First sound versus zero sound in finite Fermi systems

The nuclear surface as a collective variable

“…Within this approximation it is the same as in the case of semiinfinite matter [5]. It satisfies asymptotic conditions Pedge=P;dge=0 (9) at ~= oo and approaches unity as an exponent at =-oo. (The primes mark i-derivatives here).…”

“…This microscopic definition is, however, hardly needed because, as a phenomenological constant, is known better than any Skyrme force. It should also be noted that properties of Peage, as determined in (8,9), are so specific that simple parametrization of this quantity in the form of Fermi-distribution-like function with empirical value of the diffuseness parameter can well be used, unless for some special reasons more detailed behavior of p(r) in the edge region is required, see also in Sect. 4.…”

“…Our derivation shows that such a solution takes into account the diffuseness of the nuclear surface in the first order in all. Widely spread criticism of the so-called sharp surface approximation is, therefore, groundless, and one should not be surprized by close agreement of result of numerical solutions of hydrodynamical equations [9] with the simple model suggested by Bohr-Mottelson. To this it must be added that the characteristic equation (49), as well as (6.676) of [8] are valid in the monopole case, too, in spite of reservations stated in [8].…”

“…1 (fat lines). For comparison are also presented results of numerical integration of hydrodynamical equations in [9]. Parameters R=7Fm and a=0.5Fm in (55) are the same as in [9].…”

Scaling calculation of isoscalar giant resonances in relativistic Thomas–Fermi theory

“…Semiclassical techniques like nuclear fluid dynamics [24] and the extended Thomas-Fermi method [25,26,27] have been applied to study giant resonances in non-relativistic models. In the relativistic context, the nuclear fluid dynamics approach has been utilized, e.g., in Refs.…”