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Herwig  7.1.4
Herwig::TwoMesonRhoKStarCurrent Class Reference

Weak current for the production of two mesons via the $\rho$ or $K^*$ resonances. More...

#include <TwoMesonRhoKStarCurrent.h>

Inheritance diagram for Herwig::TwoMesonRhoKStarCurrent:

Public Member Functions

 TwoMesonRhoKStarCurrent ()
 Default constructor.
 
virtual vector< LorentzPolarizationVectorEcurrent (const int imode, const int ichan, Energy &scale, const ParticleVector &decay, DecayIntegrator::MEOption meopt) const
 Hadronic current. More...
 
virtual bool accept (vector< int > id)
 Accept the decay. More...
 
virtual unsigned int decayMode (vector< int > id)
 Return the decay mode number for a given set of particles in the current. More...
 
virtual void dataBaseOutput (ofstream &os, bool header, bool create) const
 Output the setup information for the particle database. More...
 
Methods for the construction of the phase space integrator.
virtual bool createMode (int icharge, unsigned int imode, DecayPhaseSpaceModePtr mode, unsigned int iloc, unsigned int ires, DecayPhaseSpaceChannelPtr phase, Energy upp)
 Complete the construction of the decay mode for integration. More...
 
virtual tPDVector particles (int icharge, unsigned int imode, int iq, int ia)
 The particles produced by the current. 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 Herwig::WeakDecayCurrent
 WeakDecayCurrent ()
 Default constructor.
 
unsigned int numberOfModes () const
 Return the number of modes handled by this current.
 
void decayModeInfo (unsigned int imode, int &iq, int &ia) const
 Information on a decay mode. 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::Interfaced
virtual bool defaultInit ()
 
PPtr getParticle (PID) const
 
PDPtr getParticleData (PID) const
 
bool used () const
 
void useMe () const
 
tEGPtr generator () const
 
void persistentOutput (PersistentOStream &os) const
 
void persistentInput (PersistentIStream &is, int version)
 
PPtr getParticle (PID) const
 
PDPtr getParticleData (PID) const
 
bool used () const
 
void useMe () const
 
tEGPtr generator () const
 
void persistentOutput (PersistentOStream &os) const
 
void persistentInput (PersistentIStream &is, int version)
 
- Public Member Functions inherited from ThePEG::InterfacedBase
string fullName () const
 
string name () const
 
string path () const
 
string comment () const
 
void setup (istream &is)
 
virtual void debugme () const
 
void update ()
 
void init ()
 
virtual bool preInitialize () const
 
void initrun ()
 
void finish ()
 
void touch ()
 
void reset ()
 
void clear ()
 
InitState state () const
 
bool locked () const
 
bool touched () const
 
void persistentOutput (PersistentOStream &os) const
 
void persistentInput (PersistentIStream &is, int version)
 
void update ()
 
void init ()
 
virtual bool preInitialize () const
 
void initrun ()
 
void finish ()
 
void touch ()
 
void reset ()
 
void clear ()
 
InitState state () const
 
bool locked () const
 
bool touched () const
 
void persistentOutput (PersistentOStream &os) const
 
void persistentInput (PersistentIStream &is, int version)
 
- Public Member Functions inherited from ThePEG::Base
void debug () const
 
- Public Member Functions inherited from ThePEG::Pointer::ReferenceCounted
CounterType referenceCount () const
 
- Public Member Functions inherited from ThePEG::Named
 Named (const string &newName=string())
 
const string & name () const
 
bool operator== (const Named &other) const
 
bool operator< (const Named &other) const
 

Static Public Member Functions

static void Init ()
 Standard Init function used to initialize the interfaces.
 
- Static Public Member Functions inherited from Herwig::WeakDecayCurrent
static void Init ()
 Standard Init function used to initialize the interfaces.
 
- Static Public Member Functions inherited from ThePEG::Interfaced
static void Init ()
 
- Static Public Member Functions inherited from ThePEG::InterfacedBase
static void Init ()
 
- Static Public Member Functions inherited from ThePEG::Base
static void Init ()
 

Protected Member Functions

Clone Methods.
virtual IBPtr clone () const
 Make a simple clone of this object. More...
 
virtual IBPtr fullclone () const
 Make a clone of this object, possibly modifying the cloned object to make it sane. More...
 
Standard Interfaced functions.
virtual void doinit ()
 Initialize this object after the setup phase before saving and EventGenerator to disk. More...
 
- Protected Member Functions inherited from Herwig::WeakDecayCurrent
void addDecayMode (int iq, int ia)
 Add a decay mode to the list. More...
 
void setInitialModes (unsigned int nmodes)
 Set initial number of modes. More...
 
