Soft Dipole Mode in $^{8}$He

• Published in: Physics of particles and nuclei letters Vol. 6; pp. 118 - 125
• Main Authors: Grigorenko, L.V., Golovkov, M.S., Ter-Akopian, G.M., Fomichev, A.S., Oganessian, Yu.Ts, A. Gorshkov, V., Krupko, S.A., M. Rodin, A., I. Sidorchuk, S., S. Slepnev, R., V. Stepantsov, S., Wolski, R., Y. Pang, D., Chudoba, V., Korsheninnikov, A.A., A. Kuzmin, E., Nikolskii, E.Yu, Novatskii, B.G., Stepanov, D.N., Roussel-Chomaz, P., Mittig, W., Ninane, A., Hanappe, F., Stuttgé, L., Yukhimchuk, A.A., Perevozchikov, V.V., Vinogradov, Yu.I., K. Grishechkin, S., Zlatoustovskiy, S.V.
• Format: Journal Article
• Language: English
• Published: MAIK Nauka/Interperiodica ; Pleiades Publishing [2007-....] 2009
• Subjects: Nuclear Experiment; Physics
• ISSN: 1547-4771; 1531-8567
• DOI: 10.1134/S1547477109020046

The low-lying spectrum of 8 He was studied in the 3 H( 6 He, p ) 8 He transfer reaction for small center of mass angles. The 0 + ground state (g.s.) of 8 He and excited states, 2 + at 3.6–3.9 MeV and (1 + ) at 5.3–5.5 MeV, were populated with cross sections of 200, 100–250, and 90–125 μ b/sr. Some evidence for the excited state at about 7.5 MeV can be found in the data. The possible nature of the near-threshold anomaly above 2.14 MeV in 8 He is related to the population of a 1 – continuum (soft dipole excitation) with a peak energy value at about 3 MeV. This assumption can probably resolve the problem of a large uncertainty existing in the experimental data on the 8 He 2 + state energy.