In-Beam γ -Ray Spectroscopy of Mg34,36,38: Merging the N=20 and N=28 Shell Quenching

Doornenbal, P.; Scheit, H.; Takeuchi, S.; Aoi, N.; Li, K.; Matsushita, M.; Steppenbeck, D.; Wang, H.; Baba, H.; Crawford, H.; Hoffman, C. R.; Hughes, R.; Ideguchi, E.; Kobayashi, N.; Kondo, Y.; Lee, J.; Michimasa, S.; Motobayashi, T.; Sakurai, H.; Takechi, M.; Togano, Y.; Winkler, R.; Yoneda, K.

doi:10.1103/PhysRevLett.111.212502

In-Beam $γ$ -Ray Spectroscopy of ${}^{34, 36, 38}{Mg}$ : Merging the $N = 20$ and $N = 28$ Shell Quenching

Journal Article · Tue Nov 19 04:00:00 EST 2013 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.111.212502· OSTI ID:1407207

Doornenbal, P. ^[1]; Scheit, H. ^[2]; Takeuchi, S. ^[1]; Aoi, N. ^[1]; Li, K. ^[2]; Matsushita, M. ^[3]; Steppenbeck, D. ^[1]; Wang, H. ^[2]; Baba, H. ^[1]; Crawford, H. ^[4]; Hoffman, C. R. ^[5]; Hughes, R. ^[6]; Ideguchi, E. ^[7]; Kobayashi, N. ^[8]; Kondo, Y. ^[8]; Lee, J. ^[1]; Michimasa, S. ^[7]; Motobayashi, T. ^[1]; Sakurai, H. ^[1]; Takechi, M. ^[1] more »

RIKEN Nishina Center, Wako (Japan)
RIKEN Nishina Center, Wako (Japan); Peking Univ., Beijing (China)
RIKEN Nishina Center, Wako (Japan); Rikkyo Univ., Tokyo (Japan)
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Argonne National Lab. (ANL), Argonne, IL (United States)
Univ. of Richmond, VA (United States)
Univ. of Tokyo, Wako (Japan)
Tokyo Inst. of Technology (Japan)
Michigan State Univ., East Lansing, MI (United States)

Neutron-rich N = 22, 24, 26 magnesium isotopes were studied in this paper via in-beam γ-ray spectroscopy at the RIKEN Radioactive Isotope Beam Factory following secondary fragmentation reactions on a carbon target at ≈ 200 MeV /nucleon. In the one- and two-proton removal channels from ³⁹Al and ⁴⁰Si beams, two distinct γ-ray transitions were observed in ³⁸Mg, while in the one-proton removal reaction from ³⁷Al a new transition was observed in addition to the known 2⁺₁ → 0 ⁺_g.s. decay. From the experimental systematics and comparison to theoretical predictions it is concluded that the transitions belong to the 2⁺₁ → 0 ⁺_g.s. and 4⁺₁ → 2⁺₁ decays in ³⁶Mg and ³⁸Mg, respectively. For ³⁴Mg, previously reported 2⁺₁ and 4⁺₁ level energies were remeasured. Finally, the deduced E(4⁺₁)/E(2⁺₁) ratios for ^34,36,38Mg of 3.14(5), 3.07(5), and 3.07(5) are almost identical and suggest the emergence of a large area of deformation extending from the N = 20 to the N = 28 shell quenching.

Research Organization:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); Japan-U.S. Experimental Inst. for Physics with Exotic Beams (JUSEIPEN)

DOE Contract Number:: AC02-05CH11231; AC02-06CH11357

OSTI ID:: 1407207

Journal Information:: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 21 Vol. 111; ISSN 0031-9007

Publisher:: American Physical Society (APS)

Country of Publication:: United States

Language:: English

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