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[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_
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
90d7b703 235 break;
236 case kPyDPlusPbPbMNR:
237 // Tuning of Pythia parameters aimed to get a resonable agreement
238 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
239 // c-cbar single inclusive and double differential distributions.
240 // This parameter settings are meant to work with Pb-Pb collisions
241 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
242 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
243 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
244
245 // All QCD processes
246 SetMSEL(1);
247
248 // No multiple interactions
249 SetMSTP(81,0);
250 SetPARP(81,0.0);
251 SetPARP(82,0.0);
252
253 // Initial/final parton shower on (Pythia default)
254 SetMSTP(61,1);
255 SetMSTP(71,1);
256
257 // 2nd order alpha_s
258 SetMSTP(2,2);
259
260 // QCD scales
261 SetMSTP(32,2);
262 SetPARP(34,1.0);
263
264 // Intrinsic <kT>
265 SetMSTP(91,1);
266 SetPARP(91,1.304);
267 SetPARP(93,6.52);
268
269 // Set c-quark mass
270 SetPMAS(4,1,1.2);
271
8d2cd130 272 break;
adf4d898 273 case kPyCharmpPbMNR:
274 case kPyD0pPbMNR:
275 // Tuning of Pythia parameters aimed to get a resonable agreement
276 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
277 // c-cbar single inclusive and double differential distributions.
278 // This parameter settings are meant to work with p-Pb collisions
279 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
280 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
281 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
282
283 // All QCD processes
284 SetMSEL(1);
285
286 // No multiple interactions
287 SetMSTP(81,0);
288 SetPARP(81,0.0);
289 SetPARP(82,0.0);
290
291 // Initial/final parton shower on (Pythia default)
292 SetMSTP(61,1);
293 SetMSTP(71,1);
294
295 // 2nd order alpha_s
296 SetMSTP(2,2);
297
298 // QCD scales
299 SetMSTP(32,2);
300 SetPARP(34,1.0);
301
302 // Intrinsic <kT>
303 SetMSTP(91,1);
304 SetPARP(91,1.16);
305 SetPARP(93,5.8);
306
307 // Set c-quark mass
308 SetPMAS(4,1,1.2);
309
90d7b703 310 break;
311 case kPyDPluspPbMNR:
312 // Tuning of Pythia parameters aimed to get a resonable agreement
313 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
314 // c-cbar single inclusive and double differential distributions.
315 // This parameter settings are meant to work with p-Pb collisions
316 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
317 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
318 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
319
320 // All QCD processes
321 SetMSEL(1);
322
323 // No multiple interactions
324 SetMSTP(81,0);
325 SetPARP(81,0.0);
326 SetPARP(82,0.0);
327
328 // Initial/final parton shower on (Pythia default)
329 SetMSTP(61,1);
330 SetMSTP(71,1);
331
332 // 2nd order alpha_s
333 SetMSTP(2,2);
334
335 // QCD scales
336 SetMSTP(32,2);
337 SetPARP(34,1.0);
338
339 // Intrinsic <kT>
340 SetMSTP(91,1);
341 SetPARP(91,1.16);
342 SetPARP(93,5.8);
343
344 // Set c-quark mass
345 SetPMAS(4,1,1.2);
346
adf4d898 347 break;
348 case kPyCharmppMNR:
349 case kPyD0ppMNR:
350 // Tuning of Pythia parameters aimed to get a resonable agreement
351 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
352 // c-cbar single inclusive and double differential distributions.
353 // This parameter settings are meant to work with pp collisions
354 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
355 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
356 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
357
358 // All QCD processes
359 SetMSEL(1);
360
361 // No multiple interactions
362 SetMSTP(81,0);
363 SetPARP(81,0.0);
364 SetPARP(82,0.0);
365
366 // Initial/final parton shower on (Pythia default)
367 SetMSTP(61,1);
368 SetMSTP(71,1);
369
370 // 2nd order alpha_s
371 SetMSTP(2,2);
372
373 // QCD scales
374 SetMSTP(32,2);
375 SetPARP(34,1.0);
376
377 // Intrinsic <kT^2>
378 SetMSTP(91,1);
379 SetPARP(91,1.);
380 SetPARP(93,5.);
381
382 // Set c-quark mass
383 SetPMAS(4,1,1.2);
384
90d7b703 385 break;
386 case kPyDPlusppMNR:
387 // Tuning of Pythia parameters aimed to get a resonable agreement
388 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
389 // c-cbar single inclusive and double differential distributions.
