Faculty of Physics
M.V.Lomonosov Moscow State University
Review Article

# Analogues of the exotic hoyle state in the $^{12}$C nucleus

## S. A. Goncharov$^1$, A. S. Demyanova$^2$, A. A. Ogloblin$^2$, A. N. Danilov$^2$, T. L. Belyaeva$^3$, and W. Trzaska$^4$

### Moscow University Physics Bulletin 2015. 70. N 5. P. 333

• Article
Annotation

Experimental data on inelastic scattering of alpha particles by the $^{11}$B, $^{12}$C, and $^{13}$C nuclei are analyzed using the modified diffraction model and the radii of these nuclei in some <<abnormal>> excited states are found. It is shown that the $0_{2}^{+}$ (7.65 MeV) Hoyle state in the $^{12}$C nucleus is the base state for a new $0_{2}^{+}-2_{2}^{+}-4_{2}^{+}$ rotational band (in addition to the ground-state band), in which the third member is the discovered $4_{2}^{+}$ (13.75 MeV) state. The radii of the $^{12}$C nucleus in the above-mentioned three states are 25–30% larger than its ground state radius. It is found that the radii of the $1/2^{–}$ (8.86 MeV) state in the $^{13}$C nucleus and the $3/2^{–}$ (8.56 MeV) state in the $^{11}$B nucleus are close to the radius of the Hoyle state in $^{12}$C and that a similar rotational band is based on the 8.56 MeV state. The above $^{13}$C and $^{11}$B states can be regarded as analogues of the Hoyle state. The prediction of the alpha-condensation model that a similar analogue in $^{11}$B is the 12.56 MeV state with a radius that is comparable with the nuclear radius of uranium was not confirmed.

Received: 2015 June 1
Approved: 2015 November 13
PACS:
25.55.Ci Elastic and inelastic scattering
21.10.Re Collective levels
24.10.Ht Optical and diffraction models
Rissian citation:
С.А. Гончаров, А.С. Демьянова, А.А. Оглоблин, А.Н. Данилов, Т.Л. Беляева, В. Трзаска.
Вестн. Моск. ун-та. Сер. 3. Физ. Астрон. 2015. № 5. С. 3.
Authors
S. A. Goncharov$^1$, A. S. Demyanova$^2$, A. A. Ogloblin$^2$, A. N. Danilov$^2$, T. L. Belyaeva$^3$, and W. Trzaska$^4$
$^1$Department of Physics, Moscow State University, Moscow, 119991 Russia
$^2$Kurchatov Institute National Research Center, Moscow, 123182 Russia
$^3$Universidad Autonomo del Estado de Mexico, Toluca, 5000 Mexico
$^4$University of Jyväskylä, Jyväskylä, Finland

### Science News of the Faculty of Physics, Lomonosov Moscow State University

This new information publication, which is intended to convey to the staff, students and graduate students, faculty colleagues and partners of the main achievements of scientists and scientific information on the events in the life of university physicists.