G4GGNuclNuclCrossSection.cc

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00025 //
00026 // 24.11.08 V. Grichine - first implementation
00027 // 25.10.12 W.Pokorski - following Vladimir's advice, I removed Z>1 condition
00028 //
00029 
00030 #include "G4GGNuclNuclCrossSection.hh"
00031 
00032 #include "G4PhysicalConstants.hh"
00033 #include "G4SystemOfUnits.hh"
00034 #include "G4ParticleTable.hh"
00035 #include "G4IonTable.hh"
00036 #include "G4ParticleDefinition.hh"
00037 #include "G4HadTmpUtil.hh"
00038 #include "G4HadronNucleonXsc.hh"
00039 
00040 // factory
00041 #include "G4CrossSectionFactory.hh"
00042 //
00043 G4_DECLARE_XS_FACTORY(G4GGNuclNuclCrossSection);
00044 
00045 
00046 G4GGNuclNuclCrossSection::G4GGNuclNuclCrossSection() 
00047  : G4VCrossSectionDataSet(Default_Name()),
00048    fUpperLimit(100000*GeV), fLowerLimit(0.1*MeV),
00049    fRadiusConst(1.08*fermi),  // 1.1, 1.3 ?
00050    fTotalXsc(0.0), fElasticXsc(0.0), fInelasticXsc(0.0), fProductionXsc(0.0),
00051    fDiffractionXsc(0.0), fHadronNucleonXsc(0.0)
00052 {
00053   theProton   = G4Proton::Proton();
00054   theNeutron  = G4Neutron::Neutron();
00055   hnXsc = new G4HadronNucleonXsc();
00056 }
00057 
00058 
00059 G4GGNuclNuclCrossSection::~G4GGNuclNuclCrossSection()
00060 {
00061   delete hnXsc;
00062 }
00063 
00064 void
00065 G4GGNuclNuclCrossSection::CrossSectionDescription(std::ostream& outFile) const
00066 {
00067   outFile << "G4GGNuclNuclCrossSection calculates total, inelastic and\n"
00068           << "elastic cross sections for nucleus-nucleus collisions using\n"
00069           << "the Glauber model with Gribov corrections.  It is valid for\n"
00070           << "all incident energies above 100 keV./n";
00071 }
00072 
00073 G4bool 
00074 G4GGNuclNuclCrossSection::IsElementApplicable(const G4DynamicParticle*, 
00075                                               G4int, const G4Material*)
00076 {
00077   G4bool applicable = true;
00078 //  G4double kineticEnergy = aDP->GetKineticEnergy();
00079 
00080 //  if (kineticEnergy >= fLowerLimit) applicable = true;
00081   return applicable;
00082 }
00083 
00085 //
00086 // Calculates total and inelastic Xsc, derives elastic as total - inelastic 
00087 // accordong to Glauber model with Gribov correction calculated in the dipole 
00088 // approximation on light cone. Gaussian density helps to calculate rest 
00089 // integrals of the model. [1] B.Z. Kopeliovich, nucl-th/0306044 
00090 
00091 
00092 G4double G4GGNuclNuclCrossSection::
00093 GetElementCrossSection(const G4DynamicParticle* aParticle, G4int Z,
00094                        const G4Material*)
00095 {
00096   G4int A = G4lrint(G4NistManager::Instance()->GetAtomicMassAmu(Z));
00097   return GetZandACrossSection(aParticle, Z, A);
00098 }
00099 
00101 //
00102 // Calculates total and inelastic Xsc, derives elastic as total - inelastic 
00103 // accordong to Glauber model with Gribov correction calculated in the dipole 
00104 // approximation on light cone. Gaussian density of point-like nucleons helps 
00105 // to calculate rest integrals of the model. [1] B.Z. Kopeliovich,
00106 // nucl-th/0306044 + simplification above
00107 
00108 
00109 G4double G4GGNuclNuclCrossSection::
