Study of rlastic and inelastic {sup 11}B +α scattering and search for cluster states of enlarged radius in {sup 11}B

Journal Article · Tue Sep 15 04:00:00 EDT 2015 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778815060071· OSTI ID:22472159

Demyanova, A. S.; Dmitriev, S. V.; Ogloblin, A. A. ^[1]; Belyaeva, T. L. ^[2]; Goncharov, S. A. ^[3]; Gurov, Yu. B. ^[4]; Maslov, V. A.; Sobolev, Yu. G. ^[5]; Trzaska, W. ^[6]; Khlebnikov, S. V. ^[7]; Heikkinen, P.; Julin, R.; Tyurin, G. P. ^[6]; Burtebaev, N.; Zholdybayev, T. ^[8]

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1. National Research Center Kurchatov Institute (Russian Federation)
2. UniversidadAutonoma del Estado de Mexico, Codigo Postal (Mexico)
3. Moscow State University, Faculty of Physics (Russian Federation)
4. National Research Nuclear University MEPhI (Russian Federation)
5. Joint Institute for Nuclear Research (Russian Federation)
6. Jyväskylän yliopisto (Finland)
7. Khlopin Radium Institute (Russian Federation)
8. National Nuclear Center of Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)

The differential cross sections for elastic and inelastic {sup 11}B + α scattering were measured at the alpha-particle energy of 65 MeV, the inelastic-scattering processes leading to the excitation of known states of {sup 11}B up to excitation energies of about 14 MeV. Data on elastic scattering were analyzed together with those that were published earlier for lower energies. The cross sections for inelastic scattering were analyzed on the basis of the distorted-wave method. A modified diffractionmodel was used to determine the root-mean-square radii of excited states. The radii of states whose excitation energies were below about 7MeV were found to agree with radius of the ground state to within 0.1 to 0.15 fm. This result complieswith the traditional idea that the low-lying states of {sup 11}B have a shell structure. The possibility that these states belong to the predicted rotational bands, which, if any, are truncated to three states, cannot be ruled out either. The majority of the observed highly excited states are distributed among four rotational bands. The moments of inertia of these bands are close; for the band based on the 3/2{sup −} state at E* = 8.56 MeV, they are even higher than those of the Hoyle state in the {sup 12}C nucleus. The measured radii of states associated with these bands of {sup 11}B are larger than the ground-state radius by 0.7 to 1.0 fm and are also close to the radius of the Hoyle state. The results of the present study agree with the existing predictions that the cluster structure of the {sup 11}B nucleus is diverse at high excitation energies. The hypothesis that the {sup 11}B nucleus features a “giant” state of size commensurate with those in heavy nuclei was not confirmed.

• OSTI ID: 22472159
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 6 Vol. 78; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
BORON 11
BORON 11 TARGET
CARBON 12
DIFFERENTIAL CROSS SECTIONS
DISTORTED WAVE THEORY
ELASTIC SCATTERING
EXCITATION
GROUND STATES
INELASTIC SCATTERING
MEV RANGE
MOMENT OF INERTIA
NUCLEAR STRUCTURE
ROTATIONAL STATES
SHELL MODELS