Q-phonons, Q-invariants, and company.

The paper discusses the concept of Q-phonons and its connection to the concept of Qinvariants and the shape parameters of nuclei. It will also discuss some useful relations between Q-invariants and observables. These relations allow one to determine crucial nuclear observables such as the square of the quadrupole moment of the first 2[SUP+] state from lifetime data of the gammaand ground band which may have applications, in future measurements with tare isotopes beams. These concepts are discussed for the Barium, Xenon and Cerium nuclei with mass numbers around A = 130, because some of these concepts were either introduced or at least heavily used in the discussion of the nuclear structure of these nuclei. [ABSTRACT FROM AUTHOR]