**author:
**R. Herrmann

**abstract:
**Based on the Riemann- and Caputo definition of the fractional derivative we use the fractional extensions of the standard rotation group SO(3) to construct a higher dimensional representation of a fractional rotation group with mixed derivative types. An extended symmetric rotor model is derived, which predicts the sequence of magic proton and neutron numbers accurately. The ground state properties of nuclei are correctly reproduced within the framework of this model.

**download:** arxiv: 0806.2300v2 [physics.gen-ph]

**reference:** Physica A **389** (2010) 693