Low-Lying Levels of ⁵⁸Co

Abstract

The odd–odd nucleus 58Co has been investigated experimentally by the 59Co(d,t)58Co and the 55Mn(α,nγ)58Co reactions. In the pickup studies deuteron energies of 15 and 16.5 MeV were used and levels at 0, 25, 52, 112, 365, 375, 456, 888, 1043, and 1078 keV were observed. DWBA analysis showed mixed ln = 1 and 3 transfers for all levels except the last named, which is pure ln = 3. High resolution gamma–gamma coincidence work using the (α,nγ) reaction has revealed the decay properties of a large number of levels up to 1.5 MeV, including all those seen in (d,t), and has allowed tentative spin assignments for a comparison with the theoretical calculations of Vervier. Qualitatively the agreement is good.

A Search for Isobaric Analogue States in 58Co from the 57Fe(p,γ)58Co Reaction

“…Table I11 gives excitation energies and their gamma ray decay observed in this experiment. Here also are shown the transitions found by Robertson et al [3] and Zenoulis et al [2] and their intensities.…”

“…The first figure may be too high for reasons mentioned above. Robertson et al[3] have also reported a 684.1 keV transition to the 365 keV level. The ratios of these transitions are 61 : 34 : 5 in agreement with our results.…”

“…Recently 68C0 has been the subject of experiments using a variety of reactions. The gamma ray decay of states excited by particle reactions have been investigated by Hardie et al [l] by the ('He,py) reaction, Xenoulis et al [2] and Robertson et al [3] who both used the (a,ny) reaction. Higher levels have been investigated by means of ( 4 4 [41, 131, ('He,p) [5,6,71, ('He,d) 141, ('He,t) 181 and ('He,a) [4] reactions.…”

Coupled-channel effects in elastic scattering and near-barrier fusion induced by weakly bound nuclei and exotic halo nuclei

“…The projectile-like overlap spectroscopic factors were taken from [63] and the transferred nucleons were bound in Woods-Saxon wells of radius r 0 = 1.25 fm and diffuseness a = 0.65 fm, plus a spin-orbit component of the same geometry with a fixed depth of 6 MeV, the depth of central part being adjusted to give the correct binding energy. The spectroscopic factors and binding potentials for the target-like overlaps were taken from [64,65,66,67].…”

Decay of Com58

“…The 58 Co nucleus has two long-lived isomeric states [1], formed by the parallel and antiparallel coupling of πf 7/2 and νp 3/2 single-particle states [2,3]. The J π = 5 + metastable state decays with a half-life of approximately 9 hours to the 71-day J π = 2 + ground state [4] via a highly converted 25-keV internal transition [5][6][7] of multipolarity M 3 [8,9].…”