First lifetime measurement of 21+ state in 12Be

Autor: Susumu Shimoura, H. Kawasaki, Takashi Kubo, Hironori Iwasaki, K. Yoneda, Hiroshi Watanabe, A. Gelberg, Hooi Jin Ong, H. Baba, N. Imai, Naoki Fukuda, K. Kurita, Shin'ichiro Michimasa, Zs. Fülöp, Tsuyoshi Ohnishi, Ken Ishikawa, Hiroyoshi Sakurai, T. Motobayashi, Masahiro Notani, Zs. Dombrádi, Nori Aoi, E. Kaneko, K. Demichi, Shuichi Takeuchi, Masamichi Ishihara, Tomoko Gomi, S. Kanno, M. Miura, Akito Saito, M. K. Suzuki, E. Takeshita, Toshiyuki Minemura, Z. Elekes, Takashi Nakamura, M. Tamaki, Yosuke Kondo, T. Kishida, H. Hasegawa, Takashi Sugimoto
Rok vydání: 2009
Předmět:
Zdroj: Physics Letters B. 673:179-182
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2009.02.039
Popis: The lifetime of the 2 1 + state at 2.1 MeV in 12Be has been measured using inelastic scattering of a 12Be beam at 43 MeV/nucleon with a gold target. Through the Doppler shift attenuation method, the mean-life of the 2 1 + state has been determined as 2.5 ± 0.7 (stat) ± 0.3 (syst) ps, which gives a B ( E 2 ; 2 1 + → 0 g.s. + ) value of 4.9 ± 1.3 ± 0.5 in Weisskopf units. The result shows a large quadrupole strength in the ground state transition, providing further evidence on the disappearance of the N = 8 magic number. The B ( E 2 ; 2 1 + → 0 g.s. + ) value together with the deformation length measured by proton inelastic scattering yields a neutron quadrupole matrix element two times larger than those for 14C and 16O.
Databáze: OpenAIRE
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