Neutron Reflectometry and Short-Range Modifications of Gravity

Using the precise measurements of the scattering length of neutron–matter interaction obtained through the method of neutron reflectometry by gravity, we establish new empirical constraints on deviations from the standard behavior of the gravitational interaction at short distances predicted by large extra-dimensional models. We compute explicitly, in the thick-brane scenario, the corrections to the neutron–nucleus scattering length arising from the influence of hidden dimensions. The experimental data allow us to place empirical bounds on the free parameters of the extra-dimensional model, expressed as a function of the nuclear scattering length.