Signatures of a novel fermi liquid in a two-dimensional composite particle metal

Quasiparticle excitation gaps of the ν=p(2p+1) fractional quantum Hall states in a low-disorder two-dimensional hole system are observed to scale linearly with (e2εB)(2p+1), predicted by the Chern-Simons gauge field theory if a hole-flux composite particle Fermi liquid forms around filling ν=12 (B is the magnetic length). The effective mass and quantum lifetime of these new particles reveal a remarkable renormalization structure, including a strongly diverging mass and enhanced scattering close to the Fermi surface, suggesting a novel class of marginal Fermi liquid behavior.