00110 GetZandACrossSection(const G4DynamicParticle* aParticle,
00111                      G4int tZ, G4int tA)
00112 {
00113   G4double xsection;
00114   G4double sigma;
00115   G4double cofInelastic = 2.4;
00116   G4double cofTotal = 2.0;
00117   G4double nucleusSquare;
00118   G4double cB;
00119   G4double ratio;
00120 
00121   G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
00122   G4double pA = aParticle->GetDefinition()->GetBaryonNumber();
00123 
00124   G4double pTkin = aParticle->GetKineticEnergy();  
00125   pTkin /= pA;
00126 
00127   G4double pN = pA - pZ;
00128   if( pN < 0. ) pN = 0.;
00129 
00130   G4double tN = tA - tZ;
00131   if( tN < 0. ) tN = 0.;
00132 
00133   G4double tR = GetNucleusRadius( G4double(tZ),G4double(tA) );  
00134   G4double pR = GetNucleusRadius(pZ,pA); 
00135 
00136   cB = GetCoulombBarier(aParticle, G4double(tZ), G4double(tA), pR, tR);
00137 
00138   if ( cB > 0. ) 
00139   {
00140     G4DynamicParticle* dProton = new G4DynamicParticle(theProton,
00141                                               G4ParticleMomentum(1.,0.,0.), 
00142                                               pTkin);
00143 
00144     G4DynamicParticle* dNeutron = new G4DynamicParticle(theNeutron,
00145                                               G4ParticleMomentum(1.,0.,0.), 
00146                                               pTkin);
00147 
00148     sigma = (pZ*tZ+pN*tN)*hnXsc->GetHadronNucleonXscNS(dProton, theProton);
00149 
00150     G4double ppInXsc = hnXsc->GetInelasticHadronNucleonXsc();
00151 
00152     sigma += (pZ*tN+pN*tZ)*hnXsc->GetHadronNucleonXscNS(dNeutron, theProton);
00153 
00154     G4double npInXsc = hnXsc->GetInelasticHadronNucleonXsc();
00155 
00156       delete dProton;
00157       delete dNeutron;
00158       
00159     // G4cout<<"ppInXsc = "<<ppInXsc/millibarn<<"; npInXsc = "<<npInXsc/millibarn<<G4endl;
00160     // G4cout<<"npTotXsc = "<<hnXsc->GetTotalHadronNucleonXsc()/millibarn<<"; npElXsc = "
00161     //                      <<hnXsc->GetElasticHadronNucleonXsc()/millibarn<<G4endl;
00162 
00163     nucleusSquare = cofTotal*pi*( pR*pR + tR*tR );   // basically 2piRR
00164 
00165     ratio      = sigma/nucleusSquare;
00166     xsection   = nucleusSquare*std::log( 1. + ratio );
00167     fTotalXsc  = xsection;
00168     fTotalXsc *= cB;
00169 
00170     fInelasticXsc = nucleusSquare*std::log( 1. + cofInelastic*ratio )/cofInelastic;
00171 
00172     fInelasticXsc *= cB;
00173     fElasticXsc   = fTotalXsc - fInelasticXsc;
00174 
00175     // if (fElasticXsc < DBL_MIN) fElasticXsc = DBL_MIN;
00176     /*    
00177     G4double difratio = ratio/(1.+ratio);
00178 
00179     fDiffractionXsc = 0.5*nucleusSquare*( difratio - std::log( 1. + difratio ) );
00180     */
00181     // production to be checked !!! edit MK xsc
00182 
00183     //sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscMK(theProton, pTkin, theProton) +
00184     //      (pZ*tN+pN*tZ)*GetHadronNucleonXscMK(theProton, pTkin, theNeutron);
00185 
00186     sigma = (pZ*tZ+pN*tN)*ppInXsc + (pZ*tN+pN*tZ)*npInXsc;
00187  
00188     ratio = sigma/nucleusSquare;
00189     fProductionXsc = nucleusSquare*std::log( 1. + cofInelastic*ratio )/cofInelastic;
00190 
00191     if (fElasticXsc < 0.) fElasticXsc = 0.;
00192   }
