#include <HISubCollisionModel.h>

Inheritance diagram for SubCollisionModel:

Classes
struct	SigEst
	Internal class to report cross section estimates. More...

Public Member Functions
	SubCollisionModel (int nParm)
	The default constructor is empty.

virtual	~SubCollisionModel ()
	Virtual destructor.

virtual bool	init (int idAIn, int idBIn, double eCMIn)
	Virtual init method. More...

void	initPtr (NucleusModel &projIn, NucleusModel &targIn, SigmaTotal &sigTotIn, Settings &settingsIn, Info &infoIn, Rndm &rndmIn)
	Initialize the pointers.

double	sigTot () const
	The target total nucleon-nucleon cross section. More...

double	sigEl () const
	The target elastic cross section.

double	sigCDE () const
	The target central diffractive excitation cross section.

double	sigSDE () const
	The target single diffractive excitation cross section (both sides).

double	sigSDEP () const
	The target single diffractive excitation cross section (projectile).

double	sigSDET () const
	The target single diffractive excitation cross section (target).

double	sigDDE () const
	The target double diffractive excitation cross section.

double	sigND () const
	The target non-diffractive (absorptive) cross section.

double	bSlope () const
	The target elastic b-slope parameter.

double	avNDB () const
	Return the average non-diffractive impact parameter.

void	updateSig ()
	Update internally stored cross sections. More...

double	Chi2 (const SigEst &sigs, int npar) const
	Calculate the Chi2 for the given cross section estimates. More...

void	setKinematics (double eCMIn)
	Set beam kinematics. More...

bool	evolve (int nGenerations, double eCM)
	Use a genetic algorithm to fit the parameters. More...

int	nParms () const
	Get the number of free parameters for the model.

void	setParm (const vector< double > &parmIn)
	Set the parameters of this model.

vector< double >	getParm () const
	Get the current parameters of this model.

virtual vector< double >	minParm () const =0
	Get the minimum allowed parameter values for this model.

virtual vector< double >	defParm () const =0
	Get the default parameter values for this model.

virtual vector< double >	maxParm () const =0
	Get the maximum allowed parameter values for this model.

virtual SubCollisionSet	getCollisions (Nucleus &proj, Nucleus &targ)=0

virtual SigEst	getSig () const =0
	Calculate the cross sections for the given set of parameters.

Static Public Member Functions
static shared_ptr< SubCollisionModel >	create (int model)
	Create a new SubCollisionModel of the given model. More...

Protected Attributes
vector< double >	parmSave
	Saved parameters.

int	NInt

int	NPop

double	sigFuzz

double	impactFudge

bool	fitPrint

double	avNDb

NucleusModel *	projPtr
	Info from the controlling HeavyIons object.

NucleusModel *	targPtr

SigmaTotal *	sigTotPtr

Settings *	settingsPtr

Info *	infoPtr

Rndm *	rndmPtr

Logger *	loggerPtr

int	idASave
	For variable energies.

int	idBSave

bool	doVarECM

double	eMin {}

double	eMax {}

int	eCMPts

vector< LogInterpolator >	subCollParms

Detailed Description

The SubCollisionModel is is able to model the collision between two nucleons to tell which type of collision has occurred. The model may manipulate the corresponding state of the nucleons.

Member Function Documentation

double Chi2	(	const SigEst &	se,
		int	npar
	)		const

Calculate the Chi2 for the given cross section estimates.

Calculate the Chi^2 for the cross section that model in a subclass tries to model.

shared_ptr< SubCollisionModel > create ( int model )

static

Create a new SubCollisionModel of the given model.

The SubCollisionModel base class for modeling the collision between two nucleons to tell which type of collision has occurred. The model may manipulate the corresponing state of the nucleons.

bool evolve	(	int	nGenerations,
		double	eCM
	)

Use a genetic algorithm to fit the parameters.

A simple genetic algorithm for fitting the parameters in a subclass to reproduce desired cross sections.

We're going to use a home-made genetic algorithm. We start by creating a population of random parameter points.

Population of parameter sets. The most accurate sets will propagate to the next generation.

Now we evolve our population for a number of generations.

Calculate Chi2 for each parameter set and order them.

Keep the best one, and move the other closer to a better one or kill them if they are too bad.

Kill this individual and create a new one.

Pick one of the better parameter sets and move this closer.

Update resulting parameter set.

Output information.

Done.

virtual SubCollisionSet getCollisions	(	Nucleus &	proj,
		Nucleus &	targ
	)

pure virtual

Take two nuclei and produce the corresponding subcollisions. The states of the nucleons may be changed if fluctuations are allowed by the model.

Implemented in FluctuatingSubCollisionModel, NaiveSubCollisionModel, and BlackSubCollisionModel.

bool init	(	int	idAIn,
		int	idBIn,
		double	eCMIn
	)

virtual

Virtual init method.

Initialize the base class. Subclasses should consider calling this in overriding functions.

Store input.

Read basic settings.

If there are parameters, no further initialization is necessary.

First try to load configuration from file, if requested.

If parameters were not loaded, generate from scratch.

Set parameters at the correct kinematics.

Set initial avNDb

Save parameters to disk, if requested.

Done.

void setKinematics ( double eCMIn )

Set beam kinematics.

Update the parameters to the interpolated value at the given eCM.

double sigTot ( ) const

inline

The target total nucleon-nucleon cross section.

Access the nucleon-nucleon cross sections assumed for this model.

void updateSig ( )

Update internally stored cross sections.

preliminarily set average ND impact parameter as if black disk.

Member Data Documentation

double avNDb

protected

The estimated average impact parameter distance (in femtometer) for absorptive collisions.

int NInt

protected

The parameters stearing the fitting of internal parameters to the different nucleon-nucleon cross sections.

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

include/Pythia8/HISubCollisionModel.h
src/HISubCollisionModel.cc

Classes

Public Member Functions

Static Public Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation