About
Scientists in the Particle Physics and Astrophysics Directorate search for answers to fundamental questions about the building blocks of matter and the nature of space and time. They carry out experiments on the Earth's surface, underground and in space. They help design and build the instruments used in these quests, including underground detectors, precision silicon tracking systems for colliders, a space telescope and the world’s biggest digital camera. Theorists, experimenters and experts in computer simulation, mechanical engineering and other technical fields all join forces to push these studies ahead.
The research takes place on three frontiers, each with a unique approach to making discoveries and advancing our understanding of fundamental particles and the forces that govern their interactions.
ENERGY FRONTIER
At the energy frontier, scientists smash particles together at the highest possible energies to produce exotic forms of matter that haven’t existed since the start of the universe. SLAC is involved in the highest-energy experiments ever undertaken, at Europe’s Large Hadron Collider. And it’s helping develop a next-generation accelerator that will reach higher energies still.
INTENSITY FRONTIER
At the intensity frontier, scientists use powerful particle accelerators and ultra-sensitive detectors to find and measure the rarest processes in nature. This gives them another important window into how the universe operates. SLAC experiments at the intensity frontier are delving into the nature of the neutrino and what happened to all of the antimatter produced in the Big Bang.
COSMIC FRONTIER
At the cosmic frontier, scientists use the cosmos as a laboratory for studying how the laws of physics shaped the formation and evolution of the universe. Two of the biggest puzzles in this realm are the nature of the dark matter and dark energy that make up 95 percent of the universe. SLAC is pursuing these and other questions with telescopes on the ground and in space and a detector deep underground. Many of these efforts involve scientists at the joint SLAC/Stanford Kavli Institute for Particle Astrophysics and Cosmology (KIPAC).
