Speaker
Dr
Hooi Jin ONG
(RCNP, Osaka University)
Description
The nuclear magic numbers, as we know in stable nuclei, consist of two different series of numbers. The first series – 2, 8, 20 – is attributed to the harmonic oscillator potential, while the second one – 28, 50, 82, and 126 – is due to the spin-orbit interactions. The spin-orbit interactions are known to be significant and responsible for the large (spin-orbit) splitting of the single-particle states in heavy nuclei. These interactions, however, are expected to diminish in light nuclei due to the low orbital angular momenta. This general expectation is supported by the fact that there is an apparent lack of fingerprints for a `magic number’ (subshell closure) at 6 or 14 [1], which might have arisen from the widening 1p1/2-1p3/2 and 1d3/2-1d5/2 gaps, respectively, in the stable nuclei. A possible subshell closure at N=6 has been suggested both theoretically [2] and experimentally [3] in the very neutron-rich 8He isotope. For Z=6 and 14, possible subshell closures have been suggested [4] in the semi-magic 14C and 34Si.
In this talk, we will present experimental evidence for a prevalent subshell closure at proton number Z=6 in the neutron-rich carbon isotopes. We investigated (i) the point proton density distribution radii, combining our recent data for Be, B and C isotopes measured at RCNP, Osaka University and GSI, Darmstadt, with the available data from Ref. [5]; (ii) the atomic masses [6]; and (iii) the electromagnetic transition strengths [7] for a wide range of isotopes. Our systematic analysis revealed marked regularities which support a prominent proton `magic number’ Z=6 in 13−20C.
References:
[1] M. G. Mayer, Nobel Lectures in Physics, 20 – 37 (1963).
[2] T. Otsuka et al., Phys. Rev. Lett. 87, 082502 (2001).
[3] F. Skaza et al., Phys. Rev. C 73, 044301 (2006).
[4] I. Angeli and K. P. Marinova, J. Phys. G: Nucl. Part. Phys. 42, 055108 (2015).
[5] I. Angeli and K. P. Marinova, At. Data Nucl. Data Tables 99, 69 – 95 (2013).
[6] M. Wang et al., Chinese Phys. C 36, 1603 – 2014 (2012).
[7] B. Pritychenko et al., At. Data Nucl. Data Tables 107, 1 – 139 (2016).
Primary authors
Mr
Dinh Trong Tran
(Research Center for Nuclear Physics, Osaka University)
Dr
Hooi Jin ONG
(RCNP, Osaka University)
Co-authors
Prof.
Akira Ozawa
(Institute of Physics, University of Tsukuba)
Ms
Azusa Inoue
(RCNP, Osaka University)
Prof.
Christoph Scheidenberger
(GSI)
Dr
Daiki Nishimura
(Tokyo University of Science)
Dr
Daisuke Nagae
(RIKEN Nishina Center)
Prof.
Eiji Ideguchi
(RCNP, Osaka University)
Prof.
Hans Geissel
(GSI)
Prof.
Harutaka Sakaguchi
(RCNP, Osaka University)
Prof.
Isao Tanihata
(Beihang university and RCNP Osaka university)
Dr
Junki Tanaka
(Konan University)
Prof.
Kensaku Matsuta
(Department of Physics, Osaka University)
Prof.
Le Hong Khiem
(IOP, VAST)
Dr
Maya Takechi
(Niigata University)
Prof.
Mitsunori Fukuda
(Department of Physics, Osaka University)
Dr
Mototsugu Mihara
(Department of Physics, Osaka University)
Prof.
Muhsin N. Harakeh
(KVI, University of Groningen)
Dr
Ngoc Duy Nguyen
(Dong Nai University)
Prof.
Nori Aoi
(RCNP, Osaka University)
Ms
Pei Pei Ren
(IMP, CAS)
Ms
Phaik Ying Chan
(RCNP, Osaka University)
Prof.
Ritu Kanungo
(Saint Mary's University)
Prof.
Roy Wada
(IMP, CAS / TAMU)
Prof.
Sadao Momota
(Kochi University of Technology)
Dr
Satoru Terashima
(Beihang University)
Prof.
Takaharu Otsuka
(Department of Physics, University of Tokyo)
Prof.
Takahiro KAWABATA
(Department of Physics, Kyoto University)
Dr
Takashi Hashimoto
(Rare Isotope Science Project, Institute for Basic Sciences)
Prof.
Tatsushi Shima
(RCNP, Osaka University)
Mr
Tetsuya Yamamoto
(RCNP, Osaka University)
Ms
Thi Ha Hoang
(RCNP, Osaka University)
Prof.
Toshio Suzuki
(Nihon University)
Mr
Tran Tho Nguyen
(Pham Ngoc Thach University of Medicine)
Dr
Wei Ping Lin
(IMP, CAS)
Dr
Yassid Ayyad
(Research Center for Nuclear Physics)
Prof.
Yoshiko Kanada-En'yo
(Department of Physics, Kyoto University)