Degeneracy patterns and hyper-multiplet structure in the spectrum of the su($m|n$) supersymmetric Polychronakos spin chain are studied by use of the "motif''. Using the recursion relation of the supersymmetric Rogers-Szeg{ \"o} polynomials which are closely related to the partition function of the $N$ spin chain, we give the representation for motif in terms of the supersymmetric skew Young diagrams. We also study the distribution function for quasi-particles. The character formulae for $N\to \infty$ are briefly discussed.
Categories: math-ph cond-mat.stat-mech hep-th math.MP nlin.SI solv-int