Long-range axion forces and hadronic CP violation

Shohei Okawa, Maxim Pospelov, Adam Ritz

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Axions and other pseudoscalar fields comprise an interesting class of ultralight dark matter candidates, that may independently play a role in solving the strong CP problem. In the presence of CP-violating sources, these pseudoscalar fields can develop a coherent nonderivative coupling to nucleons, g¯aNN, thus mediating 'mass-mass' and 'mass-spin' forces in matter that can be probed experimentally. We revisit the nonperturbative generation of these CP-odd axion forces, and refine estimates of g¯aNN generated by the electric dipole moments and color electric dipole moments of quarks. We also revisit the Standard Model contribution to CP-odd axion couplings generated by the phase of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

Original languageEnglish (US)
Article number075003
JournalPhysical Review D
Issue number7
StatePublished - Apr 1 2022
Externally publishedYes

Bibliographical note

Funding Information:
M. P. would like to thank J. Redondo for encouragement to revisit the CKM contribution to . The work of S. O. and A. R. is supported in part by NSERC, Canada, and M. P. is supported in part by U.S. Department of Energy (Grant No. desc0011842). S. O. also acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science and Innovation through the “Unit of Excellence María de Maeztu 2020-2023” award to the Institute of Cosmos Sciences (CEX2019-000918-M) and Grants No. PID2019–105614 GB-C21 and No. 2017-SGR-929.

Publisher Copyright:
© 2022 authors. Published by the American Physical Society..


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