- Protected Member Functions inherited from ThePEG::Interfaced
void reporeg (IBPtr object, string name) const
 
bool setDefaultReference (PtrT &ptr, string classname, string objectname)
 
 Interfaced (const string &newName)
 
 Interfaced (const Interfaced &i)
 
void setGenerator (tEGPtr generator)
 
- Protected Member Functions inherited from ThePEG::InterfacedBase
 InterfacedBase (string newName)
 
 InterfacedBase (const InterfacedBase &i)
 
virtual void readSetup (istream &is)
 
virtual void doupdate ()
 
virtual void doinitrun ()
 
virtual void dofinish ()
 
virtual IVector getReferences ()
 
virtual void rebind (const TranslationMap &)
 
virtual void readSetup (istream &is)
 
virtual void doupdate ()
 
virtual void doinitrun ()
 
virtual void dofinish ()
 
virtual IVector getReferences ()
 
virtual void rebind (const TranslationMap &)
 
- Protected Member Functions inherited from ThePEG::Pointer::ReferenceCounted
 ReferenceCounted (const ReferenceCounted &)
 
ReferenceCountedoperator= (const ReferenceCounted &)
 
 ReferenceCounted (const ReferenceCounted &)
 
ReferenceCountedoperator= (const ReferenceCounted &)
 
- Protected Member Functions inherited from ThePEG::Named
const Namedoperator= (const Named &other)
 
const string & name (const string &newName)
 

Private Member Functions

TwoMesonRhoKStarCurrentoperator= (const TwoMesonRhoKStarCurrent &)
 Private and non-existent assignment operator.
 
Breit-Wigner functions
Complex BreitWigner (Energy2 q2, unsigned int imodel, unsigned int itype, unsigned int ires) const
 $p$-wave breit wigner for form-factors More...
 
double GSModelDParameter (const unsigned int ires) const
 The $d$ parameter in the GS model of the propagator. More...
 
InvEnergy2 GSModeldhdq2Parameter (const unsigned int ires) const
 The $\frac{dh}{dq^2}$ function in the GS model for the propagator evaluated at $q^2=m^2$. More...
 
double GSModelhFunction (const unsigned int ires, const Energy q) const
 The $h$ function in the GS model. More...
 
Energy pcm (const unsigned int ires, const Energy q) const
 The momentum of the decay products for the running width. More...
 

Private Attributes

int _pimodel
 Model to use for the $\rho$ propagator.
 
int _kmodel
 Model to use for the $K^*$ propagator.
 
bool _rhoparameters
 Option not to use the physical masses and widths for the $\rho$.
 
vector< Energy > _rhomasses
 The masses of the $\rho$ resonances.
 
vector< Energy > _rhowidths
 The widths of the $\rho$ resonances.
 
bool _kstarparameters
 Option not to use the physical masses and widths for the $K^*$.
 
vector< Energy > _kstarmasses
 The masses of the $K^*$ resonances.
 
vector< Energy > _kstarwidths
 The masses of the $K^*$ resonances.
 
vector< Complex_piwgt
 Weights for the different $\rho$ resonances in the current, $\alpha_k$. More...
 
vector< double > _pimag
 The magnitude for input.
 
vector< double > _piphase
 The phase for input.
 
vector< Complex_kwgt
 Weights for the different $K^*$ resonances in the current, $\alpha_k$. More...
 
vector< double > _kmag
 The magnitude for input.
 
vector< double > _kphase
 The phase for input.
 
vector< Energy > _mass
 Parameters for the Breit-Wigners. More...
 
vector< Energy > _width
 The widths of the resonances.
 
vector< Energy2 > _mass2
 squares of the masses
 
vector< Energy2 > _massw
 product of the mass and the width
 
vector< Energy > _massa
 Masses of the decay products for the momentum calculation.
 
vector< Energy > _massb
 
vector< Energy > _mom
 The decay for the on-shell mass momentum.
 
vector< InvEnergy2 > _dhdq2
 The function $\frac{dh}{dq^2}$ at $q^2=m^2$ for the GS form of the Breit-Wigner.
 
vector< double > _hm2
 The function $h$ at $q^2=m^2$ for the GS form of the Breit-Wigner.
 
vector< double > _dparam
 The $d$ parameter for the GS form of the Breit-Wigner.
 

Static Private Attributes

static ClassDescription< TwoMesonRhoKStarCurrentinitTwoMesonRhoKStarCurrent
 Describe a concrete class with persistent data.
 

