Twisted bimodules and Hochschild cohomology for self-injective algebras ofclass A(n)

We study stable homomorphisms for twisted bimodule structures on a finite-d imensional self-injective algebra. We use this to give a presentation for t he Hochschild cohomology ring of self-injective Nakayama algebras. By deriv ed equivalence, this gives also the Hochschild cohomology ring for arbitrar y self-injective whose stable Auslander-Reiten quiver is of the form ZA(n)/ [tau(e]). Moreover, we obtain a new characterization of self-injective Naka yama algebras.