Short representations of SU(2,2/N) and harmonic superspace analyticity

Abstract

We consider the harmonic superspaces associated to SU(2,2/N) superconformal algebras. For arbitrary N, we show that massless representations, other than the chiral ones, correspond to [N/2] ``elementary'' ultrashort analytic superfields whose first component is a scalar in the k antisymmetric irrep of SU(N) (k=1... [N/2]) with top spin $J_{\mathrm{top}}=(N/2-k/2,0)$. For N=2n we analyze UIR's obtained by tensoring the self-conjugate ultrashort multiplet $J_{\mathrm{top}}$= (n/2,0) and show that N-1 different basic products give rise to all possible UIR's with residual shortening.

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