skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Predicting Narrow States in the Spectrum of a Nucleus beyond the Proton Drip Line

Abstract

Properties of particle-unstable nuclei lying beyond the proton drip line can be ascertained by considering the (usually known) properties of its mirror neutron-rich system. We have used a multichannel algebraic scattering theory to map the known properties of the neutron-{sup 14}C system to those of the proton-{sup 14}O one from which we deduce that the particle-unstable {sup 15}F will have a spectrum of two low-lying broad resonances of positive parity and, at higher excitation, three narrow negative-parity ones. A key feature is to use coupling to Pauli-hindered states in the target.

Authors:
;  [1];  [2]; ;  [3]
  1. Istituto Nazionale di Fisica Nucleare, Sezione di Padova, e Dipartimento di Fisica dell'Universita di Padova, via Marzolo 8, Padova I-35131 (Italy)
  2. Department of Physics and Astronomy, University of Manitoba, and Winnipeg Institute for Theoretical Physics, Winnipeg, Manitoba, R3T 2N2 (Canada)
  3. School of Physics, University of Melbourne, Victoria 3010 (Australia)
Publication Date:
OSTI Identifier:
20778649
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevLett.96.072502; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CARBON 14; EXCITATION; FLUORINE 15; NEUTRONS; NUCLEAR REACTIONS; OXYGEN 14; PARITY; PROTONS; RESONANCE; SCATTERING

Citation Formats

Canton, L., Pisent, G., Svenne, J.P., Amos, K., and Karataglidis, S. Predicting Narrow States in the Spectrum of a Nucleus beyond the Proton Drip Line. United States: N. p., 2006. Web. doi:10.1103/PHYSREVLETT.96.0.
Canton, L., Pisent, G., Svenne, J.P., Amos, K., & Karataglidis, S. Predicting Narrow States in the Spectrum of a Nucleus beyond the Proton Drip Line. United States. doi:10.1103/PHYSREVLETT.96.0.
Canton, L., Pisent, G., Svenne, J.P., Amos, K., and Karataglidis, S. Fri . "Predicting Narrow States in the Spectrum of a Nucleus beyond the Proton Drip Line". United States. doi:10.1103/PHYSREVLETT.96.0.
@article{osti_20778649,
title = {Predicting Narrow States in the Spectrum of a Nucleus beyond the Proton Drip Line},
author = {Canton, L. and Pisent, G. and Svenne, J.P. and Amos, K. and Karataglidis, S.},
abstractNote = {Properties of particle-unstable nuclei lying beyond the proton drip line can be ascertained by considering the (usually known) properties of its mirror neutron-rich system. We have used a multichannel algebraic scattering theory to map the known properties of the neutron-{sup 14}C system to those of the proton-{sup 14}O one from which we deduce that the particle-unstable {sup 15}F will have a spectrum of two low-lying broad resonances of positive parity and, at higher excitation, three narrow negative-parity ones. A key feature is to use coupling to Pauli-hindered states in the target.},
doi = {10.1103/PHYSREVLETT.96.0},
journal = {Physical Review Letters},
number = 7,
volume = 96,
place = {United States},
year = {Fri Feb 24 00:00:00 EST 2006},
month = {Fri Feb 24 00:00:00 EST 2006}
}
  • Two high-lying states in {sup 15}F and {sup 16}Ne, unbound with respect to one-proton (1p) and two-proton (2p) emissions, have been observed in the fragmentation of {sup 17}Ne at intermediate energies. They undergo mainly sequential emissions of protons via intermediate states in {sup 14}O and {sup 15}F and have decay energies of 7.8(2) and 7.6(2) MeV, respectively. The widths of the newly observed states in {sup 15}F and {sup 16}Ne are much smaller than the Wigner limits for single-particle configurations, of 0.4(4) and 0.8({sub +8}{sup -4}) MeV, respectively. In addition, narrow widths of 0.2(2) MeV are derived for two othermore » high-lying states in {sup 15}F with Q{sub p} of 4.9 and 6.4 MeV, which match features of the recently predicted narrow odd-parity {sup 15}F states with two valence protons in the sd shell. All energies and widths have been obtained by analyzing angular correlations of the decay products, p-p-{sup 14}O and p-p-{sup 13}N, whose trajectories have been measured by a tracking technique with silicon microstrip detectors.« less
  • Yrast states of {sup 106}Sb have been investigated in the {sup 54}Fe({sup 58}Ni,{alpha}pn) reaction using in-beam {gamma}-spectroscopic methods and in the {sup 50}Cr({sup 58}Ni,pn) reaction performing delayed {gamma} and conversion electron studies. A new isomeric state was found at 103 keV with t{sub 1/2}=232(21) ns. The number of states and transitions in the proposed level scheme have been doubled. The experimental results are discussed within the framework of the shell model. {copyright} {ital 1999} {ital The American Physical Society}
  • Fine structure in proton emission from the 7/2{sup -}[523] ground state and from the 1/2{sup +}[411] isomer in deformed nucleus {sup 141}Ho was studied by means of fusion-evaporation reactions and digital signal processing. Proton transitions to the first excited 2{sup +} state in {sup 140}Dy, with the branching ratio of I{sub p}{sup gs}(2{sup +}) = 0.9 {+-} 0.2% and I{sub p}{sup m}(2{sup +}) = 1.7 {+-} 0.5%, were observed. The data are analyzed within the non-adiabatic weak coupling model assuming a large quadrupole deformation of the daughter nucleus {sup 140}Dy as predicted by the self-consistent theory. Implications of this resultmore » on coexistence effects around N = 74 are discussed. Significant modifications of the proton shell structure when going from the valley of beta stability to the proton drip line are discussed in terms of self-consistent theory involving the two-body tensor interaction.« less
  • A level scheme has been constructed for the proton-unbound, T{sub z}=3/2 nuclide {sub 53}{sup 109}I{sub 56} following a recoil-decay-tagging experiment using the {sup 58}Ni({sup 54}Fe, p2n{gamma}) reaction at a beam energy of 195 MeV. The experiment was performed using the highly efficient JUROGAM {gamma}-ray spectrometer in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer. Cranking calculations are used to interpret band structures built on {pi}g{sub 7/2} and {pi}h{sub 11/2} states in a weakly deformed, triaxial nucleus.
  • The Daresbury recoil separator has been used to measure proton radioactivity from the nuclei [sup 150]Lu, [sup 151]Lu, and [sup 147]Tm, produced using the reactions [sup 58]Ni+[sup 96]Ru[r arrow][sup 154]Hf[sup *] and [sup 58]Ni+[sup 92]Mo[r arrow][sup 150]Yb[sup *]. The half-life of [sup 150]Lu has been measured for the first time as 35[plus minus]10 ms, which identifies the proton decay as an [ital l]=5 transition from the [ital h][sub 11/2] proton state. New half-life and energy measurements have been made for the known proton transitions from [sup 147]Tm and [sup 151]Lu, which have been unambiguously assigned using the direct mass identificationmore » of the recoil separator. A new half-life measurement of the proton emitter [sup 109]I is also reported.« less