PYTHIA  8.303
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)
 Functions to approximate pdfs for ISR. More...
 
double gammaPDFRefScale (int)
 
int sampleGammaValFlavor (double Q2)
 Set the valence content for photons. More...
 
double xfIntegratedTotal (double Q2)
 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 ()
 Destructor.
 
virtual bool isSetup ()
 Confirm that PDF has been set up (important for LHAPDF and H1 Pomeron).
 
virtual void newValenceContent (int idVal1In, int idVal2In)
 Dynamic choice of meson valence flavours for pi0, K0S, K0L, Pomeron.
 
virtual void setExtrapolate (bool)
 Allow extrapolation beyond boundaries. This is optional.
 
virtual double xf (int id, double x, double Q2)
 Read out parton density. More...
 
virtual double xfVal (int id, double x, double Q2)
 Read out valence and sea part of parton densities. More...
 
virtual 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 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.
 

Additional Inherited Members

- Protected Member Functions inherited from PDF
void setValenceContent ()
 Resolve valence content for assumed meson. Possibly modified later. More...
 
void printErr (string errMsg, Info *infoPtr=0)
 Small routine for error printout, depending on infoPtr existing or not.
 
- Protected Attributes inherited from PDF
int idBeam
 Store relevant quantities.
 
int idBeamAbs
 
int idSav
 
int idVal1
 
int idVal2
 
double xSav
 
double Q2Sav
 
double xu
 
double xd
 
double xs
 
double xubar
 
double xdbar
 
double xsbar
 
double xc
 
double xb
 
double xg
 
double xlepton
 
double xgamma
 
double xuVal
 
double xuSea
 
double xdVal
 
double xdSea
 
bool isSet
 
bool isInit
 
double xsVal
 More valence and sea flavors for photon PDFs.
 
double xcVal
 
double xbVal
 
double xsSea
 
double xcSea
 
double xbSea
 
bool hasGammaInLepton
 True if a photon beam inside a lepton beam, otherwise set false.
 

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)
virtual

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   
)
virtual

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)
virtual

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)
virtual

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: