“…Furthermore, this collectivity coupled to a s.p. orbital with spin j, occupied by a few nucleons, may result in the socalled anomalous coupling, producing a multiplet of closelying states with spins j, j − 1, j − 2 [30], as observed in N = 53 even-odd isotones in this region [2][3][4][5]. Such states, also called "dressed" [31,32] can be interpreted as seniority coupling [33] or, more generally though less specific, as being due to the so-called Jahn-Teller effect [34], which removes the degeneracy of an orbital populated by several particles due to coupling to a collective excitation.…”