title: Clustering of Fermi particles with arbitrary spin.
abstract: A single l-shell model is investigated for a system of fermions of spin s and an attractive s-wave, spin channel independent, interaction. The spectra and eigenvectors are determined exactly for different l,s values and particle numbers N. As a generalization of Cooper pairing it is shown that when N=mu(2s+1), mu=1,2,..., 2l+1, the ground state consists of clusters of (2s+1) particles. The relevance of the results for more general situations including the homogeneous system is briefly discussed.
authors.affiliation: Research Group for Statistical Physics of the Hungarian Academy of Sciences, Pázmány P. Sétány 1/A, H-1117 Budapest, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Csordás
authors.forename: Péter
authors.initials: P
authors.lastname: Szépfalusy
authors.forename: Eva
authors.initials: E
authors.lastname: Szoke