# In-beam γ -ray spectroscopy of $^{63}$Mn

Abstract : Background: Neutron-rich, even-mass chromium and iron isotopes approaching neutron number N = 40 have been important benchmarks in the development of shell-model effective interactions incorporating the effects of shell evolution in the exotic regime. Odd-mass manganese nuclei have received less attention, but provide important and complementary sensitivity to these interactions. Purpose:We report the observation of two newγ -ray transitions in 63Mn,which establish the (9/2−) and (11/2−) levels on top of the previously known (7/2−) first-excited state. The lifetime for the (7/2−) and (9/2−) excited states were determined for the first time, while an upper limit could be established for the (11/2−) level. Method: Excited states in 63Mn have been populated in inelastic scattering from a 9Be target and in the fragmentation of 65Fe. γγ coincidence relationships were used to establish the decay level scheme. A Doppler line-shape analysis for the Doppler-broadened (7/2−) → 5/2−, (9/2−)→ (7/2−), and (11/2−) → (9/2−) transitions was used to determine (limits for) the corresponding excited-state lifetimes. Results: The low-lying level scheme and the excited-state lifetimes were compared with large-scale shell-model calculations using different model spaces and effective interactions in order to isolate important aspects of shell evolution in this region of structural change. Conclusions: While the theoretical (7/2−) and (9/2−) excitation energies show little dependence on the model space, the calculated lifetime of the (7/2−) level and calculated energy of the (11/2−) level reveal the importance of including the neutron g9/2 and d5/2 orbitals in the model space. The LNPS effective shell-model interaction provides the best overall agreement with the new data.
Type de document :
Article dans une revue
Physical Review C, American Physical Society, 2016, 93 (1), pp.014313. 〈10.1103/PhysRevC.93.014313〉

http://hal.in2p3.fr/in2p3-01260353
Contributeur : Michel Lion <>
Soumis le : vendredi 22 janvier 2016 - 08:51:49
Dernière modification le : jeudi 1 février 2018 - 01:25:47

### Citation

T. Baugher, A. Gade, R.V.F. Janssens, S.M. Lenzi, Dominique Bazin, et al.. In-beam γ -ray spectroscopy of $^{63}$Mn. Physical Review C, American Physical Society, 2016, 93 (1), pp.014313. 〈10.1103/PhysRevC.93.014313〉. 〈in2p3-01260353〉

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