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Herwig
7.2.1
Decay
VectorMeson
a1SimpleDecayer.h
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// -*- C++ -*-
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//
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// a1SimpleDecayer.h is a part of Herwig - A multi-purpose Monte Carlo event generator
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// Copyright (C) 2002-2019 The Herwig Collaboration
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//
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// Herwig is licenced under version 3 of the GPL, see COPYING for details.
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// Please respect the MCnet academic guidelines, see GUIDELINES for details.
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//
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#ifndef HERWIG_a1SimpleDecayer_H
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#define HERWIG_a1SimpleDecayer_H
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//
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// This is the declaration of the a1SimpleDecayer class.
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//
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#include "Herwig/Decay/DecayIntegrator.h"
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#include "Herwig/Decay/DecayPhaseSpaceMode.h"
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#include "ThePEG/Helicity/LorentzPolarizationVector.h"
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namespace
Herwig
{
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using namespace
ThePEG
;
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class
a1SimpleDecayer
:
public
DecayIntegrator
{
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public
:
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a1SimpleDecayer
();
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virtual
int
modeNumber(
bool
& cc,
tcPDPtr
parent,
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const
tPDVector
& children)
const
;
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double
me2(
const
int
ichan,
const
Particle
& part,
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const
ParticleVector
& decay,
MEOption
meopt)
const
;
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virtual
WidthCalculatorBasePtr threeBodyMEIntegrator(
const
DecayMode
& dm)
const
;
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virtual
double
threeBodyMatrixElement(
const
int
imode ,
const
Energy2 q2,
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const
Energy2 s3,
const
Energy2 s2,
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const
Energy2 s1,
const
Energy m1,
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const
Energy m2,
const
Energy m3)
const
;
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virtual
void
dataBaseOutput(ofstream & os,
bool
header)
const
;
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public
:
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void
persistentOutput(
PersistentOStream
& os)
const
;
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void
persistentInput(
PersistentIStream
& is,
int
version);
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static
void
Init();
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protected
:
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virtual
IBPtr
clone
()
const
{
return
new_ptr(*
this
);}
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virtual
IBPtr
fullclone
()
const
{
return
new_ptr(*
this
);}
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protected
:
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virtual
void
doinit();
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virtual
void
doinitrun();
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private
:
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Complex
rhoBreitWigner
(Energy2 q2,
unsigned
int
ires)
const
{
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Energy q(
sqrt
(q2));
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Energy mass = _rhomass[ires], width = _rhowidth[ires];
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Energy pcm0(
Kinematics::pstarTwoBodyDecay
(mass,_mpi,_mpi));
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Energy pcm = 2.*_mpi<q ?
Kinematics::pstarTwoBodyDecay
(q,_mpi,_mpi) :
ZERO
;
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Energy gamrun(width*mass*Math::Pow<3>(pcm/pcm0)/q);
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return
-
sqr
(mass)/complex<Energy2>(q2-mass*mass,mass*gamrun);
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}
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Complex
rhoFormFactor(Energy2 q2,
int
ires)
const
;
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private
:
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a1SimpleDecayer
& operator=(
const
a1SimpleDecayer
&) =
delete
;
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private
:
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vector<Energy>
_rhomass
;
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vector<Energy>
_rhowidth
;
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vector<double>
_rhowgts
;
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bool
_localparameters
;
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InvEnergy
_coupling
;
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mutable
double
_onemax
;
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mutable
double
_twomax
;
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mutable
double
_threemax
;
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mutable
vector<double>
_onewgts
;
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mutable
vector<double>
_twowgts
;
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mutable
vector<double>
_threewgts
;
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Energy
_mpi
;
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mutable
RhoDMatrix
_rho
;
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mutable
vector<Helicity::LorentzPolarizationVector>
_vectors
;
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};
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}
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#endif
/* HERWIG_a1SimpleDecayer_H */
ThePEG::PersistentIStream
Herwig::a1SimpleDecayer::_onewgts
vector< double > _onewgts
Weights for the channels for the one charged pion channel.
Definition:
a1SimpleDecayer.h:230
sqrt
double sqrt(int x)
Herwig::a1SimpleDecayer::_twomax
double _twomax
Maximum weight for the two charged pion channel.
