Decay pattern of pygmy states observed in neutron-rich 26Ne.

Coulomb excitation of the exotic neutron-rich nucleus Ne-26 on a Pb-208 target was measured at 58 A.MeV in order to search for low-lying E1 strength above the neutron emission threshold. The radioactive beam was produced by fragmentation of a 95 A.MeV Ar beam delivered by the RIKEN Accelerator Research Facility. The set-up included a NaI(Tl) gamma-ray array, a charged fragment hodoscope and a neutron wall. Using the invariant mass method in the Ne-25+n channel, we observe by multipole decomposition a sizable amount of E1 strength between 6 and 10 MeV excitation energy. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured.