Invariant-mass spectroscopy of "1"0Li and "1"1Li

Break-up of secondary "1"1Li ion beams (280 MeV/nucleon) on C and Pb targets into "9Li and neutrons is studied experimentally. Cross sections and neutron multiplicity distributions are obtained, characterizing different reaction mechanisms. Invariant-mass spectroscopy for "1"1Li and "1"0Li is performed. The E1 strength distribution, deduced from electromagnetic excitation of "1"1Li up to an excitation energy of 4 MeV comprises #approx#8% of the Thomas-Reiche-Kuhn energy-weighted sum-rule strength. Two low-lying resonance-like structures are observed for "1"0Li at decay energies of 0.21(5) and 0.62(10) MeV, the former one carrying 26(10)% of the strength and likely to be associated with an s-wave neutron decay. A strong di-neutron correlation in "1"1Li can be discarded. Calculations in a quasi-particle RPA approach are compared with the experimental results for "1"0Li and "1"1Li. (orig.)SIGLEAvailable from TIB Hannover: RO 801(97-14) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Neutron momentum distribution from ''core break-up'' reactions of halo nuclei

Neutron angular distributions from violent break-up reactions of "1"1Li and "1"1Be have been measured at 28 MeV/u and 280 MeV/u and at 41 MeV/u and 460 MeV/u, respectively. The derived neutron momentum distributions show a narrow component in transverse momentum that is within uncertainties independent of beam energy and target charge. This component is suggested to be simply related to the momentum distribution of the loosely bound halo neutron(s) in the projectiles. (orig.)SIGLEAvailable from TIB Hannover: RO 801(95-02) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

"6He and neutron momentum distributions from "8He in nuclear break-up reactions at 240 MeV/u

Neutron and "6He momentum distributions from "8He break-up reactions in a C-target have been measured at 240 MeV/u. The two-neutron removal cross section was found to be #sigma#_-_2_n=0.27#+-#0.03 b. The nature of the momentum distributions is interpreted in some simple reaction scenarios. (orig.)32 refs.SIGLEAvailable from TIB Hannover: RO 801(96-04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman