Axion Induced Oscillating Electric Dipole Moment of the Electron

Journal Article · 12 January 2016 · Physical Review. D, Particles, Fields, Gravitation and Cosmology

DOI: https://doi.org/10.1103/PhysRevD.93.025007 · OSTI ID:1223242

Hill, Christopher T. ^[1]

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1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

A cosmic axion, via the electromagnetic anomaly, induces an oscillating electric dipole for the electron of frequency ma and strength ~(few) x 10^-32 e-cm, two orders of magnitude above the nucleon, and within a few orders of magnitude of the present standard model constant limit. We give a detailed study of this phenomenon via the interaction of the cosmic axion, through the electromagnetic anomaly, with particular emphasis on the decoupling limit of the axion, ∂_ta(t) ∝ m_α → 0. The analysis is subtle, and we find the general form of the action involves a local contact interaction and a nonlocal contribution, analogous to the “transverse current” in QED, that enforces the decoupling limit. We carefully derive the effective action in the Pauli-Schroedinger non-relativistic formalism, and in Georgi’s heavy quark formalism adapted to the “heavy electron” (m_e >> m_a). We compute the electric dipole radiation emitted by free electrons, magnets and currents, immersed in the cosmic axion field, and discuss experimental configurations that may yield a detectable signal.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: AC02-07CH11359
• OSTI ID: 1223242
• Alternate ID(s): OSTI ID: 1234767
• Report Number(s): FERMILAB-PUB-15-350-T; arXiv eprint number arXiv:1508.04083
• Journal Information: Physical Review. D, Particles, Fields, Gravitation and Cosmology, Vol. 93, Issue 2; ISSN 1550-7998
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English