source: trunk/source/processes/hadronic/cross_sections/src/G4GGNuclNuclCrossSection.cc@ 1340

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25//
26//
27// 24.11.08 V. Grichine - first implementation
28//
29
30#include "G4GGNuclNuclCrossSection.hh"
31
32#include "G4ParticleTable.hh"
33#include "G4IonTable.hh"
34#include "G4ParticleDefinition.hh"
35#include "G4HadTmpUtil.hh"
36
37
38///////////////////////////////////////////////////////////////////////////////
39//
40//
41
42G4GGNuclNuclCrossSection::G4GGNuclNuclCrossSection()
43: fUpperLimit( 100000 * GeV ),
44 fLowerLimit( 0.1 * MeV ),
45 fRadiusConst( 1.08*fermi ) // 1.1, 1.3 ?
46{
47 theProton = G4Proton::Proton();
48 theNeutron = G4Neutron::Neutron();
49}
50
51///////////////////////////////////////////////////////////////////////////////
52//
53//
54
55G4GGNuclNuclCrossSection::~G4GGNuclNuclCrossSection()
56{}
57
58///////////////////////////////////////////////////////////////////////////////
59//
60//
61
62
63G4bool
64G4GGNuclNuclCrossSection::IsApplicable(const G4DynamicParticle* aDP,
65 const G4Element* anElement)
66{
67 G4int Z = G4lrint(anElement->GetZ());
68 G4int N = G4lrint(anElement->GetN());
69 return IsIsoApplicable(aDP, Z, N);
70}
71
72///////////////////////////////////////////////////////////////////////////////
73//
74//
75
76G4bool
77G4GGNuclNuclCrossSection::IsIsoApplicable(const G4DynamicParticle* aDP,
78 G4int Z, G4int)
79{
80 G4bool applicable = false;
81 G4double kineticEnergy = aDP->GetKineticEnergy();
82
83 if (kineticEnergy >= fLowerLimit && Z > 1) applicable = true;
84 return applicable;
85}
86
87///////////////////////////////////////////////////////////////////////////////
88//
89// Calculates total and inelastic Xsc, derives elastic as total - inelastic
90// accordong to Glauber model with Gribov correction calculated in the dipole
91// approximation on light cone. Gaussian density helps to calculate rest
92// integrals of the model. [1] B.Z. Kopeliovich, nucl-th/0306044
93
94
95G4double G4GGNuclNuclCrossSection::
96GetCrossSection(const G4DynamicParticle* aParticle, const G4Element* anElement,
97 G4double T)
98{
99 G4int Z = G4lrint(anElement->GetZ());
100 G4int N = G4lrint(anElement->GetN());
101 return GetZandACrossSection(aParticle, Z, N, T);
102}
103
104///////////////////////////////////////////////////////////////////////////////
105//
106// Calculates total and inelastic Xsc, derives elastic as total - inelastic
107// accordong to Glauber model with Gribov correction calculated in the dipole
108// approximation on light cone. Gaussian density of point-like nucleons helps
109// to calculate rest integrals of the model. [1] B.Z. Kopeliovich,
110// nucl-th/0306044 + simplification above
111
112
113G4double G4GGNuclNuclCrossSection::
114GetZandACrossSection(const G4DynamicParticle* aParticle,
115 G4int tZ, G4int tA, G4double)
116{
117 G4double xsection;
118 G4double sigma;
119 G4double cofInelastic = 2.4;
120 G4double cofTotal = 2.0;
121 G4double nucleusSquare;
122 G4double cB;
123 G4double ratio;
124
125 G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
126 G4double pA = aParticle->GetDefinition()->GetBaryonNumber();
127
128 G4double pTkin = aParticle->GetKineticEnergy();
129 pTkin /= pA;
130
131 G4double pN = pA - pZ;
132 if( pN < 0. ) pN = 0.;
133
134 G4double tN = tA - tZ;
135 if( tN < 0. ) tN = 0.;
136
137 G4double tR = GetNucleusRadius(tA);
138 G4double pR = GetNucleusRadius(pA);
