Pathways to Explore Neutrino Physics Fred Gilman NuFact03 New York June 5, 2003

Physics Opportunities The discovery of neutrino mass and oscillations has opened up a new domain to explore. We are in the early stages of probing physics that goes beyond the Standard Model This physics includes the possibility of CP violation and a connection to leptogenesis It also could give us information on physics at the grand unification scale. Experiments underway or under construction have begun to map out some of this new domain.

Future Neutrino Physics Projects There were five neutrino physics projects (Neutrinoless Double-Beta Decay, Off-Axis Neutrino Detector, Neutrino Super Beam, Next Generation Underground Detector, Neutrino Factory) in the HEP Facilities report in March 2003 that were recommended to the DOE Office of Science for its twenty-year strategic plan Similarly, there were two neutrino physics projects in the Nuclear Physics Facilities report to the DOE Office of Science.

Future Neutrino Physics Projects - 2 The NSF is considering a National Underground Laboratory and possible neutrino experiments. There are projects at various stages of discussion and preparation in Europe and in Asia. New ideas and options are being developed. There was a discussion at HEPAP in March 2003 of forming a “Neutrino Physics Study Group” to better understand and develop the pathways on the roadmap for neutrino physics.

Where Do We Go From Here? How do we move from the many ideas on the table and others that are being developed to well- defined projects that we will begin to construct during this decade? The broader community should be an integral part of this process. How should the DPF/DNP/DPB, HEPAP/NSAC, and the international physics community be involved? Who should take a lead role?