Hiro Ejiri RCNP Osaka Univ., & JASRI Spring 8 For the ELEGANT Collaboration

1. Oto Cosmo Observatory　　　　Present and Future Hiro Ejiri RCNP Osaka Univ., & JASRI Spring 8For the ELEGANT Collaboration 1. Oto Cosmo Observatory 2. Detectors and Physics Results 3. Future Plans 4. Progress of Oto Lab.

2. Ring Cycrotron lab. 0.4-0.5 GeV p, & light ions RCNPResearch Center for Nuclear Physics National Nuclear Physics Lab. Nucleon, Meson, and Quark Lepton Nuclear Physics. National and International users RCNP laboratory complex

3. RCNP & PhysicsOsaka Univ.Neutrinos and DM research programs. • I. Oto Cosmo Observatory Underground Lab. • n masses and natures by bb with ELEGANT V & VI • DM WIMPs search by nuclear scattering . • II. Cyclotron Lab. Charge exchange spin flip reactions to study • nuclear responses for charged weak currents. • III. Laser Electron Photon Lab. at Spring 8. • Nuclear responses for neutral weak currenta.

4. Oto Lab. is close to Osaka Univ. 100 km Kansai/Osaka Airport 40 km SK Osaka Univ. Air port Oto

5. Oto Cosmo Observatory 60 km south of Osaka, near Int. Airport Oto Nishiyoshino Unused 5 km railway tunnel.　 1400 m we Lab.I, lab.II, lab.III New labs can be set in the center region of the 5 km tunnel. H. Ohsumi Proc. XI RCNP. Symp., World Scientific, (1996) 274-279 http://www.rcnp. Osaka-u.ac.jp/ Divisions/ np1-c/index.html . Lab.I, III Lab.II To Osaka Lab. II. 45 m2 ELEGANT V, bb of 100Mo and DM with NaI Lab.I. 33 m2 ELEGANT VI bb of 48Ca and DM with CaF2

6. Experimental Roon I

7. Muon fluxat underground labs. in the worldm4 10-3 /m2/sNeutron 4 10-1/m2/sRn 10 Bq/m3(Detector container10 m Bq /m3) Oto Cosmo Observatory 1400 m w.e

8. III. ELEGANT V • ELEctron GAmma-ray Neutrino Telescope

9. H. Ejiri et al. NIM A302 1991 304 bb of100Mo,116Cd bb-ray E&T PL g-ray by NaI DM –nucleus recoil E by NaI ELEGANT V 　　 • .

10. 100Mo 0nbb by ELEGANT V • 100M0 95% enriched. 0.17 kg. • Most stringent limit by exclusive(bb tracking) • T0n > 1.0 (0.55) 1023y • 68(90)%CL • <mn> < 1.5 (2.1) eV • <gB> < 9 (11) 10-5 H.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 ’01, 65501

11. Present

12. ELEGANT　VI　CaF2 for 48Ca bb and 19F Spin Coupled DM

13. ELEGANT　IV　CaF2 for 48Ca bb and 19F Spin Coupled DM CaF2(pure) as light guide & active shield against PMT CaF2(Eu) is not transparent for U.V. light. bb & DM signalsselected by role off ratio

14. Measurement　of 48Ca bb at Oto BG (sim) 0nbb window 2nbb (sim) T0n > 1.8 1022y 90 % CLI. Ogawa　et al., PANIC02, Nucl.Phys.2003

15. ELEGANT　VI　CaF219F light mass and simple large spin matrix element I. Ogawa, et al. Nucl. Phys. 663(2000) 869c R. Hazama, NIM A482 (2002) 297

16. Results of ELEGANT’s Double beta decays EL III . Ge with NaI for bb of 76Ge : Limit of 1.9 eV (68% CL) on mn and 1st stringent limit on 0nbb to 2+ state. EL IV. 100Mo with Si detector array and Nal. EL V. Drift chamber for bb tracks , plastic scintillators for bb and NaI for g. 1st 2nbb lives for 100Mo and 116Cd. • Most stringent limits on onbb 100Mo mn < 1.5 eV(68% CL). • EL VI. Ca(F)2 Crystals with CsI. Limit on 0nbb of 48Ca: 7 eV • Dark matter • EL V. NaI 760 kg , annular modulation of WIMPS . • Most stringent limits at the low mass region. • EL VI. Ca(F)2 Spin-coupled WIMPS. • http://www.rcnp.osak-u.ac.jp/~ejiri/PUB.html

17. V. Future Experiments • A. MOON • Molybdenum Observatory Of Neutrinos for • bb and low energy solar n’s. • MOON 1 Proto - type MOON and R&D. • B. CANDLES • CA lcium fluoride for studies of Neutrinos and • Dark Matters by Low Energy Spectrometers