139
140 cB = GetCoulombBarier(aParticle, G4double(tZ), G4double(tA), pR, tR);
141 if (cB > 0.) {
142
143 sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) +
144 (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron);
145
146 nucleusSquare = cofTotal*pi*( pR*pR + tR*tR ); // basically 2piRR
147
148 ratio = sigma/nucleusSquare;
149 xsection = nucleusSquare*std::log( 1. + ratio );
150 fTotalXsc = xsection;
151 fTotalXsc *= cB;
152
153 fInelasticXsc = nucleusSquare*std::log( 1. + cofInelastic*ratio )/cofInelastic;
154
155 fInelasticXsc *= cB;
156 fElasticXsc = fTotalXsc - fInelasticXsc;
157
158 // if (fElasticXsc < DBL_MIN) fElasticXsc = DBL_MIN;
159 /*
160 G4double difratio = ratio/(1.+ratio);
161
162 fDiffractionXsc = 0.5*nucleusSquare*( difratio - std::log( 1. + difratio ) );
163 */
164 // production to be checked !!! edit MK xsc
165
166 //sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscMK(theProton, pTkin, theProton) +
167 // (pZ*tN+pN*tZ)*GetHadronNucleonXscMK(theProton, pTkin, theNeutron);
168
169 sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) +
170 (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron);
171
172 ratio = sigma/nucleusSquare;
173 fProductionXsc = nucleusSquare*std::log( 1. + cofInelastic*ratio )/cofInelastic;
174
175 if (fElasticXsc < 0.) fElasticXsc = 0.;
176 }
177 else
178 {
179 fInelasticXsc = 0.;
180 fTotalXsc = 0.;
181 fElasticXsc = 0.;
182 fProductionXsc = 0.;
183 }
184 return fInelasticXsc; // xsection;
185}
186
187///////////////////////////////////////////////////////////////////////////////
188//
189//
190
191G4double G4GGNuclNuclCrossSection::
192GetCoulombBarier(const G4DynamicParticle* aParticle, G4double tZ, G4double tA,
193 G4double pR, G4double tR)
194{
195 G4double ratio;
196 G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
197
198 G4double pTkin = aParticle->GetKineticEnergy();
199 // G4double pPlab = aParticle->GetTotalMomentum();
200 G4double pM = aParticle->GetDefinition()->GetPDGMass();
201 // G4double tM = tZ*proton_mass_c2 + (tA-tZ)*neutron_mass_c2; // ~ 1% accuracy
202 G4double tM = G4ParticleTable::GetParticleTable()->GetIonTable()->GetIonMass( G4int(tZ), G4int(tA) );
203 G4double pElab = pTkin + pM;
204 G4double totEcm = std::sqrt(pM*pM + tM*tM + 2.*pElab*tM);
205 // G4double pPcm = pPlab*tM/totEcm;
206 // G4double pTcm = std::sqrt(pM*pM + pPcm*pPcm) - pM;
207 G4double totTcm = totEcm - pM -tM;
208
209 G4double bC = fine_structure_const*hbarc*pZ*tZ;
210 bC /= pR + tR;
211 bC /= 2.; // 4., 2. parametrisation cof ??? vmg
212
213 // G4cout<<"pTkin = "<<pTkin/GeV<<"; pPlab = "
214 // <<pPlab/GeV<<"; bC = "<<bC/GeV<<"; pTcm = "<<pTcm/GeV<<G4endl;
215
216 if( totTcm <= bC ) ratio = 0.;
217 else ratio = 1. - bC/totTcm;
218
219 // if(ratio < DBL_MIN) ratio = DBL_MIN;
220 if( ratio < 0.) ratio = 0.;
221
222 // G4cout <<"ratio = "<<ratio<<G4endl;
223 return ratio;
224}
225
226
227//////////////////////////////////////////////////////////////////////////
228//
229// Return single-diffraction/inelastic cross-section ratio
230
231G4double G4GGNuclNuclCrossSection::
232GetRatioSD(const G4DynamicParticle* aParticle, G4double tA, G4double tZ)
233{
234 G4double sigma, cofInelastic = 2.4, cofTotal = 2.0, nucleusSquare, ratio;
235
236 G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
237 G4double pA = aParticle->GetDefinition()->GetBaryonNumber();
238
239 G4double pTkin = aParticle->GetKineticEnergy();