00193   else
00194   {
00195     fInelasticXsc  = 0.;
00196     fTotalXsc      = 0.;
00197     fElasticXsc    = 0.;
00198     fProductionXsc = 0.;
00199   }
00200     
00201   return fInelasticXsc;   // xsection; 
00202 }
00203 
00205 //
00206 //
00207 
00208 G4double G4GGNuclNuclCrossSection::
00209 GetCoulombBarier(const G4DynamicParticle* aParticle, G4double tZ, G4double tA,
00210                  G4double pR, G4double tR)
00211 {
00212   G4double ratio;
00213   G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
00214 
00215   G4double pTkin = aParticle->GetKineticEnergy();
00216   // G4double pPlab = aParticle->GetTotalMomentum();
00217   G4double pM    = aParticle->GetDefinition()->GetPDGMass();
00218   // G4double tM    = tZ*proton_mass_c2 + (tA-tZ)*neutron_mass_c2; // ~ 1% accuracy
00219   G4double tM    = G4ParticleTable::GetParticleTable()->GetIonTable()->GetIonMass( G4int(tZ), G4int(tA) );
00220   G4double pElab = pTkin + pM;
00221   G4double totEcm  = std::sqrt(pM*pM + tM*tM + 2.*pElab*tM);
00222   // G4double pPcm  = pPlab*tM/totEcm;
00223   // G4double pTcm  = std::sqrt(pM*pM + pPcm*pPcm) - pM;
00224   G4double totTcm  = totEcm - pM -tM;
00225 
00226   G4double bC    = fine_structure_const*hbarc*pZ*tZ;
00227            bC   /= pR + tR;
00228            bC   /= 2.;  // 4., 2. parametrisation cof ??? vmg
00229 
00230            // G4cout<<"pTkin = "<<pTkin/GeV<<"; pPlab = "
00231            // <<pPlab/GeV<<"; bC = "<<bC/GeV<<"; pTcm = "<<pTcm/GeV<<G4endl;
00232 
00233   if( totTcm <= bC ) ratio = 0.;
00234   else             ratio = 1. - bC/totTcm;
00235 
00236   // if(ratio < DBL_MIN) ratio = DBL_MIN;
00237   if( ratio < 0.) ratio = 0.;
00238 
00239   // G4cout <<"ratio = "<<ratio<<G4endl;
00240   return ratio;
00241 }
00242 
00243 
00245 //
00246 // Return single-diffraction/inelastic cross-section ratio
00247 
00248 G4double G4GGNuclNuclCrossSection::
00249 GetRatioSD(const G4DynamicParticle* aParticle, G4double tA, G4double tZ)
00250 {
00251   G4double sigma, cofInelastic = 2.4, cofTotal = 2.0, nucleusSquare, ratio;
00252 
00253   G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
00254   G4double pA = aParticle->GetDefinition()->GetBaryonNumber();
00255 
00256   G4double pTkin = aParticle->GetKineticEnergy();  
00257   pTkin /= pA;
00258 
00259   G4double pN = pA - pZ;
00260   if( pN < 0. ) pN = 0.;
00261 
00262   G4double tN = tA - tZ;
00263   if( tN < 0. ) tN = 0.;
00264 
00265   G4double tR = GetNucleusRadius(tZ,tA);  
00266   G4double pR = GetNucleusRadius(pZ,pA); 
00267 
00268   sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) +
00269           (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron);
00270 
00271   nucleusSquare = cofTotal*pi*( pR*pR + tR*tR );   // basically 2piRR
00272   ratio = sigma/nucleusSquare;
00273   fInelasticXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic;
00274   G4double difratio = ratio/(1.+ratio);
00275 
00276   fDiffractionXsc = 0.5*nucleusSquare*( difratio - std::log( 1. + difratio ) );
00277 
00278   if (fInelasticXsc > 0.) ratio = fDiffractionXsc/fInelasticXsc;
00279   else                    ratio = 0.;
00280 
00281   return ratio; 
00282 }
00283 
00285 //
00286 // Return quasi-elastic/inelastic cross-section ratio
