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De Gregorio G, Knapp F, Lo Iudice N, Veselý P. The equation of motion phonon method and its application in the neutron rich oxygen region. EPJ Web Conf 2018. [DOI: 10.1051/epjconf/201819401003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
An equation of motion phonon method, developed for even-even nuclear systems and extended to odd nuclei, is applied to 22O and to its odd neighbors 23O and 23F. A calculation using the chiral potential NNLOopt is carried out in a space encompassing up to two phonons. The computed dipole cross section in 22O and the spectra of 22O and 23O are in a satisfactory agreement with the experimental data. However, the calculation describes poorly the spectrum of 23F. This discrepancy originates from the strong coupling between the odd proton and the 22O phonons of neutron nature. This coupling pushes down in energy several states enhancing the level density at low energy. We suggest that a viable route for the solution of this problem could be the inclusion of the three-body interaction using the new chiral potential NNLOsat.
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Chen Q, Xiong L, Luo M, Wang J, Hu C, Zhang X, Yu S, Li Y, Sun D. Synthesis, larvicidal activities and antifungal activities of novel chlorantraniliprole derivatives and their target in the ryanodine receptor. Molecules 2015; 20:3854-67. [PMID: 25738534 DOI: 10.3390/molecules20033854] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/15/2015] [Accepted: 02/24/2015] [Indexed: 11/24/2022] Open
Abstract
In order to identify novel chlorantraniliprole derivatives as potential insecticides or fungicides, 25 analogues of chlorantraniliprole were synthesized. The insecticidal activities against oriental armyworm and the antifungal activities against five typical fungi of these derivatives were tested. Compounds 2u, 2x and 2y exhibited good activities against oriental armyworm, especially compounds 2u and 2x which showed higher larvicidal activities than indoxacarb. Moreover, all of the tested compounds exhibited activities against five typical fungi. The Ki values of all synthesized compounds were calculated using AutoDock4. The relationship between the Ki values and the results of insecticidal activities against oriental armyworm further indicated that the membrane-spanning domain protein of the ryanodine receptor might contain chlorantraniliprole binding sites.
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Bogner SK, Hergert H, Holt JD, Schwenk A, Binder S, Calci A, Langhammer J, Roth R. Nonperturbative shell-model interactions from the in-medium similarity renormalization group. Phys Rev Lett 2014; 113:142501. [PMID: 25325636 DOI: 10.1103/physrevlett.113.142501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Indexed: 06/04/2023]
Abstract
We present the first ab initio construction of valence-space Hamiltonians for medium-mass nuclei based on chiral two- and three-nucleon interactions using the in-medium similarity renormalization group. When applied to the oxygen isotopes, we find experimental ground-state energies are well reproduced, including the flat trend beyond the drip line at (24)O. Similarly, natural-parity spectra in (21,22,23,24)O are in agreement with experiment, and we present predictions for excited states in (25,26)O. The results exhibit a weak dependence on the harmonic-oscillator basis parameter and reproduce spectroscopy within the standard sd valence space.
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Affiliation(s)
- S K Bogner
- Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48844, USA
| | - H Hergert
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - J D Holt
- Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48844, USA and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - A Schwenk
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany and Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - S Binder
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - A Calci
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - J Langhammer
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - R Roth
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
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Abstract
Invariant mass measurements and breakup reactions of neutron-rich nuclei have been instrumental in the study of nuclear structure effects at the limit of nuclear existence. The measurements of neutron-unbound states rely on the detection of neutrons in coincidence with fragments at energies between 100 and 1000 MeV/u. Charged particle and γ-ray coincidence measurements yield additional information. The production and detection methods for these experiments and examples of results in light nuclei are presented. Future opportunities with new facilities and the development of new detectors are described.
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Affiliation(s)
- T Baumann
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321, USA.
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Catford WN, Timis CN, Lemmon RC, Labiche M, Orr NA, Fernández-Domínguez B, Chapman R, Freer M, Chartier M, Savajols H, Rejmund M, Achouri NL, Amzal N, Ashwood NI, Baldwin TD, Burns M, Caballero L, Casadjian JM, Curtis N, de France G, Gelletly W, Liang X, Pain SD, Pucknell VPE, Rubio B, Sorlin O, Spohr K, Theisen C, Warner DD. Migration of nuclear shell gaps studied in the d(24Ne,pγ)25Ne reaction. Phys Rev Lett 2010; 104:192501. [PMID: 20866960 DOI: 10.1103/physrevlett.104.192501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Indexed: 05/29/2023]
Abstract
The transfer of neutrons onto 24Ne has been measured using a reaccelerated radioactive beam of 24Ne to study the (d,p) reaction in inverse kinematics. The unusual raising of the first 3/2+ level in 25Ne and its significance in terms of the migration of the neutron magic number from N=20 to N=16 is put on a firm footing by confirmation of this state's identity. The raised 3/2+ level is observed simultaneously with the intruder negative parity 7/2- and 3/2- levels, providing evidence for the reduction in the N=20 gap. The coincident gamma-ray decays allowed the assignment of spins as well as the transferred orbital angular momentum. The excitation energy of the 3/2+ state shows that the established USD shell model breaks down well within the sd model space and requires a revised treatment of the proton-neutron monopole interaction.
