Monopole Catalysis from Standard Model Anomalies

We study the generalized symmetries associated with Standard Model flavor and their fate in the presence of magnetic monopoles. This illuminates a striking phenomenological consequence: even when baryon and lepton number are classically conserved, the electroweak anomaly induces $\mathrm{\Delta }B=\mathrm{\Delta }L\in 3\mathbb{Z}$ in monopole-fermion scattering for any monopole activating the anomaly. We demonstrate this mechanism in Pati-Salam theory and trinification.