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

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

RCNP & Physics Osaka Univ. Neutrinos and DM research programs. I. Oto Cosmo Observatory Underground Lab.  masses and natures by  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.

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

Oto Cosmo Observatory Unused 5 km railway tunnel 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) Osaka-u.ac.jp/ Divisions/ np1-c/index.html  Lab.II Lab.I, III Nishiyoshino Oto To Osaka Lab.I. 33 m 2 ELEGANT VI  of 48 Ca and DM with CaF 2 Lab. II. 45 m 2 ELEGANT V,  of 100 Mo and DM with NaI 60 km south of Osaka, near Int. Airport

Experimental Roon I

Muon flux at underground labs. in the world  /m 2 /s Neutron /m 2 /s Rn 10 Bq/m 3 (Detector container 10 m Bq /m) Muon flux at underground labs. in the world  /m 2 /s Neutron /m 2 /s Rn 10 Bq/m 3 (Detector container 10 m Bq /m 3 ) Oto Cosmo Observatory 1400 m w.e

III. ELEGANT V ELEctron GAmma-ray Neutrino Telescope

ELEGANT V  f     Cd  -ray E&T PL  -ray by NaI DM –nucleus recoil E by NaI. H. Ejiri et al. NIM A

100 Mo 0  by ELEGANT V 100 M0 95% enriched kg. Most stringent limit by exclusive(  tracking) T  > 1.0 (0.55) y 68(90)%CL < 1.5 (2.1) eV < 9 (11) H.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 ’01, 65501

Present

ELEGANT VI CaF 2 for 48 Ca  and 19 F Spin Coupled DM

ELEGANT IV CaF 2 for 48 Ca  and 19 F Spin Coupled DM CaF 2 (pure) as light guide & active shield against PMT CaF 2 (Eu) is not transparent for U.V. light.  DM signals  selected by role off ratio

Measurement of 48 Ca  at Oto 2  (sim) BG (sim) 0  window Isotope 48 Ca 76 Ge 82 Se 100 Mo 116 Cd 136 Xe 150 Nd Q-value (MeV) G 0v × (year -1 eV -2 )      y  CL   Ogawa et al., PANIC02, Nucl.Phys.2003 

ELEGANT VI CaF 2 ELEGANT VI CaF 2 19 F light mass and simple large spin matrix element I. Ogawa, et al. Nucl. Phys. 663(2000) 869c R. Hazama, NIM A482 (2002) 297

Results of ELEGANT’s Double beta decays EL III. Ge with NaI for  of 76 Ge : Limit of 1.9 eV (68% CL) on m and 1 st stringent limit on 0  to 2 + state. EL IV. 100 Mo with Si detector array and Nal. EL V. Drift chamber for  tracks, plastic scintillators for  and NaI for   st 2  lives for 100 Mo and 116 Cd.   Most stringent limits on o  100  m   eV(68% CL).  EL VI. Ca(F) 2 Crystals with CsI. Limit on 0  of 48 Ca: 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.

V. Future Experiments A. MOON Molybdenum Observatory Of Neutrinos for  and low energy solar ’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

V. Future Experiments I MOON. Molybdenum Observatory Of Neutrinos for  and low energy  solar and supernova ’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

MOON Objectives. MOON Objectives.  studies in 100 Mo : large responses for  & low E e ’s. Double beta (  ) decays with m ~0.03 eV. Low E solar and SN e. Two charged particle (  ) spectroscopy with high localization in time & space. MOON, a super module of ~1 ton 100 Mo & scintillators with modest volume and realistic purity. H.Ejiri,, Phys, Rev. Lett.,85 (2000) 2917

MOON Hybrid Detector MOON Hybrid Detector  o film Super modules of fiber-plate scintillators with 100 Mo films. 1. Position read-out Fibers (x-y)  m - 2 mm mm 2. Energy read-out Plate scintillator with  E ~  ~ 2 % 3. Modest volume with enriched Mo 4. Enriched Mo 85 % in 100 Mo Centrifuges MoF 6 gas Laser MOON 1. Proto type 100 Mo 1 kg. M ~0.3 eV MOON 2. 1 unit : 100 Mo 0.25 ton 2m – 2m – 1.7 m, M ~0.05 eV MOON 3. 4 units: 100 Mo 1 ton. 2m – 2m -- 7 m, M ~0.02eV Fiber x

EL VI ---CANDLES 48 Ca for  large Q   4.27 MeV, small 0.19% 48 Ca 7.7 g (EL VI) to O(10kg) & Enrichment  of 1  l crystals of CaF 2 in iiquid scintillator 3.1 kg of 48 Ca in 3.2 ton n CaF 2 Goal 0.1 eV sensitivity. R & D Osaka Univ.Physics. Future Experiments Future Experiments II CANDLES

VII. Progress & Grants I. ELEGANTs at Kamoka Start  and project at Osaka 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 – 1990 ELEGANT V Mo Cd Drift Chamber & NaI Grant Special Project 1990 – EL V Starts run – 1995 EL VI CaF 2 with CsI Construction Grant Basic Research

Oto Underground Lab New underground lab. & DM project start – 1995 survey of new underground lab Select Oto and proposal Start construction Grant COE lab Commencement of Oto Lab. Improve EL V and set at Oto 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.

References Nuclear responses for neutrinos. Review H.Ejiri, Phys. Rep. 338 (2000) 265. GR and , solar & sn ’s  H.Ejiri, Nucl. Phys. A 687 (2001) 350c LI reactions. 3 He H.Ejiri, et al. PLB 433 (1998) B, 11 Li H. Ejiri, K. Takahisa, et al., 1997, Double beta decays and neutrinos.  L V  H.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 (2001) Review H.Ejiri, Nucl. Phys.B 91 (2001) 255, v2000 proc MOON  and solar  H.Ejiri, J.Engel, G.Hazama, P.Krastev, N.Kudomi, R.G.H.Robertson, Phys, Rev. Lett.,85 (2000) 2917 Supernova  H.Ejiri, J.Engel, N.Kudomi, PL B530 (2002) 27

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.

Thank you for attension.

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.