#include <G4PolarizedBhabhaCrossSection.hh>
Inheritance diagram for G4PolarizedBhabhaCrossSection:
Public Member Functions | |
G4PolarizedBhabhaCrossSection () | |
virtual | ~G4PolarizedBhabhaCrossSection () |
void | Initialize (G4double x, G4double y, G4double phi, const G4StokesVector &p0, const G4StokesVector &p1, G4int flag=0) |
G4double | XSection (const G4StokesVector &pol2, const G4StokesVector &pol3) |
G4double | TotalXSection (G4double xmin, G4double xmax, G4double y, const G4StokesVector &pol0, const G4StokesVector &pol1) |
G4StokesVector | GetPol2 () |
G4StokesVector | GetPol3 () |
Definition at line 52 of file G4PolarizedBhabhaCrossSection.hh.
G4PolarizedBhabhaCrossSection::G4PolarizedBhabhaCrossSection | ( | ) |
G4PolarizedBhabhaCrossSection::~G4PolarizedBhabhaCrossSection | ( | ) | [virtual] |
G4StokesVector G4PolarizedBhabhaCrossSection::GetPol2 | ( | ) | [virtual] |
Reimplemented from G4VPolarizedCrossSection.
Definition at line 298 of file G4PolarizedBhabhaCrossSection.cc.
00299 { 00300 // Note, mean polarization can not contain correlation 00301 // effects. 00302 return 1./phi0 * phi2; 00303 }
G4StokesVector G4PolarizedBhabhaCrossSection::GetPol3 | ( | ) | [virtual] |
Reimplemented from G4VPolarizedCrossSection.
Definition at line 304 of file G4PolarizedBhabhaCrossSection.cc.
00305 { 00306 // Note, mean polarization can not contain correlation 00307 // effects. 00308 return 1./phi0 * phi3; 00309 }
void G4PolarizedBhabhaCrossSection::Initialize | ( | G4double | x, | |
G4double | y, | |||
G4double | phi, | |||
const G4StokesVector & | p0, | |||
const G4StokesVector & | p1, | |||
G4int | flag = 0 | |||
) | [virtual] |
Reimplemented from G4VPolarizedCrossSection.
Definition at line 62 of file G4PolarizedBhabhaCrossSection.cc.
References G4StokesVector::IsZero(), and G4VPolarizedCrossSection::SetXmax().
00069 { 00070 SetXmax(1.); 00071 00072 G4double re2 = classic_electr_radius * classic_electr_radius; 00073 G4double gamma2 = gamma*gamma; 00074 G4double gamma3 = gamma2*gamma; 00075 G4double gmo = (gamma - 1.); 00076 G4double gmo2 = (gamma - 1.)*(gamma - 1.); 00077 G4double gmo3 = gmo2*(gamma - 1.); 00078 G4double gpo = (gamma + 1.); 00079 G4double gpo2 = (gamma + 1.)*(gamma + 1.); 00080 G4double gpo3 = gpo2*(gamma + 1.); 00081 G4double gpo12 = std::sqrt(gpo); 00082 G4double gpo32 = gpo*gpo12; 00083 G4double gpo52 = gpo2*gpo12; 00084 00085 G4double pref = re2/(gamma - 1.0); 00086 G4double sqrttwo=std::sqrt(2.); 00087 G4double d = std::sqrt(1./e - 1.); 00088 G4double e2 = e*e; 00089 G4double e3 = e2*e; 00090 00091 // *** new *** 00092 G4double gmo12 = std::sqrt(gmo); 00093 G4double gmo32 = gmo*gmo12; 00094 G4double egmp32 = std::pow(e*(2 + e*gmo)*gpo,(3./2.)); 00095 G4double e32 = e*std::sqrt(e); 00096 00097 G4bool polarized=(!pol0.IsZero())||(!pol1.IsZero()); 00098 00099 if (flag==0) polarized=false; 00100 // Unpolarised part of XS 00101 // *AS* UnpME . OK 00102 phi0 = 0.; 00103 phi0+= e2*gmo3/gpo3; 00104 phi0+= -2.*e*gamma*gmo2/gpo3; 00105 phi0+= (3.*gamma2 + 6.*gamma + 4.)*gmo/gpo3; 00106 phi0+= -(2.*gamma2 + 4.