Analogs of the giant dipole and spin-dipole resonances in {sup 4}He and in {alpha} clusters of {sup 6,7}Li studied by the {sup 4}He,{sup 6,7}Li({sup 7}Li,{sup 7}Be{gamma}) reactions

Journal Article · Tue Jul 15 04:00:00 EDT 2008 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.78.014303· OSTI ID:21192020

Nakayama, S; Matsumoto, E; Fushimi, K; Hayami, R; Kawasuso, H; Yasuda, K ^[1]; Yamagata, T; Akimune, H; Ikemizu, H ^[2]; Asaji, S; Ishida, T; Kudoh, T; Sagara, K ^[3]; Fujiwara, M; Hashimoto, H; Kawase, K; Nakanishi, K; Oota, T; Yosoi, M ^[4]; Greenfield, M B ^[5]

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1. Department of Physics, University of Tokushima, Tokushima 770-8502 (Japan)
2. Department of Physics, Konan University, Kobe 658-8501 (Japan)
3. Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)
4. Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan)
5. Department of Physics, International Christian University, Tokyo 181-0015 (Japan)

We studied analogs of the giant dipole resonance (GDR) and spin-dipole resonance (SDR) in {sup 4}He and in the {alpha} clusters of {sup 6,7}Li via the ({sup 7}Li,{sup 7}Be{gamma}) reactions on {sup 4}He, {sup 6}Li, and {sup 7}Li at an incident energy of 455 MeV and at a scattering angle of 0 deg. by measuring spin-nonflip and spin-flip spectra. The reaction Q-values for the analogs of the GDR and SDR in the {alpha} clusters of {sup 6,7}Li were found to be more negative than those in {sup 4}He by 2.0{+-}0.5 MeV. The ratios of the cross section for the analog of the GDR to that for the analog of the SDR in {sup 4}He and in the {alpha} clusters of {sup 6}Li and {sup 7}Li were found to be the same within errors, 0.5{+-}0.1. The cross sections for the analogs of the GDR as well as those for the analogs of the SDR in the {alpha} clusters of {sup 6,7}Li were 0.6{approx}0.8 times smaller than those in {sup 4}He. These results suggest that excitations of {alpha} clusters embedded in nuclei are suppressed as compared with excitations of free {alpha} particles.

• OSTI ID: 21192020
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 1 Vol. 78; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
CLUSTER MODEL
CROSS SECTIONS
DIPOLES
EXCITATION
GIANT RESONANCE
HELIUM 4
LITHIUM 6
LITHIUM 7
MEV RANGE 100-1000
RESONANCE
SCATTERING
SPECTRA
SPIN
SPIN FLIP