Neutrino Mass from Triplet and Doublet Scalars at the TeV Scale

If the minimal standard model of particle interactions is extended to include a scalar triplet with lepton number $L=-2$ and a scalar doublet with $L=-1$, neutrino masses $m_{\nu }\sim {\mu }_{12}^4{v}^2\mathrm{/}{M}^5\sim {10}^{-2}$ eV is possible, where $v\sim {10}^2$ GeV is the electroweak symmetry breaking scale, $M\sim 1$ TeV is the typical mass of the new scalars, and ${\mu }_{12}\sim 1$ GeV is a soft lepton-number-violating parameter.