Speaker
Description
Upcoming experiments are set to dramatically improve the search for charged lepton flavor violation, with the sensitivity to the rates of $\mu \to eee$ decay and $\mu N\to e N$ conversion expected to improve by four orders of magnitude in the near future. I discuss the impact of these measurements in reshaping our picture of the flavor structure of fundamental interactions and in connection with the Higgs hierarchy puzzle. I evaluate this in the broad scenario of Strongly Interacting Light Higgs and considering the mechanism of partial compositeness. In generic models of partial compositeness, the existing constraints from $\mu \to e \gamma$ and electric dipole moment (EDM) of electron, require the scale of Higgs compositeness to be above $\sim \mathcal{O}(100)$ TeV, pushing these models outside the reach of the LHC and future colliders. Moreover in this case the upcoming $\mu \to eee$ and $\mu N \to e N$ measurements will provide barely comparable bounds despite their remarkable improvement. I will show, however, that models where the strongly coupled sector have an accidental $SU(3)\times \rm{CP}$ symmetry, broken by the elementary-composite mixings: (1) lead to an accidental alignment of Yukawa and dipole couplings, substantially suppressing the bound from the $\mu \to e \gamma$ and electron EDM on the compositeness scale to below a TeV. (2) are probed by the upcoming $\mu \to eee$ and $\mu N\to e N$ experiments for compositeness scale at a few TeV. (3) provide a direct target for current and future collider experiments. I will discuss how the accidental symmetry can arise in the infrared compatible with the dynamical generation of flavor hierarchies in the ultraviolet. I will also survey the bounds and projections for models with other flavor symmetry groups.