Hunting Dark Matter: A New Frontier
Dark matter is the invisible glue that keeps galaxies from falling apart. Back in the 1930s, Fritz Zwicky suspected its existence, and in the 1970s Vera Rubin proved that without it, stars would fly apart.
Neural Network Cleans Up Noise to Catch Xenon Decay
In a dark mine under the Italian Alps, a tank holds three tons of liquid xenon. When a particle hits it, it knocks faint flashes of light and electron clouds out of the atoms. Following these tracks, physicists hope to see an ultra-rare decay: a xenon-136 nucleus turning into barium-136, emitting two electrons and no neutrinos.
Catchers of Solar Ghosts
Deep beneath the Apennine Mountains, in a tank holding three tons of liquid xenon, something gives a barely perceptible shudder every few days. It's a solar neutrino, a ghostly particle born in the Sun's thermonuclear furnace, that has traveled 150 million kilometers through empty space and solid rock to finally collide with a xenon nucleus.
The Muon Pendulum Swings Its Last
In a giant ring of magnets outside Chicago, muons whirled like figure skaters on an ice rink. But instead of music, there's a magnetic field, and instead of spinning, there's a barely perceptible wobble of the spin. Physicists call this wobble the anomalous magnetic moment.