Additional Inherited Members

- Public Types inherited from ThePEG::InterfacedBase
enum  InitState
 
- Public Types inherited from ThePEG::Pointer::ReferenceCounted
typedef unsigned int CounterType
 
- Public Attributes inherited from ThePEG::InterfacedBase
 initializing
 
 uninitialized
 
 initialized
 
 runready
 
- Public Attributes inherited from ThePEG::Pointer::ReferenceCounted
const unsigned long uniqueId
 
- Static Protected Member Functions inherited from ThePEG::Interfaced
static void registerRepository (IBPtr)
 
static void registerRepository (IBPtr, string newName)
 

Detailed Description

Weak current for the production of two mesons via the $\rho$ or $K^*$ resonances.

These currents are taken from tau decays.

The current takes the form

\[J^\mu = \frac{\sqrt{2}}{\sum_k\alpha_k}\left((p_1-p_2)^\mu-\frac{(p_1-p_2)\cdot q}{q^2}q^\mu))\right) \sum_k \alpha_k B_{R_k}(q^2) \]

where

  • $p_{1,2}$ are the momenta of the outgoing mesons,
  • $q=p_1+p_2$,
  • $B_{R_k}(q^2)$ is the Breit-Wigner distribution for the intermediate vector meson $R_k$.
  • $\alpha_k$ is the weight for the resonance.

    The Breit-Wigner term is summed over the $\rho$ or $K^*$ resonances that can contribute to a given decay.

The models of either Kuhn and Santamaria (Z. Phys. C48, 445 (1990)) or Gounaris and Sakurai Phys. Rev. Lett. 21, 244 (1968) are supported for the shape of the Breit-Wigner distribution. The mixing parameters are taken from Phys.Rev.D61:112002,2000 (CLEO) for the decay $\pi^\pm\pi^0$ and the CLEO version of TAUOLA for the $K\pi$ decays.

See also
WeakDecayCurrent.
Author
Peter Richardson

Definition at line 53 of file TwoMesonRhoKStarCurrent.h.

Member Function Documentation

◆ accept()

virtual bool Herwig::TwoMesonRhoKStarCurrent::accept ( vector< int >  id)
virtual

Accept the decay.

Checks the particles are the allowed mode.

Parameters
idThe id's of the particles in the current.
Returns
Can this current have the external particles specified.

Implements Herwig::WeakDecayCurrent.

◆ BreitWigner()

Complex Herwig::TwoMesonRhoKStarCurrent::BreitWigner ( Energy2  q2,
unsigned int  imodel,
unsigned int  itype,
unsigned int  ires 
) const
inlineprivate

$p$-wave breit wigner for form-factors

Parameters
q2The scale $q^2$ for the Breit-Wigner
imodelWhich of the two models for the Breit-Wigner shape to use.
itypeWhether this is a $\rho$ or $K^*$ resonance.
iresWhich of the different multiplets to use.
Returns
The value of the Breit-Wigner distribution.

Definition at line 207 of file TwoMesonRhoKStarCurrent.h.

References sqr(), and sqrt().

◆ clone()

virtual IBPtr Herwig::TwoMesonRhoKStarCurrent::clone ( ) const
inlineprotectedvirtual

Make a simple clone of this object.

Returns
a pointer to the new object.

Implements ThePEG::InterfacedBase.

Definition at line 161 of file TwoMesonRhoKStarCurrent.h.

◆ createMode()

virtual bool Herwig::TwoMesonRhoKStarCurrent::createMode ( int  icharge,
unsigned int  imode,
DecayPhaseSpaceModePtr  mode,
unsigned int  iloc,
unsigned int  ires,
DecayPhaseSpaceChannelPtr  phase,
Energy  upp 
)
virtual

Complete the construction of the decay mode for integration.

This version just adds the intermediate resonances, two outgoing mesons and photon.

Parameters
ichargeThe total charge of the outgoing particles in the current.
imodeThe mode in the current being asked for.
modeThe phase space mode for the integration
ilocThe location of the of the first particle from the current in the list of outgoing particles.
iresThe location of the first intermediate for the current.
phaseThe prototype phase space channel for the integration.
uppThe maximum possible mass the particles in the current are allowed to have.
Returns
Whether the current was sucessfully constructed.

Implements Herwig::WeakDecayCurrent.

◆ current()

virtual vector<LorentzPolarizationVectorE> Herwig::TwoMesonRhoKStarCurrent::current ( const int  imode,
const int  ichan,
Energy &  scale,
const ParticleVector decay,
DecayIntegrator::MEOption  meopt 
) const
virtual

Hadronic current.

This version returns the hadronic current described above.

Parameters
imodeThe mode
ichanThe phase-space channel the current is needed for
scaleThe invariant mass of the particles in the current.
decayThe decay products
meoptOption for the calculation of the matrix element
Returns
The current.

Implements Herwig::WeakDecayCurrent.

◆ dataBaseOutput()

virtual void Herwig::TwoMesonRhoKStarCurrent::dataBaseOutput ( ofstream &  os,
bool  header,
bool  create 
) const
virtual

Output the setup information for the particle database.

