Mass-deformed $mathcal{N} = 3$ Supersymmetric Chern-Simons-Matter Theory

The maximal extension of supersymmetric Chern-Simons theory coupled to fundamental matter has $mathcal{N} = 3$ supersymmetry. In this short note, we provide the explicit form of the action for the mass-deformed $mathcal{N} = 3$ supersymmetric $U(N)$ Chern-Simons-Matter theory. The theory admits a unique triplet mass deformation term consistent with supersymmetry. We explicitly construct the mass-deformed $mathcal{N} = 3$ theory in $mathcal{N} = 1$ superspace using a fundamental and an anti-fundamental superfield.