Author/Authors :
L.V. Chulkov، نويسنده , , H. Simon، نويسنده , , I.J. Thompson، نويسنده , , T. Aumann، نويسنده , , M.J.G. Borge، نويسنده , , Th.W. Elze، نويسنده , , H. Emling، نويسنده , , H. Geissel، نويسنده , , L.V. Grigorenko، نويسنده , , M. Hellstrom، نويسنده , , B. Jonson، نويسنده , , J.W.V. Kratz، نويسنده , , R. Kulessa، نويسنده , , K. Markenroth، نويسنده , , M. Meister، نويسنده , , S. Hofmann and G. Münzenberg، نويسنده , , F. Nickel، نويسنده , , T. Nilsson، نويسنده , , G. Nyman، نويسنده , , V. Pribora، نويسنده , , et al.، نويسنده ,
Abstract :
Dissociation of 6He on a lead target has been studied at 240 MeV/u. The four-momenta of the two neutrons in coincidence with α-particles have been measured and used to reconstruct the three-body energy and angular correlations in the final state. For the first time, three-body correlations were included in the analysis of the 6He dissociation data, and compared with calculations assuming a dipole mode for the electromagnetic dissociation. In addition, the experimental data have been analyzed using a series expansion of the final transition amplitude into hyperspherical functions, showing the importance of both nn and αn final-state interactions. It is shown that the dissociation process is governed by a transition of one neutron from the p-shell in the 6He ground state to the s-shell in the continuum further indicating that the role of the transition through an intermediate 5He(3/2−) state is more important than expected.
Keywords :
Unstable nuclei , Coulomb excitation , 6He , Particle correlations
