Giacomo De Angelis, LNL Legnaro
Vendredi 26 Juin 2009 à 10h30 - Salle des Séminaires
Symmetry is a unifying concept in the description of natural properties. It is used in all fields of physics as for example to explore the geometric arrangements of atoms in molecules and crystals. Using group theory, the symmetries in molecules, fullerenes, atomic nuclei and other quantum objects were successfully described. Recently several theoretical studies based on nuclear mean field have predicted the existence of high rank symmetries leading to nuclei with tetrahedral and octahedral shape. Such shapes are expected to appear in different regions of the nuclear chart. Due to their intrinsic symmetry they are characterized by a basic octupole character with a vanishing quadrupole deformation. Another symmetry which has been recently studied in nuclei is the Chiral symmetry. It can be realized in nuclei due to the geometrical arrangement of the valence particles coupled to a triaxial core. Electromagnetic transition matrix elements are one of the possible signature for the existence of such structures. Recent results obtained in the A=130-160 mass regions will be discussed.
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