Lecturer: Prof. A. Leviatan
Affiliation: Racah Institute of Physics,
Hebrew University of Jerusalem
Abstract:
Quantum phase transitions (QPTs) are
structural changes in the properties of a
physical system induced by a variation of
parameters in the quantum Hamiltonian.
In the present talk, we examine the
order and chaos and persisting
symmetries, accompanying a first-order
QPT in nuclei. The Hamiltonian employed
describes a QPT between spherical and
deformed shapes, associated with U(5)
and SU(3) dynamical symmetries,
respectively. A classical analysis reveals a
rich but simply-divided phase space
structure with a Henon-Heiles type of
chaotic dynamics ascribed to the
spherical minimum, coexisting with a
robustly regular dynamics ascribed to
the deformed minimum in the Landau
potential. A quantum analysis discloses
regular U(5)-like multiplets in the
spherical region and regular SU(3)-like
rotational bands in the deformed region,
which retain their identity amidst a
complicated environment of other
states. A symmetry analysis shows that
these regular subsets of states, are
associated with partial U(5) dynamical
symmetry (PDS) and SU(3) quasi-
dynamical symmetry (QDS), respectively.
Additional details of the upcoming Israeli
Joint Nuclear Physics' Seminars can be
found on the following link