Moriond EW 2025

At the 59th Rencontres de Moriond on Electroweak Interactions and Unified Theories in La Thuile, I gave a plenary on quantum-information approaches to fundamental interactions. Between sessions, the nearby slopes gave the meeting its characteristic Alpine rhythm.

The Cabibbo-Kobayashi-Maskawa (CKM) matrix, which controls flavor mixing between the three generations of quark fermions, is a key input to the Standard Model of particle physics. In this work, we identify a surprising connection between quantum entanglement and the degree of quark mixing. Focusing on a specific limit of 2-to-2 quark scattering mediated by electroweak bosons, we find that the quantum entanglement generated by scattering is minimized when the CKM matrix is almost (but not exactly) diagonal, in qualitative agreement with observation. With the discovery of neutrino masses and mixings, additional angles are needed to parameterize the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix in the lepton sector. Applying the same logic, we find that quantum entanglement is minimized when the PMNS matrix features two large angles and a smaller one, again in qualitative agreement with observation, plus a hint for suppressed CP violation. We speculate on the unlikely but tantalizing possibility that minimization of quantum entanglement might be a fundamental principle that determines particle-physics input parameters.

Paper: Flavor patterns of fundamental particles from quantum entanglement. The slides and the official event page are also available.