Direct Evidence for the νd512 Orbital in 69Ni: Implications for the N=40 Island of Inversion
Artikel i vetenskaplig tidskrift, 2025

Shape coexistence, a collective manifestation of nuclear structure, emerges from the underlying single-particle dynamics and is prominently observed in the region below 68Ni. Theoretical studies have emphasized the key role of the vd512 orbital, the quadrupole partner of vg912, in driving deformation. However, experimental constraints on the location and properties of neutron orbitals in neutron-rich isotopes in this region remain scarce. In this Letter, the single-particle structure of 69Ni was investigated via the 68Ni(d; p) reaction in inverse kinematics, performed at the ISOLDE Solenoidal Spectrometer at CERN. Several new excited states were observed, and comparisons with adiabatic distorted wave approximation (ADWA) calculations enabled l-value assignments for the most strongly populated states. In particular, a state at 2.56 MeV is interpreted as the dominant fragment of the vd512 strength. The experimental findings are well reproduced by Large-Scale Shell Model calculations using a modified LNPS interaction with an increased vg912-vd512 energy gap. These results provide new insight into the structure of 69Ni and underscore the crucial role of the vd512 orbital in the onset of collectivity at the N 1/4 40 island of inversion.

Författare

A. Ceulemans

KU Leuven

R. Raabe

KU Leuven

F. Nowacki

Université de Strasbourg

A. Alharbi

University of Liverpool

Qassim University

H. Ayatollahzadeh

Scottish Universities Physics Alliance

University of the West of Scotland

S. A. Bennett

University of Manchester

F. Browne

CERN

P. A. Butler

University of Liverpool

A. Camaiani

Istituto Nazionale di Fisica Nucleare

KU Leuven

Universita degli Studi di Firenze

D. Clarke

University of Manchester

A. J. Dolan

University of Liverpool

Z. Eleme

University of Ioannina

C. T. A. Everett

University of Liverpool

F. Flavigny

Normandie Université

S. Fracassetti

KU Leuven

S. J. Freeman

CERN

University of Manchester

L. P. Gaffney

University of Liverpool

G. Georgiev

Université Paris-Saclay

S. Goula

University of Ioannina

Andreas Heinz

Subatomär, högenergi- och plasmafysik

Anna Kawecka

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

J. M. Keatings

Scottish Universities Physics Alliance

University of the West of Scotland

M. Labiche

UNITED KINGDOM RESEARCH AND INNOVATION

I. Lazarus

UNITED KINGDOM RESEARCH AND INNOVATION

P. T. MacGregor

CERN

University of Ioannina

University of Manchester

Maria Vittoria Managlia

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

J. Ojala

Jyväskylän Yliopisto

University of Liverpool

B. Olaizola

CERN

Instituto de Nanociencia y Materiales de Aragón (INMA)

R. D. Page

University of Liverpool

N. Patronis

University of Ioannina

O. Poleshchuk

KU Leuven

A. M. Sanchez-Benitez

Universidad de Huelva

D. K. Sharp

University of Manchester

Hans Törnqvist

Subatomär, högenergi- och plasmafysik

A. Youssef

KU Leuven

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 135 25 252502

Hur bildas tunga grundämnen i krockar mellan neutronstjärnor?

Knut och Alice Wallenbergs Stiftelse (2020.0076), 2021-01-01 -- 2025-12-31.

Ämneskategorier (SSIF 2025)

Subatomär fysik

DOI

10.1103/tdfs-5qzw

Mer information

Senast uppdaterat

2026-01-16