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The influence of atomic electron shells on the constant of alpha decay of heavy and mediummass nuclei was considered in detail. A method for simultaneously taking into account the change in the potential-barrier shape and the effect of reflection of a diverging Coulomb wave in the classically allowed region was developed. The ratios of decay probabilities per unit time for a bare nucleus and the respective neutral atom were found for some alpha-decaying isotopes. 相似文献
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R. Wolsky I. A. Gnilozub S. D. Kurgalin Yu. M. Tchuvil’sky 《Physics of Atomic Nuclei》2010,73(8):1405-1415
States that exhibit the properties of an α-cluster or an α-binucleon condensate are studied in 1p-shell nuclei. The generalized Hamiltonian of the Elliott SU(3) model is used to classify these states and to calculate their spectra. The results of the calculations are found to be
in good agreement with experimental data. States not observed so far in the cluster spectra of the 12C, 16O, 10Be, and 12Be nuclei are predicted. 相似文献
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The T-odd correlation (k α · [σ × k γ])(k α · k γ), where σ is the vector of the neutron polarization and the symbols k denote the respective linear momenta (all vectors are unit ones), in the sequential alpha-gamma cascade induced by a thermal-neutron capture is studied. The study is performed in the one-resonance approximation. Both the final-state interaction of the alpha particle with the residual nucleus and the actual T-noninvariant phase shift are considered as possible origins of the correlation. The problem of suitable target isotopes is analyzed. Related correlations in other neutron- and proton-induced reactions are discussed. 相似文献
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JETP Letters - The spectrum of the 10Be nucleus in a wide range of excitation energies has been calculated within the no-core shell model. An extrapolation procedure has been used to refine the... 相似文献
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Three different approaches to taking into account exchange effects in heavy-ion collisions are studied. Within the first of
them, the lowest eigenstates of the Hamiltonian are treated as forbidden states. In the second approach, the eigenstates of
the normalization kernel of the resonating-group model that correspond to zero eigenvalues are treated as forbidden states.
The third approach takes additionally into account semiforbidden states. The 16O + 16O system is considered. A hybrid approach that combines the methods of discrete and continuous mathematics is developed for
calculating the widths of narrow resonance states. The resonance width calculated within the approach that takes into account
semiforbidden states proves to be sharply different from the widths obtained within traditional approaches. 相似文献
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Description of alpha-clustering of 8Be nucleus states in high-precision theoretical approach 下载免费PDF全文
Scrupulous theoretical study of 8Be nucleus states, both clustered and non-clustered, is performed over a wide range of excitation energies. The quantities that characterize the degree of the alpha-clustering of these states, i.e., spectroscopic factors, cluster form factors, and alpha-decay widths, are computed in the framework of the developed accurate ab initio approach. Other basic properties of the 8Be spectrum, including the binding and excitation energies and the mean values of the isospin, are calculated simultaneously. In the majority of instances, the results of the computation turn out to be in good agreement with the spectroscopic data. A number of predictions are made, and corresponding verification experiments are proposed. Prospects of the developed approach for nuclear spectroscopy are demonstrated. 相似文献
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Yu. M. Tchuvil’sky 《Physics of Atomic Nuclei》2011,74(12):1740-1746
It is established that the set of solutions of the Hamiltonian of the generalized Elliott SU(3) model in the space of A-fermion wave functions contains a subset of multicluster solutions ΨΔ
A
which can be precisely represented in terms of solutions of the Hamiltonian of the same form acting in the reduced space
of certain intercluster coordinates. The conditions imposed on a multicluster partition which exhibits such properties are
determined by applying the group-theory methods. 相似文献
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A class of A-nucleon (for even N = Z) Hamiltonians is found such that they admit, among others, solutions that can be exactly related to solutions to the problem of A/4 alpha particles in the sense that the respective eigenvalues of the two problems coincide and that the A-nucleon solutions can be constructed from the alpha-particle solutions within a procedure that follows from the resonating-group model. It is shown that an effective nuclear Hamiltonian close to a realistic one possesses these properties, the alpha-particle states in nuclei having basic properties of an alpha condensate and, frequently, a normal nuclear density. The statistics of alpha particles (and other composite bosons) proves to be different from Bose-Einstein and Fermi-Dirac statistics and from parastatistics. 相似文献
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