Probing Charged Lepton Flavor Violation in the General Two-Higgs Doublet Model

Girish Kumar^1*, Wei-Shu Hou¹

¹Department of Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Girish Kumar, email:girishk@hep1.phys.ntu.edu.tw

The rates of charged lepton flavor violating (cLFV) processes in the Standard Model (SM) are highly suppressed–practically zero–due to tiny neutrino masses. Therefore, the observation of cLFV phenomena would be an indisputable sign of physics beyond the SM. In this talk, we will discuss cLFV processes in the framework of the general two-Higgs doublet model (g2HDM) without the Z₂ symmetry. The g2HDM naturally contains flavor violating Yukawa couplings, which can induce cLFV transitions. We will cover τ-decays: τ→μγ, τ→3μ; muon decays: μ→eγ, μ→3e, and μ→e conversion on nuclei, and reassess the possibility of their potential discovery at the upcoming array of experiments. In particular, we will emphasize the importance of two-loop contributions driven by the extra flavor conserving top Yukawa coupling, ρtt, which is naturally Ο(λt) ≈1, and show that these contributions can enhance the cLFV rates to the vicinity of experimental sensitivity. We will briefly discuss the implications for the flavor violation in B-meson decays as well.

Keywords: flavor physics, charged lepton flavor violation, B-decays, two-Higgs doublet model, beyond the standard model physics