I discuss a set of conditions under which the strong CP problem is solved by spontaneous CP violation. Such conditions find their natural realization in anomaly-free modular invariant supersymmetric theories, suggesting a common solution to the strong CP problem and the flavor puzzle. In its minimal realization, this solution requires a single chiral multiplet, beyond those of the MSSM. If one...
We report the result of the search for the decay µ+ → e+ γ undertaken at the Paul Scherrer
Institut in Switzerland with the MEG II experiment using the data collected in the 2021–2022
physics runs. The MEG II detector consists of a spectrometer built around a solenoidal
magnet delivering a gradient field, consisting of a large cylindrical drift chamber and a
highly segmented timing counter...
We investigate an extension of the Dine–Fischler–Srednicki–Zhitnitsky (DFSZ) axion model that realizes spontaneous CP violation and explores its implications for leptonic flavor structure within the framework of the minimal seesaw mechanism. By introducing singlet heavy Majorana neutrinos and an additional complex singlet scalar, we construct the extended Yukawa and scalar sectors necessary...
