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Improved Limit on the Electric Dipole Moment of the Electron

Andreev, V. and Hutzler, N. R. (2018) Improved Limit on the Electric Dipole Moment of the Electron. Nature, 562 (7727). pp. 355-360. ISSN 0028-0836. doi:10.1038/s41586-018-0599-8.

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[img] Image (JPEG) (Extended Data Fig. 1: Switching timescales) - Supplemental Material
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[img] Image (JPEG) (Extended Data Fig. 2: The ∂BBz/∂z×δ×∂EEnr/∂z systematic error) - Supplemental Material
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[img] Image (JPEG) (Extended Data Table 1: Parameters varied in the search for systematic errors) - Supplemental Material
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The standard model of particle physics accurately describes all particle physics measurements made so far in the laboratory. However, it is unable to answer many questions that arise from cosmological observations, such as the nature of dark matter and why matter dominates over antimatter throughout the Universe. Theories that contain particles and interactions beyond the standard model, such as models that incorporate supersymmetry, may explain these phenomena. Such particles appear in the vacuum and interact with common particles to modify their properties. For example, the existence of very massive particles whose interactions violate time-reversal symmetry, which could explain the cosmological matter–antimatter asymmetry, can give rise to an electric dipole moment along the spin axis of the electron. No electric dipole moments of fundamental particles have been observed. However, dipole moments only slightly smaller than the current experimental bounds have been predicted to arise from particles more massive than any known to exist. Here we present an improved experimental limit on the electric dipole moment of the electron, obtained by measuring the electron spin precession in a superposition of quantum states of electrons subjected to a huge intramolecular electric field. The sensitivity of our measurement is more than one order of magnitude better than any previous measurement. This result implies that a broad class of conjectured particles, if they exist and time-reversal symmetry is maximally violated, have masses that greatly exceed what can be measured directly at the Large Hadron Collider.

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Hutzler, N. R.0000-0002-5203-3635
Additional Information:© 2018 Springer Nature Limited. Received 12 June 2018; Accepted 20 August 2018; Published 17 October 2018. Code availability: The computer codes used for the analysis of the data are available from the corresponding authors on reasonable request. Data availability: The data that support the conclusions of this article are available from the corresponding authors on reasonable request. This work was supported by the NSF. J.H. was supported by the Department of Defense. D.G.A. was partially supported by the Amherst College Kellogg University Fellowship. We thank M. Reece and M. Schwartz for discussions and S. Cotreau, J. MacArthur and S. Sansone for technical support. Reviewer information: Nature thanks E. Hinds and Y. Shagam for their contribution to the peer review of this work. Author Contributions: All authors contributed to one or more of the following areas: proposing, leading and running the experiment; design, construction, optimization and testing of the experimental apparatus and data acquisition system; setup and maintenance during the data runs; data analysis and extraction of physics results from measured traces; modelling and simulation of systematic errors; and the writing of this article. The corresponding authors are D.D., J.M.D. and G.G. ( The authors declare no competing interests.
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Department of DefenseUNSPECIFIED
Amherst CollegeUNSPECIFIED
Issue or Number:7727
Record Number:CaltechAUTHORS:20180907-204924610
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:89472
Deposited By: George Porter
Deposited On:24 Oct 2018 20:48
Last Modified:16 Nov 2021 00:35

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