When the LHC has outlined the territory of Terascale physics, more precise and sensitive measurements will be needed. For that purpose, a new accelerator facility that collides electrons and positrons will be required. The committee believes that the United States should invest the capital needed to host the proposed ILC as the essential component of U.S. leadership in particle physics in the decades ahead.
The committee recognizes that more than one strategy could be pursued in the next decade, but in its judgment the priorities it has outlined have the highest risk-adjusted return and constitute the strategy most likely to sustain U.S. leadership in particle physics.
The next few decades will represent a culmination of the human effort to understand the elementary constituents of the universe. The United States has an unprecedented opportunity, as a leader of nations, to undertake this profound scientific challenge.