PYTHIA  8.303
Public Member Functions | List of all members
DGLAP Class Reference

A class containing DGLAP splitting functions for limit checking. More...

#include <VinciaAntennaFunctions.h>

Public Member Functions

 DGLAP ()
 Constructor.
 
double Pg2gg (double z, int hA=9, int hB=9, int hC=9)
 DGLAP splitting functions. More...
 
double Pg2qq (double z, int hA=9, int hB=9, int hC=9, double mu=0.)
 
double Pq2qg (double z, int hA=9, int hB=9, int hC=9, double mu=0.)
 
double Pq2gq (double z, int hA=9, int hB=9, int hC=9, double mu=0.)
 
double Pg2qq (double z, double mu)
 Wrappers to get unpolarized massive Altarelli-Pariis kernels (mu = m/Q).
 
double Pq2qg (double z, double mu)
 
double Pq2gq (double z, double mu)
 
double Pg2ggLin (double z, int polA=9, int polB=9, int polC=9)
 Pg2ggLin, written without factor 2 normalization convention. More...
 
double Pg2qqLin (double z, int polA=9, int hB=9, int hC=9, double mu=0.)
 
double Pq2qgLin (double z, int hA=9, int hB=9, int polC=9, double mu=0.)
 
double Pq2gqLin (double z, int hA=9, int polB=9, int hC=9, double mu=0.)
 

Detailed Description

A class containing DGLAP splitting functions for limit checking.

Member Function Documentation

double Pg2gg ( double  z,
int  hA = 9,
int  hB = 9,
int  hC = 9 
)

DGLAP splitting functions.

Helicity-dependent Altarelli-Parisi kernels (mu = m/Q). Note, Pg2gg is written with standard factor 2 normalization convention.

DGLAP splitting kernels with helicity-dependence (from Larkoski, Peskin, http:///arxiv.org/abs/arXiv:0908.2450). Note, Pg2gg is written with the standard factor 2 normalization convention and gives a factor 2 difference with respect PYTHIA FSR. The difference is related to whether P is interpreted as the probability for gluon A to branch to BC (without factor 2), or as the probability for gluon B to have originated from A (with factor 2). Both quarks and gluons have definite helicities: 9: unpolarized +1: right-handed -1: left-handed where z is momentum fraction taken by B in A -> BC. Pg2gg, written with the standard factor 2 normalization convention.

If A unpolarized, treat as unpolarized.

Expressions coded for hA = 1. Flip helicities if hA = -1.

double Pg2ggLin ( double  z,
int  polA = 9,
int  polB = 9,
int  polC = 9 
)

Pg2ggLin, written without factor 2 normalization convention.

Altarelli-Parisi kernels with linear in/out polarizations for gluons: pol = +1 for in-plane, -1 for out-of-plane.

DGLAP splitting kernels with polarization-dependence (from Ellis, Stirling, Webber) Gluons are plane polarized, quarks have helicities: 9: unpolarized +1: in plane / right-handed -1: out-of-plane / left-handed where z is momentum fraction taken by B in A -> BC.

If A unpolarized, treat as unpolarized.

A in-plane polarized.

A out-of-plane polarized.

double Pg2qq ( double  z,
int  hA = 9,
int  hB = 9,
int  hC = 9,
double  mu2 = 0. 
)

Pg2qq, B is quark, C is antiquark. Note, mass corrections not implemented.

If A unpolarized, treat as unpolarized.

Preserve quark helicity.

Expressions coded for hA = 1. Flip helicities if hA = -1.

double Pg2qqLin ( double  z,
int  polA = 9,
int  hB = 9,
int  hC = 9,
double  mu = 0. 
)

Pg2qqLin, B is quark, C is antiquark. Note, mass corrections not implemented.

If A unpolarized, treat as unpolarized.

Preserve quark helicity.

A in-plane polarized.

A out-of-plane polarized.

double Pq2gq ( double  z,
int  hA = 9,
int  hB = 9,
int  hC = 9,
double  mu = 0. 
)

Pq2qg, B is gluon, C is quark. Note, mass corrections not implemented for polarised.

double Pq2gqLin ( double  z,
int  hA = 9,
int  polB = 9,
int  hC = 9,
double  mu = 0. 
)

Pq2qgLin, B is gluon, C is quark. Note, mass corrections not implemented.

double Pq2qg ( double  z,
int  hA = 9,
int  hB = 9,
int  hC = 9,
double  mu2 = 0. 
)

Pq2qg, B is quark, C is gluon. Note, mass corrections not implemented for polarised.

If A unpolarized, treat as unpolarized.

Preserve quark helicity

Expressions coded for hA = +1. Flip helicities if hA = -1.

double Pq2qgLin ( double  z,
int  hA = 9,
int  hB = 9,
int  polC = 9,
double  mu = 0. 
)

Pq2qgLin, B is quark, C is gluon. Note, mass corrections not implemented.

If A unpolarized, treat as unpolarized.

Preserve quark helicity.

Gluon polarized in plane.

Gluon polarized out of plane.


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