Beam requirements for dark-sector searches

Particle accelerators can contribute to dark sector searches over a large energy range. Present and proposed lepton and hadron colliders can search for sterile neutrinos and feebly coupled particles, including forward detectors at the LHC and an LHC-based Gamma Factory. Also, a muon storage ring could play a role for dark neutrino searches. A different approach to the dark sector is beam dump experiments, using either proton, like SHIP, or electron beams, such as BDX and LDMX. Both indirect and direct detection is pursued. In particular, for beam dump experiments with electron beams, advanced accelerator concepts could offer an attractive path forward, such as plasma acceleration based on the AWAKE scheme for direct searches. In this paper we identify and discuss dielectric laser acceleration (DLA) as a promising candidate for indirect searches, by delivering interesting rates of individual electrons in the 5-100 GeV energy range or beyond. We present a baseline parameter set for a DLA-based dark sector searcher. Enhancements with dielectric laser deflectors and segmented detector or by making the dielectric structure be part of the laser oscillator might offer a performance well exceeding the “Extended LDMX” proposal based on LCLS-II.