# Supported Models

## Supported models and features

In SARAH all parts of a model can be changed with respect to the SM/MSSM:

## Input needed by SARAH to define a model

SARAH is optimized for the handling of a wide range of SUSY and non-SUSY models. The basic idea of SARAH was to give the user the possibility to implement models in an easy, compact and straightforward way. Most tasks to get the Lagrangian are fully automatized: it is sufficient to define just the fundamental properties of the model. That means, that the necessary input to completely define the gauge eigenstates with all their interactions are:

1. Global symmetries
2. Gauge symmetries
3. Chiral superfields respectively Matter fields
4. (Super)potential

That means that SARAH automatizes many steps to derive the Lagrangian from that input:

1. All interactions of matter fermions and the $F$-terms are derived from the superpotential
2. All vector boson and gaugino interactions as well as $D$-terms are derived from gauge invariance
3. All gauge fixing terms are derived by demanding that scalar–vector mixing vanishes in the kinetic terms
4. All ghost interactions are derived from the gauge fixing terms
5. All soft-breaking masses for scalars and gauginos as well as the soft-breaking counterparts to the superpotential couplings are added automatically

Of course, the Lagrangian of the gauge eigenstates is not the final aim. Usually one is interested in the mass eigenstates after gauge symmetry breaking. To perform the necessary rotations to the new eigenstates, the user has to give some more information:

1. Definition of the fields which get a vacuum expectation value (VEV) to break gauge symmetries
2. Definition of what vector bosons, scalars and fermions mix among each other

Using this information, all necessary re-definitions and fields rotations are done by SARAH. Also the gauge fixing terms are derived for the new eigenstates and the ghost interactions are added. For all eigenstates plenty of information can be derived by SARAH at tree-level and even loop level.