The study of entanglement in particle physics has been gathering pace in the past few years. It is
a new field that is providing important results about the possibility of detecting entanglement
and testing Bell inequality at colliders for final states as diverse as top-quark, tau-lepton pairs
and Lambda baryons, massive gauge bosons and vector mesons. In this review, after presenting
definitions, tools and basic results that are necessary for understanding these developments, we
summarize the main findings—as published by the beginning of year 2024—including analyses
of experimental data in B meson decays and top-quark pair production. We include a detailed
discussion of the results for both qubit and qutrits systems, that is, final states containing
spin one-half and spin one particles. Entanglement has also been proposed as a new tool to
constrain new particles and fields beyond the Standard Model and we introduce the reader to
this promising feature as well.
