28 research outputs found

    Gamow-Teller strength distributions for double-beta-decaying nuclei within continuum-QRPA

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    A version of the pn-continuum-QRPA is outlined and applied to describe the Gamow-Teller strength distributions for ββ\beta\beta-decaying open-shell nuclei. The calculation results obtained for the pairs of nuclei 116^{116}Cd-Sn and 130^{130}Te-Xe are compared with available experimental data.Comment: 8 pages, 3 figures, To appear in the proceedings of "Nucleus-2007: Fundamental problems of nuclear physics, atomic power engineering and nuclear technologies" Voronezh, Russia, June 25-29, 200

    Novel hydrodynamic cumulation mechanism caused by quantum shell effects

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    The computational and theoretical analysis carried out in this article demonstrates the existence of a nontrivial mechanism for the compression of a submicron-sized gas bubble formed by a gas of classical ions and a gas of degenerate electrons. This mechanism fundamentally differs from conventional compression mechanisms. It is shown that taking into account the quantum effect of a large spatial scale in the distribution of electrons qualitatively changes the character of cumulative processes. Because of a large-scale electric field caused by quantum shell effects, the compression process is characterized by the formation of multiple shock waves. The values of gas temperature and pressure achieved during compression occur higher by two orders of magnitude as compared with the classical adiabatic regime. The analysis is carried out within the framework of the following model: the dynamics of the electron subsystem is described by equations of a quantum electron fluid, while the hydrodynamic approximation is adopted for the ionic subsystem. The large scale effect is taken into account by means of effective external field acting on electrons. The theoretical analysis carried out within this approach clarifies the nature of the cumulative process in the system under consideration; some quantitative characteristics obtained with numerical simulation are presented. The possibility of experimental observation of this cumulative mechanism is analyzed. It is suggested that the manifestation of the effect can be observed during laser compression of a system of submicron targets by measuring the neutron yield.Comment: 49 pages, pdf onl

    Exchange effects in composite-particle interaction

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    Algebraic version of the orthogonality conditions model is developed by analogy with the algebraic version of the resonating group model. It is shown that all exchange terms excluding ones originated by the exchange kernel of the potential energy can be easily taken into account in the frame of the formalism of the version. The potential term as a whole is modelled phenomenologically. Both direct algebraic approach and the method basing on the solution of the integro-differential Schrödinger equation containing nonlocal terms related to the forbidden and the semi-forbidden states are proposed. This equation turns out to be preferable in studies of narrow resonances. It is demonstrated that decay width of a system into two-heavy-fragment channel is strongly affected by the nonlocal terms

    On damping of the gamow-teller resonance in 118Sb

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    Section III. Theory of Atomic Nucleus and Fundamental InteractionsThis work is partially supported by RFBR (grant No. 12-02-01303-a)

    Problems of experimental and theoretical studies of the Gamow-Teller giant resonance in

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    Properties of the Gamow-Teller giant resonance (GTGR) in 118Sb are described within the semi-microscopic approach based on the extended version of the "charge-exchange" continuum-quasiparticle-random-phase-approximation and phenomenological treatment of the spreading effect. The structure effect of the configuration splitting of this GTGR is confirmed. With taking this effect into account the experimental data on excitation of the GTGR in direct and resonance reactions are analyzed
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