Response of nuclear surface onto fast proton scattering

Response of semi-infinite Fermi liquid to a periodical external force acting on its surface is considered on the basis of the semi-classical Landau theory of Fermi liquid. The obtained surface response function coincides with the classical limit of the quantum response function derived in the random-phase approximation. The theory is applied to the description of a response of nuclear surface to fast proton scattering at small momentum and energy transfers. The non-resonance component of the experimental spectrum (a smooth substrate in the region of giant nuclear resonance) is fairly reproduced by the theory