*gamma + 1.)/(e*gpo2); 00107 phi0+= gamma2/(e2*(gamma2 - 1.)); 00108 phi0*=0.25; 00109 // Initial state polarisarion dependence 00110 if (polarized) { 00111 // G4cout<<"Polarized differential Bhabha cross section"<<G4endl; 00112 // G4cout<<"Initial state polarisation contributions"<<G4endl; 00113 // G4cout<<"Diagonal Matrix Elements"<<G4endl; 00114 // *** new *** 00115 G4double xx = -((e*gmo - gamma)*(-1 - gamma + e*(e*gmo - gamma)*(3 + gamma)))/(4*e*gpo3); 00116 G4double yy = (e3*gmo3 - 2*e2*gmo2*gamma - gpo*(1 + 2*gamma) + e*(-2 + gamma2 + gamma3))/(4*e*gpo3); 00117 G4double zz = ((e*gmo - gamma)*(e2*gmo*(3 + gamma) - e*gamma*(3 + gamma) + gpo*(1 + 2*gamma)))/(4*e*gpo3); 00118 // *** 00119 00120 phi0 += xx*pol0.x()*pol1.x() + yy*pol0.y()*pol1.y() + zz*pol0.z()*pol1.z(); 00121 00122 { 00123 G4double xy = 0; 00124 G4double xz = (d*(e*gmo - gamma)*(-1 + 2*e*gmo - gamma))/(2*sqrttwo*gpo52); 00125 G4double yx = 0; 00126 G4double yz = 0; 00127 G4double zx = xz; 00128 G4double zy = 0; 00129 // G4cout<<"Non-diagonal Matrix Elements"<<G4endl; 00130 phi0+=yx*pol0.y()*pol1.x() + xy*pol0.x()*pol1.y(); 00131 phi0+=zx*pol0.z()*pol1.x() + xz*pol0.x()*pol1.z(); 00132 phi0+=zy*pol0.z()*pol1.y() + yz*pol0.y()*pol1.z(); 00133 } 00134 } 00135 // Final state polarisarion dependence 00136 phi2=G4ThreeVector(); 00137 phi3=G4ThreeVector(); 00138 00139 if (flag>=1) { 00140 // 00141 // Final Positron Ppl 00142 // 00143 // initial positron Kpl 00144 if (!pol0.IsZero()) { 00145 00146 G4double xxPplKpl = -((-1 + e)*(e*gmo - gamma)*(-(gamma*gpo) + e*(-2 + gamma + gamma2)))/ 00147 (4*e2*gpo*std::sqrt(gmo*gpo*(-1 + e + gamma - e*gamma)* (1 + e + gamma - e*gamma))); 00148 G4double xyPplKpl = 0; 00149 G4double xzPplKpl = ((e*gmo - gamma)*(-1 - gamma + e*gmo*(1 + 2*gamma)))/ 00150 (2*sqrttwo*e32*gmo*gpo2*std::sqrt(1 + e + gamma - e*gamma)); 00151 G4double yxPplKpl = 0; 00152 G4double yyPplKpl = (gamma2*gpo + e2*gmo2*(3 + gamma) - 00153 e*gmo*(1 + 2*gamma*(2 + gamma)))/(4*e2*gmo*gpo2); 00154 G4double yzPplKpl = 0; 00155 G4double zxPplKpl = ((e*gmo - gamma)*(1 + e*(-1 + 2*e*gmo - 2*gamma)*gmo + gamma))/ 00156 (2*sqrttwo*e*gmo*gpo2*std::sqrt(e*(1 + e + gamma - e*gamma))); 00157 G4double zyPplKpl = 0; 00158 G4double zzPplKpl = -((e*gmo - gamma)*std::sqrt((1 - e)/(e - e*gamma2 + gpo2))* 00159 (2*e2*gmo2 + gamma + gamma2 - e*(-2 + gamma + gamma2)))/ 00160 (4*e2*(-1 + gamma2)); 00161 00162 phi2[0] += xxPplKpl*pol0.x() + xyPplKpl*pol0.y() + xzPplKpl*pol0.z(); 00163 phi2[1] += yxPplKpl*pol0.x() + yyPplKpl*pol0.y() + yzPplKpl*pol0.z(); 00164 phi2[2] += zxPplKpl*pol0.x() + zyPplKpl*pol0.y() + zzPplKpl*pol0.z(); 00165 } 00166 // initial electron Kmn 00167 if (!pol1.IsZero()) { 00168 G4double xxPplKmn = ((-1 + e)*(e*(-2 + gamma)*gmo + gamma))/(4*e*gpo32*std::sqrt(1 + e2*gmo + gamma - 2*e*gamma)); 00169 G4double xyPplKmn = 0; 00170 G4double xzPplKmn = (-1 + e*gmo + gmo*gamma)/(2*sqrttwo*gpo2* std::sqrt(e*(1 + e + gamma - e*gamma))); 00171 G4double yxPplKmn = 0; 00172 G4double yyPplKmn = (-1 - 2*gamma + e*gmo*(3 + gamma))/(4*e*gpo2); 00173 G4double yzPplKmn = 0; 