390 // This parameter settings are meant to work with pp collisions
391 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
392 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
393 // has to be set to 2.1GeV. Example in ConfigCharmPPR.C.
394
395 // All QCD processes
396 SetMSEL(1);
397
398 // No multiple interactions
399 SetMSTP(81,0);
400 SetPARP(81,0.0);
401 SetPARP(82,0.0);
402
403 // Initial/final parton shower on (Pythia default)
404 SetMSTP(61,1);
405 SetMSTP(71,1);
406
407 // 2nd order alpha_s
408 SetMSTP(2,2);
409
410 // QCD scales
411 SetMSTP(32,2);
412 SetPARP(34,1.0);
413
414 // Intrinsic <kT^2>
415 SetMSTP(91,1);
416 SetPARP(91,1.);
417 SetPARP(93,5.);
418
419 // Set c-quark mass
420 SetPMAS(4,1,1.2);
421
adf4d898 422 break;
423 case kPyBeautyPbPbMNR:
8d2cd130 424 // Tuning of Pythia parameters aimed to get a resonable agreement
425 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
426 // b-bbar single inclusive and double differential distributions.
427 // This parameter settings are meant to work with Pb-Pb collisions
428 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
429 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
430 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
431
432 // All QCD processes
433 SetMSEL(1);
434
435 // No multiple interactions
436 SetMSTP(81,0);
437 SetPARP(81,0.0);
438 SetPARP(82,0.0);
439
440 // Initial/final parton shower on (Pythia default)
441 SetMSTP(61,1);
442 SetMSTP(71,1);
443
444 // 2nd order alpha_s
445 SetMSTP(2,2);
446
447 // QCD scales
448 SetMSTP(32,2);
449 SetPARP(34,1.0);
450 SetPARP(67,1.0);
451 SetPARP(71,1.0);
452
adf4d898 453 // Intrinsic <kT>
8d2cd130 454 SetMSTP(91,1);
455 SetPARP(91,2.035);
456 SetPARP(93,10.17);
457
458 // Set b-quark mass
459 SetPMAS(5,1,4.75);
460
adf4d898 461 break;
462 case kPyBeautypPbMNR:
463 // Tuning of Pythia parameters aimed to get a resonable agreement
464 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
465 // b-bbar single inclusive and double differential distributions.
466 // This parameter settings are meant to work with p-Pb collisions
467 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
468 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
469 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
470
471 // All QCD processes
472 SetMSEL(1);
473
474 // No multiple interactions
475 SetMSTP(81,0);
476 SetPARP(81,0.0);
477 SetPARP(82,0.0);
478
479 // Initial/final parton shower on (Pythia default)
480 SetMSTP(61,1);
481 SetMSTP(71,1);
482
483 // 2nd order alpha_s
484 SetMSTP(2,2);
485
486 // QCD scales
487 SetMSTP(32,2);
488 SetPARP(34,1.0);
489 SetPARP(67,1.0);
490 SetPARP(71,1.0);
491
492 // Intrinsic <kT>
493 SetMSTP(91,1);
494 SetPARP(91,1.60);
495 SetPARP(93,8.00);
496
497 // Set b-quark mass
498 SetPMAS(5,1,4.75);
499
500 break;
501 case kPyBeautyppMNR:
502 // Tuning of Pythia parameters aimed to get a resonable agreement
503 // between with the NLO calculation by Mangano, Nason, Ridolfi for the
504 // b-bbar single inclusive and double differential distributions.
505 // This parameter settings are meant to work with pp collisions
506 // (AliGenPythia::SetNuclei) and with kCTEQ4L PDFs.
507 // To get a good agreement the minimum ptHard (AliGenPythia::SetPtHard)
508 // has to be set to 2.75GeV. Example in ConfigBeautyPPR.C.
