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ThePEG  2.1.0
ThePEG::Decayer Class Referenceabstract

Decayer is an abstract base class to specify objects modelling the decay of a particle. More...

#include <Decayer.h>

Inheritance diagram for ThePEG::Decayer:

Classes

struct  DecayFailure
 Exception class used if something goes wrong in DecayParticle(). More...
 

Public Member Functions

Ptr< Amplitude >::pointer amplitude () const
 Return an amplitude associated with this decay matrix element. More...
 
Virtual functions to be overridden in sub-classes.
virtual bool accept (const DecayMode &dm) const =0
 Check if this decayer can perfom the decay specified by the given decay mode. More...
 
virtual bool needsFullStep () const
 Return true if this Decayer need to access the full current step when a particle is decayed. More...
 
virtual ParticleVector decay (const DecayMode &dm, const Particle &p) const =0
 Perform a decay for a given DecayMode and a given Particle instance. More...
 
virtual ParticleVector decay (const DecayMode &dm, const Particle &p, Step &step) const
 Perform a decay for a given DecayMode and a given Particle instance. More...
 
virtual double brat (const DecayMode &dm, const ParticleData &pd, double oldbrat) const
 Calculate branching ratio. More...
 
virtual double brat (const DecayMode &dm, const Particle &p, double oldbrat) const
 Calculate branching ratio. More...
 
virtual ParticleVector getChildren (const DecayMode &dm, const Particle &parent) const
 Produce the children. More...
 
virtual void finalBoost (const Particle &parent, const ParticleVector &children) const
 Boost the decay products. More...
 
virtual void setScales (const Particle &parent, const ParticleVector &children) const
 Set the scales. More...
 
Functions used by the persistent I/O system.
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently. More...
 
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently. More...
 
- Public Member Functions inherited from ThePEG::HandlerBaseT< UseRandom >
double rnd () const
 Return a simple flat random number in the range ]0,1[.
 
double rnd (double xu) const
 Return a simple flat random number in the range ]0,xu[.
 
double rnd (double xl, double xu) const
 Return a simple flat random number in the range ]xl,xu[.
 
bool rndbool () const
 Return true with 50% probability.
 
bool rndbool (double p) const
 Return a true with probability p.
 
bool rndbool (double p1, double p2) const
 Return a true with probability p1/(p1+p2).
 
int rndsign (double p1, double p2, double p3) const
 Return -1, 0, or 1 with relative probabilities p1, p2, p3.
 
int rnd2 (double p0, double p1) const
 Return an integer $i$ with probability p $i$/(p0+p1).
 
int rnd3 (double p0, double p1, double p2) const
 Return an integer $i$ with probability p $i$/(p0+p1+p2).
 
int rnd4 (double p0, double p1, double p2, double p3) const
 Return an integer/ $i$ with probability p $i$(p0+p1+p2+p3).
 
long irnd (long xu=2) const
 Return a simple flat random integrer number in the range [0,xu[.
 
long irnd (long xl, long xu) const
 Return a simple flat random integrer number in the range [xl,xu[.
 
const StandardModelBaseSM () const
 Return a reference to the object containing the standard model parameters for this run.
 
tSMPtr standardModel () const
 Return a pointer to the object containing the standard model parameters for this run.
 
virtual ~HandlerBaseT ()
 Destructor.
 
- Public Member Functions inherited from ThePEG::Interfaced
virtual ~Interfaced ()
 Empty virtual destructor.
 
virtual bool defaultInit ()
 Functions which are to be used during the actual event generation, after the setup is complete. More...
 
PPtr getParticle (PID) const
 Create a new Particle instance given a id number.
 
PDPtr getParticleData (PID) const
 Return a pointer to the ParticleData object corresponding to the given id number.
 
bool used () const
 Returns true if this object has actally been used.
 
void useMe () const
 Should be called to indicate that this object has actually been used.
 
tEGPtr generator () const
 Return a pointer to the EventGenerator controlling the run. More...
 
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently. More...
 
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently. More...
 
