A look at the future of particle physics

US particle physicists have recently been debating where they will find the most exciting physics and what future facilities will best enable them to pursue it. The dialog intensified last summer at a study sponsored by the American Physical Society Division of Particles and Fields and continued through the Division’s annual meeting at the University of Maryland at the end of October. About 150 high‐energy physicists participated in the DPF Summer Study on Particle Physics and Future Facilities, which was held in Snowmass, Colorado (near Aspen), from 28 June to 16 July. Its stated purpose was to assess the physics topics that might be interesting in the future, to explore the limits of technological capabilities and to consider the nature of future facilities for particle physics in the US. Charles Baltay (Columbia University), chairman of the organizing committee, stressed to us that the role of the summer session was to study the physics but not to arrive at any specific conclusions.