Speaker
Description
The discovery of charged lepton flavor violation (cLFV) would provide incontrovertible evidence for physics beyond the Standard Model. Among the various cLFV channels, photon-photon interactions offer a remarkably clean probe of electromagnetic phenomena. In this work, we explore the prospects of searching for the cLFV process $e^+ e^- \to e^+ e^- e \mu$ at future circular colliders (CEPC and FCC-ee). Adopting an effective field theory (EFT) framework, we investigate the $\gamma\gamma e \mu$ interaction generated by dimension-7 operators, ensuring consistency with stringent experimental limits from the $\mu \to e \gamma$ decay.
Leveraging the clean environment of $e^+ e^-$ collisions, we identify distinctive kinematic distributions—such as the transverse momentum of the scattered electron ($p_T^{(e^-\text{scattered})}$) and the central muon ($p_T^\mu$)—for efficient signal-background separation. By implementing a neural network classifier, we significantly enhance the sensitivity over traditional cut-based analyses. Our findings indicate that a $5\sigma$ discovery is attainable at the CEPC ($\sqrt{s} = 240$ GeV) with $3000\text{ fb}^{-1}$ and the FCC-ee ($\sqrt{s} = 350$ GeV) with just $200\text{ fb}^{-1}$, probing effective couplings down to $\mathcal{O}(10^{-10})$.
| Academic position of the presenting author | Professor |
|---|
