# Higher dimensionsal terms in superpotential

## General

SARAH is mainly restricted to renormalisable operators. The only exception are the possibility to include interactions of four superfields in the Superpotential:

`SuperPotential = ... + [Coefficient] EffOp [Contraction] SuperField1.SuperField2.SuperField3.SuperField4`

SARAH can't so far not include the entire impact of this operator but the following aspects are covered:

- A soft-term involving four scalars is added (
`Q[EffOp]`

) - The RGEs for the superpotential term and the soft-term are calculated
- The four scalar and two scalar-two fermion interactions are added to the Lagrangian. However, for the FFSS interactions only those terms are included in the calculation where at least one scalar is replaced by a VEV, i.e. effective FFS and FF terms are generated.

## Example

Despite the many limitations in the support of such terms, the given functionality is sufficient to include all important effects from the Weinberg operator. Adding the term

`SuperPotential = WOp/2 Hu.l.Hu.l`

to the superpotential, SARAH calculates the RGEs for `WOp`

and uses it to obtain neutrino masses.