00287 
00288 G4double G4GGNuclNuclCrossSection::
00289 GetRatioQE(const G4DynamicParticle* aParticle, G4double tA, G4double tZ)
00290 {
00291   G4double sigma, cofInelastic = 2.4, cofTotal = 2.0, nucleusSquare, ratio;
00292 
00293   G4double pZ = aParticle->GetDefinition()->GetPDGCharge();
00294   G4double pA = aParticle->GetDefinition()->GetBaryonNumber();
00295 
00296   G4double pTkin = aParticle->GetKineticEnergy();  
00297   pTkin /= pA;
00298 
00299   G4double pN = pA - pZ;
00300   if( pN < 0. ) pN = 0.;
00301 
00302   G4double tN = tA - tZ;
00303   if( tN < 0. ) tN = 0.;
00304 
00305   G4double tR = GetNucleusRadius(tZ,tA);  
00306   G4double pR = GetNucleusRadius(pZ,pA); 
00307 
00308   sigma = (pZ*tZ+pN*tN)*GetHadronNucleonXscNS(theProton, pTkin, theProton) +
00309           (pZ*tN+pN*tZ)*GetHadronNucleonXscNS(theProton, pTkin, theNeutron);
00310 
00311   nucleusSquare = cofTotal*pi*( pR*pR + tR*tR );   // basically 2piRR
00312   ratio = sigma/nucleusSquare;
00313   fInelasticXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic;
00314 
00315   //  sigma = GetHNinelasticXsc(aParticle, tA, tZ);
00316   ratio = sigma/nucleusSquare;
00317   fProductionXsc = nucleusSquare*std::log(1. + cofInelastic*ratio)/cofInelastic;
00318 
00319   if (fInelasticXsc > fProductionXsc) ratio = (fInelasticXsc-fProductionXsc)/fInelasticXsc;
00320   else                                ratio = 0.;
00321   if ( ratio < 0. )                   ratio = 0.;
00322 
00323   return ratio; 
00324 }
00325 
00327 //
00328 // Returns hadron-nucleon Xsc according to differnt parametrisations:
00329 // [2] E. Levin, hep-ph/9710546
00330 // [3] U. Dersch, et al, hep-ex/9910052
00331 // [4] M.J. Longo, et al, Phys.Rev.Lett. 33 (1974) 725 
00332 
00333 G4double 
00334 G4GGNuclNuclCrossSection::GetHadronNucleonXsc(const G4DynamicParticle* aParticle, 
00335                                               const G4Element* anElement)
00336 {
00337   G4int At = G4lrint(anElement->GetN());  // number of nucleons 
00338   G4int Zt = G4lrint(anElement->GetZ());  // number of protons
00339   return GetHadronNucleonXsc(aParticle, At, Zt);
00340 }
00341 
00342 
00343 
00344 
00346 //
00347 // Returns hadron-nucleon Xsc according to differnt parametrisations:
00348 // [2] E. Levin, hep-ph/9710546
00349 // [3] U. Dersch, et al, hep-ex/9910052
00350 // [4] M.J. Longo, et al, Phys.Rev.Lett. 33 (1974) 725 
00351 
00352 G4double 
00353 G4GGNuclNuclCrossSection::GetHadronNucleonXsc(const G4DynamicParticle* aParticle, 
00354                                                    G4int At, G4int Zt)
00355 {
00356   G4double xsection = 0.;
00357 
00358   G4double targ_mass = G4ParticleTable::GetParticleTable()->
00359   GetIonTable()->GetIonMass(Zt, At);
00360   targ_mass = 0.939*GeV;  // ~mean neutron and proton ???
00361 
00362   G4double proj_mass = aParticle->GetMass();
00363   G4double proj_momentum = aParticle->GetMomentum().mag();
00364   G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum );
00365 
00366   sMand /= GeV*GeV;  // in GeV for parametrisation
00367   proj_momentum /= GeV;
00368   const G4ParticleDefinition* pParticle = aParticle->GetDefinition();
00369 
00370   if(pParticle == theNeutron) // as proton ??? 