240 pTkin /= pA;
241
242 G4double pN = pA - pZ;
243 if( pN < 0. ) pN = 0.;
244
245 G4double tN = tA - tZ;
246 if( tN < 0. ) tN = 0.;
247
248 G4double tR = GetNucleusRadius(tA);
249 G4double pR = GetNucleusRadius(pA);
250
251 sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) +
252 (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron);
253
254 nucleusSquare = cofTotal*pi*( pR*pR + tR*tR ); // basically 2piRR
255 ratio = sigma/nucleusSquare;
256 fInelasticXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic;
257 G4double difratio = ratio/(1.+ratio);
258
259 fDiffractionXsc = 0.5*nucleusSquare*( difratio - std::log( 1. + difratio ) );
260
261 if (fInelasticXsc > 0.) ratio = fDiffractionXsc/fInelasticXsc;
262 else ratio = 0.;
263
264 return ratio;
265}
266
267//////////////////////////////////////////////////////////////////////////
268//
269// Return quasi-elastic/inelastic cross-section ratio
270
271G4double G4GGNuclNuclCrossSection::
272GetRatioQE(const G4DynamicParticle* aParticle, G4double tA, G4double tZ)
273{
274 G4double sigma, cofInelastic = 2.4, cofTotal = 2.0, nucleusSquare, ratio;
275
276 G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
277 G4double pA = aParticle->GetDefinition()->GetBaryonNumber();
278
279 G4double pTkin = aParticle->GetKineticEnergy();
280 pTkin /= pA;
281
282 G4double pN = pA - pZ;
283 if( pN < 0. ) pN = 0.;
284
285 G4double tN = tA - tZ;
286 if( tN < 0. ) tN = 0.;
287
288 G4double tR = GetNucleusRadius(tA);
289 G4double pR = GetNucleusRadius(pA);
290
291 sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) +
292 (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron);
293
294 nucleusSquare = cofTotal*pi*( pR*pR + tR*tR ); // basically 2piRR
295 ratio = sigma/nucleusSquare;
296 fInelasticXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic;
297
298 // sigma = GetHNinelasticXsc(aParticle, tA, tZ);
299 ratio = sigma/nucleusSquare;
300 fProductionXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic;
301
302 if (fInelasticXsc > fProductionXsc) ratio = (fInelasticXsc-fProductionXsc)/fInelasticXsc;
303 else ratio = 0.;
304 if ( ratio < 0. ) ratio = 0.;
305
306 return ratio;
307}
308
309///////////////////////////////////////////////////////////////////////////////
310//
311// Returns hadron-nucleon Xsc according to differnt parametrisations:
312// [2] E. Levin, hep-ph/9710546
313// [3] U. Dersch, et al, hep-ex/9910052
314// [4] M.J. Longo, et al, Phys.Rev.Lett. 33 (1974) 725
315
316G4double
317G4GGNuclNuclCrossSection::GetHadronNucleonXsc(const G4DynamicParticle* aParticle,
318 const G4Element* anElement)
319{
320 G4int At = G4lrint(anElement->GetN()); // number of nucleons
321 G4int Zt = G4lrint(anElement->GetZ()); // number of protons
322 return GetHadronNucleonXsc(aParticle, At, Zt);
323}
324
325
326
327
328///////////////////////////////////////////////////////////////////////////////
329//
330// Returns hadron-nucleon Xsc according to differnt parametrisations:
331// [2] E. Levin, hep-ph/9710546
332// [3] U. Dersch, et al, hep-ex/9910052
333// [4] M.J. Longo, et al, Phys.Rev.Lett. 33 (1974) 725
334
335G4double
336G4GGNuclNuclCrossSection::GetHadronNucleonXsc(const G4DynamicParticle* aParticle,
337 G4int At, G4int Zt)
338{
339 G4double xsection = 0.;
340
341 G4double targ_mass = G4ParticleTable::GetParticleTable()->
342 GetIonTable()->GetIonMass(Zt, At);
343 targ_mass = 0.939*GeV; // ~mean neutron and proton ???
