Connections between the superdeformed and normal-deformed states in ,43 Eu have been established by measuring energy sums of two consecutive /-ray transitions in the linking cascade. Six decay paths have been observed connecting discrete states in the two potential wells. The absolute excitation energy and the most likely spin of a superdeformed band have been determined directly for the first time.PACS numbers: 23.20.Lv, 21.10.Re, 25.70.Gh, 27.60.+J Discrete /-ray transitions between superdeformed (SD) states were first observed [1] in the nucleus 152 Dy as a rotational band at very high spin. This band corresponds to a nucleus with a very elongated prolate shape (/?2 -0.6) rotating about an axis perpendicular to its symmetry axis. Later, many SD bands have been observed in various mass regions (see, e.g., review articles Refs.[2] and [3]). In all cases studied so far the connection between the SD and the normal-deformed (ND) states has been unknown, most probably due to a highly fragmented decay path out of the SD bands. This has left the spin, the parity, and the excitation energy of the SD bands undetermined. In this paper we present results of a new experimental approach where we take advantage of triple and higher fold coincidences to study the decay out of a SD band. The method provides us with an excitation energy and a most likely spin assignment for a SD band for the first time.It is known from previous work [2,3] that the decay out of a SD band starts from a few of the lowest lying observed states of the band and ends in a few near yrast ND states. We assume that a significant fraction of the decay proceeds through cascades of only two transitions. Because of the high level density there are a large number of intermediate levels in the cascade, but the sum of the two consecutive y-ray energies has a well-defined value. In the triple coincidence events we set a gate on one /-ray transition of the SD band and sum up the two other /-ray energies to produce a sum spectrum. In this spectrum we can identify discrete peaks related to the deexcitation of the SD band.The experiment was carried out at the Niels Bohr Institute Tandem Accelerator Laboratory using the NORDBALL detector array which consisted of 20 Compton-suppressed Ge detectors, one of which was a LEP detector, and a BaF 2 inner ball for multiplicity and sum energy selection. The states in l43 Eu were populated by the reaction 1,0 Pd( 37 Cl,4«) 143 Eu at a beam energy of 160 MeV. The target consisted of 2-3 self-supporting foils isotopically enriched to 98.6% in ,10 Pd with a total thickness of 1.2 mg/cm 2 . A total of 10 9 triple (Ge-GeGe) and higher fold coincidence events were collected. In the analysis a narrow energy-dependent time gate was set on the Ge energies and a carefully selected gate was put on BaF 2 fold (> 12) and high sum energy. After these cuts a total number of 500 xlO 6 3 or higher fold and 50x 10 6 4 or higher fold events remained and were used in the final analysis. Figure 1 shows a double gated /-ray spectrum with both gates...
