Scalar-tensor multiplet in four dimensional $$\mathcal{N}$$ = 2 conformal supergravity

A bstract We study various $$\mathcal{N}$$ = 2 multiplets in four dimensions by looking at the supersymmetric truncation of four dimensional $$\mathcal{N}$$ = 3 multiplets. Under supersymmetric truncation, the off-shell $$\mathcal{N}$$ = 3 Weyl multiplet reduces to the off-shell N = 2 Weyl multiplet and the off-shell $$\mathcal{N}$$ = 2 vector multiplet (which we will refer to as the central charge multiplet). Under the same truncation, the on-shell $$\mathcal{N}$$ = 3 vector multiplet reduces to the on-shell $$\mathcal{N}$$ = 2 vector multiplet and an on-shell massive hypermultiplet with a broken rigid SU(2) and a non-trivial central charge transformation. We use the field equations of this hypermultiplet to eliminate some of the fields of the central charge multiplet in terms of the fields of the hypermultiplet and a dual tensor gauge field (similar in spirit to how a dilaton Weyl multiplet is constructed). This results in a new off-shell matter multiplet, with 8 + 8 degrees of freedom, containing scalar fields and a tensor gauge field, which we refer to as the scalar-tensor multiplet.