344
345 G4double proj_mass = aParticle->GetMass();
346 G4double proj_momentum = aParticle->GetMomentum().mag();
347 G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum );
348
349 sMand /= GeV*GeV; // in GeV for parametrisation
350 proj_momentum /= GeV;
351 const G4ParticleDefinition* pParticle = aParticle->GetDefinition();
352
353 if(pParticle == theNeutron) // as proton ???
354 {
355 xsection = G4double(At)*(21.70*std::pow(sMand,0.0808) + 56.08*std::pow(sMand,-0.4525));
356 }
357 else if(pParticle == theProton)
358 {
359 xsection = G4double(At)*(21.70*std::pow(sMand,0.0808) + 56.08*std::pow(sMand,-0.4525));
360 }
361
362 xsection *= millibarn;
363 return xsection;
364}
365
366
367///////////////////////////////////////////////////////////////////////////////
368//
369// Returns hadron-nucleon Xsc according to PDG parametrisation (2005):
370// http://pdg.lbl.gov/2006/reviews/hadronicrpp.pdf
371
372G4double
373G4GGNuclNuclCrossSection::GetHadronNucleonXscPDG(const G4DynamicParticle* aParticle,
374 const G4Element* anElement)
375{
376 G4int At = G4lrint(anElement->GetN()); // number of nucleons
377 G4int Zt = G4lrint(anElement->GetZ()); // number of protons
378 return GetHadronNucleonXscPDG( aParticle, At, Zt );
379}
380
381
382///////////////////////////////////////////////////////////////////////////////
383//
384// Returns hadron-nucleon Xsc according to PDG parametrisation (2005):
385// http://pdg.lbl.gov/2006/reviews/hadronicrpp.pdf
386// At = number of nucleons, Zt = number of protons
387
388G4double
389G4GGNuclNuclCrossSection::GetHadronNucleonXscPDG(const G4DynamicParticle* aParticle,
390 G4int At, G4int Zt)
391{
392 G4double xsection = 0.;
393
394 G4double Nt = At-Zt; // number of neutrons
395 if (Nt < 0.) Nt = 0.;
396
397 G4double targ_mass = G4ParticleTable::GetParticleTable()->
398 GetIonTable()->GetIonMass(Zt, At);
399 targ_mass = 0.939*GeV; // ~mean neutron and proton ???
400
401 G4double proj_mass = aParticle->GetMass();
402 G4double proj_momentum = aParticle->GetMomentum().mag();
403 G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum );
404 sMand /= GeV*GeV; // in GeV for parametrisation
405
406 // General PDG fit constants
407
408 G4double s0 = 5.38*5.38; // in Gev^2
409 G4double eta1 = 0.458;
410 G4double eta2 = 0.458;
411 G4double B = 0.308;
412
413 const G4ParticleDefinition* pParticle = aParticle->GetDefinition();
414
415 if(pParticle == theNeutron) // proton-neutron fit
416 {
417 xsection = G4double(Zt)*( 35.80 + B*std::pow(std::log(sMand/s0),2.)
418 + 40.15*std::pow(sMand,-eta1) - 30.*std::pow(sMand,-eta2));
419 xsection += Nt*(35.45 + B*std::pow(std::log(sMand/s0),2.)
