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