Experimental Elementary Particle Physics

Particle physics plays an essential role in the broader enterprise of the physical sciences. It inspires U.S. students, attracts talent from around the world, and drives critical intellectual and technological advances in other fields. And Iit is entering an era of unprecedented potential as a result of new discoveries about matter and energy in the Universe. and Particle physics addresses fundamental questions in three overlapping domains: the Energy Frontier, the Intensity Frontier and the Cosmic Frontier.The Particle Physics program seeks to explore the fundamental nature of matter, energy, space, and time. It asks such questions as: What are the origins of mass? Can the basic forces of nature be unified? How did the universe begin? How will it evolve in the future? What are dark matter and dark energy? Are there extra dimensions of space-time? Formerly separate questions in cosmology (the universe on the largest scales) and quantum phenomena (the universe on the smallest scales) become connected through our understanding that the early universe can be explored through the techniques of particle physics.At the NSF, particle physics is supported by three programs within the Division of Physics: (1) the Theory program, which includes fundamental research on the forces of nature and the early history of the universe as well as support for the experimental program by providing guidance and analysis for high energy experiments; (2) the Elementary Particle Physics (EPP) program, which supports particle physics at accelerators, and (3) the Particle Astrophysics (PA) program, which supports non-accelerator experiments. The EPP program supports, for example, accelerator-based experiments at Fermilab, Batavia, Illinois and collider experiments utilizing the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. The challenge of designing detectors for the LHC is unprecedented, as they are required to observe up to 600 million collisions each second. Yet some of the phenomena physicists are searching for will take place at the rate of only a few per day. Among these are a particle called the Higgs boson that is thought to endow other particles with mass, new forms of matter that explain the mysterious dark matter pervading the cosmos and even phenomena that reveal new dimensions of space-time.A new generation of neutrino experiments is underway, using beams from Fermilab and other accelerators in Europe and Japan, to study the properties of these elusive, quantum-oscillating particles under laboratory-controlled conditions. The beams travel hundreds of miles through the Earth to underground detectors that measure changes in the composition of the neutrino beam.EPP also supports advances in accelerator physics and detectors at accelerators and new methods of utilizing distributed computing in support of collaborative research, for example, grid development, both nationally and internationally. The program also engages K-12 educators, who participate in experiments with university scientists, staff and students.