Gabriele Cosmo
126 lines
4.1 KiB
C++
126 lines
4.1 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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#ifndef G4DiffElasticHadrNucleus_h
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#define G4DiffElasticHadrNucleus_h 1
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#include "G4Nucleus.hh"
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#include "G4DynamicParticle.hh"
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#include "G4HadronValues.hh"
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#include "G4IntegrHadrNucleus.hh"
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class G4DiffElasticHadrNucleus: public //G4HadronValues
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G4IntegrHadrNucleus
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{
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public:
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G4DiffElasticHadrNucleus() : // G4HadronValues(),
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G4IntegrHadrNucleus() {Factors();}
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~G4DiffElasticHadrNucleus() {;}
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G4double HadrNuclDifferCrSec(
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const G4DynamicParticle * aHadron,
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G4Nucleus * aNucleus,
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G4double Q2);
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void GetNucleusParameters(G4Nucleus * aNucleus);
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private:
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// ++++++++++++++++++++++++++++++++++++++++++++++++++
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G4double binom(G4int N, G4int M)
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{
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G4double Fact1 = 1;
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if ((N>1) & (N>=M))
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{
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Fact1 = Factorials[N]/Factorials[M]/
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Factorials[N-M];
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}
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return Fact1;
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}
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// +++++++++++++++++++++++++++++++++++++++++++++++++++
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G4double Factorial(G4int N)
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{
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G4double Res;
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Res = 1;
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if(N == 0) return Res;
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if(N < 100) for(G4int M = 1; M<=N; M++) Res = Res*M;
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if(N >= 100) Res = 2.50662827*exp(-N-1.0)*pow(N+1.0,N+0.5)*
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(1+1/12/(N+1)+1/288/(N+1)/(N+1)-
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139/51840/(N+1)/(N+1)/(N+1)-
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571/2488320/(N+1)/(N+1)/(N+1)/(N+1));
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return Res;
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}
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// +++++++++++++++++++++++++++++++++++++++++++++++++++
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void Factors()
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{
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G4int ii, ll, mm;
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G4double Sum1, Fac1, Fac3, Sum3;
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Factorials[0] = 1;
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for( ii = 1; ii<250; ii++)
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{
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if(ii >= 100) Mnoj[ii] = 3.03; // there is the saturation
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else
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{
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Sum1 = 0;
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Fac1 = 1;
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Factorials[ii] = Factorial(ii);
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for( ll = 0; ll<=ii; ll++)
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{
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Fac1 = binom(ii,ll);
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Fac3 = 1;
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Sum3 = 1;
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for( mm = 1; mm<=ii-ll; mm++)
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{
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Fac3 = binom(ii-ll,mm);
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Sum3 = Sum3 + 1/Fac3;
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} // mm
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Sum1 = Sum1 + Sum3/Fac1;
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} // ll
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Mnoj[ii] = Sum1;
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} // else
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} // ii
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Mnoj[0] = 1;
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} // Factors
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// --------------------------------------------------------
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G4double Mnoj[250], Factorials[250];
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public:
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G4double R1, R2, Pnucl, Aeff, AIm, ARe, DIm;
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};
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#endif
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