Direct evidence of octupole deformation in neutron-rich 144Ba

Brian Bucher; S. Zhu; C. Y. Wu; R. V. F. Janssens; D. Cline; A. B. Hayes; M. Albers; A.D. Ayangeakaa; P. A. Butler; C. Campbell; M. P. Carpenter; C. J. Chiara; J.A. Clark; H. Crawford; M. Cromaz; H.M. David; C. Dickerson; E. T. Gregor; J. Harker; C.R. Hoffman; B. P. Kay; F. G. Kondev; A. Korichi; T. Lauritsen; A.O. Machiavelli; R.C. Pardo; A. Richard; M.A. Riley; G. Savard; Marcus Scheck; D. Seweryniak; M.K. Smith; R. Vondrasek; A. Wiens

doi:10.1103/PhysRevLett.116.112503

Direct evidence of octupole deformation in neutron-rich ¹⁴⁴Ba

Brian Bucher^*, S. Zhu, C. Y. Wu, R. V. F. Janssens, D. Cline, A. B. Hayes, M. Albers, A.D. Ayangeakaa, P. A. Butler, C. Campbell, M. P. Carpenter, C. J. Chiara, J.A. Clark, H. Crawford, M. Cromaz, H.M. David, C. Dickerson, E. T. Gregor, J. Harker, C.R. HoffmanB. P. Kay, F. G. Kondev, A. Korichi, T. Lauritsen, A.O. Machiavelli, R.C. Pardo, A. Richard, M.A. Riley, G. Savard, Marcus Scheck, D. Seweryniak, M.K. Smith, R. Vondrasek, A. Wiens

^*Corresponding author for this work

School of Computing, Engineering and Physical Sciences

Research output: Contribution to journal › Letter › peer-review

127 Citations (Scopus)

Abstract

The neutron-rich nucleus Ba144 (t1/2=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV Ba144 beam on a 1.0−mg/cm2 Pb208 target. The measured value of the matrix element, ⟨31−∥M(E3)∥01+⟩=0.65(+17−23) eb3/2, corresponds to a reduced B(E3) transition probability of 48(+25−34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

Original language	English
Article number	112503
Journal	Physical Review Letters
Volume	116
DOIs	https://doi.org/10.1103/PhysRevLett.116.112503
Publication status	Published - 17 Mar 2016

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10.1103/PhysRevLett.116.112503

Marcus Scheck
- School of Computing, Engineering and Physical Sciences - Professor
Person: Academic

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Bucher, B., Zhu, S., Wu, C. Y., Janssens, R. V. F., Cline, D., Hayes, A. B., Albers, M., Ayangeakaa, A. D., Butler, P. A., Campbell, C., Carpenter, M. P., Chiara, C. J., Clark, J. A., Crawford, H., Cromaz, M., David, H. M., Dickerson, C., Gregor, E. T., Harker, J., ... Wiens, A. (2016). Direct evidence of octupole deformation in neutron-rich ¹⁴⁴Ba. Physical Review Letters, 116, Article 112503. https://doi.org/10.1103/PhysRevLett.116.112503

@article{190379a5145a404793d09c139ea0ee2a,

title = "Direct evidence of octupole deformation in neutron-rich 144Ba",

abstract = "The neutron-rich nucleus Ba144 (t1/2=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV Ba144 beam on a 1.0−mg/cm2 Pb208 target. The measured value of the matrix element, ⟨31−∥M(E3)∥01+⟩=0.65(+17−23) eb3/2, corresponds to a reduced B(E3) transition probability of 48(+25−34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.",

author = "Brian Bucher and S. Zhu and Wu, {C. Y.} and Janssens, {R. V. F.} and D. Cline and Hayes, {A. B.} and M. Albers and A.D. Ayangeakaa and Butler, {P. A.} and C. Campbell and Carpenter, {M. P.} and Chiara, {C. J.} and J.A. Clark and H. Crawford and M. Cromaz and H.M. David and C. Dickerson and Gregor, {E. T.} and J. Harker and C.R. Hoffman and Kay, {B. P.} and Kondev, {F. G.} and A. Korichi and T. Lauritsen and A.O. Machiavelli and R.C. Pardo and A. Richard and M.A. Riley and G. Savard and Marcus Scheck and D. Seweryniak and M.K. Smith and R. Vondrasek and A. Wiens",

year = "2016",

month = mar,

day = "17",

doi = "10.1103/PhysRevLett.116.112503",

language = "English",

volume = "116",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

}

Bucher, B, Zhu, S, Wu, CY, Janssens, RVF, Cline, D, Hayes, AB, Albers, M, Ayangeakaa, AD, Butler, PA, Campbell, C, Carpenter, MP, Chiara, CJ, Clark, JA, Crawford, H, Cromaz, M, David, HM, Dickerson, C, Gregor, ET, Harker, J, Hoffman, CR, Kay, BP, Kondev, FG, Korichi, A, Lauritsen, T, Machiavelli, AO, Pardo, RC, Richard, A, Riley, MA, Savard, G, Scheck, M, Seweryniak, D, Smith, MK, Vondrasek, R & Wiens, A 2016, 'Direct evidence of octupole deformation in neutron-rich ¹⁴⁴Ba', Physical Review Letters, vol. 116, 112503. https://doi.org/10.1103/PhysRevLett.116.112503

TY - JOUR

T1 - Direct evidence of octupole deformation in neutron-rich 144Ba

AU - Bucher, Brian

AU - Zhu, S.

AU - Wu, C. Y.

AU - Janssens, R. V. F.

AU - Cline, D.

AU - Hayes, A. B.

AU - Albers, M.

AU - Ayangeakaa, A.D.

AU - Butler, P. A.

AU - Campbell, C.

AU - Carpenter, M. P.

AU - Chiara, C. J.

AU - Clark, J.A.

AU - Crawford, H.

AU - Cromaz, M.

AU - David, H.M.

AU - Dickerson, C.

AU - Gregor, E. T.

AU - Harker, J.

AU - Hoffman, C.R.

AU - Kay, B. P.

AU - Kondev, F. G.

AU - Korichi, A.

AU - Lauritsen, T.

AU - Machiavelli, A.O.

AU - Pardo, R.C.

AU - Richard, A.

AU - Riley, M.A.

AU - Savard, G.

AU - Scheck, Marcus

AU - Seweryniak, D.

AU - Smith, M.K.

AU - Vondrasek, R.

AU - Wiens, A.

PY - 2016/3/17

Y1 - 2016/3/17

N2 - The neutron-rich nucleus Ba144 (t1/2=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV Ba144 beam on a 1.0−mg/cm2 Pb208 target. The measured value of the matrix element, ⟨31−∥M(E3)∥01+⟩=0.65(+17−23) eb3/2, corresponds to a reduced B(E3) transition probability of 48(+25−34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

AB - The neutron-rich nucleus Ba144 (t1/2=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV Ba144 beam on a 1.0−mg/cm2 Pb208 target. The measured value of the matrix element, ⟨31−∥M(E3)∥01+⟩=0.65(+17−23) eb3/2, corresponds to a reduced B(E3) transition probability of 48(+25−34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

U2 - 10.1103/PhysRevLett.116.112503

DO - 10.1103/PhysRevLett.116.112503

M3 - Letter

SN - 0031-9007

VL - 116

JO - Physical Review Letters

JF - Physical Review Letters

M1 - 112503

ER -

Direct evidence of octupole deformation in neutron-rich 144Ba

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Direct evidence of octupole deformation in neutron-rich ¹⁴⁴Ba