Supported matter sector
One can define up to 99 matter fields in a single model in SARAH. Each one of them can come with an arbitrary number of generations and can transform as any irreducible representation with respect to the defined gauge groups.
Supersymmetric models
The matter interactions in SUSY models are usually fixed by the superpotential and the soft SUSY-breaking terms. SARAHtakes as input the renormalisable terms in the superpotential
W = cLLiϕ̂i + cMMi**jϕ̂iϕ̂j + cTYijkϕ̂iϕ̂jϕ̂k
which the user has to write in the model file, and automatically generates the corresponding soft-breaking terms
LS**B, W = cLtiϕi + cMBi**jϕiϕj + cTTijkϕiϕjϕk + h.c.
cL, cM, cT are real coefficients, while the linear, bilinear, and trilinear parameters are treated by default in the most general way by taking them as complex tensors of appropriate order and dimension. If identical fields are involved in the same coupling, SARAHalso derives the symmetry properties for the parameter.
In recent years models with Dirac gauginos have been largely explored. They feature mass terms of the form mDϕ̂iAλAψi < mat**h > ,where < mat**h > λA is a gaugino and ψi the fermionic component of a chiral superfield ϕ̂i in the adjoint representation of the gauge group A. In addition, there are new D-term couplings . To generate Dirac mass terms for all the gauginos, these models always come with an extended matter sector, including at least one singlet, one triplet under S**U(2), and one octet under S**U(3). Furthermore, these models generate new structures in the RGEs . All these are fully supported in SARAH.
Non-Supersymmetric models
For non-supersymmetric models, SARAH supports all general, renormalisable Lagrangians of the form
L = m_{ij}^2 \phi_i \phi_j + \frac{1}{3} \kappa_{ijk} \phi_i \phi_j \phi_k + \frac{1}{4} \lambda \phi_i \phi_j \phi_k \phi_l + M^F_{ij} \psi_i \psi_j + Y_{ijk} \phi_i \psi_i \psi_j
for scalars ϕi, and Weyl fermions ψj. The Lagrangian needs to be defined by the user in the model file. Note, that we have omitted a tadpole term, t**ϕ, for a gauge singlet, as it can always be absorbed in a shift of ϕ.