WP 4.3.4 - Study of RICH detectors for future electron-positron colliders

The focus of this task is the conceptual design, and the investigation of the key components, of a RICH detector for a future high-energy e+e− collider, in particular FCC-ee. The physics capabilities of an experiment at such a machine can be greatly enhanced by the addition of particle-identification capabilities. Applications include heavy-flavour studies, and the flavour tagging of jets in Higgs, W, and top decays. These goals imply a momentum range of around 1 to 50 GeV/c, which can naturally be covered by a RICH detector with dual radiators. This detector must be compact, taking no more than ∼20 cm in extent, and low mass, so as not to compromise the other aspects of the experiment’s design. An initial design, the ARC detector, has been proposed, comprising an aerogel and gas radiator, low-mass mirrors and SiPM photodetectors, deployed in an array of cells. The goals of the task are to optimise the layout of the ARC and investigate other possible solutions. Important challenges involve the possible use of aerogel as a thermal insulator, as well as a radiator, the choice of radiator gas, and whether it must be pressurised, lightweight mirrors, and the need for compact photodetectors with high geometrical efficiency.