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The alpha cluster states of 16C are investigated by using the antisymmetrized molecular dynamics. It is shown that two different types of alpha cluster states exist: triangular and linear-chain states. The former has an approximate…

Nuclear Theory · Physics 2015-06-23 T. Baba , Y. Chiba , M. Kimura

Cluster structures of $^{14}$C were investigated with a method of antisymmetrized molecular dynamics (AMD) combined with a $3\alpha+nn$ cluster model while focusing on the monopole excitations and linear-chain $3\alpha$ band. Variation…

Nuclear Theory · Physics 2020-01-29 Yoshiko Kanada-En'yo , Kazuyuki Ogata

The existence of the $0_3^+$ and $0_4^+$ states around 10 MeV excitation energy in ${^{12}{\rm C}}$ is confirmed by a fully microscopic 3$\alpha$ cluster model. Firstly, a GCM (generator coordinate method) calculation is performed by…

Nuclear Theory · Physics 2016-11-09 Bo Zhou , Akihiro Tohsaki , Hisashi Horiuchi , Zhongzhou Ren

We investigate structure of $^{13}_\Lambda{\rm C}$ and discuss the difference and similarity between the structures of $^{12}{\rm C}$ and $^{13}_\Lambda{\rm C}$ by answering the questions if the linear-chain and gaslike cluster states,…

Nuclear Theory · Physics 2017-10-11 Y. Funaki , M. Isaka , E. Hiyama , T. Yamada , K. Ikeda

Knowledge of the low-lying monopole strength in $\mathrm{^{12}C}$ $-$ the Hoyle state in particular $-$ is crucial for our understanding of both the astrophysically important $3\alpha$ reaction and of $\alpha$-particle clustering. Multiple…

To clarify the effects of $\alpha$-cluster breaking on 3$\alpha$ cluster structures in $^{12}$C, we investigate $^{12}$C using a hybrid model that combines the Brink-Bloch cluster model with the $p_{3/2}$ subshell closure wave function. We…

Nuclear Theory · Physics 2015-06-23 Tadahiro Suhara , Yoshiko Kanada-En'yo

The energy level structure of ${}^{12}$C nucleus at a few MeV above the three-$\alpha$ threshold is still unsatisfactory known. For instance, most microscopic calculations predicted that there exist one $0^+$-state in this energy region…

Nuclear Theory · Physics 2017-01-09 Souichi Ishikawa

We investigate the existence of weakly coupled gas-like states comprised of three $\alpha$ particles around an $^{16}$O core in $^{28}$Si. We calculate the excited states in $^{28}$Si using the multi-configuration mixing method based on the…

Nuclear Theory · Physics 2015-06-05 T. Ichikawa , N. Itagaki , Y. Kanada-En'yo , Tz. Kokalova , W. von Oertzen

The existence of a rotational band with the $\alpha$+$^{12}$C($0_2^+$) cluster structure, in which three $\alpha$ particles in $^{12}$C($0_2^+$) are locally condensed, is demonstrated near the four-$\alpha$ threshold of $^{16}$O in…

Nuclear Theory · Physics 2015-03-18 S. Ohkubo , Y. Hirabayashi

The spatial structure of the lowest 0$_1^+$, 0$_2^+$, 2$_1^+$ and 2$_2^+$ states of the $^{12}$C nucleus is studied within the 3$\alpha$ model with the Buck, Friedrich, and Wheatley $\alpha \alpha$ potential with Pauli forbidden states in…

Nuclear Theory · Physics 2023-03-15 E. M. Tursunov , M. Z. Saidov , M. M. Begijonov

We report an investigation of the structure of $^{12}$C nucleus employing a newly developed configuration-mixing method. In the three-dimensional coordinate-space representation, we generate a number of Slater determinants with various…

Nuclear Theory · Physics 2013-08-09 Y. Fukuoka , S. Shinohara , Y. Funaki , T. Nakatsukasa , K. Yabana

The $0^{+}$ states of $^{12}\mathrm{C}$ are considered within the framework of the microscopic three-$\alpha$-cluster model. The main attention is paid to accurate calculation of the width of the extremely narrow near-threshold $0^+_2$…

Nuclear Theory · Physics 2009-11-10 S. I. Fedotov , O. I. Kartavtsev , V. I. Kochkin , A. V. Malykh

In $^{16}$O, we investigate the relation between the $E0$ monopole transition matrix elements and cluster-shell competition using antisymmetrized quasi cluster model (AQCM), where the dissolution of $alpha$ clusters into quasi clusters due…

Nuclear Theory · Physics 2016-01-25 H. Matsuno , N. Itagaki

The relation between the monopole transition strength and existence of cluster structure in the excited states is discussed based on an algebraic cluster model. The structure of $^{12}$C is studied with a 3$\alpha$ model, and the wave…

Nuclear Theory · Physics 2011-02-21 T. Yoshida , N. Itagaki , K. Katō

We reanalyze $2\alpha+t$ cluster features of $3/2^-$ states in $^{11}$B by investigating the $t$ cluster distribution around a $2\alpha$ core in $^{11}$B, calculated with the method of antisymmetrized molecular dynamics (AMD). In the…

Nuclear Theory · Physics 2015-06-23 Yoshiko Kanada-En'yo , Tadahiro Suhara

The structure of neutron-rich $\Lambda$ hypernucleus, $^7_{\Lambda}$He is studied within the framework of an $\alpha +\Lambda +n+n$ four-body cluster model. We predict second $3/2^+$ and $5/2^+$ states, corresponding to a $0s$ $\Lambda$…

Nuclear Theory · Physics 2015-06-11 E. Hiyama , M. Isaka , M. Kamimura , T. Myo , T. Motoba

The structures of the ground and excited states of 12Be were studied with antisymmetrized molecular dynamics. The ground state was found to be a state with a developed 2-alpha core with two neutrons occupying the intruder orbits. The energy…

Nuclear Theory · Physics 2009-11-10 Yoshiko Kanada-En'yo , Hisashi Horiuchi

The negative parity states of $^{11}$B and $^{11}$C were studied based on the calculations of antisymmetrized molecular dynamics(AMD). The calculations well reproduced the experimental strengths of Gamov-Teller(GT), $M1$ and monopole…

Nuclear Theory · Physics 2008-11-26 Yoshiko Kanada-En'yo

The excited states in ${^{12}{\rm C}}$ are investigated by using an extended version of the so-called Tohsaki-Horiuchi- Schuck-R\"opke (THSR) wave function, where both the $3\alpha$ condensate and ${^{8}{\rm Be}} + \alpha$ cluster…

Nuclear Theory · Physics 2015-08-12 Y. Funaki