509
510 // All QCD processes
511 SetMSEL(1);
512
513 // No multiple interactions
514 SetMSTP(81,0);
515 SetPARP(81,0.0);
516 SetPARP(82,0.0);
517
518 // Initial/final parton shower on (Pythia default)
519 SetMSTP(61,1);
520 SetMSTP(71,1);
521
522 // 2nd order alpha_s
523 SetMSTP(2,2);
524
525 // QCD scales
526 SetMSTP(32,2);
527 SetPARP(34,1.0);
528 SetPARP(67,1.0);
529 SetPARP(71,1.0);
530
531 // Intrinsic <kT>
532 SetMSTP(91,1);
533 SetPARP(91,1.);
534 SetPARP(93,5.);
535
536 // Set b-quark mass
537 SetPMAS(5,1,4.75);
538
8d2cd130 539 break;
540 }
541//
542// Initialize PYTHIA
543 SetMSTP(41,1); // all resonance decays switched on
544
545 Initialize("CMS","p","p",fEcms);
546
547}
548
549Int_t AliPythia::CheckedLuComp(Int_t kf)
550{
551// Check Lund particle code (for debugging)
552 Int_t kc=Pycomp(kf);
553 printf("\n Lucomp kf,kc %d %d",kf,kc);
554 return kc;
555}
556
557void AliPythia::SetNuclei(Int_t a1, Int_t a2)
558{
559// Treat protons as inside nuclei with mass numbers a1 and a2
560// The MSTP array in the PYPARS common block is used to enable and
561// select the nuclear structure functions.
562// MSTP(52) : (D=1) choice of proton and nuclear structure-function library
563// =1: internal PYTHIA acording to MSTP(51)
564// =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET
565// If the following mass number both not equal zero, nuclear corrections of the stf are used.
566// MSTP(192) : Mass number of nucleus side 1
567// MSTP(193) : Mass number of nucleus side 2
568 SetMSTP(52,2);
569 SetMSTP(192, a1);
570 SetMSTP(193, a2);
571}
572
573
574AliPythia* AliPythia::Instance()
575{
576// Set random number generator
577 if (fgAliPythia) {
578 return fgAliPythia;
579 } else {
580 fgAliPythia = new AliPythia();
581 return fgAliPythia;
582 }
583}
584
585void AliPythia::PrintParticles()
586{
587// Print list of particl properties
588 Int_t np = 0;
c31f1d37 589 char* name = new char[16];
8d2cd130 590 for (Int_t kf=0; kf<1000000; kf++) {
591 for (Int_t c = 1; c > -2; c-=2) {
8d2cd130 592 Int_t kc = Pycomp(c*kf);
593 if (kc) {
594 Float_t mass = GetPMAS(kc,1);
595 Float_t width = GetPMAS(kc,2);
596 Float_t tau = GetPMAS(kc,4);
c31f1d37 597
8d2cd130 598 Pyname(kf,name);
599
600 np++;
601
602 printf("\n mass, width, tau: %6d %s %10.3f %10.3e %10.3e",
603 c*kf, name, mass, width, tau);
604 }
605 }
606 }
607 printf("\n Number of particles %d \n \n", np);
608}
609
610void AliPythia::ResetDecayTable()
611{
612// Set default values for pythia decay switches
613 Int_t i;
614 for (i = 1; i < 501; i++) SetMDCY(i,1,fDefMDCY[i]);
615 for (i = 1; i < 2001; i++) SetMDME(i,1,fDefMDME[i]);
616}
617
618void AliPythia::SetDecayTable()
619{
620// Set default values for pythia decay switches
621//
622 Int_t i;
623 for (i = 1; i < 501; i++) fDefMDCY[i] = GetMDCY(i,1);
624 for (i = 1; i < 2001; i++) fDefMDME[i] = GetMDME(i,1);
625}
626
627void AliPythia::Pyclus(Int_t& njet)
628{
629// Call Pythia clustering algorithm
630//
631 pyclus(njet);
632}
633
634void AliPythia::Pycell(Int_t& njet)
635{
636// Call Pythia jet reconstruction algorithm
637//
638 pycell(njet);
639}
640
452af8c7 641void AliPythia::Pyshow(Int_t ip1, Int_t ip2, Double_t qmax)
642{
643// Call Pythia jet reconstruction algorithm
644//
452af8c7 645 pyshow(ip1, ip2, qmax);
646}
647
648void AliPythia::Pyrobo(Int_t imi, Int_t ima, Double_t the, Double_t phi, Double_t bex, Double_t bey, Double_t bez)
649{
650 pyrobo(imi, ima, the, phi, bex, bey, bez);
651}
652
653
654
0f482ae4 655void AliPythia::InitQuenching(Float_t cMin, Float_t cMax, Float_t qTransport, Float_t maxLength, Int_t iECMethod)
656{
657// Initializes
658// (1) The quenching model using quenching weights according to C. Salgado and U. Wiedemann
659// (2) The nuclear geometry using the Glauber Model
660//
661
662
663 fGlauber = new AliFastGlauber();
664 fGlauber->Init(2);
665 fGlauber->SetCentralityClass(cMin, cMax);
666
667 fQuenchingWeights = new AliQuenchingWeights();
668 fQuenchingWeights->InitMult();
669 fQuenchingWeights->SetQTransport(qTransport);
670 fQuenchingWeights->SetECMethod(AliQuenchingWeights::kECMethod(iECMethod));
671 fQuenchingWeights->SetLengthMax(Int_t(maxLength));
672 fQuenchingWeights->SampleEnergyLoss();
673
674}
675
676
452af8c7 677void AliPythia::Quench()
678{
679//
680//
681// Simple Jet Quenching routine:
682// =============================
683// The jet formed by all final state partons radiated by the parton created
0f482ae4 684// in the hard collisions is quenched by a factor (1-z) using light cone variables in
685// the initial parton reference frame:
452af8c7 686// (E + p_z)new = (1-z) (E + p_z)old
687//
0f482ae4 688//
689//
690//
452af8c7 691// The lost momentum is first balanced by one gluon with virtuality > 0.
