Invariant-mass spectroscopy of Li-10 and Li-11

• Break-up of secondary Li-11 ion beams (280 MeV/nucleon) on C and Pb targets into Li-9 and neutrons is studied experimentally. Cross sections and neutron multiplicity distributions are obtained, characterizing different reaction mechanisms. Invariant-mass spectroscopy for Li-11 and Li-10 is performed. The E1 strength distribution, deduced from electromagnetic excitation of Li-11 up to an excitation energy of 4 MeV comprises similar to 8% of the Thomas-Reiche-Kuhn energy-weighted sumrule strength. Two low-lying resonance-like structures are observed for Li-10 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 Li-11 can be discarded. Calculations in a quasi-particle RPA approach are compared with the experimental results for Li-10 and Li-11. (C) 1997 Elsevier Science B.V.

Ämnesord

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

Nyckelord

Li-10 deduced resonances

NEUTRONS

E=280 MeV/nucleon

INTERACTION CROSS-SECTIONS

Pb(Li-11

BEAMS

breakup sigma

MOMENTUM DISTRIBUTIONS

features

multiplicity

measured neutron

Li-11

NUCLEAR RADII

gamma-decay associated sum-rule strengths

decay

BREAK-UP

ELECTROMAGNETIC DISSOCIATION

NUCLEAR REACTIONS C

chi n)

EXCITATION

FRAGMENTATION

STATES

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)