets->P[2][ig] = w.Mag();
1163 }
1164*/
1165 } // kGluon
1166
6e90ad26 1167
4e383037 1168 // Check energy conservation
0f482ae4 1169 Double_t pxs = 0.;
1170 Double_t pys = 0.;
1171 Double_t pzs = 0.;
1172 Double_t es = 14000.;
1173
1174 for (Int_t i = 0; i < numpart; i++)
1175 {
1176 kst = fPyjets->K[0][i];
1177 if (kst != 1 && kst != 2) continue;
1178 pxs += fPyjets->P[0][i];
1179 pys += fPyjets->P[1][i];
1180 pzs += fPyjets->P[2][i];
1181 es -= fPyjets->P[3][i];
1182 }
1183 if (TMath::Abs(pxs) > 1.e-2 ||
1184 TMath::Abs(pys) > 1.e-2 ||
1185 TMath::Abs(pzs) > 1.e-1) {
1186 printf("%e %e %e %e\n", pxs, pys, pzs, es);
4e383037 1187// Fatal("Quench()", "4-Momentum non-conservation");
452af8c7 1188 }
4e383037 1189
1190 } // end quenching loop (systems)
6e90ad26 1191// Clean-up
0f482ae4 1192 for (Int_t i = 0; i < numpart; i++)
1193 {
4e383037 1194 imo = fPyjets->K[2][i];
1195 if (imo > 1000) {
1196 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1197 }
0f482ae4 1198 }
4e383037 1199// this->Pylist(1);
0f482ae4 1200} // end quench
90d7b703 1201