September 15, 2014 to October 10, 2014
Nordita, Stockholm
Europe/Stockholm timezone

Afternoon Session: Modern approaches to nuclear structure

Sep 23, 2014, 2:30 PM
2h
132:028 (Nordita, Stockholm)

132:028

Nordita, Stockholm

Speakers

Andrea Idini Toshio Suzuki

Description

T. Suzuki Nuclear shell structure, nuclear forces and nuclear weak processes Shell-model study of spin modes in nuclei have been done with new shell-model Hamiltonians which have proper tensor components, and applied to nuclear weak processes at stellar environments. Roles of nuclear forces, especially the tensor and three-body interactions, on nuclear structure and shell evolutions are investigated. New shell-model Hamiltonians for p-shell (SFO [1]) and pf-shell (GXPF1[2]) and VMU (monopole-based universal interaction) [3], are found to describe spin-dependent modes in nuclei very well such as Gamow-Teller (GT) strength in 12C [1], 40Ar [4], 56Fe and 56Ni [5] and magnetic moments of p-shell nuclei [1,6], as well as shell evolutions toward drip-lines [3,7]. We discuss some of the following topics on nuclear weak processes at stellar environments with the use of the new transition strengths: (1) New neutrino-nucleus reaction cross sections on light nuclei are used to study light-element nucleosynthesis in supernova explosions [8], and the production yield ratio for 11B/7LI is pointed out to be useful to determine the neutrino-mass hierarchy [9]. (2) New neutrino-induced cross sections are obtained for 13C [10] and 40Ar [4], which are useful targets for detection of solar and supernova neutrinos. (3) New electron-capture rates in Ni isotopes [11] are obtained with GXPF1 and implications on element synthesis are studied. (4) E-capture and beta-decay rates in sd-shell are used to study nuclear URCA processes in O-Ne-Mg core stars [12]. Roles of the three-body forces, especially the Fujita-Miyazawa force, on proper shell evolutions of neutron-rich isotopes [13], as well as on the closed-shell nature of 48Ca and M1 transition in 48Ca are also studied on top of the two-body G-matrix obtained by including core-polarization effects in larger spaces. 1. T. Suzuki, R. Fujimoto and T. Otsuka, Phys. Rev. C 67, 044302 (2003). 2. M. Honma et al., Phys. Rev. C 65, 061301(R) (2002); 69, 034335 (2004). 3. T. Otsuka, T. Suzuki, H. Honma, Y. Utsuno, N. Tsunoda, K. Tsukiyama and M. Hjorth-Jensen, Phys. Rev. Lett. 104, 012501 (2010). 4. T. Suzuki and M. Honma, Phys. Rev. C 87, 014607 (2013). 5. T. Suzuki et al., Phys. Rev. C 79, 061603 (2009). 6. C. Yuan, T. Suzuki, T. Otsuka, F. Xu and N. Tsunoda, Phys. Rev. C 85, 064324 (2012). 7. T. Otsuka, T. Suzuki, R. Fujimoto, H. Grawe, and Y. Akaishi, Phys. Rev. Lett. 95, 232502 (2005). 8. T. Suzuki et al., Phys. Rev. C 74, 034307 (2006). 9. T. Suzuki and T. Kajino, J. Phys. G: Nucl. Part. Phys. 40, 083101 (2013). 10. T. Suzuki, A. B. Balantekin and T. Kajino, Phys. Rev. C 86, 015502 (2012). 11. T. Suzuki, M. Honma, H. Mao, T. Otsuka and T. Kajino, Phys. Rev. C 83, 044619 (2011). 12. H. Toki, T. Suzuk, K. Nomoto, S. Jones and R. Hirschi, Phys. Rev. C 88, 015806 (2013); S. Jones et al., Astrophys. J. 772, 150 (2913). 13. T. Otsuka, T. Suzuki, J. D. Holt, A. Schwenk, and Y. Akaishi, Phys. Rev. Lett.105, 032501 (2010); J. D. Holt, T. Otsuka, A. Schwenk and T. Suzuki, J. Phys. G 39, 085111 (2012). --------------------------------------------------------------------- A. Idini Nuclear Field Theory, Shell Model, Nuclear Reactions and Nuclear Astrophysics Mean field, independent particles, picture is the starting point of our understanding of the nuclear many-body system. Many development across those lines in terms of treatment and effecting interaction, culminating in the last EDF efforts, enable us to study globally, across the whole nuclear chart, the bulk properties of nuclei. However including more complex nuclear correlations, is customary to exploit the richness of nuclear structure in the related fields of nuclear reactions and astrophysics shedding light on specific, important cases and open problems like the origin of pairing in nuclei or the importance of forbidden decays in astrophysical processes. This can be achieved in terms of including correlation starting from a mean field, and then considering the interweaving of collective and single particle degrees of freedom (Nuclear Field Theory), which gives a reasonable estimate over several type of nuclear structure observables, remarking the dual origin of nuclear pairing and enabling a quantitative account of direct nuclear reaction's absolute cross sections. From another point of view, considering the contributions of the possible configurations, effectively interacting in a defined valence space (Shell Model), gives a precise estimate of ground and low-lying states. This is of outmost importance in order to estimate quantities related to beta decay and electron capture, key in several astrophysical process, thus providing important insight to nuclear astrophysics. * A. Idini et al., Dual Origin of Pairing in Nuclei, http://arxiv.org/abs/1404.7365 * G. Potel et al., Cooper pair transfer in nuclei, RPP 76, 106301. http://iopscience.iop.org/0034-4885/76/10/106301 * A. Idini et al., Quasiparticle renormalization and pairing correlations in spherical superfluid nuclei, PRC 85, 014331. http://journals.aps.org/prc/abstract/10.110 /PhysRevC.85.014331

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