Observation of the proton emitter 116La59

Wei Zhang; Bo Cederwall; Özge Aktas; Xiaoyu Liu; Aysegül Ertoprak; Ayse Nyberg; Kalle Auranen; Betool Alayed; Hussam Badran; Helen Boston; Maria Doncel; Ulrika Forsberg; Tuomas Grahn; Paul T. Greenlees; Song Guo; Jacob Heery; Joshua Hilton; David Jenkins; Rauno Julin; Sakari Juutinen; Minna Luoma; Olavi Neuvonen; Joonas Ojala; Robert D. Page; Janne Pakarinen; Jari Partanen; Edward S. Paul; Costel Petrache; Panu Rahkila; Panu Ruotsalainen; Mikael Sandzelius; Jan Sarén; Stuart Szwec; Holly Tann; Juha Uusitalo; Robert Wadsworth

doi:10.1038/s42005-022-01069-w

Observation of the proton emitter ¹¹⁶La₅₉

Wei Zhang^*, Bo Cederwall, Özge Aktas, Xiaoyu Liu, Aysegül Ertoprak, Ayse Nyberg, Kalle Auranen, Betool Alayed, Hussam Badran, Helen Boston, Maria Doncel, Ulrika Forsberg, Tuomas Grahn, Paul T. Greenlees, Song Guo, Jacob Heery, Joshua Hilton, David Jenkins, Rauno Julin, Sakari JuutinenMinna Luoma, Olavi Neuvonen, Joonas Ojala, Robert D. Page, Janne Pakarinen, Jari Partanen, Edward S. Paul, Costel Petrache, Panu Rahkila, Panu Ruotsalainen, Mikael Sandzelius, Jan Sarén, Stuart Szwec, Holly Tann, Juha Uusitalo, Robert Wadsworth

^*Corresponding author for this work

Physics

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

Abstract

The quantum tunneling and emission of a single constituent nucleon provide a beautifully simple and unique window into the complex properties of atomic nuclei at the extreme edge of nuclear existence. In particular, for odd-odd proton emitting nuclides, the associated decay energy and partial half-life can be used to probe the correlations between the valence neutrons and protons which have been theoretically predicted to favour a new type of nuclear superfluidity, isoscalar neutron-proton pairing, for which the experimental “smoking gun" remains elusive. In the present work, proton emission from the lanthanum isotope 57116La₅₉, 23 neutrons away from the only stable isotope 57139La₈₂, is reported. ¹¹⁶La nuclei were synthesised in the fusion-evaporation reaction ⁵⁸Ni(⁶⁴Zn, p5n)¹¹⁶La and identified via their proton radioactivity using the mass spectrometer MARA (Mass Analysing Recoil Apparatus) and the silicon detectors placed at its focal plane. Comparisons of the measured proton energy (E_p = 718 ± 9 keV) and half-life (T_1/2 = 50 ± 22 ms) with values calculated using the Universal Decay Law approach indicate that the proton is emitted with an orbital angular momentum l = 2 and that its emission probability is enhanced relative to its closest, less exotic, odd-even lanthanum isotope (57117La₆₀) while the proton-emission Q-value is lower. We propose this to be a possible signature for the presence of strong neutron-proton pair correlations in this exotic, neutron deficient system. The observations of γ decays from isomeric states in ¹¹⁶La and ¹¹⁷La are also reported.

Original language	English
Article number	285
Journal	Communications Physics
Volume	5
Issue number	1
DOIs	https://doi.org/10.1038/s42005-022-01069-w
Publication status	Published - 14 Nov 2022

Bibliographical note

© The Author(s) 2022

Funding Information:
This work was supported by the Swedish Research Council under Grant No. 2019-04880; the United Kingdom Science and Technology Facilities Council (STFC) under Grants Nos. ST/P003885/1, ST/V001035/1, ST/P004598/1, and ST/V001027/1; the EU 7th Framework Programme, Integrating Activities Transnational Access, project No.262010 ENSAR; and the Academy of Finland under the Finnish Centre of Excellence Programme (Nuclear and Accelerator Based Physics Programme at JYFL). We thank the JYFL Accelerator laboratory staff for excellent operation of the K130 cyclotron and D. Delion, R. Liotta, N. Sandulescu, and C. Qi for fruitful discussions.

Publisher Copyright:
© 2022, The Author(s).

