1. Oto Cosmo Observatory

2. Detectors and Physics Results

3. Future Plans

4. Progress of Oto Lab.

Oto Cosmo ObservatoryOto Cosmo Observatory 　　　 　 　 　　 　 　 　 Present and FuturePresent and Future

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

RCNPRCNPResearch Center Research Center

for for Nuclear PhysicsNuclear Physics

National Nuclear Physics Lab.

Nucleon, Meson,

and

Quark Lepton

Nuclear Physics.

Ring Cycrotron lab. 0.4-0.5 GeV p, & light ions

National and International usersRCNP laboratory complex

RCNP & PhysicsRCNP & Physics Osaka UnivOsaka Univ..

Neutrinos and DM research programsNeutrinos 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 toOsaka Univ. 100 kmKansai/Osaka Airport 40 km

Oto Cosmo ObservatoryUnused 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.II Lab.I, IIINishiyoshino Oto

ToOsaka

Lab.I. 33 m2

ELEGANT VIof 48Ca and DM

with CaF2

Lab. II. 45 m2

ELEGANT V, of100Mo and

DM with NaI

60 km south of Osaka, near Int. Airport

Experimental Roon I

Muon fluxMuon flux at at

underground underground labs. in the labs. in the

worldworld

4 104 10-3-3 /m /m22/s/s

Neutron Neutron 4 104 10-1-1/m/m22/s/s

　　　　　　　　　　　　 Rn 10 Bq/mRn 10 Bq/m33

(Detector container(Detector container 10 m Bq /m10 m Bq /m3))

Oto Cosmo Observatory 1400 m w.e

III. ELEGANT V ELEctron GAmma-ray Neutrino Telescope

ELEGANT V 　 　fCd -ray E&T PL -ray by NaI

DM –nucleus recoil E by NaI

.H. Ejiri et al. NIM A302 1991 304

100100Mo 0Mo 0 by ELEGANT V by ELEGANT V 100M0 95% enriched. 0.17 kg.

Most stringent limit by exclusive( tracking)

T> 1.0 (0.55) 1023y 68(90)%CL

<m> < 1.5 (2.1) eV <gB> < 9 (11) 10-5

H.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 ’01, 65501

Present

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

ELEGANT 　 IV 　CaF2 for 48Ca and 19F Spin Coupled DM

CaF2(pure) as light guide & active shield against PMT

CaF2(Eu) is not transparent for U.V. light.

DM signalsselected by role off ratio

Measurement 　 of 48Ca at Oto

48Ca double beta decay

10 -1

1

10

10 2

10 3

2000 3000 4000 5000

Energy (keV)

no events in 0 window

(Q0=4.27 MeV)

T1/2 > 1.8× 1022 yr (90%C.L.)2(sim)

BG (sim)

0 window

Isotope 48Ca 76Ge 82Se 100Mo 116Cd 136Xe 150Nd

Q-value (MeV) 4.27 2.04 3.00 3.03 2.80 2.48 3.37

G0v×10-25 (year-1eV-2) 2.44 0.244 1.08 1.75 1.89 1.81 8.00

yCLOgawa 　 et al., PANIC02, Nucl.Phys.2003 　

　　 ELEGANTELEGANT 　　 VIVI 　　 CaFCaF2219F 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’sResults of ELEGANT’s Double beta decays EL III . Ge with NaI for of 76Ge : Limit of 1.9 eV (68% CL) on

m and 1st stringent limit on 0 to 2+ state. EL IV. 100Mo with Si detector array and Nal. EL V. Drift chamber for tracks , plastic scintillators for and NaI for st 2 lives for 100Mo and 116Cd. Most stringent limits on o100meV(68% CL). EL VI. Ca(F)2 Crystals with CsI. Limit on 0 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

V. Future ExperimentsV. 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 ExperimentsV. Future Experiments IIMOON.MOON.

MMolybdenumolybdenum O Observatory bservatory OOff N Neutrinoseutrinos for for http://http://ewiewi..nplnpl..washingtonwashington..eduedu..

. and low energysolar 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 ObjectivesMOON Objectives . . studies in 100Mo : 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 100Mo & scintillators with modest volume and realistic purity.

H.Ejiri,, Phys, Rev. Lett.,85 (2000) 2917

MOON Hybrid DetectorMOON Hybrid Detector

o film

Super modules of fiber-plate scintillators with 100Mo films.

1. Position read-out Fibers (x-y) m - 2 mm - 0.4 mm 2. Energy read-out Plate scintillator with E ~ ~ 2 % 3. Modest volume with enriched Mo 4. Enriched Mo 85 % in 100Mo

Centrifuges MoF6 gas Laser

MOON 1. Proto type 100Mo 1 kg. M ~0.3 eV

MOON 2. 1 unit : 100Mo 0.25 ton 2m – 2m – 1.7 m, M ~0.05 eV

MOON 3. 4 units: 100Mo 1 ton. 2m – 2m -- 7 m, M ~0.02eV

Fiber x

EL VI ---CANDLES 48Ca for large Q 4.27 MeV, small 0.19%

48Ca 7.7 g (EL VI) to O(10kg) & Enrichmentof 1l crystals of CaF2 in iiquid scintillator 3.1 kg of 48Ca in 3.2 ton nCaF2

Goal 0.1 eV sensitivity.

R & D Osaka Univ.Physics.

Future ExperimentsFuture Experiments II CANDLES

VII. Progress & Grants VII. Progress & Grants

I. ELEGANTs at Kamoka 1982--1994 1981 Start and 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

Oto Underground Lab.Oto Underground Lab. 1994 New underground lab. & 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.

ReferencesReferencesNuclear responses for neutrinos. Review H.Ejiri, Phys. Rep. 338 (2000) 265. GR and , solar & sn ’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. L VH.Ejiri, N.Kudomi, et al., Phys. Rev. C 63 (2001) 65501 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) 2917Supernova H.Ejiri, J.Engel, N.Kudomi, PL B530 (2002) 27http://www.rcnp.osak-u.ac.jp/~ejiri/PUB.html

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 attensionThank 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.