PYTHIA  8.311
Public Member Functions | List of all members
CJKL Class Reference

#include <PartonDistributions.h>

Inheritance diagram for CJKL:
PDF

Public Member Functions

 CJKL (int idBeamIn=22, Rndm *rndmPtrIn=0)
 Constructor. Needs the randon number generator to sample valence content.
 
double gammaPDFxDependence (int id, double) override
 Functions to approximate pdfs for ISR. More...
 
double gammaPDFRefScale (int) override
 
int sampleGammaValFlavor (double Q2) override
 Set the valence content for photons. More...
 
double xfIntegratedTotal (double Q2) override
 The total x-integrated PDFs. Relevant for MPIs with photon beams. More...
 
- Public Member Functions inherited from PDF
 PDF (int idBeamIn=2212)
 Constructor.
 
virtual ~PDF ()
 Virtual destructor.
 
virtual bool init (int, string, int, Logger *)
 
bool isSetup ()
 Confirm that PDF has been set up (important for LHAPDF and H1 Pomeron).
 
virtual void setBeamID (int idBeamIn)
 Switch to new beam particle identities; for similar hadrons only.
 
void resetValenceContent ()
 Set valence content. More...
 
void setValenceContent (int idVal1In, int idVal2In, int idVal3In)
 
virtual void setExtrapolate (bool)
 Allow extrapolation beyond boundaries. This is optional.
 
double xf (int id, double x, double Q2)
 Read out parton density. More...
 
double xfVal (int id, double x, double Q2)
 Read out valence and sea part of parton densities. More...
 
double xfSea (int id, double x, double Q2)
 Only sea part of parton densities. More...
 
virtual bool insideBounds (double, double)
 Check whether x and Q2 values fall inside the fit bounds (LHAPDF6 only).
 
virtual double alphaS (double)
 Access the running alpha_s of a PDF set (LHAPDF6 only).
 
virtual double mQuarkPDF (int)
 Return quark masses used in the PDF fit (LHAPDF6 only).
 
virtual int nMembers ()
 Return number of members of this PDF family (LHAPDF6 only).
 
virtual void calcPDFEnvelope (int, double, double, int)
 Calculate PDF envelope.
 
virtual void calcPDFEnvelope (pair< int, int >, pair< double, double >, double, int)
 
virtual PDFEnvelope getPDFEnvelope ()
 
virtual double xGamma ()
 Return the sampled value for x_gamma.
 
virtual void xPom (double=-1.0)
 Keep track of pomeron momentum fraction.
 
virtual double xfFlux (int, double, double)
 Return accurate and approximated photon fluxes and PDFs.
 
virtual double xfApprox (int, double, double)
 
virtual double xfGamma (int, double, double)
 
virtual double intFluxApprox ()
 
virtual bool hasApproxGammaFlux ()
 
virtual double getXmin ()
 Return the kinematical limits and sample Q2 and x.
 
virtual double getXhadr ()
 
virtual double sampleXgamma (double)
 
virtual double sampleQ2gamma (double)
 
virtual double fluxQ2dependence (double)
 
virtual double xfMax (int id, double x, double Q2)
 Normal PDFs unless gamma inside lepton -> an overestimate for sampling.
 
virtual double xfSame (int id, double x, double Q2)
 Normal PDFs unless gamma inside lepton -> Do not sample x_gamma.
 
virtual void setVMDscale (double=1.)
 Allow for new scaling factor for VMD PDFs.
 
bool sSymmetric () const
 Return if s/sbar, c/cbar, and b/bbar PDFs are symmetric.
 
bool cSymmetric () const
 
bool bSymmetric () const
 
void sSymmetric (bool sSymmetricIn)
 Set s/sbar, c/cbar, and b/bbar PDFs symmetric.
 
void cSymmetric (bool cSymmetricIn)
 
void bSymmetric (bool bSymmetricIn)
 

Additional Inherited Members

- Protected Member Functions inherited from PDF
void printErr (string loc, string errMsg, Logger *loggerPtr=nullptr)
 Small routine for error printout, depending on loggerPtr existing or not.
 
double xfRaw (int id) const
 Get the raw stored value for the quark variable corresponding to the id. More...
 
bool isValence (int id) const
 Check whether the specified id is a valence quark.
 
- Protected Attributes inherited from PDF
int idBeam
 Store relevant quantities.
 
int idBeamAbs
 
int idSav
 
int idVal1
 
int idVal2
 
int idVal3
 
double xSav
 
double Q2Sav
 
double xu
 Stored quantities.
 
double xd
 
double xs
 
double xubar
 
double xdbar
 
double xsbar
 
double xc
 
double xb
 
double xcbar
 
double xbbar
 
double xg
 
double xlepton
 
double xgamma
 
bool isSet
 
bool isInit
 
int beamType
 
bool hasGammaInLepton
 True if a photon beam inside a lepton beam, otherwise set false.
 
bool sSymmetricSave = false
 Whether to treat flavoured PDFs as symmetric, for efficiency.
 
bool cSymmetricSave = true
 
bool bSymmetricSave = true
 

Detailed Description

Gives the CJKL leading order parton distribution function set in parametrized form for the real photons. Authors: F.Cornet, P.Jankowski, M.Krawczyk and A.Lorca, Phys. Rev. D68: 014010, 2003.

Member Function Documentation

double gammaPDFRefScale ( int  id)
overridevirtual

Returns the reference scale for the logarithmic scale dependence to approximate the PDFs in ISR. Mass squared for heavy quarks and 0.2 for others.

Reimplemented from PDF.

double gammaPDFxDependence ( int  id,
double   
)
overridevirtual

Functions to approximate pdfs for ISR.

Returns the x-dependence decoupled from the logarithmic scale dependence to approximate the PDFs from below for ISR. Currently flat in x (no second argument), could be improved.

Reimplemented from PDF.

int sampleGammaValFlavor ( double  Q2)
overridevirtual

Set the valence content for photons.

Set valence content of the photon beam using parametrized Q2-dependence.

Freeze the scale below the initial scale.

Calculate the x-integrated valence part of hadron-like contribution.

Set the reference scales and charges.

For u- and d-quarks valence contribution from hadron-like part.

Normalization of the point-like part.

Logarithmic Q^2 evolution of gamma -> qqbar splitting for each flavor.

Sample the valence flavor.

Reimplemented from PDF.

double xfIntegratedTotal ( double  Q2)
overridevirtual

The total x-integrated PDFs. Relevant for MPIs with photon beams.

Sum of integrated PDFs dx x f(x,Q^2) at given scale Q^2. Integrals parametrized as a0 + a1*log(Q^2/Q0^2).

Freeze the scale below the initial scale.

Set the reference scales and relative contributions. Gluons and u/d quarks has some non-perturbative contribution, others only radiative contributions. Derived by fitting by eye to a0 + a1*log(Q^2/Q0^2).

Logarithmic Q^2 evolution for each flavor. quarks two times, gluon coefficents scaled appropriately.

Reimplemented from PDF.


The documentation for this class was generated from the following files: