New physics has traditionally been expected in the high-pT region at high-energy collider experiments. If new particles are light and weakly-coupled, however, this focus may be completely misguided: light particles are typically highly concentrated within a few mrad of the beam line, allowing sensitive searches with small detectors, and even extremely weakly-coupled particles may be produced in large numbers there. In this talk I will discuss the recent proposal of FASER, ForwArd Search ExpeRiment at the LHC: a detector placed 480 m downstream of the ATLAS interaction point (IP) in the very forward region and operated concurrently there. Long-lived, weakly coupled TeV-energy particles can traverse the intervening rock and LHC infrastructure before decaying inside FASER, with little background from Standard Model processes. The collimated nature of the signal allows FASER to be compact, and re-use of components from other experiments allow it to be constructed quickly and inexpensively. FASER will be installed during the current LHC long shutdown and begin collecting data in 2022.