420 + 42.53*std::pow(sMand,-eta1) - 33.34*std::pow(sMand,-eta2)); // pp for nn
421 }
422 else if(pParticle == theProton)
423 {
424 xsection = G4double(Zt)*(35.45 + B*std::pow(std::log(sMand/s0),2.)
425 + 42.53*std::pow(sMand,-eta1) - 33.34*std::pow(sMand,-eta2));
426
427 xsection += Nt*(35.80 + B*std::pow(std::log(sMand/s0),2.)
428 + 40.15*std::pow(sMand,-eta1) - 30.*std::pow(sMand,-eta2));
429 }
430 xsection *= millibarn; // parametrised in mb
431 return xsection;
432}
433
434
435///////////////////////////////////////////////////////////////////////////////
436//
437// Returns nucleon-nucleon cross-section based on N. Starkov parametrisation of
438// data from mainly http://wwwppds.ihep.su:8001/c5-6A.html database
439// projectile nucleon is pParticle with pTkin shooting target nucleon tParticle
440
441G4double
442G4GGNuclNuclCrossSection::GetHadronNucleonXscNS(G4ParticleDefinition* pParticle,
443 G4double pTkin,
444 G4ParticleDefinition* tParticle)
445{
446 G4double xsection(0), Delta, A0, B0;
447 G4double hpXsc(0);
448 G4double hnXsc(0);
449
450 G4double targ_mass = tParticle->GetPDGMass();
451 G4double proj_mass = pParticle->GetPDGMass();
452
453 G4double proj_energy = proj_mass + pTkin;
454 G4double proj_momentum = std::sqrt(pTkin*(pTkin+2*proj_mass));
455
456 G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum );
457
458 sMand /= GeV*GeV; // in GeV for parametrisation
459 proj_momentum /= GeV;
460 proj_energy /= GeV;
461 proj_mass /= GeV;
462
463 // General PDG fit constants
464
465 // G4double s0 = 5.38*5.38; // in Gev^2
466 // G4double eta1 = 0.458;
467 // G4double eta2 = 0.458;
468 // G4double B = 0.308;
469
470 if( proj_momentum >= 10. ) // high energy: pp = nn = np
471 // if( proj_momentum >= 2.)
472 {
473 Delta = 1.;
474 if (proj_energy < 40.) Delta = 0.916+0.0021*proj_energy;
475
476 if (proj_momentum >= 10.) {
477 B0 = 7.5;
478 A0 = 100. - B0*std::log(3.0e7);
479
480 xsection = A0 + B0*std::log(proj_energy) - 11
481 + 103*std::pow(2*0.93827*proj_energy + proj_mass*proj_mass+
482 0.93827*0.93827,-0.165); // mb
483 }
484 }
485 else // low energy pp = nn != np
486 {
487 if(pParticle == tParticle) // pp or nn // nn to be pp
488 {
489 if( proj_momentum < 0.73 )
490 {
491 hnXsc = 23 + 50*( std::pow( std::log(0.73/proj_momentum), 3.5 ) );
492 }
493 else if( proj_momentum < 1.05 )
494 {
495 hnXsc = 23 + 40*(std::log(proj_momentum/0.73))*
496 (std::log(proj_momentum/0.73));
497 }
498 else // if( proj_momentum < 10. )
499 {
500 hnXsc = 39.0 +
501 75*(proj_momentum - 1.2)/(std::pow(proj_momentum,3.0) + 0.15);
502 }
503 xsection = hnXsc;
504 }
505 else // pn to be np
506 {
507 if( proj_momentum < 0.8 )
508 {
509 hpXsc = 33+30*std::pow(std::log(proj_momentum/1.3),4.0);
510 }
511 else if( proj_momentum < 1.4 )
512 {
513 hpXsc = 33+30*std::pow(std::log(proj_momentum/0.95),2.0);
