Solve the differential equation in alphaS using an implementation of RK4. More...
#include <AlphaS.h>
Inheritance diagram for LHAPDF::AlphaS_ODE:
Public Member Functions | |
| std::string | type () const |
| Implementation type of this solver. | |
| double | alphasQ2 (double q2) const |
| Calculate alphaS(Q2) | |
| void | setMZ (double mz) |
| Set MZ, and also the caching flag. | |
| void | setAlphaSMZ (double alphas) |
| Set alpha_s(MZ), and also the caching flag. | |
| void | setMassReference (double mref) |
| Set reference mass, and also the caching flag. | |
| void | setAlphaSReference (double alphas) |
| Set alpha_s(MZ), and also the caching flag. | |
| void | setQValues (const std::vector< double > &qs) |
| Set the array of Q values for interpolation, and also the caching flag. | |
| void | setQ2Values (std::vector< double > q2s) |
| Set the array of Q2 values for interpolation, and also the caching flag. More... | |
 Public Member Functions inherited from LHAPDF::AlphaS | |
| AlphaS () | |
| Base class constructor for default param setup. | |
| virtual | ~AlphaS () |
| Destructor. | |
| double | alphasQ (double q) const |
| Calculate alphaS(Q) | |
| int | numFlavorsQ (double q) const |
| Calculate the number of active flavours at energy scale Q. | |
| virtual int | numFlavorsQ2 (double q2) const |
| Calculate the number of active flavours at energy scale Q2. | |
| double | quarkMass (int id) const |
| Get a quark mass by PDG code. | |
| void | setQuarkMass (int id, double value) |
| Set quark masses by PDG code. More... | |
| double | quarkThreshold (int id) const |
| Get a flavor scale threshold by PDG code. More... | |
| void | setQuarkThreshold (int id, double value) |
| Set a flavor threshold by PDG code (= quark masses by default) More... | |
| int | orderQCD () |
| void | setOrderQCD (int order) |
| Set the order of QCD (expressed as number of loops) More... | |
| void | setMZ (double mz) |
| Set the Z mass used in this alpha_s. More... | |
| void | setAlphaSMZ (double alphas) |
| Set the alpha_s(MZ) used in this alpha_s. More... | |
| void | setMassReference (double mref) |
| Set the Z mass used in this alpha_s. More... | |
| void | setAlphaSReference (double alphas) |
| Set the alpha_s(MZ) used in this alpha_s. More... | |
| virtual void | setLambda (unsigned int, double) |
| Set the {i}th Lambda constant for i active flavors. More... | |
| void | setFlavorScheme (FlavorScheme scheme, int nf=-1) |
| Set flavor scheme of alpha_s solver. | |
| FlavorScheme | flavorScheme () const |
| Get flavor scheme. | |
Private Member Functions | |
| double | _derivative (double t, double y, const std::vector< double > &beta) const |
| Calculate the derivative at Q2 = t, alpha_S = y. | |
| double | _decouple (double y, double t, unsigned int ni, unsigned int nf) const |
| void | _rk4 (double &t, double &y, double h, const double allowed_change, const vector< double > &bs) const |
| Calculate the next step using RK4 with adaptive step size. | |
| void | _solve (double q2, double &t, double &y, const double &allowed_relative, double h, double accuracy) const |
| Solve alpha_s for q2 using RK4. | |
| void | _interpolate () const |
| Create interpolation grid. | |
Private Attributes | |
| std::vector< double > | _q2s |
| Vector of Q2s in case specific anchor points are used. | |
| bool | _calculated |
| Whether or not the ODE has been solved yet. | |
| AlphaS_Ipol | _ipol |
| The interpolation used to get Alpha_s after the ODE has been solved. | |
Additional Inherited Members | |
| Public Types inherited from LHAPDF::AlphaS | |
| enum | FlavorScheme { FIXED , VARIABLE } |
| Enum of flavor schemes. | |
| Protected Member Functions inherited from LHAPDF::AlphaS | |
| double | _beta (int i, int nf) const |
| std::vector< double > | _betas (int nf) const |
| Protected Attributes inherited from LHAPDF::AlphaS | |
| int | _qcdorder |
| Order of QCD evolution (expressed as number of loops) | |
| double | _mz |
| Mass of the Z boson in GeV. | |
| double | _alphas_mz |
| Value of alpha_s(MZ) | |
| double | _mreference |
| Reference mass in GeV. | |
| double | _alphas_reference |
| Value of alpha_s(reference mass) | |
| bool | _customref |
| Decides whether to use custom reference values or fall back on MZ/AlphaS_MZ. | |
| std::map< int, double > | _quarkmasses |
| std::map< int, double > | _flavorthresholds |
| FlavorScheme | _flavorscheme |
| The flavor scheme in use. | |
| int | _fixflav |
| The allowed numbers of flavours in a fixed scheme. | |
Detailed Description
Solve the differential equation in alphaS using an implementation of RK4.
Member Function Documentation
◆ _decouple()
|
private |
Calculate the decoupling relation when going from num. flav. = ni -> nf abs(ni - nf) must be = 1
◆ setQ2Values()
|
inline |
Set the array of Q2 values for interpolation, and also the caching flag.
Writes to the same internal array as setQValues, appropriately transformed.
The documentation for this class was generated from the following file:
- /builds/hepcedar/lhapdf/include/LHAPDF/AlphaS.h
