#include <SigmaTotal.h>

Inheritance diagram for SigmaSaSDL:

Public Member Functions
	SigmaSaSDL ()
	Constructor.

virtual void	init (Info *infoPtrIn)
	Store pointers and initialize data members. More...

double	sigmaTotal (int idAin, int idBin, double sIn, double mAin, double mBin)
	Fast method uniquely to return total cross section. More...

virtual bool	calcTotEl (int idAin, int idBin, double sIn, double mAin, double mBin)
	Calculate integrated total/elastic cross sections. More...

virtual double	dsigmaEl (double t, bool useCoulomb=false, bool=false)
	Differential elastic cross section. More...

virtual bool	calcDiff (int idAin, int idBin, double sIn, double mAin, double mBin)
	Calculate integrated diffractive cross sections. More...

virtual double	dsigmaSD (double xi, double t, bool isXB, int=0)
	Differential single diffractive cross section. More...

virtual double	dsigmaDD (double xi1, double xi2, double t, int=0)
	Differential double diffractive cross section. More...

virtual double	dsigmaCD (double xi1, double xi2, double t1, double t2, int=0)
	Differential central diffractive cross section. More...

virtual double	mMinCD ()
	Minimal central diffractive mass.

Public Member Functions inherited from SigmaTotAux
	SigmaTotAux ()
	Constructor.

virtual	~SigmaTotAux ()
	Destructor.

virtual bool	calcTot (int, int, double)
	Calculate total cros section only. Only implemented for SigmaSaSDL.

virtual bool	splitDiff ()
	Possibility to separate xi and t choices for diffraction.

pair< double, double >	tRange (double sIn, double s1In, double s2In, double s3In, double s4In)

bool	tInRange (double tIn, double sIn, double s1In, double s2In, double s3In, double s4In)

double	pFormFac (double tIn)
	Commonly used proton form factor.

Additional Inherited Members
Public Attributes inherited from SigmaTotAux
bool	isExpEl
	Store total and elastic cross section properties.

bool	hasCou

double	sigTot

double	rhoOwn

double	sigEl

double	bEl

double	sigTotCou

double	sigElCou

double	sigXB
	Store diffractive cross sections. Possibly also sigmaND.

double	sigAX

double	sigXX

double	sigAXB

double	sigNDtmp

Protected Member Functions inherited from SigmaTotAux
virtual bool	initCoulomb (Settings &settings, ParticleData *particleDataPtrIn)
	Initialize Coulomb correction parameters. More...

virtual bool	addCoulomb ()
	Add Coulomb corrections to the elastic and total cross sections. More...

virtual double	dsigmaElCoulomb (double t)
	Coulomb contribution to the differential elastic cross sections. More...

Protected Attributes inherited from SigmaTotAux
int	idA
	Initialization data, normally only set once.

int	idB

bool	tryCoulomb
	Add Coulomb corrections to the elastic cross section.

double	chgSgn

double	tAbsMin

double	lambda

double	phaseCst

ParticleData *	particleDataPtr
	Pointer to the particle data table.

Rndm *	rndmPtr
	Pointer to the random number generator.

Static Protected Attributes inherited from SigmaTotAux
static const int	NPOINTS = 1000
	Constants: could only be changed in the code itself. More...

static const double	ALPHAEM = 0.00729353
	alpha_em(0). More...

static const double	CONVERTEL = 0.0510925
	Conversion coefficients = 1/(16pi) * (mb <-> GeV^2).

static const double	MPROTON = 0.9382720
	Proton and pion masses, and their squares. Euler's constant.

static const double	SPROTON = 0.8803544

static const double	MPION = 0.1349766

static const double	SPION = 0.0182187

static const double	GAMMAEUL = 0.577215665

static const double	TABSREF = 2e-3
	Reference scale for nominal definition of t slope.

static const double	TABSMAX = 1.

static const double	MINSLOPEEL = 10.

Detailed Description

The SigmaSaSDL class parametrizes total, elastic and diffractive cross sections according to Schuler and Sjostrand, starting from Donnachie and Landshoff.

Member Function Documentation

bool calcDiff	(	int	idAin,
		int	idBin,
		double	sIn,
		double	mAin,
		double	mBin
	)

virtual

Calculate integrated diffractive cross sections.

Diffractive cross sections.

Find appropriate combination of incoming beams.

Use simple behaviour close to threshold; around 10 GeV for normal hadrons.

Ordinary hadron-hadron collisions.

Lookup coefficients for single and double diffraction.

Single diffractive scattering A + B -> X + B cross section.

Extension to low energies.

Single diffractive scattering A + B -> A + X cross section.

Extension to low energies.

Order single diffractive correctly.

Double diffractive scattering A + B -> X1 + X2 cross section.

Extension to low energies.

Central diffractive scattering A + B -> A + X + B, only p and pbar.

Option with user-requested damping of diffractive cross sections.

gamma + p: loop over VMD states on side A.

Lookup coefficients for single and double diffraction.

Single diffractive scattering A + B -> X + B cross section.