692// Subsequently the gluon splits to yield two gluons with E = p.
693//
0f482ae4 694//
695//
4e383037 696 static Float_t eMean = 0.;
697 static Int_t icall = 0;
0f482ae4 698
699 Double_t p0[2][5];
700 Double_t p1[2][5];
701 Double_t p2[2][5];
452af8c7 702 Int_t klast[2] = {-1, -1};
452af8c7 703
704 Int_t numpart = fPyjets->N;
0f482ae4 705 Double_t px = 0., py = 0., pz = 0., e = 0., m = 0., p = 0., pt = 0., theta = 0.;
706 Double_t pxq[2], pyq[2], pzq[2], eq[2], yq[2], mq[2], pq[2], phiq[2], thetaq[2], ptq[2];
707 Bool_t quenched[2];
708 Double_t phi;
709 Double_t zInitial[2], wjtKick[2];
4e383037 710 Int_t nGluon[2];
711
0f482ae4 712 Int_t imo, kst, pdg;
511db649 713//
0f482ae4 714// Primary partons
511db649 715//
4e383037 716
717
0f482ae4 718
719 for (Int_t i = 6; i <= 7; i++) {
720 Int_t j = i - 6;
452af8c7 721
0f482ae4 722 pxq[j] = fPyjets->P[0][i];
723 pyq[j] = fPyjets->P[1][i];
724 pzq[j] = fPyjets->P[2][i];
725 eq[j] = fPyjets->P[3][i];
726 mq[j] = fPyjets->P[4][i];
4e383037 727 yq[j] = 0.5 * TMath::Log((eq[j] + pzq[j] + 1.e-14) / (eq[j] - pzq[j] + 1.e-14));
0f482ae4 728 pq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j] + pzq[j] * pzq[j]);
729 phiq[j] = TMath::Pi()+TMath::ATan2(-pyq[j], -pxq[j]);
730 ptq[j] = TMath::Sqrt(pxq[j] * pxq[j] + pyq[j] * pyq[j]);
731 thetaq[j] = TMath::ATan2(ptq[j], pzq[j]);
732 phi = phiq[j];
733
734 // Quench only central jets
735 if (TMath::Abs(yq[j]) > 2.5) {
736 zInitial[j] = 0.;
737 } else {
738 pdg = fPyjets->K[1][i];
739
740 // Get length in nucleus
741 Double_t l;
742 fGlauber->GetLengthsForPythia(1, &phi, &l, -1.);
743 //
744 // Energy loss for given length and parton typr
745 Int_t itype = (pdg == 21) ? 2 : 1;
4e383037 746
0f482ae4 747 Double_t eloss = fQuenchingWeights->GetELossRandom(itype, l, eq[j]);
4e383037 748 if (eq[j] > 80. && TMath::Abs(yq[j]) < 0.5) {
749 icall ++;
750 eMean += eloss;
751 }
752
0f482ae4 753 //
754 // Extra pt
4e383037 755
0f482ae4 756 wjtKick[j] = TMath::Sqrt(l * fQuenchingWeights->GetQTransport());
757 //
758 // Fractional energy loss
759 zInitial[j] = eloss / eq[j];
760 //
761 // Avoid complete loss
762 //
763 if (zInitial[j] == 1.) zInitial[j] = 0.95;
764 //
765 // Some debug printing
4e383037 766 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",
767 j, itype, eq[j], phi, l, eloss, wjtKick[j], eMean / Float_t(icall+1), yq[j]);
768
769 zInitial[j] = 1.;
770 while (zInitial[j] >= 0.95) zInitial[j] = gRandom->Exp(0.2);
0f482ae4 771 }
4e383037 772
0f482ae4 773 quenched[j] = (zInitial[j] > 0.01);
4e383037 774 } // primary partons
0f482ae4 775
6e90ad26 776 Double_t pNew[1000][4];
777 Int_t kNew[1000];
778 Int_t icount = 0;
779//
4e383037 780// System Loop
781 for (Int_t isys = 0; isys < 2; isys++) {
6e90ad26 782// Skip to next system if not quenched.
4e383037 783 if (!quenched[isys]) continue;
784
785 nGluon[isys] = 1 + Int_t(zInitial[isys] / (1. - zInitial[isys]));
786 if (nGluon[isys] > 6) nGluon[isys] = 6;
787 zInitial[isys] = 1. - TMath::Power(1. - zInitial[isys], 1./Double_t(nGluon[isys]));
788 wjtKick[isys] = wjtKick[isys] / TMath::Sqrt(Double_t(nGluon[isys]));
0f482ae4 789
4e383037 790
791
792 Int_t igMin = -1;
793 Int_t igMax = -1;
794 Double_t pg[4] = {0., 0., 0., 0.};
795
796//
797// Loop on radiation events
798
799 for (Int_t iglu = 0; iglu < nGluon[isys]; iglu++) {
6e90ad26 800 Double_t zHeavy = zInitial[isys];
6e90ad26 801//
4e383037 802
6e90ad26 803 while (1) {
804 icount = 0;
805 for (Int_t k = 0; k < 4; k++)
806 {
807 p0[isys][k] = 0.;
808 p1[isys][k] = 0.;
809 p2[isys][k] = 0.;
810 }
811// Loop over partons
812 for (Int_t i = 0; i < numpart; i++)
813 {
814 imo = fPyjets->K[2][i];
815 kst = fPyjets->K[0][i];
816 pdg = fPyjets->K[1][i];
817
818
819
0f482ae4 820// Quarks and gluons only
6e90ad26 821 if (pdg != 21 && TMath::Abs(pdg) > 6) continue;
0f482ae4 822// Particles from hard scattering only
6e90ad26 823 if (imo > 8 && imo < 1000) imo = fPyjets->K[2][imo - 1];
4e383037 824 if (imo != (isys + 7) && (imo % 1000) != (isys + 7)) continue;
6e90ad26 825
0f482ae4 826// Skip comment lines
6e90ad26 827 if (kst != 1 && kst != 2) continue;
0f482ae4 828//
829// Parton kinematic
6e90ad26 830 px = fPyjets->P[0][i];
831 py = fPyjets->P[1][i];
832 pz = fPyjets->P[2][i];
833 e = fPyjets->P[3][i];
834 m = fPyjets->P[4][i];
835 pt = TMath::Sqrt(px * px + py * py);
836 p = TMath::Sqrt(px * px + py * py + pz * pz);
837 phi = TMath::Pi() + TMath::ATan2(-py, -px);
838 theta = TMath::ATan2(pt, pz);
839
0f482ae4 840//
841// Save 4-momentum sum for balancing
6e90ad26 842 Int_t index = imo - 7;
4e383037 843 if (index >= 1000) index = imo % 1000 - 7;
6e90ad26 844
845 p0[index][0] += px;
846 p0[index][1] += py;
847 p0[index][2] += pz;
848 p0[index][3] += e;
6e90ad26 849
850 klast[index] = i;
851
0f482ae4 852//
853// Fractional energy loss
6e90ad26 854 Double_t z = zInitial[index];
4e383037 855
856// Don't fully quench radiated gluons
857//
858 if (imo > 1000) {
859// This small factor makes sure that the gluons are not too close in phase space to avoid recombination
860//
861
862 z = 0.05;
863 }
864
865//
866
6e90ad26 867 if (m > 0.) z = zHeavy;
868
869 //
870 //
871 // Transform into frame in which initial parton is along z-axis
872 //
873 TVector3 v(px, py, pz);
874 v.RotateZ(-phiq[index]); v.RotateY(-thetaq[index]);
875 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pl = v.Z();
876
877 Double_t jt = TMath::Sqrt(pxs * pxs + pys * pys);
878 Double_t mt2 = jt * jt + m * m;
879 Double_t zmax = 1.;
880 //
881 // Kinematic limit on z
882 //
