Mean-field approach to weakly bound many-nucleon problems: dineutron correlation and collectivities
| Project/Area Number |
17540244
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Niigata University |
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Principal Investigator |
MATSUO Masayuki Niigata University, Institute of Science and Technology, Professor (70212214)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥2,910,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | neutron-rich nuclei / low-density nuclear matter / dineutron correlation / continuum QRPA theory / axially symmetric deformed HFB theory / neutron-rich Cr,Fe,Ti isotopes / 中性子過剰Cr,Te,Fe同位体 / ソフト双極子励起 / 強結合対相関 / Skyrme有効相互作用 / 連続状態QRPA模型 / 軸対称変形HFBコード / ソフト八重極モード / ピグミー励起 |
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| Research Abstract |
1. Study of dineutron correlation in low-density matter
Investigating the neutron pair correlation in low-density matter, we have shown that the di-neutron correlation originates from the strong coupling feature of the neutron pairing which becomes significant at low densities. We have also shown that it corresponds to the crossover region between the weak-coupling BCS limit and the Bose-Einstein condensation (BEC) of composite bosons.
2. Study of surface dineutron modes in neutron-rich nuclei
We have shown that some soft modes in neutron-rich nuclei can be interpreted as a new type of elementary excitation, which we call the surface dineutron mode. We found that when we employ a density-independent delta-type contact force whose strength is related to the large scattering length, neutron-rich nuclei generally exhibit a collective excitation mode in all the multipoles of dipole, quadrupole and octupole, whose character is clearly identified as motion of dineutrons around nuclear surface.
3. New formulation of continuum QRPA theory including the Skyrme-HFB functional
We have succeeded in formulating and coding a continuum QRPA model in which all the important terms of the Skyrme-HFB functional up to the velocity dependent terms. We have confirmed that this new formulation satisfies the energy weighted sum rule including the enhancement factor.
4. Development of an axially deformed coordinate-space HFB code and study of deformation mechanism of neutron rich isotopes in Cr region.
We have developed an axially deformed coordinate-space Skyrme-HFB code using the cylindrical coordinate system. As an application of this code, we have studied deformation mechanism of recently suggested new deformation region in neutron-rich Cr, Fe and Ti isotopes.
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Report
(4 results)
Research Products
(42 results)
