NWG 4/11/03 Executive Summary R.N. Cahn, W.C. Carithers, S.J. Freedman, K.M. Heeger, R.W. Kadel, V. Koch, K.T. Lesko, Z. Ligeti (deputy), K-B. Luk, H. Murayama, E.B. Norman, D.R. Nygren, A.M. Sessler, R.G. Stokstad (chair), J.S. Wurtele, and M.S. Zisman Neutrino Science at LBNL Present Program and Future Options Neutrino Working Group

NWG 4/11/03 Charge The working group should survey the theoretical landscape and recent experimental results to provide a framework for understanding which will be the most compelling next set of neutrino experiments world-wide. All ongoing and planned neutrino-related work at LBNL should be surveyed and placed into the above context by the working group through discussion with the proponents. The resulting theoretical context, the ongoing program, and future options should be presented at a joint one-day retreat and workshop in early December open to members of all three divisions. The future plan should lay the groundwork for development of proposals (both LDRD and external) for support of our work.

NWG 4/11/03 Science Recent Discoveries Open Questions ' s change flavor ' s have mass First physics beyond the Standard Model Standard Solar Model correct for 8 B ' s Majorana or Dirac ? Absolute Mass Scale ? Mass hierarchy ?  13 = ? CP violation ? H.E. ' s from the Cosmos ?

NWG 4/11/03 Present Program Neutrino properties SNO Solar ' s  12,  m 2 12 KamLAND Reactor ' s  12,  m 2 12 Cuoricino  decay m, Maj or Dir Neutrino Factory R&D Accelerator ' s  CP-viol.) Neutrinos as messengers SNO AMANDA IceCube R&D for next generation solar detector

NWG 4/11/03 Opportunities Must invest in the future. Exciting opportunities abound. Future will be mix of present and new experiments. Must make wise choices - science & suitability for LBNL. Solar measurements of  12, tests of SSM Long Base Line measurement of  13 Reactor measurement of  13 CUORE; Majorana; a new type of  detector National Underground Laboratory Opportunities considered:

NWG 4/11/03 Resources and Strategy Resources to pursue an opportunity are modest. Resources to implement a funded proposal can be significant. Success in pursuing an opportunity is not guaranteed a priori. pursue several opportunities Strategy: have a balance of funded experiments in progress and options being pursued. Selecting options to pursue requires setting priorities

NWG 4/11/03 Criteria Is the science outstanding? Fundamental, timely, important consequences, … Is it appropriate for LBNL? We must make a unique and important contribution. Is there local interest and expertise? Who wants to do it? Is it within the realm of possibility? Prospects for funding, interdivisional/UCB collaboration, resources, national need (long range plans), etc.

NWG 4/11/03 Priorities The first requirement in addressing the future is to meet the commitments implicit in the present program. Success in meeting present commitments provides the basis on which we build the future --- a future that will contain elements of the present program and new initiatives. Priority for opportunities: 1. Neutrinoless double beta decay 2. A reactor measurement of  Measurements of  12 and tests of the Standard Solar Model 4. Development of scientific and tech. infrastructure for NUSEL

NWG 4/11/03 Double Beta Decay Opportunities The next generation of 0  detectors will have the sensitivity to detect effective masses of ~ 10's of meV -- in the mass range suggested by oscillation experiments. CUORE (Cryogenic Underground Observatory for Rare Events) 760kg of 130 Te TeO 2 crystals at 10 o mK ~$10M proposal in preparation 40kg (Cuoricino) has begun taking data Majorana 500kg 76 Ge cooled crystals, enriched isotope, ~$100M LBNL Ge detector technology (GRETA,  -ray tracking) ideal for Majorana R&D for room temperature TPC: ions drifting in insulating liquid reveal topology of electron pairs from DBD.

NWG 4/11/03 Reactor meas. of  13 Opportunities Two detectors appropriately positioned between 2 and 10 km. Secondary oscillations determine  13.

NWG 4/11/03 Solar Neutrino Measurements of  12 Increase precision on fundamental matrix element. Definitive tests of Standard Solar Model. KamLAND-II -- reduce backgrounds to enable detection of 7 Be solar neutrinos. Next Generation Solar Neutrino detector -- detection of pp solar neutrinos. LBNL involved in R&D on HERON. Opportunities

NWG 4/11/03 NUSEL The longstanding goal of a national underground laboratory may be achieved in the near future in a facility that would be funded by the NSF. LBNL will likely be involved in experiments to be sited there. LBNL could further the cause of NUSEL by participating in the development of the scientific and technical infrastruture of the underground laboratory. Opportunities

NWG 4/11/03 History We have made good choices in the past: Sudbury Neutrino Observatory NTD Thermistors for Cuoricino (NSD joined in 1998) Neutrino Factory R&D AMANDA/IceCube KamLAND

NWG 4/11/03 FUTURE We have excellent opportunities to pursue now

NWG 4/11/03

Neutrino Science Effort IceCube14 KamLAND 9 SNO 5 Factory 3 Cuoricino 1.5 Solar R&D 1.5 Scientists14 PostDocs 6 GSRA 3 Engineers10 Presently ~34 FTE