1. Core excitations across the neutron shell gap in 207Tl.
- Author
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Wilson, E., Podolyák, Zs., Grawe, H., Brown, B.A., Chiara, C.J., Zhu, S., Fornal, B., Janssens, R.V.F., Shand, C.M., Bowry, M., Bunce, M., Carpenter, M.P., Cieplicka-Oryńczak, N., Deo, A.Y., Dracoulis, G.D., Hoffman, C.R., Kempley, R.S., Kondev, F.G., Lane, G.J., and Lauritsen, T.
- Subjects
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NUCLEAR excitation , *QUASIPARTICLES , *NEUTRONS , *SYMMETRY breaking , *NUCLEAR spin - Abstract
The single closed-neutron-shell, one proton–hole nucleus 207 Tl was populated in deep-inelastic collisions of a 208 Pb beam with a 208 Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupole phonon state and a large number of core excited states. Based on shell-model calculations, all observed single core excitations were established to arise from the breaking of the N = 126 neutron core. While the shell-model calculations correctly predict the ordering of these states, their energies are compressed at high spins. It is concluded that this compression is an intrinsic feature of shell-model calculations using two-body matrix elements developed for the description of two-body states, and that multiple core excitations need to be considered in order to accurately calculate the energy spacings of the predominantly three-quasiparticle states. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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