What message do neutrinos bring from the beginning of time?
When matter and antimatter meet, they annihilate in a puff of energy. At the birth of the universe, such puffs of energy should have produced particles and antiparticles in equal numbers. Yet somehow we live in a universe made entirely of matter. Could neutrinos, tiny particles permeating the universe, be responsible? Are neutrinos the reason we exist? The race is on to find out, using neutrino beams as well as neutrinos from reactors, the atmosphere and the sun.
Bonnie Fleming, Yale University / Fermilab, USA