ThePEG::Helicity::SpinInfo Class Reference
The SpinInfo is the base class for the spin information for the spin correlation algorithm. More...
#include <SpinInfo.h>
Public Types | |
| enum | DevelopedStatus { Undeveloped = 0, Developed = 1, NeedsUpdate = 2 } |
| Enum to store the status. | |
Public Member Functions | |
| virtual void | rebind (const EventTranslationMap &trans) |
| Rebind to cloned objects. | |
| virtual EIPtr | clone () const |
| Standard clone method. | |
| void | update () const |
| Method to handle the delelation. | |
| virtual void | transform (const LorentzMomentum &, const LorentzRotation &r) |
| Perform a lorentz rotation of the spin information. | |
Standard constructors and destructors. | |
| SpinInfo () | |
| Default constructor. | |
| SpinInfo (PDT::Spin s, const Lorentz5Momentum &p=Lorentz5Momentum(), bool time=false) | |
| Standard Constructor. | |
| SpinInfo (const SpinInfo &) | |
| Copy-constructor. | |
Access the vertices. | |
| void | setProductionVertex (VertexPtr in) const |
| Set the vertex at which the particle was produced. | |
| tcVertexPtr | getProductionVertex () const |
| Get the vertex at which the particle was produced. | |
| void | setDecayVertex (VertexPtr in) const |
| Set the vertex at which the particle decayed or branched. | |
| tcVertexPtr | getDecayVertex () const |
| Get the vertex at which the particle decayed or branched. | |
Access information about the associated particle. | |
| bool | decayed () const |
| Has the particle decayed? | |
| void | decayed (bool b) const |
| Set if the particle has decayed. | |
| DevelopedStatus | developed () const |
| Return true if the decay matrix required to perform the decays of the siblings of a particle has been calculated. | |
| void | needsUpdate () const |
| Needs update. | |
| void | decay () const |
| Calculate the rho matrix for the decay if not already done. | |
| void | develop () const |
| Set the developed flag and calculate the D matrix for the decay. | |
| PDT::Spin | iSpin () const |
| Return 2s+1 for the particle. | |
| const Lorentz5Momentum & | productionMomentum () const |
| Return the momentum of the particle when it was produced. | |
| const Lorentz5Momentum & | currentMomentum () const |
| The current momentum of the particle. | |
| bool | timelike () const |
| Return true if particle is timelike (rather than spacelike). | |
| int | productionLocation () const |
| Access to the locations. | |
| int | decayLocation () const |
| Decay Location. | |
Access the rho and D matrices. | |
| RhoDMatrix | rhoMatrix () const |
| Access the rho matrix. | |
| RhoDMatrix & | rhoMatrix () |
| Access the rho matrix. | |
| RhoDMatrix | DMatrix () const |
| Access the D matrix. | |
| RhoDMatrix & | DMatrix () |
| Access the D matrix. | |
Static Public Member Functions | |
| static void | Init () |
| Standard Init function. | |
Protected Member Functions | |
| bool | isNear (const Lorentz5Momentum &p) |
| Check if momentum is near to the current momentum. | |
Private Member Functions | |
| SpinInfo & | operator= (const SpinInfo &) |
| Private and non-existent assignment operator. | |
| void | redevelop () const |
| Set the developed flag and calculate the D matrix for the decay, and all decays further up the chain. | |
Private Attributes | |
| VertexPtr | _production |
| Pointer to the production vertex for the particle. | |
| VertexPtr | _decay |
| Pointers to the decay vertex for the particle. | |
| bool | _timelike |
| Is this is timelike (true) or spacelike (false ) particle? This is used to decide if the particle is incoming or outgoing at the production vertex. | |
| int | _prodloc |
| Location in the hard vertex array at production. | |
| int | _decayloc |
| Location in the hard vertex array at decay. | |
| bool | _decayed |
| Has the particle been decayed? (I.e. | |
| DevelopedStatus | _developed |
| Has the particle been developed? (I.e. | |
| RhoDMatrix | _rhomatrix |
| Storage of the rho matrix. | |
| RhoDMatrix | _Dmatrix |
| Storage of the decay matrix. | |
| PDT::Spin | _spin |
| The spin of the particle. | |
| Lorentz5Momentum | _productionmomentum |
| Momentum of the particle when it was produced. | |
| Lorentz5Momentum | _decaymomentum |
| Momentum of the particle when it decayed. | |
| Lorentz5Momentum | _currentmomentum |
| Current momentum of the particle. | |
Static Private Attributes | |
|
static NoPIOClassDescription < SpinInfo > | initSpinInfo |
| Describe a concrete class without persistent data. | |
| static const double | _eps |
| A small energy for comparing momenta to check if Lorentz Transformations should be performed. | |
Detailed Description
The SpinInfo is the base class for the spin information for the spin correlation algorithm.It inherits from ThePEG SpinBase class and in turn the implementations for different spin states inherit from this.
The class contains pointers to the vertex where the particle is produced and where it decays, together with methods to set/get these.
There are two flags decayed which store information on the state of the particle.
The decayed() members provides access to the _decay data member which is true if the spin density matrix required to perform the decay of a timelike particle has been calculated (this would be a decay matrix for a spacelike particle.) This is set by the decay() method which calls a method from the production vertex to calculate this matrix. The decay() method should be called by a decayer which uses spin correlation method before it uses the spin density matrix to calculate the matrix element for the decay.
The developed() member provides access to the _developed data member which is true if the decay matrix required to perform the decays of the siblings of a particle has been calculated (this would a spin density matrix for a spacelike particle.) This is set by the developed() method which calls a method from the decay vertex to calculate the matrix. The developed() method is called by a DecayHandler which is capable of performing spin correlations after all the unstable particles produced by a decaying particle are decayed.
Methods are also provided to access the spin density and decay matrices for a particle.
Definition at line 62 of file SpinInfo.h.
Constructor & Destructor Documentation
| ThePEG::Helicity::SpinInfo::SpinInfo | ( | PDT::Spin | s, | |
| const Lorentz5Momentum & | p = Lorentz5Momentum(), |
|||
| bool | time = false | |||
| ) | [inline] |
Standard Constructor.
- Parameters:
-
s the spin. p the production momentum. time true if the particle is time-like.
Definition at line 93 of file SpinInfo.h.
Member Function Documentation
| virtual void ThePEG::Helicity::SpinInfo::rebind | ( | const EventTranslationMap & | trans | ) | [virtual] |
Rebind to cloned objects.
If a FermionSpinInfo is cloned together with a whole Event and this has pointers to other event record objects, these should be rebound to their clones in this function.
Reimplemented from ThePEG::EventInfoBase.
| int ThePEG::Helicity::SpinInfo::productionLocation | ( | ) | const [inline] |
Access to the locations.
Production Location
Definition at line 246 of file SpinInfo.h.
References _prodloc.
Member Data Documentation
bool ThePEG::Helicity::SpinInfo::_decayed [mutable, private] |
Has the particle been decayed? (I.e.
has the rho matrix for the decay been calculated.)
Definition at line 341 of file SpinInfo.h.
Referenced by decayed().
DevelopedStatus ThePEG::Helicity::SpinInfo::_developed [mutable, private] |
Has the particle been developed? (I.e.
has the D matrix encoding the info about the decay been calculated)
Definition at line 347 of file SpinInfo.h.
Referenced by developed(), and needsUpdate().
The documentation for this class was generated from the following file:
