  This document describes the plans of the ALICE Collaboration for a major
upgrade of its detector, referred to as ALICE 3, which is proposed for physics
data-taking in the LHC Run 5 and beyond. ALICE 3 will enable an extensive
programme to fully exploit the LHC for the study of the properties of strongly
interacting matter with high-energy nuclear collisions. The proposed detector
layout, based on advanced silicon sensors, features superb pointing resolution,
excellent tracking and particle identification over a large acceptance and high
readout-rate capabilities. This document discusses the proposed physics
programme, the detector concept, and its physics performance for a suite of
benchmark measurements.