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Affiliation(s)
- W N Catford
- Department of Physics, University of Surrey, Guildford GU2 5XH, United Kingdom
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Kanungo R, Nociforo C, Prochazka A, Aumann T, Boutin D, Cortina-Gil D, Davids B, Diakaki M, Farinon F, Geissel H, Gernhäuser R, Gerl J, Janik R, Jonson B, Kindler B, Knöbel R, Krücken R, Lantz M, Lenske H, Litvinov Y, Lommel B, Mahata K, Maierbeck P, Musumarra A, Nilsson T, Otsuka T, Perro C, Scheidenberger C, Sitar B, Strmen P, Sun B, Szarka I, Tanihata I, Utsuno Y, Weick H, Winkler M. One-neutron removal measurement reveals 24O as a new doubly magic nucleus. Phys Rev Lett 2009; 102:152501. [PMID: 19518623 DOI: 10.1103/physrevlett.102.152501] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Indexed: 05/27/2023]
Abstract
The first measurement of the momentum distribution for one-neutron removal from (24)O at 920A MeV performed at GSI, Darmstadt is reported. The observed distribution has a width (FWHM) of 99 +/- 4 MeV/c in the projectile rest frame and a one-neutron removal cross section of 63 +/- 7 mb. The results are well explained with a nearly pure 2s_{1/2} neutron spectroscopic factor of 1.74 +/- 0.19 within the eikonal model. This large s-wave probability shows a spherical shell closure thereby confirming earlier suggestions that (24)O is a new doubly magic nucleus.
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Affiliation(s)
- R Kanungo
- Astronomy and Physics Department, Saint Mary's University, Halifax, NS B3H 3C3, Canada.
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Hoffman CR, Baumann T, Bazin D, Brown J, Christian G, DeYoung PA, Finck JE, Frank N, Hinnefeld J, Howes R, Mears P, Mosby E, Mosby S, Reith J, Rizzo B, Rogers WF, Peaslee G, Peters WA, Schiller A, Scott MJ, Tabor SL, Thoennessen M, Voss PJ, Williams T. Determination of the N=16 shell closure at the oxygen drip line. Phys Rev Lett 2008; 100:152502. [PMID: 18518100 DOI: 10.1103/physrevlett.100.152502] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Indexed: 05/26/2023]
Abstract
The neutron unbound ground state of (25)O (Z=8, N=17) was observed for the first time in a proton knockout reaction from a (26)F beam. A single resonance was found in the invariant mass spectrum corresponding to a neutron decay energy of 770_+20(-10) keV with a total width of 172(30) keV. The N=16 shell gap was established to be 4.86(13) MeV by the energy difference between the nu1s(1/2) and nu0d(3/2) orbitals. The neutron separation energies for (25)O agree with the calculations of the universal sd shell model interaction. This interaction incorrectly predicts an (26)O ground state that is bound to two-neutron decay by 1 MeV, leading to a discrepancy between the theoretical calculations and experiment as to the particle stability of (26)O. The observed decay width was found to be on the order of a factor of 2 larger than the calculated single-particle width using a Woods-Saxon potential.
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Affiliation(s)
- C R Hoffman
- Department of Physics, Florida State University, Tallahassee, FL 32303, USA.
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Schiller A, Frank N, Baumann T, Bazin D, Brown BA, Brown J, DeYoung PA, Finck JE, Gade A, Hinnefeld J, Howes R, Lecouey JL, Luther B, Peters WA, Scheit H, Thoennessen M, Tostevin JA. Selective population and neutron decay of an excited state of 23O. Phys Rev Lett 2007; 99:112501. [PMID: 17930431 DOI: 10.1103/physrevlett.99.112501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 06/29/2007] [Indexed: 05/25/2023]
Abstract
We have observed a resonance in neutron-fragment coincidence measurements that is presumably the first excited state of 23O at 2.8(1) MeV excitation energy which decays into the ground state of 22O. This interpretation is consistent with theory. The reaction mechanism supports the assignment of the observed state as the 5/2+ hole state. This assignment and the recently observed 3/2+ particle state advance the understanding of 23O.
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Affiliation(s)
- A Schiller
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
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