Definition:
a1SimpleDecayer.h:220
ThePEG::Complex
std::complex< double > Complex
ThePEG::Particle
Herwig::a1SimpleDecayer::fullclone
virtual IBPtr fullclone() const
Make a clone of this object, possibly modifying the cloned object to make it sane.
Definition:
a1SimpleDecayer.h:131
Herwig::a1SimpleDecayer::_rhowidth
vector< Energy > _rhowidth
The widths.
Definition:
a1SimpleDecayer.h:195
ThePEG::PersistentOStream
Herwig::a1SimpleDecayer::_vectors
vector< Helicity::LorentzPolarizationVector > _vectors
Polarization vectors.
Definition:
a1SimpleDecayer.h:255
ThePEG::IBPtr
ThePEG::Ptr< InterfacedBase >::pointer IBPtr
sqr
constexpr auto sqr(const T &x) -> decltype(x *x)
Herwig::a1SimpleDecayer
The a1SimpleDecayer class provides a simple model of the decay of the meson to three pions including...
Definition:
a1SimpleDecayer.h:30
ThePEG
Herwig::DecayIntegrator::MEOption
MEOption
Enum for the matrix element option.
Definition:
DecayIntegrator.h:79
Herwig::a1SimpleDecayer::clone
virtual IBPtr clone() const
Make a simple clone of this object.
Definition:
a1SimpleDecayer.h:125
Herwig::a1SimpleDecayer::_rhowgts
vector< double > _rhowgts
Weights for the different resonances.
Definition:
a1SimpleDecayer.h:200
Herwig::a1SimpleDecayer::rhoBreitWigner
Complex rhoBreitWigner(Energy2 q2, unsigned int ires) const
Breit-Wigner for the .
Definition:
a1SimpleDecayer.h:160
ThePEG::tPDVector
vector< tPDPtr > tPDVector
Herwig::a1SimpleDecayer::_localparameters
bool _localparameters
Use local values of the parameters.
Definition:
a1SimpleDecayer.h:205
Herwig::DecayIntegrator
Main class for Decayers implementing multi-channel phase space integration.
Definition:
DecayIntegrator.h:62
ThePEG::tcPDPtr
ThePEG::Ptr< ParticleData >::transient_const_pointer tcPDPtr
Herwig::Kinematics::pstarTwoBodyDecay
Energy pstarTwoBodyDecay(const Energy M, const Energy m1, const Energy m2)
For the two body decay M -> m1 + m2 it gives the module of the 3-momentum of the decay product in the...
Definition:
Kinematics.h:93
Herwig::a1SimpleDecayer::_mpi
Energy _mpi
The pion mass.
Definition:
a1SimpleDecayer.h:245
Herwig::a1SimpleDecayer::_twowgts
vector< double > _twowgts
Weights for the channels for the two charged pion channel.
Definition:
a1SimpleDecayer.h:235
Herwig::a1SimpleDecayer::_onemax
double _onemax
Maximum weight for the one charged pion channel.
Definition:
a1SimpleDecayer.h:215
Herwig::a1SimpleDecayer::_rho
RhoDMatrix _rho
Spin Density matrix.
Definition:
a1SimpleDecayer.h:250
Herwig::a1SimpleDecayer::_rhomass
vector< Energy > _rhomass
The masses.
Definition:
a1SimpleDecayer.h:190
Herwig::a1SimpleDecayer::_threewgts
vector< double > _threewgts
Weights for the channels for the three charged pion channel.
Definition:
a1SimpleDecayer.h:240
Herwig
-*- C++ -*-
Definition:
BasicConsistency.h:17
ThePEG::DecayMode
Herwig::a1SimpleDecayer::_coupling
InvEnergy _coupling
The overall coupling for the decay.
Definition:
a1SimpleDecayer.h:210
Herwig::a1SimpleDecayer::_threemax
double _threemax
Maximum weight for the three charged pion channel.
Definition:
a1SimpleDecayer.h:225
ThePEG::ParticleVector
vector< PPtr > ParticleVector
ThePEG::RhoDMatrix
ZERO
constexpr ZeroUnit ZERO
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