Molecular Structures and Clustering Effects in Reactions Induced by Light Nuclei

Abstract

A great deal of research work has been undertaken in α-clustering study since the pioneering discovery of 12 C+ 12 C molecular resonances half a century ago. Our knowledge on physics of nuclear molecules has increased considerably and nuclear clustering remains one of the most fruitful domains of nuclear physics, facing some of the greatest challenges and opportunities in the years ahead. The occurrence of "exotic" shapes in light N =Z α-like nuclei is investigated. Various approaches of the superdeformed and hyperdeformed bands associated with quasimolecular resonant structures are presented. Evolution of clustering from stability to the drip-lines is examined: clustering aspects are, in particular, discussed for light exotic nuclei with large neutron excess such as neutron-rich Oxygen isotopes with their complete spectrocopy.

Recent Experimental Results on Nuclear Cluster Physics

“…Ternary clusterizations are also predicted theoretically, but were not found experimentally in 36 Ar so far [8,58]. On the other hand, ternary fission of 56 Ni, related to its HD shapes, was identified from out-of-plane angular correlations measured in the 32 S+ 24 Mg reaction with the Binary Reaction Spectrometer at the Vivitron Tandem facility [67].…”

“…Highly deformed shapes and SD rotational bands have been discovered in several light α-like nuclei, such as 36 Ar and 40 Ca by using γ-ray spectroscopy techniques [57,59]. In particular, the extremely deformed rotational SD band in 36 Ar [57] is comparable in shape to the quasimolecular bands observed in both 12 C+ 24 Mg and 16 O+ 20 Ne reactions [8,58,64].…”

“…Furthermore, the structure of possible octupole-unstable 3:1 nuclear shapes (hyperdeformation (HD) with β 2 ≈ 1.0) has also been discussed for actinide nuclei in terms of clustering phenomena [8]. Typical examples for the link between quasimolecular bands and extremely deformed (SD/HD) shapes can be found in the literature for A = 20 − 60 α-conjugate N =Z nuclei [8,18,36,52,54,55,56,57,58,59,60,61,62,63,64,65,66,67]. Highly deformed shapes and SD rotational bands have been discovered in several light α-like nuclei, such as 36 Ar and 40 Ca by using γ-ray spectroscopy techniques [57,59].…”

“…Typical examples for the link between quasimolecular bands and extremely deformed (SD/HD) shapes can be found in the literature for A = 20 − 60 α-conjugate N =Z nuclei [8,18,36,52,54,55,56,57,58,59,60,61,62,63,64,65,66,67]. Highly deformed shapes and SD rotational bands have been discovered in several light α-like nuclei, such as 36 Ar and 40 Ca by using γ-ray spectroscopy techniques [57,59]. In particular, the extremely deformed rotational SD band in 36 Ar [57] is comparable in shape to the quasimolecular bands observed in both 12 C+ 24 Mg and 16 O+ 20 Ne reactions [8,58,64].…”

“…The topic of nuclear clusters benefits of intense theoretical activity [7] where new experimental information has come to light very recently [6,8]. Several status reports were given in conferences and their written contributions can be found in their respective proceedings [15,36,37]. 2.…”