Negative scattering asymmetry parameter for dipolar particles: Unusual   reduction of the transport mean free path and radiation pressure
  We establish a relationship between the electric magnetic dipole interaction force from a plane wave on a small magnetodielectric particle, the transport cross-section and the scattering asymmetry parameter, g. In this way, we predict negative g that minimize the transport mean free-path below values of the scattering mean free path of a dilute suspension of both perfectly reflecting spheres as well as of those that satisfy the so-called Kerker conditions, like high permittivity dielectric ones. 
R. Gomez-Medina, L. Froufe-Perez, M. Yepez, F. Scheffold, M.   Nieto-Vesperinas, and J. J. Saenz
cond-mat.mtrl-sci cond-mat.mes-hall