00371   {
00372     xsection = G4double(At)*(21.70*std::pow(sMand,0.0808) + 56.08*std::pow(sMand,-0.4525));
00373   } 
00374   else if(pParticle == theProton) 
00375   {
00376     xsection = G4double(At)*(21.70*std::pow(sMand,0.0808) + 56.08*std::pow(sMand,-0.4525));
00377   } 
00378  
00379   xsection *= millibarn;
00380   return xsection;
00381 }
00382 
00383 
00384 
00386 //
00387 // Returns hadron-nucleon Xsc according to PDG parametrisation (2005):
00388 // http://pdg.lbl.gov/2006/reviews/hadronicrpp.pdf
00389 //  At = number of nucleons,  Zt = number of protons 
00390 
00391 G4double 
00392 G4GGNuclNuclCrossSection::GetHadronNucleonXscPDG(G4ParticleDefinition* pParticle, 
00393                                                  G4double sMand, 
00394                                                  G4ParticleDefinition* tParticle)
00395 {
00396   G4double xsection = 0.;
00397   // G4bool pORn = (tParticle == theProton || nucleon == theNeutron  );  
00398   G4bool proton = (tParticle == theProton);
00399   G4bool neutron = (tParticle == theNeutron);
00400 
00401   // General PDG fit constants
00402 
00403   G4double s0   = 5.38*5.38; // in Gev^2
00404   G4double eta1 = 0.458;
00405   G4double eta2 = 0.458;
00406   G4double B    = 0.308;
00407 
00408   // const G4ParticleDefinition* pParticle = aParticle->GetDefinition();
00409   
00410   if(pParticle == theNeutron) // proton-neutron fit 
00411   {
00412     if ( proton )
00413     {
00414       xsection = ( 35.80 + B*std::pow(std::log(sMand/s0),2.) 
00415                   + 40.15*std::pow(sMand,-eta1) - 30.*std::pow(sMand,-eta2));
00416     }
00417     if ( neutron )
00418     {
00419       xsection = (35.45 + B*std::pow(std::log(sMand/s0),2.) 
00420              + 42.53*std::pow(sMand,-eta1) - 33.34*std::pow(sMand,-eta2)); // pp for nn
00421     }
00422   } 
00423   else if(pParticle == theProton) 
00424   {
00425     if ( proton )
00426     {
00427       xsection = (35.45 + B*std::pow(std::log(sMand/s0),2.) 
00428                 + 42.53*std::pow(sMand,-eta1) - 33.34*std::pow(sMand,-eta2));
00429 
00430     }
00431     if ( neutron )
00432     {
00433       xsection = (35.80 + B*std::pow(std::log(sMand/s0),2.) 
00434                   + 40.15*std::pow(sMand,-eta1) - 30.*std::pow(sMand,-eta2));
00435     }
00436   } 
00437   xsection *= millibarn; // parametrised in mb
00438   return xsection;
00439 }
00440 
00441 
00443 //
00444 // Returns nucleon-nucleon cross-section based on N. Starkov parametrisation of
00445 // data from mainly http://wwwppds.ihep.su:8001/c5-6A.html database
00446 // projectile nucleon is pParticle with pTkin shooting target nucleon tParticle
00447 
00448 G4double 
00449 G4GGNuclNuclCrossSection::GetHadronNucleonXscNS(G4ParticleDefinition* pParticle, 
00450                                                  G4double pTkin, 
00451                                                  G4ParticleDefinition* tParticle)
00452 {
00453   G4double xsection(0);
00454   // G4double Delta;   DHW 19 May 2011: variable set but not used
00455   G4double A0, B0;
00456   G4double hpXscv(0);
00457   G4double hnXscv(0);
00458 
00459   G4double targ_mass = tParticle->GetPDGMass();
00460   G4double proj_mass = pParticle->GetPDGMass(); 
00461 
00462   G4double proj_energy   = proj_mass + pTkin; 
00463   G4double proj_momentum = std::sqrt(pTkin*(pTkin+2*proj_mass));
00464 
00465   G4double sMand = CalcMandelstamS ( proj_mass , targ_mass , proj_momentum );
00466 
00467   sMand         /= GeV*GeV;  // in GeV for parametrisation
00468   proj_momentum /= GeV;
00469   proj_energy   /= GeV;
00470   proj_mass     /= GeV;
00471 
00472   // General PDG fit constants
00473 
00474   //  G4double s0   = 5.38*5.38; // in Gev^2
00475   //  G4double eta1 = 0.458;
00476   //  G4double eta2 = 0.458;
00477   //  G4double B    = 0.308;
00478   
00479   if( proj_momentum >= 373.)