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10.1038/s42005-022-01069-w

s42005-022-01069-w
© The Author(s) 2022
Final published version, 958 KBLicence: CC BY

Cite this

Zhang, W., Cederwall, B., Aktas, Ö., Liu, X., Ertoprak, A., Nyberg, A., Auranen, K., Alayed, B., Badran, H., Boston, H., Doncel, M., Forsberg, U., Grahn, T., Greenlees, P. T., Guo, S., Heery, J., Hilton, J., Jenkins, D., Julin, R., ... Wadsworth, R. (2022). Observation of the proton emitter ¹¹⁶La₅₉. Communications Physics, 5(1), Article 285. https://doi.org/10.1038/s42005-022-01069-w

@article{8a59a928d0ab4838897b25fba89bf64e,

title = "Observation of the proton emitter 116La59",

abstract = "The quantum tunneling and emission of a single constituent nucleon provide a beautifully simple and unique window into the complex properties of atomic nuclei at the extreme edge of nuclear existence. In particular, for odd-odd proton emitting nuclides, the associated decay energy and partial half-life can be used to probe the correlations between the valence neutrons and protons which have been theoretically predicted to favour a new type of nuclear superfluidity, isoscalar neutron-proton pairing, for which the experimental “smoking gun{"} remains elusive. In the present work, proton emission from the lanthanum isotope 57116La59, 23 neutrons away from the only stable isotope 57139La82, is reported. 116La nuclei were synthesised in the fusion-evaporation reaction 58Ni(64Zn, p5n)116La and identified via their proton radioactivity using the mass spectrometer MARA (Mass Analysing Recoil Apparatus) and the silicon detectors placed at its focal plane. Comparisons of the measured proton energy (Ep = 718 ± 9 keV) and half-life (T1/2 = 50 ± 22 ms) with values calculated using the Universal Decay Law approach indicate that the proton is emitted with an orbital angular momentum l = 2 and that its emission probability is enhanced relative to its closest, less exotic, odd-even lanthanum isotope (57117La60) while the proton-emission Q-value is lower. We propose this to be a possible signature for the presence of strong neutron-proton pair correlations in this exotic, neutron deficient system. The observations of γ decays from isomeric states in 116La and 117La are also reported.",

author = "Wei Zhang and Bo Cederwall and {\"O}zge Aktas and Xiaoyu Liu and Ayseg{\"u}l Ertoprak and Ayse Nyberg and Kalle Auranen and Betool Alayed and Hussam Badran and Helen Boston and Maria Doncel and Ulrika Forsberg and Tuomas Grahn and Greenlees, {Paul T.} and Song Guo and Jacob Heery and Joshua Hilton and David Jenkins and Rauno Julin and Sakari Juutinen and Minna Luoma and Olavi Neuvonen and Joonas Ojala and Page, {Robert D.} and Janne Pakarinen and Jari Partanen and Paul, {Edward S.} and Costel Petrache and Panu Rahkila and Panu Ruotsalainen and Mikael Sandzelius and Jan Sar{\'e}n and Stuart Szwec and Holly Tann and Juha Uusitalo and Robert Wadsworth",

note = "{\textcopyright} The Author(s) 2022 Funding Information: This work was supported by the Swedish Research Council under Grant No. 2019-04880; the United Kingdom Science and Technology Facilities Council (STFC) under Grants Nos. ST/P003885/1, ST/V001035/1, ST/P004598/1, and ST/V001027/1; the EU 7th Framework Programme, Integrating Activities Transnational Access, project No.262010 ENSAR; and the Academy of Finland under the Finnish Centre of Excellence Programme (Nuclear and Accelerator Based Physics Programme at JYFL). We thank the JYFL Accelerator laboratory staff for excellent operation of the K130 cyclotron and D. Delion, R. Liotta, N. Sandulescu, and C. Qi for fruitful discussions. Publisher Copyright: {\textcopyright} 2022, The Author(s).",

year = "2022",

month = nov,

day = "14",

doi = "10.1038/s42005-022-01069-w",

language = "English",

volume = "5",

journal = "Communications Physics",

issn = "2399-3650",

publisher = "Springer",

number = "1",

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Zhang, W, Cederwall, B, Aktas, Ö, Liu, X, Ertoprak, A, Nyberg, A, Auranen, K, Alayed, B, Badran, H, Boston, H, Doncel, M, Forsberg, U, Grahn, T, Greenlees, PT, Guo, S, Heery, J, Hilton, J, Jenkins, D, Julin, R, Juutinen, S, Luoma, M, Neuvonen, O, Ojala, J, Page, RD, Pakarinen, J, Partanen, J, Paul, ES, Petrache, C, Rahkila, P, Ruotsalainen, P, Sandzelius, M, Sarén, J, Szwec, S, Tann, H, Uusitalo, J & Wadsworth, R 2022, 'Observation of the proton emitter ¹¹⁶La₅₉', Communications Physics, vol. 5, no. 1, 285. https://doi.org/10.1038/s42005-022-01069-w

TY - JOUR

T1 - Observation of the proton emitter 116La59

AU - Zhang, Wei

AU - Cederwall, Bo

AU - Aktas, Özge

AU - Liu, Xiaoyu

AU - Ertoprak, Aysegül

AU - Nyberg, Ayse

AU - Auranen, Kalle

AU - Alayed, Betool

AU - Badran, Hussam

AU - Boston, Helen

AU - Doncel, Maria

AU - Forsberg, Ulrika

AU - Grahn, Tuomas

AU - Greenlees, Paul T.

