Last week the first draft of the updated European Strategy for Particle Physics was made public. This document, which remains a draft until reviewed and approved by the CERN Council in May, guides our European colleagues in their exploration and development of the field of particle physics. It is an update of the very first European strategy, originally developed in 2006.
The update process, led by the European Strategy Group, has been long and inclusive. The group includes representatives of all of the CERN member countries and participation from countries with other types of formal agreements to CERN—including the United States—and the rest of the international particle physics community. Over the past year and a half, the group has solicited many discussion papers. It also held a community workshop that brought together 500 physicists to seek input and discuss the many issues and opportunities ahead for particle physics. U.S. and Fermilab physicists contributed to both efforts. A Preparatory Group worked hard to summarize the current state of our field and future opportunities in its briefing book, used by the Strategy Group to draft the updated strategy.
The draft European Strategy is a carefully crafted, three-page-long document that outlines the principal priorities for European particle physics. It touches on all aspects of the European particle physics program and is well worth a read. Here, I will concentrate on the four recommendations regarding high-priority large-scale initiatives, which contain a great deal of overlap with activities of great importance to the United States and to our lab.
The top priority is the exploitation of the LHC and the elucidation of the new physics opened by the discovery of the Higgs. Two of the other three high-priority large-scale initiatives deal with the accelerators that would follow the LHC at the Energy Frontier. High priority is given to R&D necessary for a future global machine at CERN, either a much-higher-energy proton-proton collider or a very-high-energy electron-positron collider. The other future Energy Frontier initiative is the opportunity to build the ILC in Japan. The report notes the strong physics case and the interest of European groups, and it welcomes a proposal from Japan to discuss the region’s possible participation. The remaining high-priority large-scale initiative identified by the Strategy Group is long-baseline neutrino experiments to discover the neutrino mass hierarchy and search for CP violation. Its recommendation is two-fold:
“CERN should develop a neutrino programme to pave the way for a substantial European role in future long-baseline experiments. Europe should explore the possibility of major participation in leading neutrino projects in the U.S. and Japan.”
We are eager to welcome our European colleagues in this exploration. There are opportunities to bring liquid-argon modules of European design to LBNE since it is an experiment that is readily extensible. The additional intellectual and physical resources would allow major enhancements even in the first phase of LBNE.