ThePEG  1.8.0
Public Member Functions | Static Public Member Functions | Private Member Functions | Private Attributes | Static Private Attributes
ThePEG::QuarksToHadronsDecayer Class Reference

The QuarksToHadronsDecayer class inherits from Decayer and is able to decay particles to $n_q$ (2 or 4) quarks which then are decayed to hadrons according to phase space. More...

#include <QuarksToHadronsDecayer.h>

Inheritance diagram for ThePEG::QuarksToHadronsDecayer:
Inheritance graph
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List of all members.

Public Member Functions

virtual int getN (Energy m0, Energy summq, int Nq) const
 Get the number of hadrons to be produced, given the mass of the decaying particle, m0, and the number, Nq and summed masses of the quarks, summq.
virtual PVector getHadrons (int Nh, tcPDVector quarks) const
 Produce Nh hadrons from the specified quarks.
virtual void distribute (const Particle &parent, PVector &children) const
 Distribute the produced children in phase space.
virtual double reweight (const Particle &parent, const PVector &children) const
 Called by distribute() to reweight the default flat phase spece.
int fixedN () const
 Return the fixed number of hadrons to be produced.
int minN () const
 Return the minimum number of hadrons to be produced.
double c1 () const
 Return the parameter $c_1$ used for the multiplicity distriution.
Energy c2 () const
 Return the parameter $c_2$ used for the multiplicity distriution.
double c3 () const
 Return the parameter $c_3$ used for the multiplicity distriution.
tcFlavGenPtr flavourGenerator () const
 Return a pointer to the flavour generator to be used.
Standard constructors and destructors.
 QuarksToHadronsDecayer ()
 Default constructor.
virtual ~QuarksToHadronsDecayer ()
 Destructor.
Virtual functions required by the Decayer class.
virtual bool accept (const DecayMode &dm) const
 Check if this decayer can perfom the decay specified by the given decay mode.
virtual ParticleVector decay (const DecayMode &dm, const Particle &p) const
 Perform a decay for a given DecayMode and a given Particle instance.
Functions used by the persistent I/O system.
void persistentOutput (PersistentOStream &os) const
 Function used to write out object persistently.
void persistentInput (PersistentIStream &is, int version)
 Function used to read in object persistently.
- Public Member Functions inherited from ThePEG::Decayer
Ptr< Amplitude >::pointer amplitude () const
 Return an amplitude associated with this decay matrix element.
virtual bool needsFullStep () const
 Return true if this Decayer need to access the full current step when a particle is decayed.
virtual ParticleVector decay (const DecayMode &dm, const Particle &p, Step &step) const
 Perform a decay for a given DecayMode and a given Particle instance.
virtual double brat (const DecayMode &dm, const ParticleData &pd, double oldbrat) const
 Calculate branching ratio.
virtual double brat (const DecayMode &dm, const Particle &p, double oldbrat) const
 Calculate branching ratio.
virtual ParticleVector getChildren (const DecayMode &dm, const Particle &parent) const
 Produce the children.
virtual void finalBoost (const Particle &parent, const ParticleVector &children) const
 Boost the decay products.
virtual void setScales (const Particle &parent, const ParticleVector &children) const
 Set the scales.

Static Public Member Functions

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

Protected Member Functions

Clone Methods.
virtual IBPtr clone () const
 Make a simple clone of this object.
virtual IBPtr fullclone () const
 Make a clone of this object, possibly modifying the cloned object to make it sane.

Private Member Functions

QuarksToHadronsDecayeroperator= (const QuarksToHadronsDecayer &)
 Private and non-existent assignment operator.

Private Attributes

int theFixedN
 The fixed number of hadrons to be produced.
int theMinN
 The minimum hadrons to be produced.
double theC1
 The parameter $c_1$ of the multiplicity distribution.
Energy theC2
 The parameter $c_2$ of the multiplicity distribution.
double theC3
 The parameter $c_3$ of the multiplicity distribution.
FlavGenPtr theFlavourGenerator
 The object in charge of generating hadrons spieces from given quark flavours.

