| Co-Investigator(Kenkyū-buntansha) |
MATSUTA Kensaku Graduate School of Science, Osaka Univ., Assoc.Prof., 大学院・理学研究科, 助教授 (50181722)
MINAMISONO Tadanori Graduate School of Science, Osaka Univ., Prof, 大学院・理学研究科, 教授 (20028210)
野尻 洋一 大阪大学, 大学院・理学研究科, 教授 (90028233)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1997: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 1996: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1995: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
We have determined the nuclear magnetic moments of ^9C, ^<113>Q, ^<19>Q, and 21F.As a result, the abnormal behavier of magnetic moments seen in ^9C-^<13>0 pair, i.e. the abnormal spin expectation value or the unusual g-factor correlation, was not seen in the mirror pair of ^<13>0-^<13>B, For the cases of ^<19>O and ^<21>F, discussions using mirror-pair analyses can not be made because the partner of ^<19>Q is absent and the magnetic moment of ^<21>Mg, the partner of ^<21>F, has not been known yet. However, comparisons with theoretical calculations for each nucleus are possible. The results of calculations with the shellmodel code OXBASH (int. psdMK, PW) are all in good agreement with the experimental values within a few % for ^<13>Q, ^<19>Q, and ^<21>F.This fact has made the irregularity of ^9C-^9Li pair stand out. Therefore that is an implication that the abnormality of ^9C-^9Li pair is not a common feature of isospin T = 3/2 mirror pairs and it is due to the special situation for ^9C-^9Li pair. There has not been a successful theory yet that well reproduces the abnormality of ^9C-^9Li pair. There are still three possiblities for ^9C-^9Li pair as follows. i) Isospin symmetry breaks, ii) pairing of the even-number nucleon group breaks largely, iii) effective g-factors of nucleons are largely renormalized. If we use the effective g-factors determined experimentally at the double closed shell, the spin expectation value for ^9C-^9Li is found to get a value near the theoretical calculation. This fact makes the above iii) attract an attention. Recent theoretical works with AMD or cluster models on the nuclear structure of the A=9 system developping intensively might give a key to this problem in the near future.
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