Exclusive measurement of breakup reactions with the one-neutron halo nucleus 11Be -: art. no. 034318

Electromagnetic and nuclear inelastic scattering of the halo nucleus Be-11 have been investigated by a measurement of the one-neutron removal channel, utilizing a secondary Be-11 beam with an energy of 520 MeV/nucleon impinging on lead and carbon targets. All decay products, i.e., Be-10 fragments, neutrons, and gamma rays have been detected in coincidence. Partial cross sections for the population of ground and excited states in Be-10 were determined for nuclear diffractive breakup as well as for electromagnetically induced breakup. The partial cross sections for ground-state transitions have been differentiated further with respect to excitation energy, and the dipole-strength function associated solely with transitions of the halo 2s(1/2) neutron to the continuum has been derived. The extracted dipole strength integrated from the neutron threshold up to 6.1 MeV excitation energy amounts to 0.90(6)e(2) fm(2). A spectroscopic factor for the nu2s(1/2)circle times(10)Be(0(+)) single-particle configuration of 0.61(5) and a root-mean-square radius of the 2s(1/2) neutron wave function of 5.7(4) fm have been deduced.