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High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He
When atoms are placed into liquids, their optical spectral lines corresponding to the electronic transitions are greatly broadened compared to those of single, isolated atoms. This linewidth increase can often reach a factor of more than a million, obscuring spectroscopic structures and preventing h...
Autores principales: | , , , , , |
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Lenguaje: | eng |
Publicado: |
2022
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1038/s41586-022-04440-7 http://cds.cern.ch/record/2806094 |
_version_ | 1780972969157197824 |
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author | Sótér, Anna Aghai-Khozani, Hossein Barna, Dániel Dax, Andreas Venturelli, Luca Hori, Masaki |
author_facet | Sótér, Anna Aghai-Khozani, Hossein Barna, Dániel Dax, Andreas Venturelli, Luca Hori, Masaki |
author_sort | Sótér, Anna |
collection | CERN |
description | When atoms are placed into liquids, their optical spectral lines corresponding to the electronic transitions are greatly broadened compared to those of single, isolated atoms. This linewidth increase can often reach a factor of more than a million, obscuring spectroscopic structures and preventing high-resolution spectroscopy, even when superfuid helium, which is the most transparent, cold and chemically inert liquid, is used as the host material1–6 . Here we show that when an exotic helium atom with a constituent antiproton7–9 is embedded into superfuid helium, its visible-wavelength spectral line retains a sub-gigahertz linewidth. An abrupt reduction in the linewidth of the antiprotonic laser resonance was observed when the liquid surrounding the atom transitioned into the superfuid phase. This resolved the hyperfne structure arising from the spin–spin interaction between the electron and antiproton with a relative spectral resolution of two parts in 106 , even though the antiprotonic helium resided in a dense matrix of normal matter atoms. The electron shell of the antiprotonic atom retains a small radius of approximately 40 picometres during the laser excitation7 . This implies that other helium atoms containing antinuclei, as well as negatively charged mesons and hyperons that include strange quarks formed in superfuid helium, may be studied by laser spectroscopy with a high spectral resolution, enabling the determination of the particle masses9 . The sharp spectral lines may enable the detection of cosmic-ray antiprotons10,11 or searches for antideuterons12 that come to rest in liquid helium targets |
id | cern-2806094 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 2022 |
record_format | invenio |
spelling | cern-28060942022-04-12T09:57:07Zdoi:10.1038/s41586-022-04440-7http://cds.cern.ch/record/2806094engSótér, AnnaAghai-Khozani, HosseinBarna, DánielDax, AndreasVenturelli, LucaHori, MasakiHigh-resolution laser resonances of antiprotonic helium in superfluid $^{4}$HePhysics in GeneralCondensed MatterWhen atoms are placed into liquids, their optical spectral lines corresponding to the electronic transitions are greatly broadened compared to those of single, isolated atoms. This linewidth increase can often reach a factor of more than a million, obscuring spectroscopic structures and preventing high-resolution spectroscopy, even when superfuid helium, which is the most transparent, cold and chemically inert liquid, is used as the host material1–6 . Here we show that when an exotic helium atom with a constituent antiproton7–9 is embedded into superfuid helium, its visible-wavelength spectral line retains a sub-gigahertz linewidth. An abrupt reduction in the linewidth of the antiprotonic laser resonance was observed when the liquid surrounding the atom transitioned into the superfuid phase. This resolved the hyperfne structure arising from the spin–spin interaction between the electron and antiproton with a relative spectral resolution of two parts in 106 , even though the antiprotonic helium resided in a dense matrix of normal matter atoms. The electron shell of the antiprotonic atom retains a small radius of approximately 40 picometres during the laser excitation7 . This implies that other helium atoms containing antinuclei, as well as negatively charged mesons and hyperons that include strange quarks formed in superfuid helium, may be studied by laser spectroscopy with a high spectral resolution, enabling the determination of the particle masses9 . The sharp spectral lines may enable the detection of cosmic-ray antiprotons10,11 or searches for antideuterons12 that come to rest in liquid helium targetsWhen atoms are placed into liquids, their optical spectral lines corresponding to the electronic transitions are greatly broadened compared to those of single, isolated atoms. This linewidth increase can often reach a factor of more than a million, obscuring spectroscopic structures and preventing high-resolution spectroscopy, even when superfluid helium, which is the most transparent, cold and chemically inert liquid, is used as the host material. Here we show that when an exotic helium atom with a constituent antiproton is embedded into superfluid helium, its visible-wavelength spectral line retains a sub-gigahertz linewidth. An abrupt reduction in the linewidth of the antiprotonic laser resonance was observed when the liquid surrounding the atom transitioned into the superfluid phase. This resolved the hyperfine structure arising from the spin–spin interaction between the electron and antiproton with a relative spectral resolution of two parts in 106, even though the antiprotonic helium resided in a dense matrix of normal matter atoms. The electron shell of the antiprotonic atom retains a small radius of approximately 40 picometres during the laser excitation. This implies that other helium atoms containing antinuclei, as well as negatively charged mesons and hyperons that include strange quarks formed in superfluid helium, may be studied by laser spectroscopy with a high spectral resolution, enabling the determination of the particle masses. The sharp spectral lines may enable the detection of cosmic-ray antiprotons or searches for antideuterons that come to rest in liquid helium targets.oai:cds.cern.ch:28060942022 |
spellingShingle | Physics in General Condensed Matter Sótér, Anna Aghai-Khozani, Hossein Barna, Dániel Dax, Andreas Venturelli, Luca Hori, Masaki High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He |
title | High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He |
title_full | High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He |
title_fullStr | High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He |
title_full_unstemmed | High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He |
title_short | High-resolution laser resonances of antiprotonic helium in superfluid $^{4}$He |
title_sort | high-resolution laser resonances of antiprotonic helium in superfluid $^{4}$he |
topic | Physics in General Condensed Matter |
url | https://dx.doi.org/10.1038/s41586-022-04440-7 http://cds.cern.ch/record/2806094 |
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