00480   {
00481       return GetHadronNucleonXscPDG(pParticle,sMand,tParticle);
00482   }
00483   else if( proj_momentum >= 10. ) // high energy: pp = nn = np
00484     // if( proj_momentum >= 2.)
00485   {
00486     //  Delta = 1.;    // DHW 19 May 2011: variable set but not used
00487     //  if (proj_energy < 40.) Delta = 0.916+0.0021*proj_energy;
00488 
00489     if (proj_momentum >= 10.) {
00490       B0 = 7.5;
00491       A0 = 100. - B0*std::log(3.0e7);
00492 
00493       xsection = A0 + B0*std::log(proj_energy) - 11
00494                 + 103*std::pow(2*0.93827*proj_energy + proj_mass*proj_mass+
00495                   0.93827*0.93827,-0.165);        //  mb
00496     }
00497   }
00498   else // low energy pp = nn != np
00499   {
00500       if(pParticle == tParticle) // pp or nn      // nn to be pp
00501       {
00502         if( proj_momentum < 0.73 )
00503         {
00504           hnXscv = 23 + 50*( std::pow( std::log(0.73/proj_momentum), 3.5 ) );
00505         }
00506         else if( proj_momentum < 1.05  )
00507         {
00508           hnXscv = 23 + 40*(std::log(proj_momentum/0.73))*
00509                          (std::log(proj_momentum/0.73));
00510         }
00511         else  // if( proj_momentum < 10.  )
00512         {
00513           hnXscv = 39.0 + 
00514               75*(proj_momentum - 1.2)/(std::pow(proj_momentum,3.0) + 0.15);
00515         }
00516         xsection = hnXscv;
00517       }
00518       else  // pn to be np
00519       {
00520         if( proj_momentum < 0.8 )
00521         {
00522           hpXscv = 33+30*std::pow(std::log(proj_momentum/1.3),4.0);
00523         }      
00524         else if( proj_momentum < 1.4 )
00525         {
00526           hpXscv = 33+30*std::pow(std::log(proj_momentum/0.95),2.0);
00527         }
00528         else    // if( proj_momentum < 10.  )
00529         {
00530           hpXscv = 33.3+
00531               20.8*(std::pow(proj_momentum,2.0)-1.35)/
00532                  (std::pow(proj_momentum,2.50)+0.95);
00533         }
00534         xsection = hpXscv;
00535       }
00536   }
00537   xsection *= millibarn; // parametrised in mb
00538   return xsection;
00539 }
00540 
00542 //
00543 // Returns hadron-nucleon inelastic cross-section based on FTF-parametrisation 
00544 
00545 G4double 
00546 G4GGNuclNuclCrossSection::GetHNinelasticXscVU(const G4DynamicParticle* aParticle, 
00547                                               G4int At, G4int Zt)
00548 {
00549   G4int PDGcode = aParticle->GetDefinition()->GetPDGEncoding();
00550   G4int absPDGcode = std::abs(PDGcode);
00551   G4double Elab = aParticle->GetTotalEnergy();              
00552                           // (s - 2*0.88*GeV*GeV)/(2*0.939*GeV)/GeV;
00553   G4double Plab = aParticle->GetMomentum().mag();            
00554                           // std::sqrt(Elab * Elab - 0.88);
00555 
00556   Elab /= GeV;
00557   Plab /= GeV;
00558 
00559   G4double LogPlab    = std::log( Plab );
00560   G4double sqrLogPlab = LogPlab * LogPlab;
00561 
00562   //G4cout<<"Plab = "<<Plab<<G4endl;
00563 
00564   G4double NumberOfTargetProtons  = Zt; 
00565   G4double NumberOfTargetNucleons = At;
00566   G4double NumberOfTargetNeutrons = NumberOfTargetNucleons - NumberOfTargetProtons;
00567 
00568   if(NumberOfTargetNeutrons < 0.) NumberOfTargetNeutrons = 0.;
00569 
00570   G4double Xtotal = 0., Xelastic = 0., Xinelastic =0.;
00571 