514 }
515 else // if( proj_momentum < 10. )
516 {
517 hpXsc = 33.3+
518 20.8*(std::pow(proj_momentum,2.0)-1.35)/
519 (std::pow(proj_momentum,2.50)+0.95);
520 }
521 xsection = hpXsc;
522 }
523 }
524 xsection *= millibarn; // parametrised in mb
525 return xsection;
526}
527
528/////////////////////////////////////////////////////////////////////////////////
529//
530// Returns hadron-nucleon inelastic cross-section based on FTF-parametrisation
531
532G4double
533G4GGNuclNuclCrossSection::GetHNinelasticXscVU(const G4DynamicParticle* aParticle,
534 G4int At, G4int Zt)
535{
536 G4int PDGcode = aParticle->GetDefinition()->GetPDGEncoding();
537 G4int absPDGcode = std::abs(PDGcode);
538 G4double Elab = aParticle->GetTotalEnergy();
539 // (s - 2*0.88*GeV*GeV)/(2*0.939*GeV)/GeV;
540 G4double Plab = aParticle->GetMomentum().mag();
541 // std::sqrt(Elab * Elab - 0.88);
542
543 Elab /= GeV;
544 Plab /= GeV;
545
546 G4double LogPlab = std::log( Plab );
547 G4double sqrLogPlab = LogPlab * LogPlab;
548
549 //G4cout<<"Plab = "<<Plab<<G4endl;
550
551 G4double NumberOfTargetProtons = Zt;
552 G4double NumberOfTargetNucleons = At;
553 G4double NumberOfTargetNeutrons = NumberOfTargetNucleons - NumberOfTargetProtons;
554
555 if(NumberOfTargetNeutrons < 0.) NumberOfTargetNeutrons = 0.;
556
557 G4double Xtotal = 0., Xelastic = 0., Xinelastic =0.;
558
559 if( absPDGcode > 1000 ) //------Projectile is baryon --------
560 {
561 G4double XtotPP = 48.0 + 0. *std::pow(Plab, 0. ) +
562 0.522*sqrLogPlab - 4.51*LogPlab;
563
564 G4double XtotPN = 47.3 + 0. *std::pow(Plab, 0. ) +
565 0.513*sqrLogPlab - 4.27*LogPlab;
566
567 G4double XelPP = 11.9 + 26.9*std::pow(Plab,-1.21) +
568 0.169*sqrLogPlab - 1.85*LogPlab;
569
570 G4double XelPN = 11.9 + 26.9*std::pow(Plab,-1.21) +
571 0.169*sqrLogPlab - 1.85*LogPlab;
572
573 Xtotal = ( NumberOfTargetProtons * XtotPP +
574 NumberOfTargetNeutrons * XtotPN );
575
576 Xelastic = ( NumberOfTargetProtons * XelPP +
577 NumberOfTargetNeutrons * XelPN );
578 }
579
580 Xinelastic = Xtotal - Xelastic;
581 if(Xinelastic < 0.) Xinelastic = 0.;
582
583 return Xinelastic*= millibarn;
584}
585
586///////////////////////////////////////////////////////////////////////////////
587//
588//
589
590G4double
591G4GGNuclNuclCrossSection::GetNucleusRadius(const G4DynamicParticle* ,
592 const G4Element* anElement)
593{
594 G4double At = anElement->GetN();
595 G4double oneThird = 1.0/3.0;
596 G4double cubicrAt = std::pow (At, oneThird);
597
598 G4double R; // = fRadiusConst*cubicrAt;
599 R = fRadiusConst*cubicrAt;
600
601 G4double meanA = 21.;
602 G4double tauA1 = 40.;
603 G4double tauA2 = 10.;
604 G4double tauA3 = 5.;
605
606 G4double a1 = 0.85;
607 G4double b1 = 1. - a1;
608
609 G4double b2 = 0.3;
610 G4double b3 = 4.;
611
612 if (At > 20.) // 20.