Single diffractive scattering A + B -> A + X cross section.

Double diffractive scattering A + B -> X1 + X2 cross section.

End of VMD loop.

Order single diffractive correctly.

Option with user-requested damping of diffractive cross sections.

gamma + gamma: loop over VMD states on sides A and B.

Lookup coefficients for single and double diffraction.

Single diffractive scattering A + B -> X + B cross section.

Single diffractive scattering A + B -> A + X cross section.

Double diffractive scattering A + B -> X1 + X2 cross section.

End of VMD loop.

Option with user-requested damping of diffractive cross sections.

No diffractive scattering for Pomeron + p.

Assuming calcTotEl has already been called, nondiffractive can be found.

Done.

Reimplemented from SigmaTotAux.

bool calcTotEl	(	int	idAin,
		int	idBin,
		double	sIn,
		double	mAin,
		double	mBin
	)

virtual

Calculate integrated total/elastic cross sections.

Calculate total and (integrated) elastic cross sections.

Find appropriate combination of incoming beams.

Ordinary hadron-hadron collisions. Total cross section.

Elastic slope parameter and cross section.

gamma + p and p + gamma.

Loop over VMD states on side A for elastic cross section.

gamma + gamma

Loop over VMD states on side A and B for elastic cross section.

Primitive implementation of Pomeron + p. No elastic scattering.

Possibly add Coulomb correction and interference.

Done.

Reimplemented from SigmaTotAux.

double dsigmaCD	(	double	xi1,
		double	xi2,
		double	t1,
		double	t2,
		int	= `0`
	)

virtual

Differential central diffractive cross section.

Differential central diffractive cross sections. Simple extension of single diffraction, but without normalization.

Ordinary hadron-hadron collisions.

Calculate mass; checked to be above threshold.

Weight associated with differential AB -> AX cross section.

Weight associated with differential AB -> XB cross section.

Optional weight to tilt the mass spectrum.

Done.

No central diffraction for gamma + p, gamma + gamma or Pomeron + p.

Reimplemented from SigmaTotAux.

double dsigmaDD	(	double	xi1,
		double	xi2,
		double	t,
		int	= `0`
	)

virtual

Differential double diffractive cross section.

Calculate masses and check that they are above threshold. Optional weight.

Ordinary hadron-hadron collisions.

Return differential AB -> X1X2 cross section value.

gamma + p: loop over VMD states on side A.

Mass thresholds depend on VMD state.

Calculate and sum differential AB -> X1X2 cross section value.

gamma + gamma: loop over VMD states on side A and B.

Mass thresholds depend on VMD state.

Calculate and sum differential AB -> X1X2 cross section value.

No diffractive scattering for Pomeron + p.

Reimplemented from SigmaTotAux.

double dsigmaEl	(	double	t,
		bool	useCoulomb = `false`,
		bool	= `false`
	)

virtual

Differential elastic cross section.

Ordinary hadron-hadron collisions.

gamma + p and p + gamma: loop over VMD states on side A.

Elastic slope parameter and cross section.

Hadronic contribution: simple exponential.

gamma + gamma: loop over VMD states on side A and B.

Elastic slope parameter and cross section.

Hadronic contribution: simple exponential.

No elastic scattering for Pomeron + p.

Possibly add Coulomb contribution and interference.

Done.

Reimplemented from SigmaTotAux.

double dsigmaSD	(	double	xi,
		double	t,
		bool	isXB,
		int	= `0`
	)

virtual

Differential single diffractive cross section.

Differential single diffractive cross sections.

Calculate mass; later checked to be above threshold. Optional weight.

Ordinary hadron-hadron collisions.

Separate XB and AX cases since A and B masses/couplings may differ.

Return differential AB -> XB cross section value.

Return differential AB -> AX cross section value.

gamma + p: loop over VMD states on side A.

Mass thresholds depend on VMD state.

Calculate and sum differential AB -> XB cross section value.

Calculate and sum differential AB -> AX cross section value.

gamma + gamma: loop over VMD states on side A and B.

Mass thresholds depend on VMD state.

Calculate and sum differential AB -> XB cross section value.

Calculate and sum differential AB -> AX cross section value.

No diffractive scattering for Pomeron + p.

Reimplemented from SigmaTotAux.

void init ( Info * infoPtrIn )

virtual

Store pointers and initialize data members.

Store pointer to Info and initialize data members.

Store pointer.

Use shorthand for settings

Initialize parameters for Coulomb corrections to elastic scattering.

User-set values to dampen diffractive cross sections.

Parameters for diffractive systems.

Diffractive mass spectrum starts at m + mMin0 and has a low-mass enhancement, factor cRes, up to around m + mRes0. Special for CD.

Derived quantities.

Implements SigmaTotAux.

double sigmaTotal	(	int	idAin,
		int	idBin,
		double	sIn,
		double	mAin,
		double	mBin
	)

Fast method uniquely to return total cross section.

Calculate total cross section only, for fast decision.

Minimum action needed for total cross section.

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

include/Pythia8/SigmaTotal.h
src/SigmaTotal.cc

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation