Lifetime measurements in 105Sn: the puzzle of B(E2) strengths in Sn isotopes

Giorgia Pasqualato,Daniele Mengoni,Josè Javier Valiente Dobón,Alain Goasduff,Andrea Gottardo

doi:10.1051/epjconf/201922301048

Giorgia Pasqualato, Daniele Mengoni + Show 3 more

Open Access

https://doi.org/10.1051/epjconf/201922301048

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Abstract

One of the most studied case to explore the evolution of shell closures far from stability is the doubly-magic and self-conjugated 100Sn nucleus. Information on its doubly-magic nature can be extracted fromthe systematic study of the tin isotopic chain. In this context, the lifetimes of the neutron deficient 105Sn have been investigated with the coincidence Recoil Distance Doppler Shift (RDDS) technique throughthe reaction 50Cr(58Ni,2pn)105Sn. Preliminary results concerning the lifetimesof 105In excited states are in good agreement with the adopted lifetimes, demonstrating the feasibility to extract lifetimes with this experimental technique.

Highlights

The study of the nuclear structure of atomic nuclei with a number of protons and neutrons close to magic numbers is an effective mean to test different nucleon-nucleon interaction sets used as an input for the shell model codes.A prominent nucleus in this context is the doubly-magic and self-conjugated 100Sn
Decay-spectroscopy provided indirect indication that the Z=50 shell closure is present for this system [1]
Shell-model calculations with the CD-Bonn interaction in the full N=50−N=82 valence space show that the quadrupole strength of core-coupled states in odd-even nuclei closely follow the general trend of the corresponding even-even isotopes for the 2+ states

Summary

Introduction

The study of the nuclear structure of atomic nuclei with a number of protons and neutrons close to magic numbers is an effective mean to test different nucleon-nucleon interaction sets used as an input for the shell model codes. Shell-model calculations with the CD-Bonn interaction in the full N=50−N=82 valence space show that the quadrupole strength of core-coupled states in odd-even nuclei closely follow the general trend of the corresponding even-even isotopes for the 2+ states. In this regard, the neutron-deficient odd-even 105Sn isotope provides the opportunity for direct lifetime measurements of low-lying levels in odd Sn isotopes close to 100Sn. Since lifetimes of the order of ps are expected, the coincidence Recoil Distance Doppler Shift (RDDS) technique can be applied [6]. This method is based on the distinction, for a detected γ-ray transition, of a Doppler shifted component, emitted by nuclei in-flight, and a stopped component, emitted by nuclei at rest

Experimental Details

Analysis and Preliminary Results