Phenomenological implications of a class of non-invertible selection rules

Abstract

We demonstrate that non-invertible fusion algebras give rise to a class of selection rules with genuine organizing power in particle physics models, which we call non-invertible selection rules (NISRs). We identify the algebraic structures that distinguish NISRs from ordinary group-based selection rules and from their generic explicit breaking. As a minimal example, we study a singlet-scalar extension of the Standard Model and show that the NISR based on Fibonacci fusion rules leads to distinctive scattering patterns. We further apply the Ising fusion rules to a supersymmetric flipped $SU(5)$ model, addressing the doublet-triplet splitting problem. In this construction, the NISR plays a crucial role in forbidding the $\mu$-term, thereby evading a no-go result for ordinary Abelian symmetries. We anticipate that this class of selection rules can be applied to a wide range of models beyond the Standard Model. To facilitate such applications, we provide a pedagogical review of radiative violation of NISRs in the appendices, with a dark matter model also being discussed.