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Differential D90 Diff 388 src/EvtGenModels/EvtBtoXsgammaFermiUtil.cpp

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src/EvtGenModels/EvtBtoXsgammaFermiUtil.cpp

Show First 20 Lines • Show All 48 Lines • ▼ Show 20 Linesdouble EvtBtoXsgammaFermiUtil::FermiGaussFunc( double y,
return ( pow( 1. - ( y / coeffs[1] ), coeffs[2] ) * return ( pow( 1. - ( y / coeffs[1] ), coeffs[2] ) *
exp( -pow( coeffs[3], 2. ) * pow( 1. - ( y / coeffs[1] ), 2. ) ) ) / exp( -pow( coeffs[3], 2. ) * pow( 1. - ( y / coeffs[1] ), 2. ) ) ) /
coeffs[4]; coeffs[4];
} }
double EvtBtoXsgammaFermiUtil::FermiGaussFuncRoot( double EvtBtoXsgammaFermiUtil::FermiGaussFuncRoot(
double lambdabar, double lam1, double mb, std::vector<double>& gammaCoeffs ) double lambdabar, double lam1, double mb, std::vector<double>& gammaCoeffs )
{ {
std::vector<double> coeffs1 = {0.2, lambdabar, 0.0}; std::vector<double> coeffs1 = { 0.2, lambdabar, 0.0 };
std::vector<double> coeffs2 = {0.2, lambdabar, -lam1 / 3.}; std::vector<double> coeffs2 = { 0.2, lambdabar, -lam1 / 3. };
auto lhFunc = EvtItgTwoCoeffFcn{&FermiGaussRootFcnA, -mb, lambdabar, auto lhFunc = EvtItgTwoCoeffFcn{ &FermiGaussRootFcnA, -mb, lambdabar,
coeffs1, gammaCoeffs}; coeffs1, gammaCoeffs };
auto rhFunc = EvtItgTwoCoeffFcn{&FermiGaussRootFcnB, -mb, lambdabar, auto rhFunc = EvtItgTwoCoeffFcn{ &FermiGaussRootFcnB, -mb, lambdabar,
coeffs2, gammaCoeffs}; coeffs2, gammaCoeffs };
auto rootFinder = EvtBtoXsgammaRootFinder{}; auto rootFinder = EvtBtoXsgammaRootFinder{};
return rootFinder.GetGaussIntegFcnRoot( &lhFunc, &rhFunc, 1.0e-4, 1.0e-4, return rootFinder.GetGaussIntegFcnRoot( &lhFunc, &rhFunc, 1.0e-4, 1.0e-4,
40, 40, -mb, lambdabar, 0.2, 0.4, 40, 40, -mb, lambdabar, 0.2, 0.4,
1.0e-6 ); 1.0e-6 );
} }
double EvtBtoXsgammaFermiUtil::FermiGaussRootFcnA( double EvtBtoXsgammaFermiUtil::FermiGaussRootFcnA(
▲ Show 20 Lines • Show All 103 Lines • ▼ Show 20 Lines if ( ax < 3.75 ) {
y * ( 0.163801e-2 + y * ( -0.1031555e-1 + y * ans ) ) ) ); y * ( 0.163801e-2 + y * ( -0.1031555e-1 + y * ans ) ) ) );
ans *= ( exp( ax ) / sqrt( ax ) ); ans *= ( exp( ax ) / sqrt( ax ) );
} }
return x < 0.0 ? -ans : ans; return x < 0.0 ? -ans : ans;
} }
double EvtBtoXsgammaFermiUtil::FermiRomanFuncRoot( double lambdabar, double lam1 ) double EvtBtoXsgammaFermiUtil::FermiRomanFuncRoot( double lambdabar, double lam1 )
{ {
auto lhFunc = EvtItgFunction{&FermiRomanRootFcnA, -1.e-6, 1.e6}; auto lhFunc = EvtItgFunction{ &FermiRomanRootFcnA, -1.e-6, 1.e6 };
auto rootFinder = EvtBtoXsgammaRootFinder{}; auto rootFinder = EvtBtoXsgammaRootFinder{};
double rhSide = 1.0 - ( lam1 / ( 3.0 * lambdabar * lambdabar ) ); double rhSide = 1.0 - ( lam1 / ( 3.0 * lambdabar * lambdabar ) );
double rho = rootFinder.GetRootSingleFunc( &lhFunc, rhSide, 0.1, 0.4, 1.0e-6 ); double rho = rootFinder.GetRootSingleFunc( &lhFunc, rhSide, 0.1, 0.4, 1.0e-6 );
//rho=0.250353; //rho=0.250353;
EvtGenReport( EVTGEN_INFO, "EvtGen" ) EvtGenReport( EVTGEN_INFO, "EvtGen" )
<< "rho/2 " << rho / 2. << " bessel " << BesselK1( rho / 2. ) << endl; << "rho/2 " << rho / 2. << " bessel " << BesselK1( rho / 2. ) << endl;
▲ Show 20 Lines • Show All 46 Lines • Show Last 20 Lines