The FORMOSA experiment is a proposed scintillator-based detector that will provide critical insights into the nature of “dark matter” that makes up the vast majority of the mass in the universe. Many theories predict not a single dark matter particle but instead a “dark sector” that can be as complex in its particles and interactions as the known universe. The dark sector could communicate with our universe through “mixing” between our photon and a “dark photon”. This leads to particles with an electric charge much smaller than that of an electron (“millicharged” particles). These particles could be produced copiously at the LHC but deposit too little energy for big detectors like CMS and ATLAS to discover them. The FORMOSA detector will provide the best opportunity to discover millicharged particles at the LHC.
Detector location
The FORMOSA detector is proposed to be in the forward region of the LHC (close to the beamline) as the targeted signal has a greatly enhanced flux in this region. FORMOSA would be ideally located in the Forward Physics Facility at CERN. This facility is proposed to be constructed ~600m in front of the ATLAS IP during HL-LHC running at CERN. The FPF is comprised of four experiments that together will explore a wide range of BSM and SM phenomena.
The FORMOSA detector builds on the expertise and understanding gained by the milliQan experiment, which is located in the central region of the LHC near the CMS detector.
The FORMOSA demonstrator
The feasibility of the detector design is being proven by the FORMOSA demonstrator in the UJ12 cavern at CERN. The demonstrator was constructed at UC Davis and installed in Febuary 2024. It is collecting data from Run 3 of the CERN LHC.