Many people think of the past decade in particle physics as an era of consolidation, but in fact it has been a vibrant time, setting the stage for revolutions to come.
A NEW LAW OF NATURE
Experiments have tested the electroweak theory, a key element of the Standard Model, over a staggering range of distances, from the subnuclear to the galactic.
Particle detectors have established that neutrinos can morph from one type to another. These elusive particles must have mass, which the Standard Model does not naturally explain.
Fermilab experiments discovered the top quark in collisions of protons and their antimatter counterpart, antiprotons. The top stands out because its mass is some 40 times that of its partner, the bottom quark.
AN IMPERFECT MIRROR
KEK (the Japanese high-energy physics laboratory) and the Stanford Linear Accelerator Center detected differences between the decays of B mesons and of their antiparticles. Such subtle asymmetries bear on why the universe contains so little antimatter.
NOVEL FORMS OF MATTER AND ENERGY
A remarkable concordance of astronomical observations indicates that we live in an approximately flat universe dominated by dark matter and an unidentified form of dark energy that drives cosmic acceleration.