In the subterranean recesses of a world-class neutron beam facility within Oak Ridge National Lab (ORNL), there is a neutrino haven. A narrow basement hallway deemed “Neutrino Alley” is lined with detectors of various shapes and sizes. These detectors are metaphorical welcome mats, beckoning the teensy neutrino particles to kick up their feet, for the briefest of moments, and interact under scientists’ watchful eyes.
Scientists from Oak Ridge National Laboratory's COHERENT team attempted to detect dark matter particles by using neutrino detectors located in Neutrino Alley, an area beneath the particle accelerator SNS.
Few things carry the same aura of mystery as dark matter. The name itself radiates secrecy, suggesting something hidden in the shadows of the Universe.
, observed that low-energy neutrinos interact with an argon nucleus through the weak nuclear force in a process called coherent elastic neutrino-nucleus scattering, or CEvNS, which is pronounced “sevens.” Like a ping-pong ball bombarding a softball, a neutrino that hits a nucleus transfers only a small amount of energy to the much larger nucleus, which recoils almost imperceptibly in response to the tiny assault.
Laying the groundwork for the discovery made with the argon nucleus was a 2017 studypublished in
Science in which COHERENT collaborators used the world’s smallest neutrino detector to provide the first evidence of the CEvNS process as neutrinos interacted with larger and heavier cesium and iodine nuclei. Their recoils were even tinier, like bowling balls reacting to ping-pong balls.