4e383037 883 if (m > 0.) zmax = 1. - m / TMath::Sqrt(m * m + jt * jt);
6e90ad26 884 //
885 // Change light-cone kinematics rel. to initial parton
886 //
887 Double_t eppzOld = e + pl;
888 Double_t empzOld = e - pl;
889
890 Double_t eppzNew = (1. - z) * eppzOld;
891 Double_t empzNew = empzOld - mt2 * z / eppzOld;
892 Double_t eNew = 0.5 * (eppzNew + empzNew);
893 Double_t plNew = 0.5 * (eppzNew - empzNew);
894
895 Double_t jtNew;
896 //
897 // if mt very small (or sometimes even < 0 for numerical reasons) set it to 0
898 Double_t mt2New = eppzNew * empzNew;
899 if (mt2New < 1.e-8) mt2New = 0.;
4e383037 900 if (z < zmax) {
901 if (m * m > mt2New) {
902 //
903 // This should not happen
904 //
905 Fatal("Quench()", "This should never happen %e %e %e!", m, eppzNew, empzNew);
906 jtNew = 0;
907 } else {
908 jtNew = TMath::Sqrt(mt2New - m * m);
909 }
6e90ad26 910 } else {
4e383037 911 // If pT is to small (probably a leading massive particle) we scale only the energy
912 // This can cause negative masses of the radiated gluon
913 // Let's hope for the best ...
914 jtNew = jt;
915 eNew = TMath::Sqrt(plNew * plNew + mt2);
916
6e90ad26 917 }
6e90ad26 918 //
919 // Calculate new px, py
920 //
921 Double_t pxNew = jtNew / jt * pxs;
922 Double_t pyNew = jtNew / jt * pys;
923
924// Double_t dpx = pxs - pxNew;
925// Double_t dpy = pys - pyNew;
926// Double_t dpz = pl - plNew;
927// Double_t de = e - eNew;
928// Double_t dmass2 = de * de - dpx * dpx - dpy * dpy - dpz * dpz;
929// printf("New mass (1) %e %e %e %e %e %e %e \n", dmass2, jt, jtNew, pl, plNew, e, eNew);
930// printf("New mass (2) %e %e \n", pxNew, pyNew);
931 //
932 // Rotate back
933 //
934 TVector3 w(pxNew, pyNew, plNew);
935 w.RotateY(thetaq[index]); w.RotateZ(phiq[index]);
936 pxNew = w.X(); pyNew = w.Y(); plNew = w.Z();
937
938 p1[index][0] += pxNew;
939 p1[index][1] += pyNew;
940 p1[index][2] += plNew;
941 p1[index][3] += eNew;
942 //
943 // Updated 4-momentum vectors
944 //
945 pNew[icount][0] = pxNew;
946 pNew[icount][1] = pyNew;
947 pNew[icount][2] = plNew;
948 pNew[icount][3] = eNew;
949 kNew[icount] = i;
950 icount++;
951 } // parton loop
0f482ae4 952 //
6e90ad26 953 // Check if there was phase-space for quenching
0f482ae4 954 //
0f482ae4 955
6e90ad26 956 if (icount == 0) quenched[isys] = kFALSE;
957 if (!quenched[isys]) break;
958
959 for (Int_t j = 0; j < 4; j++)
960 {
961 p2[isys][j] = p0[isys][j] - p1[isys][j];
962 }
963 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 964 if (p2[isys][4] > 0.) {
965 p2[isys][4] = TMath::Sqrt(p2[isys][4]);
966 break;
967 } else {
968 printf("Warning negative mass squared in system %d %f ! \n", isys, zInitial[isys]);
4e383037 969 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 970 if (p2[isys][4] < -0.01) {
4e383037 971 printf("Negative mass squared !\n");
