Probing Quark Electric Dipole Moment with Topological Anomalies

Abstract

CP-odd observables originating from the strange-quark electric dipole moment ($d_s$) are identified in $\gamma^\ast\to K^+K^-\pi^0$ and evaluated in the chiral limit. A nonzero T-odd asymmetry $A_T$ requires anomalous couplings descending from a five-dimensional Chern-Simons construction. Modeling the running of $F_A$ and $F_V$ with vector-meson dominance, we estimate sensitivities to $d_s$ at the level of $\mathcal{O}(10^{-16})\,e\cdot\mathrm{cm}$ in $e^+e^-$ data at CMD-3 and $\mathcal{O}(10^{-18})\,e\cdot\mathrm{cm}$ using existing $J/\psi$ samples at BESIII. Future experiments at the Super Tau-Charm Facility and Belle~II can further improve the reach by an order of magnitude.