Parity inversion, breakdown of shell closure and particle-vibration coupling in Be-isotopes.
The properties of ﬁnite many-body systems arestrongly inﬂuenced by spatial quantization [1] leading tomarked shell structures [2]. This type of quantal sizeeﬀects are, on the other hand, renormalized in an impor-tant way by zero point ﬂuctuations [3, 4]. The smallerthe system is, the largest the surface/volume ratio is andthe strongest these eﬀects may become. In particular,the interweaving of single-particle motion and of collec-tive vibrations of the surface of atomic nuclei can leadto state dependent eﬀective masses which, for light sys-tems can even invert the sequence of particular levels,thus altering the magic numbers associated with closedshell. While the standard parametrization of the single-particle potential [2] indicates the states 0p