27 research outputs found

    Norm kernels and the closeness relation for Pauli-allowed basis functions

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    The norm kernel of the generator-coordinate method is shown to be a symmetric kernel of an integral equation with eigenfunctions defined in the Fock--Bargmann space and forming a complete set of orthonormalized states (classified with the use of SU(3) symmetry indices) satisfying the Pauli exclusion principle. This interpretation allows to develop a method which, even in the presence of the SU(3) degeneracy, provides for a consistent way to introduce additional quantum numbers for the classification of the basis states. In order to set the asymptotic boundary conditions for the expansion coefficients of a wave function in the SU(3) basis, a complementary basis of functions with partial angular momenta as good quantum numbers is needed. Norm kernels of the binary systems 6He+p, 6He+n, 6He+4He, and 8He+4He are considered in detail.Comment: 25 pages; submitted to Few-Body System

    Many-channel microscopic theory of resonance states and scattering processes in 9^{9}Be and 9^{9}B

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    We present a many-channel microscopic model that extends the three-cluster model previously formulated in \cite{2009NPA...V37}. This extended model incorporates multiple three-cluster configurations, which are subsequently reduced to a comprehensive set of binary channels. These channels dictate the dynamics of various nuclear processes and the resonance structure of a compound nucleus across a broad energy spectrum. The application of this model focuses on investigating the nature of high-energy resonance states in 9^{9}Be and 9^{9}B, as well as the astrophysical SS-factors for the reactions 7^{7}Li(d,n)αα(d,n)\alpha\alpha and 7^{7}Be(d,p)αα(d,p)\alpha\alpha, particularly pertinent to the cosmological lithium problem. Parameterization of resonance states is performed across a wide range of total angular momenta and includes states of both positive and negative parity. Dominant decay channels are identified for each resonance state. Detailed analysis of astrophysical SS factors resulting from deuteron interactions with 7^{7}Li and 7^{7}Be is conducted within an energy range from zero to 2 MeV. Four exit channels in 9^{9}Be (8^{8}Be(0+0^{+})+n+n, 8^{8}Be(2+2^{+})+n+n, 5^{5}He(3/2−3/2^{-})+α+\alpha, 5^{5}He(1/2−1/2^{-})+α+\alpha) and four in 9^{9}B (8^{8}Be(0+0^{+})+p+p, 8^{8}Be(2+2^{+})+p+p, 5^{5}Li(3/2−3/2^{-})+α+\alpha, 5^{5}Li(1/2−1/2^{-})+α+\alpha) are considered. A clear hierarchy of reactions is established for the energy range 0≤E<\leq E<1.0 MeV. Notably, reactions 7^{7}Li+d=8+d=^{8}Be(0+0^{+})+n+n and 7^{7}Be+d=8+d=^{8}Be(0+0^{+})+p+p substantially dominate over all other reactions within this energy range. The model satisfactory describes the experimental astrophysical SS factors for these reactions.Comment: 36 pages, 23 figures, to be submitted to Phys. Rev.
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