00572   if( absPDGcode > 1000 )  //------Projectile is baryon --------
00573   {
00574        G4double XtotPP = 48.0 +  0. *std::pow(Plab, 0.  ) +
00575                          0.522*sqrLogPlab - 4.51*LogPlab;
00576 
00577        G4double XtotPN = 47.3 +  0. *std::pow(Plab, 0.  ) +
00578                          0.513*sqrLogPlab - 4.27*LogPlab;
00579 
00580        G4double XelPP  = 11.9 + 26.9*std::pow(Plab,-1.21) +
00581                          0.169*sqrLogPlab - 1.85*LogPlab;
00582 
00583        G4double XelPN  = 11.9 + 26.9*std::pow(Plab,-1.21) +
00584                          0.169*sqrLogPlab - 1.85*LogPlab;
00585 
00586        Xtotal          = ( NumberOfTargetProtons  * XtotPP +
00587                            NumberOfTargetNeutrons * XtotPN  );
00588 
00589        Xelastic        = ( NumberOfTargetProtons  * XelPP  +
00590                            NumberOfTargetNeutrons * XelPN   );
00591   }
00592 
00593   Xinelastic = Xtotal - Xelastic;
00594   if(Xinelastic < 0.) Xinelastic = 0.;
00595 
00596   return Xinelastic*= millibarn;
00597 }
00598 
00600 //
00601 //
00602 
00603 G4double 
00604 G4GGNuclNuclCrossSection::GetNucleusRadius(const G4DynamicParticle* , 
00605                                            const G4Element* anElement)
00606 {
00607   G4double At = anElement->GetN();
00608   G4double oneThird = 1.0/3.0;
00609   G4double cubicrAt = std::pow (At, oneThird); 
00610 
00611   G4double R;  // = fRadiusConst*cubicrAt;
00612   R = fRadiusConst*cubicrAt;
00613 
00614   G4double meanA  = 21.;
00615   G4double tauA1  = 40.; 
00616   G4double tauA2  = 10.; 
00617   G4double tauA3  = 5.; 
00618 
00619   G4double a1 = 0.85;
00620   G4double b1 = 1. - a1;
00621 
00622   G4double b2 = 0.3;
00623   G4double b3 = 4.;
00624 
00625   if (At > 20.)   // 20.
00626   {
00627     R *= ( a1 + b1*std::exp( -(At - meanA)/tauA1) ); 
00628   }
00629   else if (At > 3.5)
00630   {
00631     R *= ( 1.0 + b2*( 1. - std::exp( (At - meanA)/tauA2) ) ); 
00632   }
00633   else 
00634   {
00635     R *= ( 1.0 + b3*( 1. - std::exp( (At - meanA)/tauA3) ) ); 
00636   }
00637 
00638   return R;
00639 }
00640 
00642 //
00643 //
00644 
00645 G4double 
00646 G4GGNuclNuclCrossSection::GetNucleusRadius(G4double Zt, G4double At)
00647 {
00648   G4double R;
00649   R = GetNucleusRadiusDE(Zt,At);
00650   // R = GetNucleusRadiusRMS(Zt,At);
00651 
00652   return R;
00653 }
00654 
00656 
00657 G4double 
00658 G4GGNuclNuclCrossSection::GetNucleusRadiusGG(G4double At)
00659 {
00660   G4double oneThird = 1.0/3.0;
00661   G4double cubicrAt = std::pow (At, oneThird); 
00662 
00663   G4double R;  // = fRadiusConst*cubicrAt;  
00664   R = fRadiusConst*cubicrAt;
00665 
00666   G4double meanA = 20.;
00667   G4double tauA  = 20.;
00668 
00669   if ( At > 20.)   // 20.
00670   {
00671     R *= ( 0.8 + 0.2*std::exp( -(At - meanA)/tauA) ); 
00672   }
00673   else
00674   {
00675     R *= ( 1.0 + 0.1*( 1. - std::exp( (At - meanA)/tauA) ) ); 
00676   }
00677 
00678   return R;
00679 }
00680 
00682 //
00683 //
00684 
00685 G4double 
00686 G4GGNuclNuclCrossSection::GetNucleusRadiusDE(G4double Z, G4double A)
00687 {
00688   // algorithm from diffuse-elastic
00689 
00690   G4double R, r0, a11, a12, a13, a2, a3;
00691 
00692   a11 = 1.26;  // 1.08, 1.16
00693   a12 = 1.;  // 1.08, 1.16
00694   a13 = 1.12;  // 1.08, 1.16
00695   a2 = 1.1;
00696   a3 = 1.;
00697 
00698   // Special rms radii for light nucleii
00699 
00700   if (A < 50.)
