#include <SplittingsOnia.h>

Inheritance diagram for SplitOnia:

Public Member Functions
	SplitOnia (int idAIn, int idBIn, int idCIn, double ldmeIn, Info infoPtrIn, AlphaStrong alphaSPtrIn)
	Constructor that needs to be called by the subclass.

virtual	~SplitOnia ()=default
	Virtual destructor.

virtual double	overestimate (const TimeDipoleEnd &dip, double pT2Min, bool enh)
	Calculate the splitting overestimate. More...

virtual double	weight (const TimeDipoleEnd &dip) const =0

virtual double	generateZ (const TimeDipoleEnd &)

bool	isActive (const TimeDipoleEnd &dip, int id, double m)

bool	isOctet ()
	Check if the emission is a colour octet state.

bool	isEnhanced ()
	Check if the emission is enhanced.

void	setEnhance (const unordered_map< string, double > &enhanceFSRs)
	Set the enhancement factor.

double	enhanceWeight ()
	Return the enhancement weight.

virtual string	enhanceName () const
	Return the name to be used if this emission is enhanced.

virtual vector< int >	addEmitted (Event &, int, int, int, int, vector< TimeDipoleEnd > &)
	Possibility to add more than one emitted particle.

virtual void	updateDipole (TimeDipoleEnd &dip)
	Update the dipole end with the generated values.

bool	updateBranchVars (const TimeDipoleEnd *dip, Event &event, int &idRadIn, int &idEmtIn, int &colRadIn, int &acolRadIn, int &colEmtIn, int &acolEmtIn, int &appendEmtIn, double &pTorigIn, double &pTcorrIn, double &pzRadPlusEmtIn, double &pzRadIn, double &pzEmtIn, double &mRadIn, double &m2RadIn, double &mEmtIn)
	Update the passed branching variables with the internal values. More...

Protected Member Functions
virtual bool	kinematics (const TimeDipoleEnd *dip, Event &event)
	Update the internal kinematics. More...

virtual void	overestimate (const TimeDipoleEnd &, double)
	Set the z limits and return the difference.

virtual double	integrateZ () const

void	setOctetID (int state, double mSplit, Info *infoPtr)
	Set the colour octet ID and ensure in particle database. More...

double	alphaScale (double m2, double pT2, double s) const
	Return alpha_s at the requested scale.

Protected Attributes
int	idA

int	idB

int	idC

double	mA

double	mB

double	mC

double	m2A

double	m2B

double	m2C

double	enhance {1}
	Enhancement, max value of alpha_S, and long-distance matrix element.

double	ldme {-1}

double	cFac {0}
	The constant and variable overestimate prefactors.

double	oFac {0}

double	zMin {0}
	The z limits used in the overestimated z-integral and generated z value.

double	zMax {1}

double	zGen {0}

int	idRad {0}
	IDs, colors, and number of emitters to append.

int	idEmt {0}

int	colRad {0}

int	acolRad {0}

int	colEmt {0}

int	acolEmt {0}

int	appendEmt {1}

double	pTorig {0}
	Transverse and longitudinal momentum, and masses.

double	pTcorr {0}

double	pzRadPlusEmt {0}

double	pzRad {0}

double	pzEmt {0}

double	mRad {0}

double	m2Rad {0}

double	mEmt {0}

int	alphaMode {1}
	Mode to evaluate the final alpha_s scale.

Logger *	loggerPtr {}
	Logger pointer.

AlphaStrong *	alphaSPtr {}
	The alphaS object in current use.

Rndm *	rndmPtr {}
	The random number generator in current use.

Detailed Description

The SplitOnia encodes the generation of a particular emission of an onium state from a parton in a dipole.

The basic generation in the shower assumes a function of the form dP(pT2, z) = alphaS/2pi dpT2/pT2 dz F(pT2, z) in an A -> B + C splitting, where B takes a fraction z of the momentum of A.

A subclass of this base clase should encode not only the function F(pT2, z), but also an overestimate and the z-integral of this overestimate:

G(pT2, z) >= F(pT2, z) and OIZ = ^1 G(pT2, z) dz

The ratio F/G for a generated point should then be used as a weight for the phase space point generated. The subclass should also be able to generate the z according to the overestimate and possible other internal variables that have been integrated out.

Member Function Documentation

virtual double generateZ ( const TimeDipoleEnd & )

inlinevirtual

Generate internal degrees of freedom (in particluar z). Default behaviour is to generate z from a flat distribution.

Reimplemented in Split2QQbarXg82QQbarX8g, Split2QQbarXq82QQbarX8g, and Split2g2QQbar3S11gg.

virtual double integrateZ ( ) const

inlineprotectedvirtual

Integrate the distribution used to generate z. Default behaviour is to integrate a flat distribution.

bool isActive	(	const TimeDipoleEnd &	dip,
		int	id,
		double	m
	)

inline

Check if this emission is available for the current dipole end with the given ID of the radiator.

bool kinematics	(	const TimeDipoleEnd *	dip,
		Event &	event
	)

protectedvirtual

Update the internal kinematics.

Set the kinematics. Suitable for 1 -> 2 onium emissions.

Reimplemented in Split2g2QQbar3S11gg.

double overestimate	(	const TimeDipoleEnd &	dip,
		double	pT2Min,
		bool	enh
	)

virtual

Calculate the splitting overestimate.

Implementation of the SplitOnia class.

Set up the the overestimate. This calculates the splitting independent factor.

Reimplemented in Split2g2QQbarX8.

void setOctetID	(	int	state,
		double	mSplit,
		Info *	infoPtr
	)

protected

Set the colour octet ID and ensure in particle database.

Set the colour octet ID and ensure in particle database. Here, the state corresponds to 0 is 3S1, 1 is 1S0, and 2 is 3PJ.

Determine quark composition and quantum numbers of the physical state.

Set the name of the physical and octet state.

Ensure the dummy particle for the colour-octet state is valid.

bool updateBranchVars	(	const TimeDipoleEnd *	dip,
		Event &	event,
		int &	idRadIn,
		int &	idEmtIn,
		int &	colRadIn,
		int &	acolRadIn,
		int &	colEmtIn,
		int &	acolEmtIn,
		int &	appendEmtIn,
		double &	pTorigIn,
		double &	pTcorrIn,
		double &	pzRadPlusEmtIn,
		double &	pzRadIn,
		double &	pzEmtIn,
		double &	mRadIn,
		double &	m2RadIn,
		double &	mEmtIn
	)

Update the passed branching variables with the internal values.

Set branch variables. Call class specific version first, then set passed variables.

virtual double weight ( const TimeDipoleEnd & dip ) const

pure virtual

Return the weight of the splitting function and Jacobian at the generated point divided by the overestimate.

Implemented in Split2QQbarXg82QQbarX8g, Split2QQbarXq82QQbarX8g, Split2g2QQbarX8, Split2Q2QQbar3PJ8Q, Split2g2QQbar3PJ1g, Split2Q2QQbar3PJ1Q, Split2Q2QQbar1P11Q, Split2g2QQbar3S11gg, Split2Q2QQbar3S11Q, Split2g2QQbar1S01g, and Split2Q2QQbar1S01Q.

Member Data Documentation

int idA

protected

The ID and mass (squared) of the radiating particle (A), the scattered radiated particle (B, taking a fraction z of A's momentum), and the emitted particle (C).

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

include/Pythia8/SplittingsOnia.h
src/SplittingsOnia.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation