Evidence for octupole collectivity in $$^{172}{\mathrm {Pt}}$$172Pt


Ertoprak, A, Cederwall, B, Qi, C, Aktas, Ö, Doncel, M, Hadinia, B, Liotta, R, Sandzelius, M, Scholey, C, Andgren, K et al (show 49 more authors) (2020) Evidence for octupole collectivity in $$^{172}{\mathrm {Pt}}$$172Pt. The European Physical Journal A, 56 (2).

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Abstract

<jats:title>Abstract</jats:title><jats:p>Excited states in the extremely neutron-deficient nucleus <jats:inline-formula><jats:alternatives><jats:tex-math>$$^{172}{\mathrm {Pt}}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow /><mml:mn>172</mml:mn></mml:msup><mml:mi>Pt</mml:mi></mml:mrow></mml:math></jats:alternatives></jats:inline-formula> were populated via <jats:inline-formula><jats:alternatives><jats:tex-math>$$^{96}\mathrm {Ru}(^{78}\mathrm {Kr},2p)$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow /><mml:mn>96</mml:mn></mml:msup><mml:mi>Ru</mml:mi><mml:mrow><mml:msup><mml:mo>(</mml:mo><mml:mn>78</mml:mn></mml:msup><mml:mi>Kr</mml:mi><mml:mo>,</mml:mo><mml:mn>2</mml:mn><mml:mi>p</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math></jats:alternatives></jats:inline-formula> and <jats:inline-formula><jats:alternatives><jats:tex-math>$$^{92}\mathrm {Mo}(^{83}\mathrm {Kr},3n)$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow /><mml:mn>92</mml:mn></mml:msup><mml:mi>Mo</mml:mi><mml:mrow><mml:msup><mml:mo>(</mml:mo><mml:mn>83</mml:mn></mml:msup><mml:mi>Kr</mml:mi><mml:mo>,</mml:mo><mml:mn>3</mml:mn><mml:mi>n</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math></jats:alternatives></jats:inline-formula> reactions. The level scheme has been extended up to an excitation energy of <jats:inline-formula><jats:alternatives><jats:tex-math>$$\approx 5~\hbox {MeV}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>≈</mml:mo><mml:mn>5</mml:mn><mml:mspace /><mml:mtext>MeV</mml:mtext></mml:mrow></mml:math></jats:alternatives></jats:inline-formula> and tentative spin-parity assignments up to <jats:inline-formula><jats:alternatives><jats:tex-math>$$I^\pi = 18^+$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>I</mml:mi><mml:mi>π</mml:mi></mml:msup><mml:mo>=</mml:mo><mml:msup><mml:mn>18</mml:mn><mml:mo>+</mml:mo></mml:msup></mml:mrow></mml:math></jats:alternatives></jats:inline-formula>. Linear polarization and angular distribution measurements were used to determine the electromagnetic E1 character of the dipole transitions connecting the positive-parity ground-state band with an excited side-band, firmly establishing it as a negative-parity band. The lowest member of this negative-parity structure was firmly assigned spin-parity <jats:inline-formula><jats:alternatives><jats:tex-math>$$3^-$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>3</mml:mn><mml:mo>-</mml:mo></mml:msup></mml:math></jats:alternatives></jats:inline-formula>. In addition, we observed an E3 transition from this <jats:inline-formula><jats:alternatives><jats:tex-math>$$3^-$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>3</mml:mn><mml:mo>-</mml:mo></mml:msup></mml:math></jats:alternatives></jats:inline-formula> state to the ground state, providing direct evidence for octupole collectivity in <jats:inline-formula><jats:alternatives><jats:tex-math>$$^{172}{\mathrm {Pt}}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow /><mml:mn>172</mml:mn></mml:msup><mml:mi>Pt</mml:mi></mml:mrow></mml:math></jats:alternatives></jats:inline-formula>. Large-scale shell model (LSSM) and total Routhian surface (TRS) calculations have been performed, supporting the interpretation of the <jats:inline-formula><jats:alternatives><jats:tex-math>$$3^-$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>3</mml:mn><mml:mo>-</mml:mo></mml:msup></mml:math></jats:alternatives></jats:inline-formula> state as a collective octupole-vibrational state.</jats:p>

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 02 Mar 2020 10:31
Last Modified: 18 Jan 2023 23:59
DOI: 10.1140/epja/s10050-020-00071-6
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3077406
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