THE 6He+6He AND α+8He CLUSTER STATES IN 12Be VIA α-INELASTIC SCATTERING

被引：25

作者：

Saito, A. ^{[1
]}

Shimoura, S. ^{[1
]}

Minemura, T. ^{[2
]}

Matsuyama, Y. U. ^{[3
]}

Baba, H. ^{[2
]}

Aoi, N. ^{[2
]}

Gomi, T. ^{[4
]}

Higurashi, Y. ^{[2
]}

Ieki, K. ^{[3
]}

Imai, N. ^{[5
]}

Iwasa, N. ^{[6
]}

Iwasaki, H. ^{[7
]}

Kanno, S. ^{[3
]}

Kubono, S. ^{[1
]}

Kunibu, M. ^{[3
]}

Michimasa, S. ^{[2
]}

Motobayashi, T. ^{[2
]}

Nakamura, T. ^{[8
]}

Ryuto, H. ^{[2
]}

Sakurai, H. ^{[2
]}

Serata, M. ^{[3
]}

Takeshita, E. ^{[3
]}

Takeuchi, S. ^{[2
]}

Teranishi, T. ^{[9
]}

Ue, K.

Yamada, K. ^{[2
]}

Yanagisawa, Y. ^{[2
]}

机构：

[1] Univ Tokyo, Ctr Nucl Study, Wako Branch, RIKEN, Wako, Saitama 3510198, Japan

[2] RIKEN, Nishina Ctr Accelerator Based Sci, Wako, Saitama 3510198, Japan

[3] Rikkyo Univ, Dept Phys, Tokyo 1718501, Japan

[4] Natl Inst Radiol Sci, Chiba 260, Japan

[5] KEK, Inst Particle & Nucl Studies, Ibaraki, Japan

[6] Tohoku Univ, Dept Phys, Sendai, Miyagi 980, Japan

[7] Univ Tokyo, Dept Phys, Tokyo 113, Japan

[8] Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan

[9] Kyushu Univ, Dept Phys, Fukuoka 812, Japan

来源：

MODERN PHYSICS LETTERS A | 2010年 / 25卷 / 21-23期

关键词：

Cluster structure; alpha-inelastic scattering; multipole decomposition analysis;

D O I：

10.1142/S0217732310000496

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Cluster structures in the neutron-rich nucleus Be-12 were experimentally investigated via alpha-inelastic scattering. Excited states in the Be-12 nucleus were populated by a Be-12(alpha,alpha') reaction at 60 A MeV in the inverse kinematics, and identified by measuring a He-6+He-6 and alpha+He-8 breakup channels in coincidence. The differential cross section and the angular correlations between the decay particles were obtained for each excitation energy at 10-20 MeV for He-6+He-6 and at 9-19 MeV for alpha+He-8, respectively, reconstructed by the measured momentum vectors of the two helium isotopes. A multipole decomposition analysis based on the distorted-wave Born approximation was applied for the angular distribution of the inelastic scattering together with the angular correlation between the decay particles with respect to the directions of the incident beam and to the momentum transfer simultaneously. From the decomposed excitation energy spectra for J=0-4, several new excited states were identified. The 0(+) excited states were candidates of the band-head of a largely deformed rotational band. The 11.3-MeV 0(+) state was found to decay only into the He-6+He-6 channel. This result support the recent theoretical result by the generalized two-center cluster model. Several negative-parity excited states were observed in the alpha+He-8 channel. These excited states possibly forming a negative-parity rotational band, which is very closed to the positive-parity band, can be connected to the existence of the extremely developed cluster structure in Be-12.

引用

页码：1858 / 1861

页数：4