학술논문
Electromagnetic properties of 21O for benchmarking nuclear Hamiltonians
Document Type
article
Author
S. Heil; M. Petri; K. Vobig; D. Bazin; J. Belarge; P. Bender; B.A. Brown; R. Elder; B. Elman; A. Gade; T. Haylett; J.D. Holt; T. Hüther; A. Hufnagel; H. Iwasaki; N. Kobayashi; C. Loelius; B. Longfellow; E. Lunderberg; M. Mathy; J. Menéndez; S. Paschalis; R. Roth; A. Schwenk; J. Simonis; I. Syndikus; D. Weisshaar; K. Whitmore
Source
Physics Letters B, Vol 809, Iss , Pp 135678- (2020)
Subject
Language
English
ISSN
0370-2693
Abstract
The structure of exotic nuclei provides valuable tests for state-of-the-art nuclear theory. In particular electromagnetic transition rates are more sensitive to aspects of nuclear forces and many-body physics than excitation energies alone. We report the first lifetime measurement of excited states in 21O, finding τ1/2+=420−32+35(stat)−12+34(sys) ps. This result together with the deduced level scheme and branching ratio of several γ-ray decays are compared to both phenomenological shell-model and ab initio calculations based on two- and three-nucleon forces derived from chiral effective field theory. We find that the electric quadrupole reduced transition probability of B(E2;1/2+→5/2g.s.+)=0.71−0.06−0.06+0.07+0.02 e2fm4, derived from the lifetime of the 1/2+ state, is smaller than the phenomenological result where standard effective charges are employed, suggesting the need for modifications of the latter in neutron-rich oxygen isotopes. We compare this result to both large-space and valence-space ab initio calculations, and by using multiple input interactions we explore the sensitivity of this observable to underlying details of nuclear forces.