LHAPDF 6.5.4
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Calculator interface for computing alpha_s(Q2) in various ways. More...
#include <AlphaS.h>
Public Member Functions | |
AlphaS () | |
Base class constructor for default param setup. | |
virtual | ~AlphaS () |
Destructor. | |
alpha_s values | |
double | alphasQ (double q) const |
Calculate alphaS(Q) | |
virtual double | alphasQ2 (double q2) const =0 |
Protected Member Functions | |
Calculating beta function values | |
double | _beta (int i, int nf) const |
std::vector< double > | _betas (int nf) const |
Protected Attributes | |
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. | |
alpha_s metadata | |
enum | FlavorScheme { FIXED , VARIABLE } |
Enum of flavor schemes. | |
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. | |
double | quarkThreshold (int id) const |
Get a flavor scale threshold by PDG code. | |
void | setQuarkThreshold (int id, double value) |
Set a flavor threshold by PDG code (= quark masses by default) | |
int | orderQCD () |
void | setOrderQCD (int order) |
Set the order of QCD (expressed as number of loops) | |
void | setMZ (double mz) |
Set the Z mass used in this alpha_s. | |
void | setAlphaSMZ (double alphas) |
Set the alpha_s(MZ) used in this alpha_s. | |
void | setMassReference (double mref) |
Set the Z mass used in this alpha_s. | |
void | setAlphaSReference (double alphas) |
Set the alpha_s(MZ) used in this alpha_s. | |
virtual void | setLambda (unsigned int, double) |
Set the {i}th Lambda constant for i active flavors. | |
virtual std::string | type () const =0 |
Get the implementation type of this AlphaS. | |
void | setFlavorScheme (FlavorScheme scheme, int nf=-1) |
Set flavor scheme of alpha_s solver. | |
FlavorScheme | flavorScheme () const |
Get flavor scheme. | |
Calculator interface for computing alpha_s(Q2) in various ways.
The design of the AlphaS classes is that they are substitutible (cf. polymorphism) and are entirely non-dependent on the PDF and Info objects: hence they can be used by external code that actually doesn't want to do anything at all with PDFs, but which just wants to do some alpha_s interpolation.
Calculate the i'th beta function given the number of active flavours Currently limited to 0 <= i <= 3 Calculated using the MSbar scheme
Calculate a vector of beta functions given the number of active flavours Currently returns a 4-element vector of beta0 – beta3
Calculate alphaS(Q2)
Implemented in LHAPDF::AlphaS_Analytic, LHAPDF::AlphaS_Ipol, and LHAPDF::AlphaS_ODE.
Calculate the number of active flavours at energy scale Q2.
Reimplemented in LHAPDF::AlphaS_Analytic.
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inline |
Get the order of QCD (expressed as number of loops)
Used explicitly in the analytic and ODE solvers.
Get a flavor scale threshold by PDG code.
Used in the analytic and ODE solvers.
Set the alpha_s(MZ) used in this alpha_s.
Used in the ODE solver.
Set the alpha_s(MZ) used in this alpha_s.
Used in the ODE solver.
Set the {i}th Lambda constant for i active flavors.
Used in the analytic solver.
Reimplemented in LHAPDF::AlphaS_Analytic.
Set the Z mass used in this alpha_s.
Used in the ODE solver.
Set the Z mass used in this alpha_s.
Used in the ODE solver.
Set the order of QCD (expressed as number of loops)
Used in the analytic and ODE solvers.
Set quark masses by PDG code.
Used in the analytic and ODE solvers.
Set a flavor threshold by PDG code (= quark masses by default)
Used in the analytic and ODE solvers.
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pure virtual |
Get the implementation type of this AlphaS.
Implemented in LHAPDF::AlphaS_Analytic, LHAPDF::AlphaS_Ipol, and LHAPDF::AlphaS_ODE.
Masses of quarks in GeV Used for working out flavor thresholds and the number of quarks that are active at energy scale Q.