Search for long-range forces by means of ultracold neutrons (1)

A method of using a gravitational spectrometer to search for long-range forces between neutrons and atoms is proposed. The constraints on the strength of long range forces within the range of $10^{-10}$–$10^{-4}\,$cm can be obtained from the experiments on measurements of the total cross section of interaction of ultracold neutrons with atoms of noble gases (He, Ne, Ar, $^{86}$Kr) and the data on the coherent neutron scattering length of the nucleus. The first result of such type analysis is presented.