Dynamics of α-clusters in N = Z nuclei
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The systematics for binding energies per α-particle in N = Z nuclei, E Bα/N α, are studied up to 164Pb. It is shown that, although a geometrical model can be used to explain the systematics for light nuclei, the binding energy per α-particle exhibits structures which are due to the well-known shells of the mean field of nucleons in nuclei. The overall dependence of E Bα/N α on N α in N = Z nuclei (for the ground-state masses) can be described in a liquid-drop model of α-particles. Conditions for a phase change with the formation of an α-particle condensate, a dilute Bose gas in excited compound nuclei are discussed for E Bα/N α = 0, at the thresholds. This is achieved when the binding energy per nucleon in nuclei is equal to or smaller than in the α-cluster. At somewhat smaller excitation energies the appearance of a Bose gas with a closed-shell core (N = Z, e.g. of 40Ca) is proposed within the same concept. The experimental observation of the decay of such condensed α-particle states is proposed with the coherent emission of several correlated α-particles not described by the Hauser-Feshbach approach for compound-nucleus decay. This decay will be observed by the emission of unbound resonances in the form of 8Be and 12C * (0+ 2) clusters.
PACS.21.10.-k Properties of nuclei; nuclear energy levels 21.60.Gx Cluster models
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- 1.Aage Bohr, Ben R. Mottelson, Nuclear Structure, Vol. I (W.A. Benjamin Inc., 1975).Google Scholar
- 2.H. Horiuchi, K. Ikeda, Cluster Model of the Nucleus, Int. Rev. Nucl. Phys., Vol. 4 (World Scientific, Singapore, 1986) p. 1 and references therein.Google Scholar
- 4.H. Horiuchi, Proceedings of the 7-th International Conference on Clustering Aspects of Nuclear Structure and Dynamics (World Scientific, 2000) p. 405.Google Scholar
- 7.T. Neff, H. Feldmeier, R. Roth, Nucl. Phys. A 752, 94 (2005).Google Scholar
- 11.H. Horiuchi, K. Ikeda, Y. Suzuki, Prog. Theor. Phys. Suppl. 52, Chapt. 3 (1972).Google Scholar
- 17.D.M. Brink, Proceedings of the International School of Physics ``Enrico Fermi'', Course XXXVI, edited by C. Bloch (Academic Press, New York, 1966) p. 247.Google Scholar
- 22.V.I. Isakov, Part. Nucl. Lett. 5, 44 (2000).Google Scholar
- 25.H. Frauenfelder, E.M. Henley, Subatomic Physics, Physics Series (Prentice Hall Inc., Englewood Cliffs, NJ, 1974) p. 546.Google Scholar
- 30.D.J. Amit, Y. Verbin, Statistical Physics, An Introductory Course (World Scientific, 1995).Google Scholar