Observation of excess events in the XENON1T dark matter experiment
Scientists from the international XENON collaboration, an international experimental group including the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), University of Tokyo; the Institute for Cosmic Ray Research (ICRR), University of Tokyo; the Institute for Space-Earth Environmental Research (ISEE), Nagoya University; the Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University; and the Graduate School of Science, Kobe University, announced today that data from their XENON1T, the world's most sensitive dark matter experiment, show a surprising excess of events. The scientists do not claim to have found dark matter. Instead, they have observed an unexpected rate of events, the source of which is not yet fully understood. The signature of the excess is similar to what might result from a tiny residual amount of tritium (a hydrogen atom with one proton and two neutrons), but could also be a sign of...