Herwig
7.2.1
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This class is the abstract class from which all types of running couplings used in the Showering derive from. More...
#include <ShowerAlpha.h>
Public Member Functions | |
Standard constructors and destructors. | |
ShowerAlpha () | |
The default constructor. | |
virtual double | value (const Energy2 scale) const =0 |
Methods to return the coupling and the scaleFactor. More... | |
virtual double | overestimateValue () const =0 |
Virtual method, which should be overridden in a derived class to provide an overestimate approximation of the alpha value. | |
virtual double | ratio (const Energy2 scale, double factor=1.) const =0 |
Virtual method which returns the ratio of the running alpha value at the input scale to the overestimated value. More... | |
double | scaleFactor () const |
It returns the factor that multiplies the scale argument, , of the running coupling. More... | |
virtual void | initialize () |
Initialize this coupling. | |
Functions used by the persistent I/O system. | |
void | persistentOutput (PersistentOStream &os) const |
Function used to write out object persistently. More... | |
void | persistentInput (PersistentIStream &is, int version) |
Function used to read in object persistently. More... | |
Public Member Functions inherited from ThePEG::Interfaced | |
virtual bool | defaultInit () |
PPtr | getParticle (PID) const |
PDPtr | getParticleData (PID) const |
bool | used () const |
void | useMe () const |
tEGPtr | generator () const |
void | persistentOutput (PersistentOStream &os) const |
void | persistentInput (PersistentIStream &is, int version) |
PPtr | getParticle (PID) const |
PDPtr | getParticleData (PID) const |
bool | used () const |
void | useMe () const |
tEGPtr | generator () const |
void | persistentOutput (PersistentOStream &os) const |
void | persistentInput (PersistentIStream &is, int version) |
Public Member Functions inherited from ThePEG::InterfacedBase | |
string | fullName () const |
string | name () const |
string | path () const |
string | comment () const |
void | setup (istream &is) |
virtual IBPtr | fullclone () const |
virtual void | debugme () const |
void | update () |
void | init () |
virtual bool | preInitialize () const |
void | initrun () |
void | finish () |
void | touch () |
void | reset () |
void | clear () |
InitState | state () const |
bool | locked () const |
bool | touched () const |
void | persistentOutput (PersistentOStream &os) const |
void | persistentInput (PersistentIStream &is, int version) |
void | update () |
void | init () |
virtual bool | preInitialize () const |
void | initrun () |
void | finish () |
void | touch () |
void | reset () |
void | clear () |
InitState | state () const |
bool | locked () const |
bool | touched () const |
void | persistentOutput (PersistentOStream &os) const |
void | persistentInput (PersistentIStream &is, int version) |
Public Member Functions inherited from ThePEG::Base | |
void | debug () const |
Public Member Functions inherited from ThePEG::Pointer::ReferenceCounted | |
CounterType | referenceCount () const |
Public Member Functions inherited from ThePEG::Named | |
Named (const string &newName=string()) | |
Named (const Named &)=default | |
const string & | name () const |
bool | operator== (const Named &other) const |
bool | operator< (const Named &other) const |
Static Public Member Functions | |
static void | Init () |
The standard Init function used to initialize the interfaces. More... | |
Static Public Member Functions inherited from ThePEG::Interfaced | |
static void | Init () |
Static Public Member Functions inherited from ThePEG::InterfacedBase | |
static void | Init () |
Static Public Member Functions inherited from ThePEG::Base | |
static void | Init () |
Private Member Functions | |
ShowerAlpha & | operator= (const ShowerAlpha &)=delete |
The assignment operator is private and must never be called. More... | |
Private Attributes | |
double | _scaleFactor |
The scale factor. | |
Additional Inherited Members | |
Public Types inherited from ThePEG::InterfacedBase | |
enum | InitState |
Public Types inherited from ThePEG::Pointer::ReferenceCounted | |
typedef unsigned int | CounterType |
Public Attributes inherited from ThePEG::InterfacedBase | |
initializing | |
uninitialized | |
initialized | |
runready | |
Public Attributes inherited from ThePEG::Pointer::ReferenceCounted | |
const unsigned long | uniqueId |
Protected Member Functions inherited from ThePEG::Interfaced | |
