Excitation of analogue isovector resonances via the (n,p) reaction at 60 MeV

Dipole Excitation ofαClusters inL6iandNakayama1, Yamagata2, Akimune3 et al. 2001Phys. Rev. Lett.18010View full textAdd to dashboardCite

“…Two resonancelike structures are observed at Q Ӎ 210 and 230 MeV in the 6 Li target and Q Ӎ 220 and 230 MeV in the 7 Li target. The excitation energies of these resonances correspond well to those observed in the (n, p) and ( 7 Li, 7 Be) reactions [4,5]. The resonances at Q Ӎ 210 MeV in 6 Li and at Q Ӎ 220 MeV in 7 Li are known as an analog of the GDR 1 SDR.…”

“…Since it is known that the ground states of 6 Li and 7 Li nuclei are well described by d 1 a and t 1 a cluster structures, respectively [3], these nuclei are suitable for the present purpose. In the ͑n, p͒ reactions on 6 Li and 7 Li, Brady et al reported a new resonance structure at Q Ӎ 230 MeV riding on a broad bump of analogs of the giant dipole resonances in 6 Li and 7 Li [4]. In the ( 7 Li, 7 Be) reaction on 6 Li, Jänecke et al also reported a structure similar to that observed in the ͑n, p͒ spectrum [5].…”

Soft Dipole Resonance in the Neutron-Skin NucleusH6e

“…A candidate for a soft dipole resonance, a dipole oscillation mode between a core cluster and a neutron skin, was observed at E x 4 6 1 MeV and with a width of 4 6 1 MeV in 6 He via the 6 Li͑ 7 Li, 7 Be͒ reaction at an incident energy of 65A MeV and forward scattering angles including 0 ± . Its cross section is deduced to be s͑0 ± ͒ 0.9 6 0.2 mb͞sr.…”

“…The nucleus 6 He is a typical neutron-skin nucleus with a very low separation energy (0.975 MeV) for a neutron pair [4]. Experimental investigations on the soft DR in 6 He have been carried out by using various reactions [5][6][7][8][9].…”

“…Experimental investigations on the soft DR in 6 He have been carried out by using various reactions [5][6][7][8][9]. In ͑n, p͒-like charge exchange reactions on 6 Li [5-7], a broad resonancelike structure was observed at an excitation energy of E x ϳ 7 MeV where an analog of the GDR is expected to be excited.…”