- Public Member Functions inherited from ThePEG::InterfacedBase
virtual ~InterfacedBase ()
 The virtual (empty) destructor;.
 
string fullName () const
 Returns the full name of this object including its path, e.g. More...
 
string name () const
 Returns the name of this object, without the path.
 
string path () const
 Returns the path to this object including the trailing '/'. More...
 
string comment () const
 Returns a comment assigned to this object.
 
void setup (istream &is)
 Read setup info from a standard istream is. More...
 
virtual IBPtr fullclone () const
 Return a full clone of this object possibly doing things to the clone to make it sane.
 
virtual void debugme () const
 Print out debugging information for this object on std::cerr. More...
 
void update ()
 Calls the doupdate() function with recursion prevention.
 
void init ()
 Calls the doinit() function with recursion prevention.
 
virtual bool preInitialize () const
 Return true if this object needs to be initialized before all other objects (except those for which this function also returns true). More...
 
void initrun ()
 Calls the doinitrun() function with recursion prevention.
 
void finish ()
 Calls the dofinish() function with recursion prevention.
 
void touch ()
 This function should be called every time something in this object has changed in a way that a sanity check with update() is needed.
 
void reset ()
 Set the state of this object to uninitialized.
 
void clear ()
 Calls reset() and unTouch().
 
InitState state () const
 Return the state of initialization of this object.
 
bool locked () const
 Return true if the BaseRepository is not allowed to change the state of this object.
 
bool touched () const
 Return true if the state of this object has been changed since the last call to update().
 
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently. More...
 
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently. More...
 
- Public Member Functions inherited from ThePEG::Base
virtual ~Base ()
 The virtual destructor.
 
void debug () const
 Print out debugging information for this object on std::cerr. More...
 
- Public Member Functions inherited from ThePEG::Pointer::ReferenceCounted
CounterType referenceCount () const
 Return the reference count.
 
- Public Member Functions inherited from ThePEG::Named
 Named (const string &newName=string())
 Constructor with name.
 
const string & name () const
 Return name.
 
bool operator== (const Named &other) const
 Test for equality.
 
bool operator< (const Named &other) const
 Lexicographical comparison.
 

Static Public Member Functions

static ParticleVector DecayParticle (tPPtr parent, Step &step, long maxtry=1000)
 Static function to administer the decay of a particle. More...
 
static void Init ()
 Standard Init function used to initialize the interfaces.
 
- Static Public Member Functions inherited from ThePEG::HandlerBase
static void Init ()
 Standard Init function used to initialize the interface.
 
- Static Public Member Functions inherited from ThePEG::Interfaced
static void Init ()
 Standard Init function.
 
- Static Public Member Functions inherited from ThePEG::InterfacedBase
static void Init ()
 Standard Init function.
 
- Static Public Member Functions inherited from ThePEG::Base
static void Init ()
 The standard Init function used to initialize the interfaces. More...
 

Private Member Functions

Decayeroperator= (const Decayer &)
 Private and non-existent assignment operator.
 

Private Attributes

Ptr< Amplitude >::pointer theAmplitude
 A possible null pointer to an amplitude associated with this matrix element.
 

Static Private Attributes

static AbstractNoPIOClassDescription< DecayerinitDecayer
 The static object used to initialize the description of this class. More...
 

Additional Inherited Members

- Public Types inherited from ThePEG::InterfacedBase
enum  InitState { initializing = -1, uninitialized = 0, initialized = 1, runready = 2 }
 Enumeration reflecting the state of an InterfacedBase object. More...
 
- Public Types inherited from ThePEG::Pointer::ReferenceCounted
typedef unsigned int CounterType
 The integer type used for counting.
 
- Public Attributes inherited from ThePEG::Pointer::ReferenceCounted
const unsigned long uniqueId
 The unique ID. More...
 
- Protected Member Functions inherited from ThePEG::Interfaced
void reporeg (IBPtr object, string name) const
 Register the given object in the Repository with the given name in a subdirectory with the same name as this object. More...
 
template<typename PtrT >
bool setDefaultReference (PtrT &ptr, string classname, string objectname)
 If the pointer, ptr, to an object is not set, create an object of class classname and register it with the Repository with the given objectname in a sib-directory with the same name as this object.
 
