[en] The nuclear fluid-dynamical Hamiltonian which takes the distortion of the local Fermi surface into account predicts the Twist mode (T = 0, J = 2^-) at a finite frequency (about 7.5 MeV for ²⁰⁸Pb). (orig.)

[en] The relaxation kinetic equation, describing the behavior of the Fermi gases, is derived. The Kramers semi-spatial task on the isothermal slip is considered. Its analytical solution is established and the function of distributing the particles, flying to the wall, is obtained in an obvious form. The analysis of the dependence of the equation itself and the slip rate on the value of the parameter, representing the ratio of the chemical potential to the product of the Boltzmann constant by the absolute temperature, is carried out

[en] By means of the Fermi-liquid approach, the effects of exchange and correlations are considered in a layered two-dimensional electron gas. A graphical derivative technique is introduced to obtain the contributions to the interparticle interactions from different channels. It is shown that the interaction in the particle-hole channel can induce the metal-insulator phase transition when the Fermi momentum is comparable with the inverse interlayer spacing, p_F approx. 1/c . It is also shown that the Cooper-like scattering processes give rise to the scaling of the Fermi liquid response as Im χ ∼ -ω/T, which leads to the linear temperature dependence of the quasiparticle damping. The possibility of superconductivity in the region between the insulator and normal metal phases, accounting for the particle-hole excitations, is discussed. The effect of the spin fluctuations on the superconductivity due to the particle-hole excitations is also considered. (author)

[en] Nuclear caloric curves have been analyzed using an expanding Fermi gas hypothesis to extract average nuclear densities. In this approach the observed flattening of the caloric curves reflects progressively increasing expansion with increasing excitation energy. This expansion results in a corresponding decrease in the density and Fermi energy of the excited system. For nuclei of medium to heavy mass apparent densities ∼0.4ρ₀ are reached at the higher excitation energies

[en] A recent set of nuclear level density parameters obtained for the constant temperature (CT) and back-shifted Fermi gas (BSFG) model is reviewed. Very simple correlations are observed between the parameters T of CT, and a of BSFG, and between E₀ of CT and E₁ of BSFG. The average behavior of the level density parameter a with mass number is found to be a∼A^0.90

[en] Full text: The investigation of interacting quantum ensembles in non-equilibrium is receiving a lot of attention, yet the theoretical understanding of experimental results often remains challenging due to the complexity of the systems and their coupling to the environment. In contrast, ultracold atoms in optical lattices offer a unique cleanliness and tunability of parameters. They are therefore well suited for the study of both equilibrium and non-equilibrium states in strongly correlated systems. We implement the Fermi-Hubbard model by trapping a repulsively interacting two-component Fermi gas in a three dimensional optical lattice. This model encompasses intriguing quantum phases near the Mott insulator and may even hold the key to understanding high-temperature superconductivity. The relaxation of highly excited states of our system, which are doubly occupied lattice sites (doublons), is investigated. After creating additional doublons by lattice modulation, we monitor the subsequent relaxation of the system over time. In units of the tunneling time, the measured doublon lifetime is found to depend exponentially on the ratio of on-site interaction energy to kinetic energy. We argue that the dominant mechanism for the relaxation is a high order scattering process. (author)

[en] A statistical method for calculating the hydrogen bond energy in metals is proposed. Within the framework of the electron Fermi-gas model an analytical expression is obtained for the average energy of hydrogen in metals of the Periodic Table of the Elements (Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Tl, Sn, Pb) as a function of the microscopic parameters of the metal. The hydrogen-metal bond energies calculated in accordance with the proposed theory are in good correlation with the experimental values

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No abstract available

[en] The superscaling observed in inclusive electron scattering is described within the dilute Fermi gas model with interaction between the particles. The comparison with the relativistic Fermi gas (RFG) model without interaction shows an improvement in the explanation of the scaling function f(ψ"') in the region ψ"' < −1, where the RFG result is f(ψ"') = 0. It is found that the behavior of f(ψ"') for ψ"' < −1 depends on the particular form of the general power-law asymptotics of the momentum distribution n(k) ∼ 1/k"4"+"m at large k. The best agreement with the empirical scaling function is found for m ≅ 4.5 in agreement with the asymptotics of n(k) in the coherent density fluctuation model where m = 4, the latter model being applied successfully to describe the superscaling phenomenon. Thus, superscaling gives information about the asymptotics of n(k) and the NN forces.