00701   {
00702     if     (std::abs(A-1.) < 0.5)                         return 0.89*fermi; // p
00703     else if(std::abs(A-2.) < 0.5)                         return 2.13*fermi; // d
00704     else if(std::abs(Z-1.) < 0.5 && std::abs(A-3.) < 0.5) return 1.80*fermi; // t
00705 
00706     else if(std::abs(Z-2.) < 0.5 && std::abs(A-3.) < 0.5) return 1.96*fermi; // He3
00707     else if(std::abs(Z-2.) < 0.5 && std::abs(A-4.) < 0.5) return 1.68*fermi; // He4
00708 
00709     else if(std::abs(Z-3.) < 0.5)                         return 2.40*fermi; // Li7
00710     else if(std::abs(Z-4.) < 0.5)                         return 2.51*fermi; // Be9
00711 
00712     else if( 10.  < A && A <= 16. ) r0  = a11*( 1 - std::pow(A, -2./3.) )*fermi;   // 1.08*fermi;
00713     else if( 15.  < A && A <= 20. ) r0  = a12*( 1 - std::pow(A, -2./3.) )*fermi;
00714     else if( 20.  < A && A <= 30. ) r0  = a13*( 1 - std::pow(A, -2./3.) )*fermi;
00715     else                            r0  = a2*fermi;
00716 
00717     R = r0*std::pow( A, 1./3. );
00718   }
00719   else
00720   {
00721     r0 = a3*fermi;
00722 
00723     R  = r0*std::pow(A, 0.27);
00724   }
00725   return R;
00726 }
00727 
00728 
00730 //
00731 // RMS radii from e-A scattering data
00732 
00733 G4double 
00734 G4GGNuclNuclCrossSection::GetNucleusRadiusRMS(G4double Z, G4double A)
00735 {
00736 
00737   if     (std::abs(A-1.) < 0.5)                         return 0.89*fermi; // p
00738   else if(std::abs(A-2.) < 0.5)                         return 2.13*fermi; // d
00739   else if(std::abs(Z-1.) < 0.5 && std::abs(A-3.) < 0.5) return 1.80*fermi; // t
00740 
00741   else if(std::abs(Z-2.) < 0.5 && std::abs(A-3.) < 0.5) return 1.96*fermi; // He3
00742   else if(std::abs(Z-2.) < 0.5 && std::abs(A-4.) < 0.5) return 1.68*fermi; // He4
00743 
00744   else if(std::abs(Z-3.) < 0.5)                         return 2.40*fermi; // Li7
00745   else if(std::abs(Z-4.) < 0.5)                         return 2.51*fermi; // Be9
00746 
00747   else                               return 1.24*std::pow(A, 0.28 )*fermi; // A > 9
00748 }
00749 
00750 
00752 //
00753 //
00754 
00755 G4double G4GGNuclNuclCrossSection::CalculateEcmValue(const G4double mp, 
00756                                                      const G4double mt, 
00757                                                      const G4double Plab)
00758 {
00759   G4double Elab = std::sqrt ( mp * mp + Plab * Plab );
00760   G4double Ecm  = std::sqrt ( mp * mp + mt * mt + 2 * Elab * mt );
00761   // G4double Pcm  = Plab * mt / Ecm;
00762   // G4double KEcm = std::sqrt ( Pcm * Pcm + mp * mp ) - mp;
00763 
00764   return Ecm ; // KEcm;
00765 }
00766 
00767 
00769 //
00770 //
00771 
00772 G4double G4GGNuclNuclCrossSection::CalcMandelstamS(const G4double mp, 
00773                                                    const G4double mt, 
00774                                                    const G4double Plab)
00775 {
00776   G4double Elab = std::sqrt ( mp * mp + Plab * Plab );
00777   G4double sMand  = mp*mp + mt*mt + 2*Elab*mt ;
00778 
00779   return sMand;
00780 }
00781 
00782 //
00783 //

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