Structure of $\mathcal{N} = 2$ superfield higher-spin abelian cubic interactions

Abstract

In this article we study the structure of the $\mathcal{N}=2$ abelian higher-spin cubic $(\mathbf{s_1}, \mathbf{s_2}, \mathbf{s_2})$ vertices and the corresponding $\mathcal{N}=2$ higher-spin supercurrents, introduced in arXiv:2408.00668. These interactions are possible only for $\mathbf{s_1} \geq 2 \mathbf{s_2}$. Conserved supercurrents are constructed as descendants of the \textit{principal supercurrent}, which is uniquely characterized by simple differential conditions and admits an explicit representation in terms of $\mathcal{N}=2$ higher-spin super-Weyl tensors. We derive the analytic form of the abelian vertices and identify the corresponding analytic higher-spin $\mathcal{N}=2$ supercurrents. We show that the vertex structure is fully determined by the analytic supercurrents $J^{++}_{\alpha(s-1)\dot{\alpha}(s-1)}$, $J^+_{\alpha(s-1)\dot{\alpha}(s-2)}$, and $\bar{J}^+_{\alpha(s-2)\dot{\alpha}(s-1)}$. The analytic form of the vertices provides a simple framework for analyzing their component structure. As an example, we explore the component content of such interactions on the Bel--Robinson diagonal. Using the superfield inverse Noether procedure, we study higher-spin gauge transformations for the $\mathcal{N}=2$ vector multiplet associated with the $(\mathbf{s}, \mathbf{1}, \mathbf{1})$ interaction. In the rigid limit, for odd $\mathbf{s}$ these transformations reduce to the $\mathcal{N}=2$ superspace generalization of zilch-type higher-spin symmetries.