Search

Coulomb excitation of the exotic neutron-rich nucleus 26Ne on a 208Pb 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 Al target to estimate the nuclear contribution. The radioactive beam was produced by fragmentation of a 95 A.MeV 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 25Ne+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV excitation energy. By performing a multipole decomposition of the differential cross-section, a reduced dipole transition probability of B(E1)=0.49±0.16 e2fm2 is deduced. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

In order to search for low energy El strength, Coulomb excitation of the neutron rich nucleus 26Ne was studied at RIKEN Accelerator Research Facility. A 58 MeV/A secondary beam of 26Ne impinged on lead and aluminum target. In this complete kinematics measurement, we measured the energy and position of the charged fragments with a silicon strip/Si(Li) telescope, and the neutrons resulting from the decay of 26Ne with a multi-element plastic wall. The photons which can be emitted from excited states are detected using a 4π NaI array. The analysis is still in progress but it so far shows strength between 8 and 10 MeV excitation energy that can be related to a pygmy dipole resonance. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]