Figure 1. A computer graphics image of a simulated event in which a Z’ boson is produced by e+e- collisions, in association with two muons (green curves and hits) and decays into invisible particles. In this figure, the Z’ boson decays into an invisible neutrino and an anti-neutrino, but it may also decay into a dark matter particle and its anti-particle. In either case, no trace is left is in the detector. ／（C) KEK, Belle II, created using Belle II in Virtual Reality developed by Zachary Duer, Tanner Upthegrove, Leo Piilonen, George Glasson, W. Jesse Barber, Samantha Spytek, Christopher Dobson at the Virginia Tech Institute for Creativity, Arts and Technology, Virginia Tech Department of Physics, Virginia Tech School of Education.