Eur. Phys. J. A (2017) 53: 27
https://doi.org/10.1140/epja/i2017-12213-x

Regular Article - Experimental Physics

Study of the decay of ^116m1In: A new interpretation of low-lying 0⁺ states in ¹¹⁶Sn

¹ Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby BC, Canada
² TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver BC, Canada
³ Department of Physics, University of Guelph, 50 Stone Road, N1G 2W1, Guelph ON, Canada
⁴ Department of Astronomy and Physics, Saint Mary’s University, 923 Robie Street, B3H 3C3, Halifax NS, Canada
⁵ CSNSM, CNRS-IN2P3, Universite Paris-Saclay, 91405, Orsay Cedex, France
⁶ School of Physics, Georgia Institute of Technology, 837 State Street, 30332-0430, Atlanta, GA, USA
⁷ Departments of Chemistry and Physics & Astronomy, University of Kentucky, 40506-0055, Lexington, KY, USA

^* e-mail: jpore@lbl.gov

Received: 6 December 2016
Accepted: 24 January 2017
Published online: 16 February 2017

Abstract

The ¹¹⁶Sn nucleus contains a collective rotational band originating from proton 2p-2h excitations across the proton shell gap. Even though this nucleus has been extensively investigated in the past, there was still missing information on the low-energy interband transitions connecting the intruder and normal structures. The low-lying structure of ¹¹⁶Sn was investigated through a high-statistics study of the decay of ^116m1In with the spectrometer and its ancillary detectors at TRIUMF. These measurements are critical in order to properly characterize the 2p-2h rotational band. Weak -decay branches are observed utilizing - coincidence spectroscopy methods, leading to the first direct observation of the 85 keV ray with a transition strength of W.u. The analysis of these results strongly suggests that the 2027 keV state should replace the previously assigned 1757 keV state as the band-head of the 2p-2h rotational band.