Shell evolution beyond Z = 28 and N = 50: Spectroscopy of 81,82,83,84Zn

C Shand ,V Lapoux,V Lapoux,V Lapoux,V Lapoux,V Lapoux,Y Tsunoda,Z Liu,J.-Y Roussé,R Taniuchi,R Taniuchi,R Taniuchi,R Taniuchi,R Taniuchi,C Santamaria,C Santamaria,C Santamaria,C Santamaria,C Santamaria,T Motobayashi,T Motobayashi,T Motobayashi,T Motobayashi,T Motobayashi,N Paul,N Paul,N Paul,N Paul,N Paul,N Nakatsuka,N Nakatsuka,N Nakatsuka,N Nakatsuka,N Nakatsuka,F Giacoppo,F Giacoppo,M Lettmann,M Lettmann,M Lettmann,M Lettmann,M Lettmann,C Louchart,C Louchart,C Louchart,C Louchart,C Louchart,A Gottardo,Zs Dombrádi,Z Patel,M Sasano,M Sasano,M Sasano,M Sasano,M Sasano,T Uesaka,T Uesaka,T Uesaka,T Uesaka,T Uesaka,I Stefan,I Stefan,I Stefan,I Stefan,I Stefan,S Momiyama,S Momiyama,S Momiyama,S Momiyama,S Momiyama,F Nowacki,F Nowacki,P Doornenbal,C Lizarazo,C Lizarazo,C Lizarazo,C Lizarazo,C Lizarazo,A Giganon,A Giganon,A Giganon,A Giganon,A Giganon,S Franchoo,S Franchoo,S Franchoo,S Franchoo,S Franchoo,S Ota,S Ota,S Ota,S Ota,S Ota,D Calvet,D Calvet,D Calvet,D Calvet,D Calvet,M Górska,T Sumikama,T Sumikama,T Sumikama,T Sumikama,T Sumikama,F Browne,F Browne,P.H Regan,H Baba,A Obertelli,A Obertelli,A Obertelli,A Obertelli,A Obertelli,A Obertelli,P.-A Söderström,K Wimmer,K Wimmer,D Suzuki,D Suzuki,D Suzuki,D Suzuki,D Suzuki,T Otsuka,V Werner,V Werner,V Werner,V Werner,V Werner,R Lozeva,R Lozeva,R Lozeva,R Lozeva,R Lozeva,J Liu,J Liu,J Liu,J Liu,J Liu,A Gillibert,A Gillibert,A Gillibert,A Gillibert,A Gillibert,A Peyaud,K Sieja,K Sieja,T Saito,T Saito,T Saito,T Saito,T Saito,S Koyama,S Koyama,S Koyama,S Koyama,S Koyama,K Matsui,K Matsui,M Nagamine,M Nagamine,M Nagamine,M Nagamine,M Nagamine,C.R Nobs,M Dewald,M Dewald,M Dewald,M Dewald,M Dewald,A Jungclaus,G Authelet,G Authelet,G Authelet,G Authelet,G Authelet,M Matsushita,M Matsushita,M Matsushita,M Matsushita,M Matsushita,J Wu,J Wu,J Wu,J Wu,J Wu,Zs Vajta,V Vaquero,V Vaquero,V Vaquero,V Vaquero,V Vaquero,D Steppenbeck,D Steppenbeck,D Steppenbeck,D Steppenbeck,D Steppenbeck,F Flavigny,F Flavigny,A Corsi,A Corsi,A Corsi,A Corsi,A Corsi,T Isobe,T Isobe,T Isobe,T Isobe,T Isobe,S Nishimura,S Nishimura,S Nishimura,S Nishimura,S Nishimura,Z Korkulu,A Delbart,A Delbart,A Delbart,A Delbart,A Delbart,H Otsu,M Rudigier,M Rudigier,M Rudigier,M Rudigier,M Rudigier,J Lee,J Lee,J Lee,J Lee,J Lee,K Yoneda,K Yoneda,L Olivier,L Olivier,L Olivier,L Olivier,L Olivier,S Chen,S Chen,R Orlandi,R Orlandi,R Orlandi,R Orlandi,R Orlandi,A Blazhev,K Moschner,K Moschner,A Château,A Château,A Château,A Château,A Château,Yuki Kubota ,Clara Péron ,Clara Péron ,Clara Péron ,Clara Péron ,Clara Péron ,Cristina Niță ,E Pollacco ,K Hadyńska-Klȩk ,K Hadyńska-Klȩk ,Takamichi Miyazaki ,Takamichi Miyazaki ,Takamichi Miyazaki ,Takamichi Miyazaki ,Takamichi Miyazaki ,B D Linh ,J.-M Gheller ,J.-M Gheller ,J.-M Gheller ,J.-M Gheller ,J.-M Gheller ,Takashi Ando ,Takashi Ando ,Takashi Ando ,Takashi Ando ,Takashi Ando ,Z Podolyák ,Yoshinori Shiga ,Satoshi Takeuchi ,Satoshi Takeuchi ,Satoshi Takeuchi ,Satoshi Takeuchi ,Satoshi Takeuchi ,H Sakuraï ,H Sakuraï ,H Sakuraï ,H Sakuraï ,H Sakuraï ,M L Cortés ,R Carroll ,J A Tostevin ,M Nııkura ,M Nııkura ,M Nııkura ,M Nııkura ,M Nııkura ,L X Chung ,E Šahin ,E Šahin ,E Šahin ,E Šahin ,E Šahin ,Handing Wang ,Handing Wang ,Handing Wang ,Handing Wang ,Handing Wang ,Bing Ding ,Bing Ding ,Bing Ding ,Bing Ding ,Bing Ding ,A M Bruce ,T Arıcı ,T Arıcı ,T Arıcı ,T Arıcı ,T Arıcı ,Z Y Xu

doi:10.1016/j.physletb.2017.09.001

Abstract

We report on the measurement of new low-lying states in the neutron-rich 81,82,83,84Zn nuclei via in-beam γ-ray spectroscopy. These include the 41+→21+ transition in 82Zn, the 21+→0g.s.+ and 41+→21+ transitions in 84Zn, and low-lying states in 81,83Zn were observed for the first time. The reduced E(21+) energies and increased E(41+)/E(2+1) ratios at N=52, 54 compared to those in 80Zn attest that the magicity is confined to the neutron number N=50 only. The deduced level schemes are compared to three state-of-the-art shell model calculations and a good agreement is observed with all three calculations. The newly observed 2+ and 4+ levels in 84Zn suggest the onset of deformation towards heavier Zn isotopes, which has been incorporated by taking into account the upper sdg orbitals in the Ni78-II and the PFSDG-U models.

Highlights

We report on the measurement of new low-lying states in the neutron-rich 81,82,83,84Zn nuclei via inbeam γ -ray spectroscopy
The deduced level schemes are compared to three state-of-the-art shell model calculations and a good agreement is observed with all three calculations
Technological advances at radioactive beam facilities have provided the means to access extremely neutron-rich regions of the nuclear chart. Studies performed in these regions have illuminated interesting phenomena that cannot be described within the traditional shell model framework

Summary

Introduction

We report on the measurement of new low-lying states in the neutron-rich 81,82,83,84Zn nuclei via inbeam γ -ray spectroscopy. Half-lives, t1/2, of ∼50 ps were considered in the simulations for the 2+1 states in 82,84Zn, in good agreement with theoretical calculations, systematic trends in the immediate region of the nuclear chart, and the measured width of the transitions. In both reaction channels a structure is observed at ∼615 keV with a deformed high-energy side of the peak.

Results

Conclusion