 Interfaced ()
 Protected default constructor.
 
 Interfaced (const string &newName)
 Protected constructor taking a name as argument.
 
 Interfaced (const Interfaced &i)
 Protected copy-constructor.
 
void setGenerator (tEGPtr generator)
 Protected function to reset the generator pointer, required for automatic decayer generation in Herwig++ BSM models.
 
- Protected Member Functions inherited from ThePEG::InterfacedBase
virtual IBPtr clone () const =0
 Return a simple clone of this object. More...
 
 InterfacedBase ()
 Protected default constructor.
 
 InterfacedBase (string newName)
 Protected constructor with the name given as argument.
 
 InterfacedBase (const InterfacedBase &i)
 Protected copy-constructor.
 
virtual void readSetup (istream &is)
 Read setup info from a standard istream is. More...
 
virtual void doupdate ()
 Check sanity of the object during the setup phase. More...
 
virtual void doinit ()
 Initialize this object after the setup phase before saving an EventGenerator to disk. More...
 
virtual void doinitrun ()
 Initialize this object. More...
 
virtual void dofinish ()
 Finalize this object. More...
 
virtual IVector getReferences ()
 Return a vector of all pointers to Interfaced objects used in this object. More...
 
virtual void rebind (const TranslationMap &)
 Rebind pointer to other Interfaced objects. More...
 
- Protected Member Functions inherited from ThePEG::Pointer::ReferenceCounted
 ReferenceCounted ()
 Default constructor.
 
 ReferenceCounted (const ReferenceCounted &)
 Copy-constructor.
 
ReferenceCountedoperator= (const ReferenceCounted &)
 Assignment.
 
- Protected Member Functions inherited from ThePEG::Named
const Namedoperator= (const Named &other)
 Assignment.
 
const string & name (const string &newName)
 Set new name.
 
- Static Protected Member Functions inherited from ThePEG::Interfaced
static void registerRepository (IBPtr)
 Register an Interfaced object with the Repository.
 
static void registerRepository (IBPtr, string newName)
 Register an Interfaced object with the Repository, giving it a name.
 

Detailed Description

Decayer is an abstract base class to specify objects modelling the decay of a particle.

See also
The interfaces defined for Decayer.
ParticleData
DecayMode

Definition at line 29 of file Decayer.h.

Member Function Documentation

◆ accept()

virtual bool ThePEG::Decayer::accept ( const DecayMode dm) const
pure virtual

Check if this decayer can perfom the decay specified by the given decay mode.

Parameters
dmthe DecayMode describing the decay.
Returns
true if this decayer can handle the given mode, otherwise false.

Implemented in ThePEG::RemnantDecayer, ThePEG::SimpleBaryonRemnantDecayer, ThePEG::QuarksToHadronsDecayer, ThePEG::Onium3GDecayer, ThePEG::V2PPDecayer, ThePEG::OmegaPhi3PiDecayer, ThePEG::ColourPairDecayer, ThePEG::DalitzDecayer, ThePEG::Tau2HadronsDecayer, ThePEG::FlatDecayer, ThePEG::WeakToHadronsDecayer, and ThePEG::DummyDecayer.

◆ amplitude()

Ptr<Amplitude>::pointer ThePEG::Decayer::amplitude ( ) const
inline

Return an amplitude associated with this decay matrix element.

May return null.

Definition at line 127 of file Decayer.h.

References DecayParticle(), and theAmplitude.

◆ brat() [1/2]

virtual double ThePEG::Decayer::brat ( const DecayMode dm,
const ParticleData pd,
double  oldbrat 
) const
virtual

Calculate branching ratio.

If this model has any oppinions on the decay rate for a given decay mode dm, for a given particle type pd, this method may be overriden to return this oppinion. oldbrat is the branching ratio specified in the DecayMode or by asking the WidthGenerator of pd.

Reimplemented in ThePEG::DummyDecayer.