613 {
614 R *= ( a1 + b1*std::exp( -(At - meanA)/tauA1) );
615 }
616 else if (At > 3.5)
617 {
618 R *= ( 1.0 + b2*( 1. - std::exp( (At - meanA)/tauA2) ) );
619 }
620 else
621 {
622 R *= ( 1.0 + b3*( 1. - std::exp( (At - meanA)/tauA3) ) );
623 }
624
625 return R;
626}
627
628///////////////////////////////////////////////////////////////////////////////
629//
630//
631
632G4double
633G4GGNuclNuclCrossSection::GetNucleusRadius(G4double At)
634{
635 G4double R;
636 R = GetNucleusRadiusDE(At);
637
638 return R;
639}
640
641///////////////////////////////////////////////////////////////////
642
643G4double
644G4GGNuclNuclCrossSection::GetNucleusRadiusGG(G4double At)
645{
646 G4double oneThird = 1.0/3.0;
647 G4double cubicrAt = std::pow (At, oneThird);
648
649 G4double R; // = fRadiusConst*cubicrAt;
650 R = fRadiusConst*cubicrAt;
651
652 G4double meanA = 20.;
653 G4double tauA = 20.;
654
655 if ( At > 20.) // 20.
656 {
657 R *= ( 0.8 + 0.2*std::exp( -(At - meanA)/tauA) );
658 }
659 else
660 {
661 R *= ( 1.0 + 0.1*( 1. - std::exp( (At - meanA)/tauA) ) );
662 }
663
664 return R;
665}
666
667
668G4double
669G4GGNuclNuclCrossSection::GetNucleusRadiusDE(G4double A)
670{
671 // algorithm from diffuse-elastic
672
673 G4double R, r0, a11, a12, a13, a2, a3;
674
675 a11 = 1.26; // 1.08, 1.16
676 a12 = 1.; // 1.08, 1.16
677 a13 = 1.12; // 1.08, 1.16
678 a2 = 1.1;
679 a3 = 1.;
680
681
682 if (A < 50.)
683 {
684 if( 10 < A && A <= 15. ) r0 = a11*( 1 - std::pow(A, -2./3.) )*fermi; // 1.08*fermi;
685 else if( 15 < A && A <= 20 ) r0 = a12*( 1 - std::pow(A, -2./3.) )*fermi;
686 else if( 20 < A && A <= 30 ) r0 = a13*( 1 - std::pow(A, -2./3.) )*fermi;
687 else r0 = a2*fermi;
688
689 R = r0*std::pow( A, 1./3. );
690 }
691 else
692 {
693 r0 = a3*fermi;
694
695 R = r0*std::pow(A, 0.27);
696 }
697 return R;
698}
699
700
701///////////////////////////////////////////////////////////////////////////////
702//
703//
704
705G4double G4GGNuclNuclCrossSection::CalculateEcmValue(const G4double mp,
706 const G4double mt,
707 const G4double Plab)
708{
709 G4double Elab = std::sqrt ( mp * mp + Plab * Plab );
710 G4double Ecm = std::sqrt ( mp * mp + mt * mt + 2 * Elab * mt );
711 // G4double Pcm = Plab * mt / Ecm;
712 // G4double KEcm = std::sqrt ( Pcm * Pcm + mp * mp ) - mp;
713
714 return Ecm ; // KEcm;
715}
716
717
718///////////////////////////////////////////////////////////////////////////////
719//
720//
721
722G4double G4GGNuclNuclCrossSection::CalcMandelstamS(const G4double mp,
723 const G4double mt,
724 const G4double Plab)
725{
726 G4double Elab = std::sqrt ( mp * mp + Plab * Plab );
727 G4double sMand = mp*mp + mt*mt + 2*Elab*mt ;
728
729 return sMand;
730}
731
732//
733//
734///////////////////////////////////////////////////////////////////////////////
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