Parameters
osThe stream to output the information to
headerWhether or not to output the information for MySQL
createWhether or not to add a statement creating the object

Reimplemented from Herwig::WeakDecayCurrent.

◆ decayMode()

virtual unsigned int Herwig::TwoMesonRhoKStarCurrent::decayMode ( vector< int >  id)
virtual

Return the decay mode number for a given set of particles in the current.

Parameters
idThe id's of the particles in the current.
Returns
The number of the mode

Implements Herwig::WeakDecayCurrent.

◆ doinit()

virtual void Herwig::TwoMesonRhoKStarCurrent::doinit ( )
protectedvirtual

Initialize this object after the setup phase before saving and EventGenerator to disk.

Exceptions
InitExceptionif object could not be initialized properly.

Reimplemented from ThePEG::InterfacedBase.

◆ fullclone()

virtual IBPtr Herwig::TwoMesonRhoKStarCurrent::fullclone ( ) const
inlineprotectedvirtual

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.

Definition at line 167 of file TwoMesonRhoKStarCurrent.h.

◆ GSModeldhdq2Parameter()

InvEnergy2 Herwig::TwoMesonRhoKStarCurrent::GSModeldhdq2Parameter ( const unsigned int  ires) const
inlineprivate

The $\frac{dh}{dq^2}$ function in the GS model for the propagator evaluated at $q^2=m^2$.

Parameters
iresWhich of the $\rho$ or $K^*$ resonances to use
Returns
The value of $\frac{dh}{dq^2}$ at $q^2=m^2$.

Definition at line 254 of file TwoMesonRhoKStarCurrent.h.

References sqr().

◆ GSModelDParameter()

double Herwig::TwoMesonRhoKStarCurrent::GSModelDParameter ( const unsigned int  ires) const
inlineprivate

The $d$ parameter in the GS model of the propagator.

Parameters
iresWhich of the $\rho$ or $K^*$ resonances to use
Returns
The $d$ parameter

Definition at line 241 of file TwoMesonRhoKStarCurrent.h.

References ThePEG::Constants::pi, and sqr().

◆ GSModelhFunction()

double Herwig::TwoMesonRhoKStarCurrent::GSModelhFunction ( const unsigned int  ires,
const Energy  q 
) const
inlineprivate

The $h$ function in the GS model.

Parameters
iresWhich of the $\rho$ or $K^*$ resonances to use
qThe scale $q$.
Returns
The value of the $h$ function at scale $q$.

Definition at line 267 of file TwoMesonRhoKStarCurrent.h.

◆ particles()

virtual tPDVector Herwig::TwoMesonRhoKStarCurrent::particles ( int  icharge,
unsigned int  imode,
int  iq,
int  ia 
)
virtual

The particles produced by the current.

This just returns the two pseudoscalar mesons and the photon.

Parameters
ichargeThe total charge of the particles in the current.
imodeThe mode for which the particles are being requested
iqThe PDG code for the quark
iaThe PDG code for the antiquark
Returns
The external particles for the current.

Implements Herwig::WeakDecayCurrent.

◆ pcm()

Energy Herwig::TwoMesonRhoKStarCurrent::pcm ( const unsigned int  ires,
const Energy  q 
) const
inlineprivate

The momentum of the decay products for the running width.

Parameters
iresWhich of the $\rho$ or $K^*$ resonances to use
qThe scale $q$.
Returns
The momenta of the decay products in the rest frame of the intermediate resonance.

Definition at line 280 of file TwoMesonRhoKStarCurrent.h.

References sqr(), sqrt(), and ZERO.

◆ persistentInput()

void Herwig::TwoMesonRhoKStarCurrent::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 Herwig::TwoMesonRhoKStarCurrent::persistentOutput ( PersistentOStream os) const

Function used to write out object persistently.

Parameters
osthe persistent output stream written to.

Member Data Documentation

◆ _kwgt

vector<Complex> Herwig::TwoMesonRhoKStarCurrent::_kwgt
private

Weights for the different $K^*$ resonances in the current, $\alpha_k$.

The Complex weight used in the calculation

Definition at line 317 of file TwoMesonRhoKStarCurrent.h.

◆ _mass

vector<Energy> Herwig::TwoMesonRhoKStarCurrent::_mass
private

Parameters for the Breit-Wigners.

The masses of the resonances

Definition at line 377 of file TwoMesonRhoKStarCurrent.h.

◆ _piwgt

vector<Complex> Herwig::TwoMesonRhoKStarCurrent::_piwgt
private

Weights for the different $\rho$ resonances in the current, $\alpha_k$.

The Complex weight used in the calculation

Definition at line 297 of file TwoMesonRhoKStarCurrent.h.


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