RIKEN Nuclear Physics Seminar
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Lecturer: Ushasi Datta Pramanik (GSI, Germany)

Title:  The study of properties of unstable nuclei at GSI

Date:   11/16/2001 (Fri.) 10:30 -

Place:  RIKEN Exhibition Office (RIKEN Gallery) 1F AV Room

                           The seminar will be given in English.

Abstract:
I would like to talk about our new experimental results of light
neutron-rich nuclei in the mass region around A $\approx$ 20. The
secondary beams ($\approx$ 500-600 MeV/nucleon) of unstable nuclei
were produced at GSI by fragmentation of ${^40}$Ar primary beam and
selected with the Fragment Separator (FRS). Inelastic scattering of
a secondary beam on Pb and C target has been studied and subsequent
neutron and $\gamma$ decay of the projectile were investigated by
using the LAND and Crystalball setup.

The $\gamma$-decay transitions measurements in Coulomb dissociation
gives access to details of the ground state configuration of loosely
bound nuclei. We investigated the $^{15,17}$C, $^{14}$B, $^{11}$ Be
isotopes. The comparison between the experimental Coulomb dissociation
cross section with the one calculated in a direct break up model,
shows that the main contributioin to the ground state configurations
of $^{15,17}$C and $^{14}$B are $^{14}$C(0$^+$)$\otimes$ $\nu_{s1/2}$,
$^{16}$C(2$^+$)$\otimes$ $\nu_{s,d}$ and $^{13}$B(0$^+$)$\otimes$ $\nu_{s,d}$
respectively. Results from systematic measurements of the dipole response
of neutron-rich Oxygen isotopes will be discussed as well.

Neutron capture process on neutron rich C, N and O isotopes play an
important role in astrophysical scenarios ranging from nucleosynthesis
in stellar He and C burning stages to possibly inhomogeneous big bang
synthesis model. The measured capture cross sections are limited. I
would like to discuss also the estimated capture cross section in this
relevant isotopes from inverse Coulomb dissociation cross section.
I may also discuss about the comparison between our measured cross section
of the fragmentation reaction of the neutron rich nuclei with several
theoretical calculations.
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        Contact persons of Nuclear Physics Seminar
        Y. Fukuyama, Y. Nishi, and T. Wakui (RI Beam Science Lab.)
        (email) seminar@rarfaxp.riken.go.jp 
	(FAX)   048-462-4689
        (WWW)   http://rarfaxp.riken.go.jp/~seminar/    
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