Serebrov, Anatoli P.Geltenbort, PeterZherebtsov, O. M.Sbitnev, S. V.Varlamov, V. E.Vassiljev, A. V.Lasakov, M. S.Krasnoschekova, I. A.Ivanov, S. N.Pushin, Dimitry A.2018-09-112018-09-112014-04-09https://dx.doi.org/10.1103/physrevc.89.044002http://hdl.handle.net/10012/13799© 2014 American Physical Society, https://dx.doi.org/10.1103/physrevc.89.044002In this work we introduce a method of measuring low-energy scattering cross section with a gravitational spectrometer. In this method we add atoms (i.e., He) to the gravitational spectrometer filled with a target gas of ultracold neutrons (UCN). We search for long-range forces between atoms and UCN by measuring transfer of a small recoil energy similar to 10(-7) eV using the gravitational spectrometer. As a result of this search we set new constraints on the strength of long-range forces within the range of the effective radius of interaction of 10(-7)-10(-4) cm.eninverse-square lawextra dimensionscross-sectionsgasestestsArticle