About 80 percent of the universe’s mass is believed to be dark matter, yet the makeup and organization of its particles remain largely unknown, leaving physicists with fundamental questions. To investigate this elusive material, scientists are working to detect photons, or light particles, that can be produced when dark matter particles collide with the ordinary matter we know.
Up to now, most searches have targeted dark matter with masses comparable to familiar elementary particles. If the particles are lighter than an electron, the leading instruments in use today, which rely on liquid xenon, are unlikely to register them.
No experiment has directly observed dark matter so far. This absence still matters, since it rules out dark matter particles within the specific mass range and interaction strengths already tested.
An international team led by Laura Baudis, Titus Neupert, Björn Penning, and Andreas Schilling from UZH’s Department of Physics has now been able to probe the existence of dark matter particles across a wide mass range below one mega electron volt (MeV). Using an improved superconducting nanowire single-photon detector (SNSPD), the researchers reached a sensitivity threshold of about one-tenth the mass of an electron, above which dark matter particles are highly unlikely to exist.
“This is the first time we’ve been able to search for dark matter particles in such a low mass range, made possible by a new detector technology,” says first author Laura Baudis.
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