Capelli identities for Lie superalgebras

We apply the technique of affine Hecke algebras to the invariant theory of the "queer" Lie superalgebra $q_N$. We give explicit formulas for the elements of a distinguished basis in the centre of $U(q_N)$, determined by "vanishing" conditions. We evaluate the corresponding differential operators on $C^{N|N}\otimes C^{M|M}$. In particular, we obtain an analogue for $q_N$ of the classical Capelli identity.