The FP420 R&D project or the FP420 experiment was an international collaboration with members from 29 institutes from 10 countries. The aim was to assess the feasibility of installing proton tagging detectors at 420 m from the interaction points of the ATLAS and CMS experiments at the Large Hadron Collider (LHC). One notable member of the team was Brian Cox, who has been involved with BBC in the production of television science documentaries including Horizon, Wonders of the Solar System in 2010 and Wonders of the Universe in 2011.
By detecting protons that have lost less than 1% of their longitudinal momentum, it is possible to obtain information that could yield insight on various phenomena of high-energy physics. These measurements would be unique at the LHC, and would be difficult to obtain at both existing and future linear colliders.