#include <HISubCollisionModel.h>

Inheritance diagram for SubCollisionModel:

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

struct	SigmaCache
	Helper class to cache cross sections at low energy. More...

Public Member Functions
	SubCollisionModel (int nParm)

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.

void	initLowEnergy (SigmaCombined *sigmaCombPtrIn)
	Initialize low energy treatment.

bool	hasXSec () const

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	sigLow () const
	The Low-energy cross sections.

double	sigLExc () const
	The Low-energy excitation cross section (code 157).

double	sigLAnn () const
	The Low-energy annihilation cross section (code 158).

double	sigLRes () const
	The Low-energy resonant cross section (code 159).

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

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

void	updateSig (int idAIn, int idBIn, double eCMIn)
	Update internally stored cross sections. More...

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

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

bool	setIDA (int idA)
	Set projectile particle.

bool	evolve (int nGenerations, double eCM, int idANow)
	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 void	generateNucleonStates (Nucleus &, Nucleus &)

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 >	sigTarg

vector< double >	sigErr

vector< vector< double > >	sigTargNN

vector< double >	parmSave
	Saved parameters.

int	NInt

int	NPop

double	sigFuzz

double	impactFudge

bool	fitPrint

double	eCMlow

double	avNDb

double	avNDolap

NucleusModel *	projPtr = {}
	Info from the controlling HeavyIons object.

NucleusModel *	targPtr = {}

SigmaTotal *	sigTotPtr = {}

SigmaCombined *	sigCmbPtr = {}

Settings *	settingsPtr = {}

Info *	infoPtr = {}

Rndm *	rndmPtr = {}

Logger *	loggerPtr = {}

ParticleData *	particleDataPtr = {}

int	idASave
	For variable energies.

int	idBSave

bool	doVarECM

bool	doVarBeams

double	eMin

double	eMax

double	eSave

int	eCMPts

vector< int >	idAList
	The list of particles that have been fitted.

vector< LogInterpolator > *	subCollParmsPtr

map< int, vector< LogInterpolator > >	subCollParmsMap
	Mapping id -> interpolator, one entry for each particle.

int	elasticMode

double	elasticFudge

SigmaCache	lowEnergyCache

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.

Constructor & Destructor Documentation

SubCollisionModel ( int nParm )

inline

The default constructor is empty. The avNDb has units femtometer.

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 corresponding state of the nucleons.

bool evolve	(	int	nGenerations,
		double	eCM,
		int	idANow
	)

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.

If the user has deemed the Chi2 too high, continue fitting.

Output information.

Done.

virtual void generateNucleonStates	(	Nucleus &	,
		Nucleus &
	)

inlinevirtual

Generate possible states for the nucleons in the projectile and target nuclei.

Reimplemented in FluctuatingSubCollisionModel.

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.

Reimplemented in FluctuatingSubCollisionModel.

bool 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	(	int	idAIn,
		int	idBIn,
		double	eCMIn
	)

Update internally stored cross sections.

Update internally stored cross sections, which in Angantyr should have units of femtometer^2.

Loop over both protons and neutrons.

Total.

Non-diffractive.

Doubly diffractive.

Diffractive (and wounded) projectile.

Diffractive (and wounded) target.

Central diffractive.

Elastic.

b-slope not used for low energy.

Low energy excitation.

Low energy annihilation.

Low energy resonance.

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.

double elasticFudge

protected

Add in elastic NN scatterings to get the generated inelastic AA cross section better described.

int elasticMode

protected

Generation of elastic NN scatterings is turned on by default, even if the cross section comes out wrong.

int NInt

protected

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

vector<double> sigTarg

protected

The nucleon-nucleon cross sections targets for this model (tot, nd, dd, sdp, sdt, cd, el, bslope) and the required precision.

vector<LogInterpolator>* subCollParmsPtr

protected

A vector of interpolators for the current particle. Each entry corresponds to one parameter, each interpolator is over the energy range.

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

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation