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A<sc>bstract</sc> We study a simple class offlavored scalarmodels, in which the couplings of a new light scalar to standard-model fermions are controlled by the flavor symmetry responsible for fermion masses and mixings. The scalar couplings are then aligned with the Yukawa matrices, with small but nonzero flavor-violating entries.D-meson decays are an important source of scalar production in these models, in contrast to models assuming minimal flavor violation, in whichBandKdecays dominate. We show that FASER2 can probe large portions of the parameter space of the models, with comparable numbers of scalars fromBandDdecays in some regions. If discovered, these particles will not only provide evidence of new physics, but they may also shed new light on the standard model flavor puzzle. Finally, the richness of theoretical models underscores the importance of model-independent interpretations. We therefore analyze the sensitivity of FASER and other experimental searches in terms of physical parameters: (i) the branching fractions of heavy mesons to the scalar, and (ii)τ/m, whereτandmare the scalar’s lifetime and mass, respectively. The results are largely independent of the new particle’s spin and can be used to extract constraints on a wide variety of models. 

A<sc>bstract</sc> The Electron-Ion Collider (EIC), a forthcoming powerful high-luminosity facility, represents an exciting opportunity to explore new physics. In this article, we study the potential of the EIC to probe the coupling between axion-like particles (ALPs) and photons in coherent scattering. The ALPs can be produced via photon fusion and decay back to two photons inside the EIC detector. In a prompt-decay search, we find that the EIC can set the most stringent bound form_a≲ 20 GeV and probe the effective scales Λ ≲ 10⁵GeV. In a displaced-vertex search, which requires adopting an EM calorimeter technology that provides directionality, the EIC could probe ALPs withm_a≲ 1 GeV at effective scales Λ ≲ 10⁷GeV. Combining the two search strategies, the EIC can probe a significant portion of unexplored parameter space in the 0.2 <m_a< 20 GeV mass range.