| Autor: |
Gibelin, J., Beaumel, D., Motobayashi, T., Aoi, N., Baba, H., Blumenfeld, Y., Elekes, Z., Fortier, S., Frascaria, N., Fukuda, N., Gomi, T., Ishikawa, K., Kondo, Y., Kubo, T., Lima, V., Nakamura, T., Saito, A., Satou, Y., Takeshita, E., Takeuchi, S., Teranishi, T., Togano, Y., Vinodkumar, A. M., Yanagisawa, Y., Yoshida, K. |
| Rok vydání: |
2007 |
| Předmět: |
|
| Zdroj: |
2nd International Conference on Collective Motion in Nuclei under Extreme Conditions - COMEX 2, Sankt Goar (2007) 153-158 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1016/j.nuclphysa.2007.01.076 |
| Popis: |
Coulomb excitation of the exotic neutron-rich nucleus $^{26}$Ne on a $^{nat}$Pb target was measured at 58 A.MeV in order to search for low-lying E1 strength above the neutron emission threshold. Data were also taken on an $^{nat}$Al target to estimate the nuclear contribution. The radioactive beam was produced by fragmentation of a 95 A.MeV $^{40}$Ar beam delivered by the RIKEN Research Facility. The set-up included a NaI gamma-ray array, a charged fragment hodoscope and a neutron wall. Using the invariant mass method in the $^{25}$Ne+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV. The reconstructed $^{26}$Ne angular distribution confirms its E1 nature. A reduced dipole transition probability of B(E1)=0.49$\pm$0.16 $e^2fm^2$ is deduced. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is obtained. The results are discussed in terms of a pygmy resonance centered around 9 MeV. |
| Databáze: |
arXiv |
| Externí odkaz: |
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