English

Constraining CP-violating electron-gluonic operators

High Energy Physics - Phenomenology 2019-07-17 v2

Abstract

We present an analysis of constraints on two types of CP-odd electron-gluonic operators (eˉiγ5e)GμνaGaμν(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu} and (eˉe)GμνaG~aμν(\bar{e}e)G_{\mu\nu}^a \tilde{G}^{a\mu\nu} from current and future electric dipole moment (EDM) experiments. The recent result from the ACME experiment using ThO molecules is used to derive an impressive lower bound on the effective scale for (eˉiγ5e)GμνaGaμν(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu} at 8 TeV, assuming a QCD one-loop factor and no helicity suppression from new physics. One interesting aspect is that (eˉiγ5e)GμνaGaμν(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu} contributes to the observable EDM in ThO experiment mainly through CP-odd electron-nucleon interaction rather than direct electron EDM which arises from three-loop running and matching. For (eˉe)GμνaG~aμν(\bar{e}e)G_{\mu\nu}^a \tilde{G}^{a\mu\nu} the current bound is much weaker and suffers from large uncertainties. We also discuss the QCD running and matching for the CP-odd electron-gluonic operators and give an estimate of the relevant nucleon matrix elements and uncertainties that are needed in the calculation.

Keywords

Cite

@article{arxiv.1904.10808,
  title  = {Constraining CP-violating electron-gluonic operators},
  author = {Kingman Cheung and Wai-Yee Keung and Ying-nan Mao and Chen Zhang},
  journal= {arXiv preprint arXiv:1904.10808},
  year   = {2019}
}

Comments

22 pages (21 pages + cover), 4 figures, 7 tables; JHEP accepted version; Introduction, footnotes, table captions, acknowledgement, and references updated; typos corrected

R2 v1 2026-06-23T08:48:19.772Z