Great new discoveries in particle physics and cosmology have vastly improved our understanding of the universe. Recent experimental results and theoretical developments strongly suggest that even greater discoveries are close at hand.
Among the outstanding issues to be addressed are:
the
origin of electroweak symmetry breaking
the
potential unification of the fundamental forces, including gravity
the
elucidation of neutrino masses and mixing
the origin
of CP-violation and the nature of flavor
the
physics of quark and gluon production and confinement, and the phases of QCD
the nature of dark matter and dark energy, and the cosmology of the early universe.
No single type of facility can illuminate all of these fundamental issues. Maintaining a diverse program is crucial for deciphering the basic laws of nature.
Strong
support for existing experimental research, including the Tevatron, the
B-factories, and the Large Hadron Collider programs, particle astrophysics
and cosmology, and the physics of heavy flavors, neutrinos and rare decays,
is critical for the continuing success of
There are fundamental questions concerning electroweak symmetry breaking and physics beyond the Standard Model that cannot be answered without a physics program at a Linear Collider overlapping that of the Large Hadron Collider. We therefore strongly recommend the expeditious construction of a Linear Collider as the next major international High Energy Physics project.
Forthcoming
discoveries will point the way for future exploration of new frontiers.
It is therefore essential that an aggressive R&D program be
pursued to develop the needed facilities and associated technologies. These
include new energy-frontier hadron and lepton colliders and detectors,
neutrino superbeams and factories, large underground detectors, and space-
and ground-based astrophysical experiments. Future large-scale projects
should involve extensive partnerships of the international community.