972 // Here we have to put the gluon back to mass shell
973 // This will lead to a small energy imbalance
974 p2[isys][4] = 0.;
975 p2[isys][3] = TMath::Sqrt(p2[isys][0] * p2[isys][0] + p2[isys][1] * p2[isys][1] + p2[isys][2] * p2[isys][2]);
976 break;
6e90ad26 977 } else {
978 p2[isys][4] = 0.;
979 break;
980 }
981 }
6e90ad26 982 /*
6e90ad26 983 zHeavy *= 0.98;
984 printf("zHeavy lowered to %f\n", zHeavy);
985 if (zHeavy < 0.01) {
986 printf("No success ! \n");
987 icount = 0;
988 quenched[isys] = kFALSE;
989 break;
990 }
4e383037 991 */
992 } // iteration on z (while)
993
6e90ad26 994// Update event record
995 for (Int_t k = 0; k < icount; k++) {
996// 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] );
997 fPyjets->P[0][kNew[k]] = pNew[k][0];
998 fPyjets->P[1][kNew[k]] = pNew[k][1];
999 fPyjets->P[2][kNew[k]] = pNew[k][2];
1000 fPyjets->P[3][kNew[k]] = pNew[k][3];
0f482ae4 1001 }
4e383037 1002 //
1003 // Add the gluons
1004 //
1005 Int_t ish = 0;
1837e95c 1006 Int_t iGlu;
4e383037 1007 if (!quenched[isys]) continue;
0f482ae4 1008//
1009// Last parton from shower i
4e383037 1010 Int_t in = klast[isys];
0f482ae4 1011//
1012// Continue if no parton in shower i selected
1013 if (in == -1) continue;
1014//
1015// If this is the second initial parton and it is behind the first move pointer by previous ish
4e383037 1016 if (isys == 1 && klast[1] > klast[0]) in += ish;
0f482ae4 1017//
1018// Starting index
452af8c7 1019
4e383037 1020// jmin = in - 1;
0f482ae4 1021// How many additional gluons will be generated
1022 ish = 1;
4e383037 1023 if (p2[isys][4] > 0.05) ish = 2;
0f482ae4 1024//
1025// Position of gluons
4e383037 1026 iGlu = numpart;
1027 if (iglu == 0) igMin = iGlu;
1028 igMax = iGlu;
0f482ae4 1029 numpart += ish;
1030 (fPyjets->N) += ish;
4e383037 1031
0f482ae4 1032 if (ish == 1) {
4e383037 1033 fPyjets->P[0][iGlu] = p2[isys][0];
1034 fPyjets->P[1][iGlu] = p2[isys][1];
1035 fPyjets->P[2][iGlu] = p2[isys][2];
1036 fPyjets->P[3][iGlu] = p2[isys][3];
1037 fPyjets->P[4][iGlu] = p2[isys][4];
0f482ae4 1038
4e383037 1039 fPyjets->K[0][iGlu] = 1;
1040 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu] = 1;
0f482ae4 1041 fPyjets->K[1][iGlu] = 21;
4e383037 1042 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
0f482ae4 1043 fPyjets->K[3][iGlu] = -1;
1044 fPyjets->K[4][iGlu] = -1;
4e383037 1045
1046 pg[0] += p2[isys][0];
1047 pg[1] += p2[isys][1];
1048 pg[2] += p2[isys][2];
1049 pg[3] += p2[isys][3];
0f482ae4 1050 } else {
1051 //
1052 // Split gluon in rest frame.
1053 //
4e383037 1054 Double_t bx = p2[isys][0] / p2[isys][3];
1055 Double_t by = p2[isys][1] / p2[isys][3];
1056 Double_t bz = p2[isys][2] / p2[isys][3];
1057 Double_t pst = p2[isys][4] / 2.;
0f482ae4 1058 //
1059 // Isotropic decay ????
