dorsal/arxiv
View SchemaSensitivity of Nuclear Transition Frequencies to Temporal Variation of the Fine Structure Constant or the Strong Interaction
| Authors | A. C. Hayes, J. L. Friar |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/0702048 |
| URL | https://arxiv.org/abs/nucl-th/0702048 |
| DOI | 10.1016/j.physletb.2007.05.021 |
| Journal | Phys.Lett.B650:229-232,2007 |
Abstract
There exist in nature a few nuclear isomers with very low (eV) excitation energies, and the combination of low energy and narrow width makes them possible candidates for laser-based investigations. The best candidate is the lowest-energy excited state known in nuclear physics, the 7.6(5) eV isomer of $^{229}$Th. A recent study suggests that a measurement of the temporal variation of the excitation energy of this isomer would have 5-6 orders of magnitude enhanced sensitivity to a variation of the fine structure constant ($\alpha \cong 1/137.036$) or of a strong interaction parameter ($m_q/\Lambda_{QCD}$). We reexamine the physics involved in these arguments. By invoking the Feynman-Hellmann Theorem we argue that there is no expectation of significantly enhanced sensitivity to a variation in the fine structure constant (beyond that obtained from experimental considerations such as the low energy and narrow width of the isomer). A similar argument applies to the strong interaction, but evaluating the shift due to temporal variations of the underlying parameters of the strong interaction may be beyond current nuclear structure techniques.
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"abstract": "There exist in nature a few nuclear isomers with very low (eV) excitation\nenergies, and the combination of low energy and narrow width makes them\npossible candidates for laser-based investigations. The best candidate is the\nlowest-energy excited state known in nuclear physics, the 7.6(5) eV isomer of\n$^{229}$Th. A recent study suggests that a measurement of the temporal\nvariation of the excitation energy of this isomer would have 5-6 orders of\nmagnitude enhanced sensitivity to a variation of the fine structure constant\n($\\alpha \\cong 1/137.036$) or of a strong interaction parameter\n($m_q/\\Lambda_{QCD}$). We reexamine the physics involved in these arguments. By\ninvoking the Feynman-Hellmann Theorem we argue that there is no expectation of\nsignificantly enhanced sensitivity to a variation in the fine structure\nconstant (beyond that obtained from experimental considerations such as the low\nenergy and narrow width of the isomer). A similar argument applies to the\nstrong interaction, but evaluating the shift due to temporal variations of the\nunderlying parameters of the strong interaction may be beyond current nuclear\nstructure techniques.",
"arxiv_id": "nucl-th/0702048",
"authors": [
"A. C. Hayes",
"J. L. Friar"
],
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"nucl-th"
],
"doi": "10.1016/j.physletb.2007.05.021",
"journal_ref": "Phys.Lett.B650:229-232,2007",
"title": "Sensitivity of Nuclear Transition Frequencies to Temporal Variation of the Fine Structure Constant or the Strong Interaction",
"url": "https://arxiv.org/abs/nucl-th/0702048"
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