◆ brat() [2/2]

virtual double ThePEG::Decayer::brat ( const DecayMode dm,
const Particle p,
double  oldbrat 
) const
virtual

Calculate branching ratio.

If this model has any oppinions on the decay rate for a given decay mode dm, for a given particle p, this method may be overriden to return this oppinion. oldbrat is the branching ratio specified in the DecayMode or by asking the WidthGenerator of p.

Reimplemented in ThePEG::DummyDecayer.

◆ decay() [1/2]

virtual ParticleVector ThePEG::Decayer::decay ( const DecayMode dm,
const Particle p 
) const
pure virtual

Perform a decay for a given DecayMode and a given Particle instance.

Parameters
dmthe DecayMode describing the decay.
pthe Particle instance to be decayed.
Returns
a ParticleVector containing the decay products.

Implemented in ThePEG::RemnantDecayer, ThePEG::QuarksToHadronsDecayer, ThePEG::Onium3GDecayer, ThePEG::V2PPDecayer, ThePEG::DalitzDecayer, ThePEG::FlatDecayer, and ThePEG::DummyDecayer.

◆ decay() [2/2]

virtual ParticleVector ThePEG::Decayer::decay ( const DecayMode dm,
const Particle p,
Step step 
) const
virtual

Perform a decay for a given DecayMode and a given Particle instance.

This version allows the decaying particle to borrow energy/momentum from its sublings in the current step. This will be called by the standard DecayHandler if the needsFullStep() function returns true.

Parameters
dmthe DecayMode describing the decay.
pthe Particle instance to be decayed.
stepthe current step in which to find possible siblings to shuffle energy with.
Returns
a ParticleVector containing the decay products.

Reimplemented in ThePEG::RemnantDecayer, and ThePEG::SimpleBaryonRemnantDecayer.

◆ DecayParticle()

static ParticleVector ThePEG::Decayer::DecayParticle ( tPPtr  parent,
Step step,
long  maxtry = 1000 
)
static

Static function to administer the decay of a particle.

The children are properly added to the particle and to the given step. Maximum maxtry attempts to decay the particle is performed.

Returns
the produced children.

Referenced by amplitude().

◆ finalBoost()

virtual void ThePEG::Decayer::finalBoost ( const Particle parent,
const ParticleVector children 
) const
virtual

Boost the decay products.

Can be used by sub-classes to perform the final boost back from the parents cms. This default version does just that.

◆ getChildren()

virtual ParticleVector ThePEG::Decayer::getChildren ( const DecayMode dm,
const Particle parent 
) const
virtual

Produce the children.

Can be used by sub-class decay() functions to produce instances of the children. This default implementation just calls the produceProducts() of the specified decay products in DecayMode object, dm.

Reimplemented in ThePEG::ColourPairDecayer.

◆ needsFullStep()

virtual bool ThePEG::Decayer::needsFullStep ( ) const
virtual

Return true if this Decayer need to access the full current step when a particle is decayed.

If true is returned the standard Decay Handler will call the decay(const DecayMode&,const Particle&,Step&) function rather than the decay(const DecayMode&,const Particle&) function.

Reimplemented in ThePEG::RemnantDecayer.

◆ persistentInput()

void ThePEG::Decayer::persistentInput ( PersistentIStream is,
int  version 
)

Function used to read in object persistently.

Parameters
isthe persistent input stream read from.
versionthe version number of the object when written.

◆ persistentOutput()

void ThePEG::Decayer::persistentOutput ( PersistentOStream os) const

Function used to write out object persistently.

Parameters
osthe persistent output stream written to.

◆ setScales()

virtual void ThePEG::Decayer::setScales ( const Particle parent,
const ParticleVector children 
) const
virtual

Set the scales.

Can be used by sub classes to set the production scale of the children. This default version sets the scale to the parents mass.

Member Data Documentation

◆ initDecayer

AbstractNoPIOClassDescription<Decayer> ThePEG::Decayer::initDecayer
staticprivate

The static object used to initialize the description of this class.

Indicates that this is an abstract class without persistent data.

Definition at line 174 of file Decayer.h.


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