Static Private Attributes

static ClassDescription
< QuarksToHadronsDecayer
initQuarksToHadronsDecayer
 Describe a concrete class with persistent data.

Detailed Description

The QuarksToHadronsDecayer class inherits from Decayer and is able to decay particles to $n_q$ (2 or 4) quarks which then are decayed to hadrons according to phase space.

The number of final hadrons can either be given by a fixed number or as a Gaussian multiplicity distribution centered around $c+n_q/4+c_3$ and a width $\sqrt{c}$, where $c = c_1 \log((m - \sum m)/c_2)$, $m$ is the mass of the decaying particle, $\sum m$ the sum of the quark masses and $c_i$ real parameters.

See also:
The interfaces defined for QuarksToHadronsDecayer.
ParticleData

Definition at line 35 of file QuarksToHadronsDecayer.h.


Member Function Documentation

virtual bool ThePEG::QuarksToHadronsDecayer::accept ( const DecayMode dm) const
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.

Implements ThePEG::Decayer.

Reimplemented in ThePEG::WeakToHadronsDecayer.

virtual IBPtr ThePEG::QuarksToHadronsDecayer::clone ( ) const
protectedvirtual

Make a simple clone of this object.

Returns:
a pointer to the new object.

Implements ThePEG::InterfacedBase.

Reimplemented in ThePEG::WeakToHadronsDecayer.

virtual ParticleVector ThePEG::QuarksToHadronsDecayer::decay ( const DecayMode dm,
const Particle p 
) const
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.

Implements ThePEG::Decayer.

virtual void ThePEG::QuarksToHadronsDecayer::distribute ( const Particle parent,
PVector children 
) const
virtual

Distribute the produced children in phase space.

This default version uses a flat phase space which can be reweighted by overriding the reweight() function.

int ThePEG::QuarksToHadronsDecayer::fixedN ( ) const
inline

Return the fixed number of hadrons to be produced.

If less than 2, the number is instead given by a gaussian multiplicity distribution.

Definition at line 110 of file QuarksToHadronsDecayer.h.

References theFixedN.

virtual IBPtr ThePEG::QuarksToHadronsDecayer::fullclone ( ) const
protectedvirtual

Make a clone of this object, possibly modifying the cloned object to make it sane.

Returns:
a pointer to the new object.

Reimplemented from ThePEG::InterfacedBase.

Reimplemented in ThePEG::WeakToHadronsDecayer.

virtual PVector ThePEG::QuarksToHadronsDecayer::getHadrons ( int  Nh,
tcPDVector  quarks 
) const
virtual

Produce Nh hadrons from the specified quarks.

The last quark is considered to be a spectator quark.

Reimplemented in ThePEG::WeakToHadronsDecayer.

void ThePEG::QuarksToHadronsDecayer::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.

Reimplemented from ThePEG::Decayer.

Reimplemented in ThePEG::WeakToHadronsDecayer.

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

Function used to write out object persistently.

Parameters:
osthe persistent output stream written to.

Reimplemented from ThePEG::Decayer.

Reimplemented in ThePEG::WeakToHadronsDecayer.

virtual double ThePEG::QuarksToHadronsDecayer::reweight ( const Particle parent,
const PVector children 
) const
virtual

Called by distribute() to reweight the default flat phase spece.

Can be overridden by sub-classes and should return a number between 0 and 1. This version returns 1.

Reimplemented in ThePEG::WeakToHadronsDecayer.


Member Data Documentation

int ThePEG::QuarksToHadronsDecayer::theFixedN
private

The fixed number of hadrons to be produced.

If less than 2, the number is instead given by a gaussian multiplicity distribution.

Definition at line 190 of file QuarksToHadronsDecayer.h.

Referenced by fixedN().


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