Constraining nonextensive statistics with plasma oscillation data

We discuss new experimental constraints on the free parameter of the nonextensive kinetic theory from measurements of the thermal dispersion relation in a collisionless plasma. For electrostatic plane-wave propagation, we show through a statistical analysis that a good agreement between theory and experiment is possible if the allowed values of the q-parameter are restricted by q=0.77±0.03 at 95% confidence level (or equivalently, 2-q=1.23, in the largely adopted convention for the entropy index q). Such a result rules out (by a large statistical margin) the standard Bohm-Gross dispersion relation which is derived assuming that the stationary Maxwellian distribution (q=1) is the unperturbed solution.