Τίτλος:
Investigating the structure of the low-lying states in Ba-140
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The neutron-rich Ba144-146 isotopes have been studied recently in terms
of their experimental B(E3) values [1, 2]. Although featuring large
uncertainties, the results were found to be significantly larger than
any theoretical calculation. Similar questions exist for the slightly
lighter isotope Ba-140, which is particularly interesting since it is
located at the onset of octupole correlations. The lifetimes of the
lower-lying states are completely unknown, with the sole exception of
the first 2(+) state [3].
In this work, we report on the outcome of a short test run, attempting
to populate the states of interest using the Ba-138(O-18 O-16)Ba-140
reaction. The experiment was carried out at IFIN-HH using a specially
manufactured Ba-nat target sandwiched between two Au layers. This was
considered imperative due to Barium’s quick oxidation in air. Four beam
energies (61,63,65,67 MeV) below the Coulomb barrier have been tested.
The subsequent gamma decay was measured using the Bucharest ROSPHERE
array, consisting of 15 Ge detectors and 10 LaBr3 (Ce) scintillators.
The preliminary results from the test run report on the level population
strengths and the limits in lifetime measurements, which are expected to
provide new information on the structural effects in neutron-rich barium
isotopes, especially regarding quadrupole and octupole degrees of
freedom. The findings are also expected to act as stringent tests to
theoretical modeling in this mass regime.
Συγγραφείς:
Khaliel, A.
Mertzimekis, T. J.
Bracco, A.
Crespi, F. C. L.
and Florea, N.
Papaioannou, D.
Zagoraios, G.
Stan, L. and
Turturica, A.
Marginean, N.
Εκδότης:
IOP Publishing Ltd
Τίτλος συνεδρίου:
27TH INTERNATIONAL NUCLEAR PHYSICS CONFERENCE (INPC2019)
DOI:
10.1088/1742-6596/1643/1/012141