00174 G4double zxPplKmn = (1 + 2*e2*gmo2 + gamma + gamma2 + e*(1 + (3 - 4*gamma)*gamma))/ 00175 (2*sqrttwo*gpo2*std::sqrt(e*(1 + e + gamma - e*gamma))); 00176 G4double zyPplKmn = 0; 00177 G4double zzPplKmn = -(std::sqrt((1 - e)/(e - e*gamma2 + gpo2))* 00178 (2*e2*gmo2 + gamma + 2*gamma2 + e*(2 + gamma - 3*gamma2)))/(4*e*gpo); 00179 00180 phi2[0] += xxPplKmn*pol1.x() + xyPplKmn*pol1.y() + xzPplKmn*pol1.z(); 00181 phi2[1] += yxPplKmn*pol1.x() + yyPplKmn*pol1.y() + yzPplKmn*pol1.z(); 00182 phi2[2] += zxPplKmn*pol1.x() + zyPplKmn*pol1.y() + zzPplKmn*pol1.z(); 00183 } 00184 // 00185 // Final Electron Pmn 00186 // 00187 // initial positron Kpl 00188 if (!pol0.IsZero()) { 00189 G4double xxPmnKpl = ((-1 + e*gmo)*(2 + gamma))/(4*gpo* std::sqrt(e*(2 + e*gmo)*gpo)); 00190 G4double xyPmnKpl = 0; 00191 G4double xzPmnKpl = (std::sqrt((-1 + e)/(-2 + e - e*gamma))* 00192 (e + gamma + e*gamma - 2*(-1 + e)*gamma2))/(2*sqrttwo*e*gpo2); 00193 G4double yxPmnKpl = 0; 00194 G4double yyPmnKpl = (-1 - 2*gamma + e*gmo*(3 + gamma))/(4*e*gpo2); 00195 G4double yzPmnKpl = 0; 00196 G4double zxPmnKpl = -((-1 + e)*(1 + 2*e*gmo)*(e*gmo - gamma))/ 00197 (2*sqrttwo*e*std::sqrt(-((-1 + e)*(2 + e*gmo)))*gpo2); 00198 G4double zyPmnKpl = 0; 00199 G4double zzPmnKpl = (-2 + 2*e2*gmo2 + gamma*(-1 + 2*gamma) + 00200 e*(-2 + (5 - 3*gamma)*gamma))/(4*std::sqrt(e*(2 + e*gmo))* gpo32); 00201 00202 phi3[0] += xxPmnKpl*pol0.x() + xyPmnKpl*pol0.y() + xzPmnKpl*pol0.z(); 00203 phi3[1] += yxPmnKpl*pol0.x() + yyPmnKpl*pol0.y() + yzPmnKpl*pol0.z(); 00204 phi3[2] += zxPmnKpl*pol0.x() + zyPmnKpl*pol0.y() + zzPmnKpl*pol0.z(); 00205 } 00206 // initial electron Kmn 00207 if (!pol1.IsZero()) { 00208 G4double xxPmnKmn = -((2 + e*gmo)*(-1 + e*gmo - gamma)*(e*gmo - gamma)* 00209 (-2 + gamma))/(4*gmo*egmp32); 00210 G4double xyPmnKmn = 0; 00211 G4double xzPmnKmn = ((e*gmo - gamma)* 00212 std::sqrt((-1 + e + gamma - e*gamma)/(2 + e*gmo))* 00213 (e + gamma - e*gamma + gamma2))/ 00214 (2*sqrttwo*e2*gmo32*gpo2); 00215 G4double yxPmnKmn = 0; 00216 G4double yyPmnKmn = (gamma2*gpo + e2*gmo2*(3 + gamma) - 00217 e*gmo*(1 + 2*gamma*(2 + gamma)))/(4*e2*gmo*gpo2); 00218 G4double yzPmnKmn = 0; 00219 G4double zxPmnKmn = -((-1 + e)*(e*gmo - gamma)*(e*gmo + 2*e2*gmo2 - gamma*gpo))/ 00220 (2*sqrttwo*e2*std::sqrt(-((-1 + e)*(2 + e*gmo)))* gmo*gpo2); 00221 G4double zyPmnKmn = 0; 00222 G4double zzPmnKmn = ((e*gmo - gamma)*std::sqrt(e/((2 + e*gmo)*gpo))* 00223 (-(e*(-2 + gamma)*gmo) + 2*e2*gmo2 + (-2 + gamma)*gpo))/(4*e2*(-1 + gamma2)); 00224 00225 phi3[0] += xxPmnKmn*pol1.x() + xyPmnKmn*pol1.y() + xzPmnKmn*pol1.z(); 00226 phi3[1] += yxPmnKmn*pol1.x() + yyPmnKmn*pol1.y() + yzPmnKmn*pol1.z(); 00227 phi3[2] += zxPmnKmn*pol1.x() + zyPmnKmn*pol1.y() + zzPmnKmn*pol1.z(); 00228 } 00229 } 00230 phi0 *= pref; 00231 phi2 *= pref; 00232 phi3 *= pref; 00233 00234 }
G4double G4PolarizedBhabhaCrossSection::TotalXSection | ( | G4double | xmin, | |
G4double | xmax, | |||
G4double | y, | |||
const G4StokesVector & | pol0, | |||
const G4StokesVector & | pol1 | |||
) | [virtual] |
Reimplemented from G4VPolarizedCrossSection.
