'Small angle scattering of slow electrons by helium atoms in a CO2 laser field: A collective model'

Varro and Ehlotzky (1995) have employed an effective laser-induced polarizability to explain the breakdown of the Kroll-Watson approximation observed for small-angle electron-helium scattering in a laser field. Their derivation omits a cancelling electronic contribution so that the coherent polarization potential they introduce is much too weak to explain the breakdown.