AU - Guo, Song

AU - Heery, Jacob

AU - Hilton, Joshua

AU - Jenkins, David

AU - Julin, Rauno

AU - Juutinen, Sakari

AU - Luoma, Minna

AU - Neuvonen, Olavi

AU - Ojala, Joonas

AU - Page, Robert D.

AU - Pakarinen, Janne

AU - Partanen, Jari

AU - Paul, Edward S.

AU - Petrache, Costel

AU - Rahkila, Panu

AU - Ruotsalainen, Panu

AU - Sandzelius, Mikael

AU - Sarén, Jan

AU - Szwec, Stuart

AU - Tann, Holly

AU - Uusitalo, Juha

AU - Wadsworth, Robert

N1 - © The Author(s) 2022 Funding Information: This work was supported by the Swedish Research Council under Grant No. 2019-04880; the United Kingdom Science and Technology Facilities Council (STFC) under Grants Nos. ST/P003885/1, ST/V001035/1, ST/P004598/1, and ST/V001027/1; the EU 7th Framework Programme, Integrating Activities Transnational Access, project No.262010 ENSAR; and the Academy of Finland under the Finnish Centre of Excellence Programme (Nuclear and Accelerator Based Physics Programme at JYFL). We thank the JYFL Accelerator laboratory staff for excellent operation of the K130 cyclotron and D. Delion, R. Liotta, N. Sandulescu, and C. Qi for fruitful discussions. Publisher Copyright: © 2022, The Author(s).

PY - 2022/11/14

Y1 - 2022/11/14

N2 - The quantum tunneling and emission of a single constituent nucleon provide a beautifully simple and unique window into the complex properties of atomic nuclei at the extreme edge of nuclear existence. In particular, for odd-odd proton emitting nuclides, the associated decay energy and partial half-life can be used to probe the correlations between the valence neutrons and protons which have been theoretically predicted to favour a new type of nuclear superfluidity, isoscalar neutron-proton pairing, for which the experimental “smoking gun" remains elusive. In the present work, proton emission from the lanthanum isotope 57116La59, 23 neutrons away from the only stable isotope 57139La82, is reported. 116La nuclei were synthesised in the fusion-evaporation reaction 58Ni(64Zn, p5n)116La and identified via their proton radioactivity using the mass spectrometer MARA (Mass Analysing Recoil Apparatus) and the silicon detectors placed at its focal plane. Comparisons of the measured proton energy (Ep = 718 ± 9 keV) and half-life (T1/2 = 50 ± 22 ms) with values calculated using the Universal Decay Law approach indicate that the proton is emitted with an orbital angular momentum l = 2 and that its emission probability is enhanced relative to its closest, less exotic, odd-even lanthanum isotope (57117La60) while the proton-emission Q-value is lower. We propose this to be a possible signature for the presence of strong neutron-proton pair correlations in this exotic, neutron deficient system. The observations of γ decays from isomeric states in 116La and 117La are also reported.

AB - The quantum tunneling and emission of a single constituent nucleon provide a beautifully simple and unique window into the complex properties of atomic nuclei at the extreme edge of nuclear existence. In particular, for odd-odd proton emitting nuclides, the associated decay energy and partial half-life can be used to probe the correlations between the valence neutrons and protons which have been theoretically predicted to favour a new type of nuclear superfluidity, isoscalar neutron-proton pairing, for which the experimental “smoking gun" remains elusive. In the present work, proton emission from the lanthanum isotope 57116La59, 23 neutrons away from the only stable isotope 57139La82, is reported. 116La nuclei were synthesised in the fusion-evaporation reaction 58Ni(64Zn, p5n)116La and identified via their proton radioactivity using the mass spectrometer MARA (Mass Analysing Recoil Apparatus) and the silicon detectors placed at its focal plane. Comparisons of the measured proton energy (Ep = 718 ± 9 keV) and half-life (T1/2 = 50 ± 22 ms) with values calculated using the Universal Decay Law approach indicate that the proton is emitted with an orbital angular momentum l = 2 and that its emission probability is enhanced relative to its closest, less exotic, odd-even lanthanum isotope (57117La60) while the proton-emission Q-value is lower. We propose this to be a possible signature for the presence of strong neutron-proton pair correlations in this exotic, neutron deficient system. The observations of γ decays from isomeric states in 116La and 117La are also reported.

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U2 - 10.1038/s42005-022-01069-w

DO - 10.1038/s42005-022-01069-w

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SN - 2399-3650

VL - 5

JO - Communications Physics

JF - Communications Physics

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ER -

Observation of the proton emitter ¹¹⁶La₅₉

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Nuclear Physics Consolidated Grant 2021-2024

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Observation of the proton emitter 116La59

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Bibliographical note

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Nuclear Physics Consolidated Grant 2021-2024

Nuclear Physics Consolidated Grant

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Observation of the proton emitter ¹¹⁶La₅₉