A bijection is defined from Littlewood-Richardson tableaux to rigged
configurations. It is shown that this map preserves the appropriate statistics,
thereby proving a quasi-particle expression for the generalized Kostka
polynomials, which are q-analogues of multiplicities in tensor products of
irreducible general linear group modules indexed by rectangular partitions.Comment: 66 pages, AMS-LaTeX, requires xy.sty and related file
