  We measure the sphaleron rate (topological susceptibility) of hot SU(2) gauge
theory, using a lattice implementation of the hard thermal loop (HTL) effective
action. The HTL degrees of freedom are implemented by an expansion in spherical
harmonics and truncation. Our results for the sphaleron rate agree with the
parametric prediction of Arnold, Son and Yaffe: Gamma ~ \alpha^5 T^4.