1060 Double_t cost = 2. * gRandom->Rndm() - 1.;
1061 Double_t sint = TMath::Sqrt(1. - cost * cost);
1062 Double_t phi = 2. * TMath::Pi() * gRandom->Rndm();
1063
1064 Double_t pz1 = pst * cost;
1065 Double_t pz2 = -pst * cost;
1066 Double_t pt1 = pst * sint;
1067 Double_t pt2 = -pst * sint;
1068 Double_t px1 = pt1 * TMath::Cos(phi);
1069 Double_t py1 = pt1 * TMath::Sin(phi);
1070 Double_t px2 = pt2 * TMath::Cos(phi);
1071 Double_t py2 = pt2 * TMath::Sin(phi);
1072
1073 fPyjets->P[0][iGlu] = px1;
1074 fPyjets->P[1][iGlu] = py1;
1075 fPyjets->P[2][iGlu] = pz1;
1076 fPyjets->P[3][iGlu] = pst;
1077 fPyjets->P[4][iGlu] = 0.;
1078
4e383037 1079 fPyjets->K[0][iGlu] = 1 ;
0f482ae4 1080 fPyjets->K[1][iGlu] = 21;
4e383037 1081 fPyjets->K[2][iGlu] = fPyjets->K[2][in] + 1000;
0f482ae4 1082 fPyjets->K[3][iGlu] = -1;
1083 fPyjets->K[4][iGlu] = -1;
1084
1085 fPyjets->P[0][iGlu+1] = px2;
1086 fPyjets->P[1][iGlu+1] = py2;
1087 fPyjets->P[2][iGlu+1] = pz2;
1088 fPyjets->P[3][iGlu+1] = pst;
1089 fPyjets->P[4][iGlu+1] = 0.;
1090
4e383037 1091 fPyjets->K[0][iGlu+1] = 1;
1092 if (iglu == nGluon[isys] - 1) fPyjets->K[0][iGlu+1] = 1;
0f482ae4 1093 fPyjets->K[1][iGlu+1] = 21;
4e383037 1094 fPyjets->K[2][iGlu+1] = fPyjets->K[2][in] + 1000;
0f482ae4 1095 fPyjets->K[3][iGlu+1] = -1;
1096 fPyjets->K[4][iGlu+1] = -1;
1097 SetMSTU(1,0);
1098 SetMSTU(2,0);
1099 //
1100 // Boost back
1101 //
1102 Pyrobo(iGlu + 1, iGlu + 2, 0., 0., bx, by, bz);
1103 }
4e383037 1104/*
1105 for (Int_t ig = iGlu; ig < iGlu+ish; ig++) {
1106 Double_t px, py, pz;
1107 px = fPyjets->P[0][ig];
1108 py = fPyjets->P[1][ig];
1109 pz = fPyjets->P[2][ig];
1110 TVector3 v(px, py, pz);
1111 v.RotateZ(-phiq[isys]);
1112 v.RotateY(-thetaq[isys]);
1113 Double_t pxs = v.X(); Double_t pys = v.Y(); Double_t pzs = v.Z();
1114 Double_t r = AliPythiaRndm::GetPythiaRandom()->Rndm();
1115 Double_t jtKick = 0.3 * TMath::Sqrt(-TMath::Log(r));
1116 if (ish == 2) jtKick = wjtKick[i] * TMath::Sqrt(-TMath::Log(r)) / TMath::Sqrt(2.);
1117 Double_t phiKick = 2. * TMath::Pi() * AliPythiaRndm::GetPythiaRandom()->Rndm();
1118 pxs += jtKick * TMath::Cos(phiKick);
1119 pys += jtKick * TMath::Sin(phiKick);
1120 TVector3 w(pxs, pys, pzs);
1121 w.RotateY(thetaq[isys]);
1122 w.RotateZ(phiq[isys]);
1123 fPyjets->P[0][ig] = w.X();
1124 fPyjets->P[1][ig] = w.Y();
1125 fPyjets->P[2][ig] = w.Z();
1126 fPyjets->P[2][ig] = w.Mag();
1127 }
1128*/
1129 } // kGluon
1130
6e90ad26 1131
4e383037 1132 // Check energy conservation
0f482ae4 1133 Double_t pxs = 0.;
1134 Double_t pys = 0.;
1135 Double_t pzs = 0.;
1136 Double_t es = 14000.;
1137
1138 for (Int_t i = 0; i < numpart; i++)
1139 {
1140 kst = fPyjets->K[0][i];
1141 if (kst != 1 && kst != 2) continue;
1142 pxs += fPyjets->P[0][i];
1143 pys += fPyjets->P[1][i];
1144 pzs += fPyjets->P[2][i];
1145 es -= fPyjets->P[3][i];
1146 }
1147 if (TMath::Abs(pxs) > 1.e-2 ||
1148 TMath::Abs(pys) > 1.e-2 ||
1149 TMath::Abs(pzs) > 1.e-1) {
1150 printf("%e %e %e %e\n", pxs, pys, pzs, es);
4e383037 1151// Fatal("Quench()", "4-Momentum non-conservation");
452af8c7 1152 }
4e383037 1153
1154 } // end quenching loop (systems)
6e90ad26 1155// Clean-up
0f482ae4 1156 for (Int_t i = 0; i < numpart; i++)
1157 {
4e383037 1158 imo = fPyjets->K[2][i];
1159 if (imo > 1000) {
1160 fPyjets->K[2][i] = fPyjets->K[2][i] % 1000;
1161 }
0f482ae4 1162 }
4e383037 1163// this->Pylist(1);
0f482ae4 1164} // end quench
90d7b703 1165