β decay of In133 : γ emission from neutron-unbound states in Sn133

M Piersa,G Benzoni,E Rapisarda,A Villa,H Mach,V Sánchez-Tembleque,G Fernández-Martínez,V Vedia,R Álvarez-Rodríguez,A Fijałkowska,Ch Sotty,E Nácher,D Galaviz,V N Fedosseev,C Mihai,D S Judson,D V Fedorov,L M Fraile,K Miernik,M Carmona,T Berry,S Pascu,I Lazarus,O Tengblad,C Costache,K Johnston,Z Janas,L Stan,V Pucknell,I Marroquín,C Henrich,J Kurcewicz,M Stănoiu,J Benito,J Konki,R D Page,A E Barzakh,A Korgul,J.-M Régis,V Karanyonchev,J G Correia,R Wadsworth,L J Harkness-Brennan,A N Andreyev,F Rotaru,W B Walters,N Mărginean,A Illana,J G Cubiss,K Chrysalidis,N Warr,P Rahkila,M Fila,M J G Borge,P Van Duppen,B Olaizola,C Mazzocchi,R Mărginean,R Lică,H De Witte,M Stryjczyk,P T Greenlees,R Grzywacz,S Rothe,S Paulaskalas,M Madurga,A Turturică ,S Víñals ,Edyta Adamska ,M Huýse ,M Martínez ,B A Marsh ,J M Udı́as ,G S Simpson ,M Kicińska‐Habior ,Á Perea ,A Negreţ ,H O U Fynbo ,T Day Goodacre

doi:10.1103/physrevc.99.024304

Abstract

Excited states in Sn-133 were investigated through the beta decay of In-133 at the ISOLDE facility. The ISOLDE Resonance Ionization Laser Ion Source (RILIS) provided isomer-selective ionization for In-133, allowing us to study separately, and in detail, the beta-decay branch of In-133 J(pi)= (9/2(+)) ground state and its J(pi) = (1/2(-)) isomer.Thanks to the large spin difference of the two beta-decaying states of In-133, it is possible to investigate separately the lower and higher spin states in the daughter, Sn-133, and thus to probe independently different single-particle and single-hole levels. We report here new gamma transitions observed in the decay of In-133, including those assigned to the deexcitation of the neutron-unbound states.

Highlights

Simple nuclear systems around doubly magic nuclei in exotic regions of the Segré chart are key to our understanding of nuclear structure
All calculations assume that when states above the neutron-separation energy (Sn) are populated in β decay, they deexcite through β-delayed neutron emission
In order to identify transitions following the β decay of 133In, we studied β-gated γ -ray spectra within a time window from the proton impact on target, ranging from two to three half-lives of 133gIn and 133mIn

Summary

Introduction

Simple nuclear systems around doubly magic nuclei in exotic regions of the Segré chart are key to our understanding of nuclear structure. Theoretical calculations predicting the evolution of shell structure require as an input complete information on s. In this context, the structure of 133Sn, only one neutron above the doubly magic 132Sn (Z = 50, N = 82), provides essential information on neutron s. All calculations assume that when states above the neutron-separation energy (Sn) are populated in β decay, they deexcite through β-delayed neutron emission. This assumption is known to be not correct [3]. The fact that the γ deexcitation of neutron-unbound states can be observed and studied opens the possibility to hunt for those s. p. as well as single-hole (s. h.)

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Discussion

Conclusion