void | reporeg (IBPtr object, string name) const |
bool | setDefaultReference (PtrT &ptr, string classname, string objectname) |
Interfaced (const string &newName) | |
Interfaced (const Interfaced &i) | |
void | setGenerator (tEGPtr generator) |
Protected Member Functions inherited from ThePEG::InterfacedBase | |
virtual IBPtr | clone () const=0 |
InterfacedBase (string newName) | |
InterfacedBase (const InterfacedBase &i) | |
virtual void | readSetup (istream &is) |
virtual void | doupdate () |
virtual void | doinit () |
virtual void | doinitrun () |
virtual void | dofinish () |
virtual IVector | getReferences () |
virtual void | rebind (const TranslationMap &) |
virtual void | readSetup (istream &is) |
virtual void | doupdate () |
virtual void | doinit () |
virtual void | doinitrun () |
virtual void | dofinish () |
virtual IVector | getReferences () |
virtual void | rebind (const TranslationMap &) |
Protected Member Functions inherited from ThePEG::Pointer::ReferenceCounted | |
ReferenceCounted (const ReferenceCounted &) | |
ReferenceCounted & | operator= (const ReferenceCounted &) |
ReferenceCounted (const ReferenceCounted &) | |
ReferenceCounted & | operator= (const ReferenceCounted &) |
Protected Member Functions inherited from ThePEG::Named | |
const Named & | operator= (const Named &other) |
const string & | name (const string &newName) |
Static Protected Member Functions inherited from ThePEG::Interfaced | |
static void | registerRepository (IBPtr) |
static void | registerRepository (IBPtr, string newName) |
This class is the abstract class from which all types of running couplings used in the Showering derive from.
The main purpose of this class, and the ones that derive from it, is to allow systematic uncertainties for the initial-state radiation and, independently, the final-state radiation effects, to be evaluated.
This is achieved by allowing a multiplicative factor, which is 1.0 for the "central value", for the scale argument, , of the running coupling. This factor, is given by the scaleFactor() member and the coupling returned by the value() member is such that
This scale factor is a parameter which is settable by the user, via the interface. Although, of course, it is not clear my how much we should scale in order to get a systematic error (but factors: 1/2 and 2 are quite common), this method provides a double side error, and it appears more sensible than the rough and one-sided evaluation obtained via turning off the I.S.R. and/or F.S.R. (possibilities which are, anyway, provided by Herwig).
Definition at line 49 of file ShowerAlpha.h.
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static |
The standard Init function used to initialize the interfaces.
Called exactly once for each class by the class description system before the main function starts or when this class is dynamically loaded.
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privatedelete |
The assignment operator is private and must never be called.
In fact, it should not even be implemented.
void Herwig::ShowerAlpha::persistentInput | ( | PersistentIStream & | is, |
int | version | ||
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Function used to read in object persistently.
is | the persistent input stream read from. |
version | the version number of the object when written. |
void Herwig::ShowerAlpha::persistentOutput | ( | PersistentOStream & | os | ) | const |
Function used to write out object persistently.
os | the persistent output stream written to. |
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pure virtual |
Virtual method which returns the ratio of the running alpha value at the input scale to the overestimated value.
scale | The scale |
Implemented in Herwig::ShowerAlphaQED, and Herwig::ShowerAlphaQCD.
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inline |
It returns the factor that multiplies the scale argument, , of the running coupling.
This is supposed to be 1.0 in normal conditions (central values) whereas different values can be useful for systematics evaluation for Initial State radiation or Final State radiation effects.
Definition at line 97 of file ShowerAlpha.h.
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pure virtual |
Methods to return the coupling and the scaleFactor.
Pure virtual method that is supposed to return the running alpha value evaluated at the input scale.
scale | The scale |
Implemented in Herwig::ShowerAlphaQED, and Herwig::ShowerAlphaQCD.