Definition at line 249 of file G4PolarizedBhabhaCrossSection.cc.
References G4cout, and G4endl.
00252 { 00253 G4double xs=0.; 00254 00255 G4double x=xmin; 00256 00257 if (xmax != 1.) G4cout<<" warning xmax expected to be 1 but is "<<xmax<< G4endl; 00258 00259 // re -> electron radius^2; 00260 G4double re2 = classic_electr_radius * classic_electr_radius; 00261 G4double gamma2=gamma*gamma; 00262 G4double gmo2 = (gamma - 1.)*(gamma - 1.); 00263 G4double gpo2 = (gamma + 1.)*(gamma + 1.); 00264 G4double gpo3 = gpo2*(gamma + 1.); 00265 G4double logMEM = std::log(x); 00266 G4double pref = twopi*re2/(gamma - 1.0); 00267 // unpolarise XS 00268 G4double sigma0 = 0.; 00269 sigma0 += -gmo2*(gamma - 1.)*x*x*x/3. + gmo2*gamma*x*x; 00270 sigma0 += -(gamma - 1.)*(3.*gamma*(gamma + 2.) +4.)*x; 00271 sigma0 += (gamma*(gamma*(gamma*(4.*gamma - 1.) - 21.) - 7.)+13.)/(3.*(gamma - 1.)); 00272 sigma0 /= gpo3; 00273 sigma0 += logMEM*(2. - 1./gpo2); 00274 sigma0 += gamma2/((gamma2 - 1.)*x); 00275 // longitudinal part 00276 G4double sigma2=0.; 00277 sigma2 += logMEM*gamma*(gamma + 1.)*(2.*gamma + 1.); 00278 sigma2 += gamma*(7.*gamma*(gamma + 1.) - 2.)/3.; 00279 sigma2 += -(3.*gamma + 1.)*(gamma2 + gamma - 1.)*x; 00280 sigma2 += (gamma - 1.)*gamma*(gamma + 3.)*x*x; 00281 sigma2 += -gmo2*(gamma + 3.)*x*x*x/3.; 00282 sigma2 /= gpo3; 00283 // transverse part 00284 G4double sigma3=0.; 00285 sigma3 += 0.5*(gamma + 1.)*(3.*gamma + 1.)*logMEM; 00286 sigma3 += (gamma*(5.*gamma - 4.) - 13.)/6.; 00287 sigma3 += 0.5*(gamma2 + 3.)*x; 00288 sigma3 += - 2.*(gamma - 1.)*gamma*x*x; // *AS* changed sign 00289 sigma3 += 2.*gmo2*x*x*x/3.; 00290 sigma3 /= gpo3; 00291 // total cross section 00292 xs+=pref*(sigma0 + sigma2*pol0.z()*pol1.z() + sigma3*(pol0.x()*pol1.x()+pol0.y()*pol1.y())); 00293 00294 return xs; 00295 }
G4double G4PolarizedBhabhaCrossSection::XSection | ( | const G4StokesVector & | pol2, | |
const G4StokesVector & | pol3 | |||
) | [virtual] |
Implements G4VPolarizedCrossSection.
Definition at line 236 of file G4PolarizedBhabhaCrossSection.cc.
References G4StokesVector::IsZero().
00238 { 00239 G4double xs=0.; 00240 xs+=phi0; 00241 00242 G4bool polarized=(!pol2.IsZero())||(!pol3.IsZero()); 00243 if (polarized) { 00244 xs+=phi2*pol2 + phi3*pol3; 00245 } 00246 return xs; 00247 }