Effect of dephasing on charge-counting statistics in chaotic cavities

We calculate the cumulants of the charge transmitted through a chaotic cavity in the limit that the two openings have a large number of scattering channels. The shot noise, which is the second cumulant, is known to be insensitive to dephasing in this limit. Unexpectedly, the fourth and higher cumulants are found to depend on dephasing: A semiclassical theory and a quantum mechanical model with strong dephasing give a result different from a fully phase-coherent quantum mechanical theory.