





title: Nomenclature for fields in supersymmetric models



permalink: /Nomenclature_for_fields_in_supersymmetric_models/










[Category:Model](/Category:Model "wikilink") In general, the names of the component fields which are used to express the SUSY Lagrangian for the gauge eigenstates are derived from the names of the vector and chiral superfields. All gauge eigenstates are named as follows:






ParticleType <> Basis <> [Indices]






With






 Type: this is just one letter and indicates the type of a field. The convention is as follows:






1. `F` for fermionic component of chiral superfield



2. `S` for scalar component of chiral superfield



3. `f` for fermionic component of vector superfield



4. `V` for bosonic component of vector superfield



5. `g` for ghost field






In addition, there are two types of auxiliary fields. This auxiliary field are not related in any way to the auxiliary components of the superfields in SUSY theories, but they are needed only for writing a CalcHep / CompHep model file. The type indicating letters are:






1. `A` for an auxiliary scalar



2. `a` for an auxiliary vector boson






 `Basis`: this is for any gauge eigenstates the name of the underlying superfield.



 `Indices`: this is alist of the indices which the particle carries. There are three different kinds of indices:






1. `generation`: For all particles which appear in more than one generation



2. `lorentz:` For all particles carrying a Lorentz index



3. `charge:` For all components of a chiral superfield charged under a nonAbelian gauge group if this indices are not implicit






Examples










To clarify the above definitions, here some examples:






1. `VB[{lorentz}]`: BBoson with one Lorentz index



2. `fB`: Bino



3. `SHd0`: Neutral down Higgs



4. `FHd0`: Neutral down Higgsino



5. `VG[{color,Lorentz}]`: Gluon with one index for the adjoint of the color group and one Lorentz index



6. `fG[{color}]`: Gluino with one adjoint index



7. `gG[{color}]`: Gluon ghost with one adjoint index



8. `SdL[{generation,color}]`: Left handed dsquark with one generation and one color index



9. `FdL[{generation,color}]`: Left handed dquark with one generation and one color index



10. `hh[{generation}]`: Neutral, CPeven Higgs (light and heavy Higgs) after EWSB






Antiparticles










There are two functions to assign antiparticles: depending on the type of the particle `conj` or `bar` are used.






1. Scalar, vector boson and Weyl spinor: `conj`, e.g. `conj[SdR]` or `conj[VWm]`.



2. Dirac fermion and ghost: `bar`, e.g `bar[Fd]` or `bar[gG]`.






SARAH checks if a particle is a real scalar or vector bosons respectively a Majorana fermion. In these cases it simplifies the expressions by using






conj[RP] := RP



bar[MF] := MF






for a real particle `RP` or also real parameter, and for a Majorana fermion `MF`. The names of all Majorana fermions of the current model are saved in the list `MajoranaPart`, and all real parameters and particles are listed in `realVar`.



Note, that the head `bar` is overloaded: it is either interpreted as hermitian or complex conjugated depending on the position of the fermions in a Dirac chains in order to build up Lorentz scalars.






See also



 


\ No newline at end of file 