Speaker
Razvan Lica
(IFIN-HH Bucharest (RO))
Description
Barium isotopes are located in a region of the Segr\`e chart characterized by a variety of
shape phenomena, including shape coexistence and presence of static octupole deformations.
In this isotopic chain alternating-parity bands, with large and constant B(E1) transition moments,
have been found in $^{140-144}$Ba; the neighboring nucleus, $^{146}$Ba, shows instead slower E1 transition rates than $^{144}$Ba~\cite{Mac92}. The same effect is expected to be present in the heavier even-even isotopes~\cite{But91}, which are the object of this study.
In this contribution results from an experiment aiming at studying the $\beta$ decay of Cs isotopes up to A=152 will be presented.
The measurement of gross quantities such as decay half-lives and $\beta$-delayed emission probabilities
P$_n$, are of great relevance for the understanding of the rapid neutron-capture process (r-process)
around the second abundance peak. Apparent beta-feedings and tentative logft values of yrast and non-yrast low-energy levels populated in the daughter $^{148-152}$Ba can be measured, providing a first access to the nuclear structure of these very neutron-rich Ba isotopes. The measurement of the lifetime of specific states gives an additional in-sight in the structure of the populated nuclei.
The experiment was performed in Dec.~2014 at the ISOLDE Decay Station (IDS) set-up using the fast tape station of K.U.-Leuven, equipped with 4 Clover detectors, 3 fast plastic scintillators and 3 LaBr$_3$(Ce) detectors, for fast-timing measurements.
The radioactive beam species were produced in proton-induced fission reactions using a UCx
target equipped with a standard surface ionizer.
Owing to rates lower than expected the decay of $^{148-150}$Cs could only be accessed.
First experimental information extracted from the data will be presented.
\begin{thebibliography}{}
\bibitem{Mac92} H.~Mach et al., \textbf{Phys. Rev. C 41}, R2469 (1990).
\bibitem{Naz92} W.Nazarewicz, \textbf{Phys. Rev. C 45}, 2226 (1992).
\bibitem{But91} P.A. Butler and W.Nazarewicz, \textbf{Nucl. Phys. A533}, 249 (1991).
Authors
Giovanna Benzoni
(Università degli Studi e INFN Milano (IT))
Razvan Lica
(IFIN-HH Bucharest (RO))
Co-authors
Anabel Morales López
(USC)
Angela Bracco
(Università di Milano e INFN)
Angie Orduz
(University of Huelva)
Carl Warren
(Astrium)
Christophe Sotty
(IFIN-HH Bucharest (RO))
Elisa Rapisarda
(KU Leuven (BE))
Fabio Celso Luigi Crespi
(Università degli Studi e INFN Milano (IT))
Henryk Andrzej Mach
(National Centre for Nuclear Research (PL))
Hilde De Witte
(KU Leuven (BE))
Ilja homm
(IKP, TU Darmstadt, Germany)
Luis M Fraile
(Universidad Complutense (ES))
Magdalena Kowalska
(CERN)
Maria Jose Garcia Borge
(CERN)
Michael Thurauf
(Technische Universitaet Darmstadt (DE))
Miguel Madurga Flores
(CERN)
Dr
Mihai stanoiu
(IFIN-HH, Bucharest, Romania)
Morten Vinther Lund
(Aarhus University (DK))
Nigel Victor Warr
(Universitaet zu Koeln (DE))
Nima Saed-Samii
(I)
Paul Thomas Greenlees
(U)
Piet Van Duppen
(KU Leuven (BE))
Radu-Emanuel mihai
(IFIN-HH, Bucharest, Romania)
Silvia Leoni
(Università degli Studi e INFN Milano (IT))
Teresa Kurtukian Nieto
(Centre National de la Recherche Scientifique (FR))
Thorsten Kroell
(Technische Universitaet Darmstadt (DE))
Ulli Koester
(Institut Max von Laue-Paul Langevin (FR))
Victoria Vedia
(Universidad Complutense de Madrid (UCM))
agnieska korgul
(Faculty of Physics, University of Warsaw, Poland)
cristian costache
(IFIN-HH, Bucharest, Romania)
Prof.
jan jolie
(IKP, University of Cologne, Germany)
Dr
nicolae marginean
(IFIN-HH, Bucharest, romania)
Dr
nives blasi
(INFN Milano)
Mr
riccardo avigo
(Universita' Degli studi di Milano)
simone ceruti
(Universita' degli studi Milano)
