Composite Fermion Hall Conductance at $\nu=1/2$
  We show that in the limit of vanishing bare electron effective mass, and in the presence of particle-hole symmetric disorder (which can be of vanishing strength), the composite fermion Hall conductance is constrained to be $-{1\over 2}\frac{e^2}{h}$. We discuss the implications of this results for the existence and nature of a composite Fermi liquid in the lowest Landau level. 
D-H Lee, Y. Krotov, J. Gan and S.A. Kivelson