$$%
\Lag = \frac{1}{2} \( \oline{\nu}_L \; \; \oline{N}_L^c \) \(
\begin{array}{cc} \mathbf{m}_{T} & \mathbf{m}_{D} \\ \mathbf{m}_{D}^{T} &
\mathbf{m}_{S} \end{array} \) \( \begin{array}{c} \nu_R^c \\ N_R
\end{array} \) + \hc .
%
\label{general}$$ Each of the four quantities in (\[general\]) are understood to be $3 \times 3$ matrices in flavor space. That is, we imagine a model with one [*species*]{} of lepton doublet $L$ (with three generations) and, if present, one [*species*]{} of right-handed neutrino field (with three generations).

We will use the name “triplet models” to refer to any model which uses electroweak triplet states alone to generate neutrino masses. That is, such a model dispenses with right-handed neutrinos altogether, and the effective neutrino mass in (\[mnu\]) is then simply identified with the entry $\mathbf{m}_{T}$ in (\[general\]). A supersymmetric extension of the MSSM capable of giving small effective masses to left-handed neutrinos would involve two new sets of fields $T_i$ and $\oline{T}_i$ which transform as triplets under $SU(2)_{L}$ and have hypercharge assignments $Y_{T} = +1$ and $Y_{\oline{T}} =
-1$, respectively [@Hambye:2000ui; @Rossi:2002zb]. For the time being we will consider just one pair of such fields, which couple to the Standard Model through the superpotential $$\begin{aligned}
%
W_{\nu} &=& (\lambda_{T})_{ij} 