18. V. Future ExperimentsIMOON.Molybdenum Observatory Of Neutrinosfor http://ewi.npl.washington.edu. • . bb-n, and low energysolar and supernova n’s. • MOON collaboration　: Interenational collaboration • RCNP/ Physics, Osaka Univ. General Arts Tokushima Univ. • Phys. ICU. Tokyo, • Phys. CENPA, Univ. Washington,LANL 　 • Univ. North Carolina. FNAL • Phys. Charles Univ. CERN • High Energy Physics, Protvino. • JINR VNIIEF • Contact persons　Hiro Ejiri and Hamish Robertson

19. MOON Objectives . n studies in 100Mo : large responses for bb-n & low Ene’s . • Double beta (bb) decays • with mn~0.03 eV. • Low Esolar and SNne. • Two charged particle (b,b) • spectroscopy with high • localization in time & space. • MOON, a super module of • ~1 ton 100Mo & scintillators with modest volume and realistic purity. H.Ejiri,, Phys, Rev. Lett.,85 (2000) 2917

20. MOON Hybrid Detector Super modules of fiber-plate scintillators with 100Mo films. 1. Position read-out Fibers (x-y) 2m - 2 mm - 0.4 mm 2. Energy read-out Plate scintillator with DE ~ s ~ 2 % 3. Modest volume with enriched Mo 4. Enriched Mo 85 % in 100Mo Centrifuges MoF6 gas Laser MOON 1. Proto type 100Mo 1 kg. Mn ~0.3 eV MOON 2. 1 unit : 100Mo 0.25 ton 2m – 2m – 1.7 m, Mn ~0.05 eV MOON 3. 4 units: 100Mo 1 ton. 2m – 2m -- 7 m, Mn ~0.02eV Fiber x Mo film

21. Future Experiments II CANDLES • EL VI ---CANDLES • 48Ca for bb large Qbb = • 4.27 MeV, small 0.19% • 48Ca 7.7 g (EL VI) to • O(10kg) & Enrichment • 1K of 1l crystals of • CaF2 in iiquid scintillator • 3.1 kg of 48Ca in 3.2 ton nCaF2 • Goal 0.1 eVsensitivity. • R & D Osaka Univ.Physics.

22. VII. Progress & Grants • I. ELEGANTs at Kamoka1982--1994 • 1981 Start bb and n project at Osaka • 1981-1982 ELEGANT I, II, Ge with NaI at Osaka • 1982 –1984 ELEGANT III. Ge wih NaI Grant A. B • 1982 – 1985 ELEGANT IV. Mo with Si. Toray Science Award • 1984 EL III Starts at Kamioka Grant A. • 1986 – 1990 ELEGANT V Mo Cd • Drift Chamber & NaI Grant Special Project • 1990 – EL V Starts run. • 1993 – 1995 EL VI CaF2 with CsI • Construction Grant Basic Research

23. Oto Underground Lab. • 1994 New underground lab. n & DM project start. • 1994 – 1995 survey of new underground lab. • 1995 Select Oto and proposal. • 1996 Start construction Grant COE lab. • 1997 Commencement of Oto Lab. • Improve EL V and set at Oto. • 1998 EL V starts run at Oto • 1999 EL IV starts run at Oto • MOON • 2000 MOON project, MOON R&D Yamada award 2001, • 2003 MOON 1 Proto-type Government Grant A. • CANDLES 2002 R&D and Government Grant A.

24. References Nuclear responses for neutrinos. Review H.Ejiri, Phys. Rep. 338 (2000) 265. GR and bb, solar & sn n’sH.Ejiri, Nucl. Phys. A 687 (2001) 350c LI reactions. 3He H.Ejiri, et al. PLB 433 (1998) 257. 11B,11Li H. Ejiri, K. Takahisa, et al., 1997, 2001. Double beta decays and neutrinos. bb EL VH.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 (2001) 65501 Review H.Ejiri, Nucl. Phys.B 91 (2001) 255, v2000 proc MOON bb and solar n H.Ejiri, J.Engel, G.Hazama, P.Krastev, N.Kudomi, R.G.H.Robertson, Phys, Rev. Lett.,85 (2000) 2917 Supernova n H.Ejiri, J.Engel, N.Kudomi, PL B530 (2002) 27 http://www.rcnp.osak-u.ac.jp/~ejiri/PUB.html

25. We would express our cordial thanks to • Oto & Nishiyoshino villages & the chiefs, • Mr T. Kitamura & Mr S．Nakagaki, • for the great and timely support for • construction of the new lab. • National Railway Corporation for transfer of • the tunnel to the two villages to be used for our • underground lab. • Japanese people for their great contributions. • Toray, Takeda, and Yamada S.F.for their timely • awards/suports.

26. Thank you for attension • .

27. Here we would like to express our cordial thanks to The distinguished chief of Oto, Mr. Toshihiro. Kitamura for great, timely , & crucial supports for our science projects.