Class PhotoPionProduction

Defined in File PhotoPionProduction.h

Inheritance Relationships

Base Type

public Module (Class Module)

Class Documentation

class PhotoPionProduction : public Module 

Photo-pion interactions of nuclei with background photons.

Public Functions

PhotoPionProduction(ref_ptr<PhotonField> photonField, bool photons = false, bool neutrinos = false, bool electrons = false, bool antiNucleons = false, double limit = 0.1, bool haveRedshiftDependence = false)

pion production on a given target photon field

Parameters

photonField – target photon field
photons – if true, secondary photons are added to the simulation
neutrinos – if true, secondary neutrinos are added to the simulation
electrons – if true, secondary electrons are added to the simulation
antiNucleons – if true, secondary anti nucleons are added to the simulation
limit – fraction of the mean free path, to which the propagation step will be limited
haveRedshiftDependence – use redshift dependent tabulated loss rates; if false, the redshift scaling of the photon field will be used

void setPhotonField(ref_ptr<PhotonField> photonField)

void setHavePhotons(bool b)

void setHaveNeutrinos(bool b)

void setHaveElectrons(bool b)

void setHaveAntiNucleons(bool b)

void setHaveRedshiftDependence(bool b)

void setLimit(double limit)

Limit the propagation step to a fraction of the mean free path

Parameters: limit – fraction of the mean free path

void setInteractionTag(std::string tag)

set a custom interaction tag to trace back this interaction

Parameters: tag – string that will be added to the candidate and output

void initRate(std::string filename)

double nucleonMFP(double gamma, double z, bool onProton) const

get the mean free path (MFP) for a single nucleon. To get the MFP for the full nucleus the nucleonMFP has to be divided by by the nucleiModification factor

Parameters

gamma – Lorentz factor of the nucleon
z – redshift
onProton – true for protons, false for neutrons

double nucleiModification(int A, int X) const

scaling factor for mean free path of the nucleus (converting the MFP of a single nucleon)

Parameters

A – mass number of the nucleus
X – charge number of the nucleus

virtual void process(Candidate *candidate) const

void performInteraction(Candidate *candidate, bool onProton) const

double lossLength(int id, double gamma, double z = 0)

Calculates the loss length E dx/dE in [m]. This is not used in the simulation.

Parameters

id – PDG particle id
gamma – Lorentz factor of particle
z – redshift

SophiaEventOutput sophiaEvent(bool onProton, double Ein, double eps) const

Direct SOPHIA interface. Output is an object SophiaEventOutput with two vectors “energy” and “id” each of length N (number of out-going particles). The i-th component of each vector corresponds to the same particle. This is not used in the simulation.

Parameters

onProton – proton or neutron
Ein – energy of nucleon
eps – energy of target photon

double sampleEps(bool onProton, double E, double z) const

SOPHIA’s photon sampling method. Returns energy [J] of a photon of the photon field.

Parameters

onProton – particle type: proton or neutron
E – energy of incoming nucleon [J]
z – redshift of incoming nucleon

double probEpsMax(bool onProton, double Ein, double z, double epsMin, double epsMax) const

called by: sampleEps

Parameters

onProton – particle type: proton or neutron
Ein – energy of incoming nucleon
z – redshift of incoming nucleon
epsMin – minimum photon energy of field
epsMax – maximum photon energy of field
- output: maximum probability of all photons in field

void setSampleLog(bool log)

void setCorrectionFactor(double factor)

ref_ptr<PhotonField> getPhotonField() const: get functions for the parameters of the class PhotoPionProduction, similar to the set functions

bool getHavePhotons() const

bool getHaveNeutrinos() const

bool getHaveElectrons() const

bool getHaveAntiNucleons() const

bool getHaveRedshiftDependence() const

double getLimit() const

bool getSampleLog() const

double getCorrectionFactor() const

std::string getInteractionTag() const

virtual std::string getDescription() const

void setDescription(const std::string &description)

inline void process(ref_ptr<Candidate> candidate) const

inline size_t addReference() const

inline size_t removeReference() const

inline int removeReferenceNoDelete() const

inline size_t getReferenceCount() const

Protected Functions

double functs(double s, bool onProton) const

double probEps(double eps, bool onProton, double Ein, double z) const

double epsMinInteraction(bool onProton, double Ein) const

called by: sampleEps

Parameters

onProton – particle type: proton or neutron
Ein – energy of incoming nucleon
- output: labframe energy [eV] of least energetic photon where PPP can occur

double momentum(bool onProton, double Ein) const

called by: probEps, epsMinInteraction

Parameters

onProton – particle type: proton or neutron
Ein – energy of incoming nucleon
- output: hadron momentum [GeV/c]

double crossection(double eps, bool onProton) const

double Pl(double eps, double xth, double xMax, double alpha) const

double Ef(double eps, double epsTh, double w) const

double breitwigner(double sigma0, double gamma, double DMM, double epsPrime, bool onProton) const

double mass(bool onProton) const

double sMin() const

Protected Attributes

ref_ptr<PhotonField> photonField

std::vector<double> tabLorentz: Lorentz factor of nucleus.

std::vector<double> tabRedshifts: redshifts (optional for haveRedshiftDependence)

std::vector<double> tabProtonRate: interaction rate in [1/m] for protons

std::vector<double> tabNeutronRate: interaction rate in [1/m] for neutrons

double limit: fraction of mean free path to limit the next step

bool havePhotons

bool haveNeutrinos

bool haveElectrons

bool haveAntiNucleons

bool haveRedshiftDependence

std::string interactionTag = "PPP"

bool sampleLog = true

double correctionFactor = 1.6

mutable size_t _referenceCount