Oto Cosmo Observatory Present and Future Hiro Ejiri
Oto Cosmo Observatory Present and Future Hiro Ejiri RCNP Osaka Univ. , & JASRI Spring 8 For the ELEGANT Collaboration 1. Oto Cosmo Observatory 2. Detectors and Physics Results 3. Future Plans 4. Progress of Oto Lab.
RCNP Ring Cycrotron lab. 0. 4 -0. 5 Ge. V p, & light ions Research Center for Nuclear Physics National Nuclear Physics Lab. Nucleon, Meson, and Quark Lepton Nuclear Physics. RCNP laboratory complex National and International users
RCNP & Physics Osaka Univ. Neutrinos and DM research programs. l l l l 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.
Oto Lab. is close to Osaka Univ. 100 km Kansai/Osaka Airport 40 km SK Osaka Univ. Air port Oto
Oto Cosmo Observatory Unused 5 km railway tunnel. 1400 m we 60 km south of Osaka, near Int. Airport Oto Nishiyoshino Lab. I, lab. III Lab. I, III To Osaka 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/ np 1 -c/index. html Lab. II. 45 m 2 ELEGANT V, bb of 100 Mo and DM with Na. I Lab. I. 33 m 2 ELEGANT VI bb of 48 Ca and DM with Ca. F 2
Experimental Roon I
Muon flux at underground labs. in the world m 4 10 -3 /m 2/s Neutron 4 10 -1/m 2/s Rn 10 Bq/m 3 (Detector container 10 m Bq /m 3) Oto Cosmo Observatory 1400 m w. e
l l III. ELEGANT V ELEctron GAmma-ray Neutrino Telescope
ELEGANT V H. Ejiri et al. NIM A 302 1991 304 bb of 100 Mo, 116 Cd bb-ray E&T PL g-ray by Na. I DM –nucleus recoil E by Na. I l.
100 Mo 0 nbb by ELEGANT V l 100 M 0 95% enriched. 0. 17 kg. l Most stringent limit by exclusive(bb tracking) l l l T 0 n > 1. 0 (0. 55) 1023 y 68(90)%CL <mn> < 1. 5 (2. 1) e. V l <g. B> < 9 (11) 10 -5 l H. Ejiri, N. Kudomi, et al. , Phys. Rev. C 63 ’ 01, 65501
Present
ELEGANT VI Ca. F 2 for 48 Ca bb and 19 F Spin Coupled DM
ELEGANT IV Ca. F 2 for 48 Ca bb and 19 F Spin Coupled DM Ca. F 2(pure) as light guide & active shield against PMT Ca. F 2(Eu) is not transparent for U. V. light. bb & DM signals selected by role off ratio
Measurement of 48 Ca bb at Oto Isotope 48 Ca 76 Ge 82 Se 100 Mo 116 Cd 136 Xe 150 Nd Q-value (Me. V) 4. 27 2. 04 3. 00 3. 03 2. 80 2. 48 3. 37 G 0 v× 10 -25 (year-1 e. V-2) 2. 44 0. 244 1. 08 1. 75 1. 89 1. 81 8. 00 BG (sim) 0 nbb window 2 nbb (sim) T 0 n > 1. 8 1022 y 90 % CL I. Ogawa et al. , PANIC 02, Nucl. Phys. 2003
19 F ELEGANT VI Ca. F 2 light mass and simple large spin matrix element I. Ogawa, et al. Nucl. Phys. 663(2000) 869 c R. Hazama, NIM A 482 (2002) 297
Results of ELEGANT’s Double beta decays EL III. Ge with Na. I for bb of 76 Ge : Limit of 1. 9 e. V (68% CL) on mn and 1 st stringent limit on 0 nbb to 2+ state. EL IV. 100 Mo with Si detector array and Nal. EL V. Drift chamber for bb tracks , plastic scintillators for bb and Na. I for g. 1 st 2 nbb lives for 100 Mo and 116 Cd. Most stringent limits on onbb 100 Mo mn < 1. 5 e. V(68% CL). EL VI. Ca(F)2 Crystals with Cs. I. Limit on 0 nbb of 48 Ca: 7 e. V Dark matter EL V. Na. I 760 kg , annular modulation of WIMPS. Most stringent limits at the low mass region. EL VI. Ca(F)2 Spin-coupled WIMPS. l http: //www. rcnp. osak-u. ac. jp/~ejiri/PUB. html
V. Future Experiments l l l l 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
V. Future Experiments I MOON. Molybdenum Observatory Of Neutrinos for http: //ewi. npl. washington. edu. l. bb-n, and low energy solar and supernova n’s. l MOON collaboration : Interenational collaboration l 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 l l l l
MOON Objectives . n studies in 100 Mo : large responses for bb-n & low E ne’s. Double beta (bb) decays l with mn~0. 03 e. V. l Low E solar and SN ne. l Two charged particle (b, b) l spectroscopy with high l localization in time & space. l MOON, a super module of l ~1 ton 100 Mo & scintillators with modest volume and realistic purity l H. Ejiri, , Phys, Rev. Lett. , 85 (2000) 2917
MOON Hybrid Detector Super modules of fiber-plate scintillators with 100 Mo films. 1. Position read-out Fibers (x-y) 2 m - 2 mm - 0. 4 mm 2. Energy read-out Plate scintillator with DE ~ s ~ 2 % Mo film 3. Modest volume with enriched Mo 4. Enriched Mo 85 % in 100 Mo Centrifuges Mo. F 6 gas Laser Fiber x MOON 1. Proto type 100 Mo 1 kg. Mn ~0. 3 e. V MOON 2. 1 unit : 100 Mo 0. 25 ton 2 m – 1. 7 m, MOON 3. 4 units: 100 Mo 1 ton. 2 m – 2 m -- 7 m, Mn ~0. 05 e. V Mn ~0. 02 e. V
Future Experiments II l. EL VI ---CANDLES 48 Ca for bb large Q = bb 4. 27 Me. V, small 0. 19% Ca 7. 7 g (EL VI) to l O(10 kg) & Enrichment 1 K of 1 l crystals of Ca. F 2 in iiquid scintillator 3. 1 kg of 48 Ca in 3. 2 ton n. Ca. F 2 Goal 0. 1 e. V sensitivity. l 48 R & D Osaka Univ. Physics. CANDLES
VII. Progress & Grants l I. ELEGANTs at Kamoka 1982 --1994 l 1981 Start bb and n project at Osaka 1981 -1982 ELEGANT I, II, Ge with Na. I at Osaka 1982 – 1984 ELEGANT III. Ge wih Na. I 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 & Na. I Grant Special Project 1990 – EL V Starts run. 1993 – 1995 EL VI Ca. F 2 with Cs. I Construction Grant Basic Research l l l l l
Oto Underground Lab. l l l l 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 l 2000 MOON project, MOON R&D Yamada award 2001, l 2003 MOON 1 Proto-type Government Grant A. l CANDLES 2002 R&D and Government Grant A. l
References Nuclear responses for neutrinos. Review H. Ejiri, Phys. Rep. 338 (2000) 265. GR and bb, solar & sn n’s H. Ejiri, Nucl. Phys. A 687 (2001) 350 c LI reactions. 3 He H. Ejiri, et al. PLB 433 (1998) 257. 11 B, 11 Li H. Ejiri, K. Takahisa, et al. , 1997, 2001. Double beta decays and neutrinos. bb EL V Review H. Ejiri, N. Kudomi, et al. , Phys. Rev. C 63 (2001) 65501 H. Ejiri, Nucl. Phys. B 91 (2001) 255, v 2000 proc MOON bb and solar n Supernova n H. Ejiri, J. Engel, G. Hazama, P. Krastev, N. Kudomi, R. G. H. Robertson, Phys, Rev. Lett. , 85 (2000) 2917 H. Ejiri, J. Engel, N. Kudomi, PL B 530 (2002) 27
l We would express our cordial thanks to l Oto & Nishiyoshino villages & the chiefs, l Mr T. Kitamura & Mr S．Nakagaki, l for the great and timely support for l construction of the new lab. l. National lthe l tunnel to the two villages to be used for our underground lab. l. Japanese l. Toray, l Railway Corporation for transfer of people for their great contributions. Takeda, and Yamada S. F. for their timely awards/suports.
l. Thank you for attension
Here we would like to express our cordial thanks The distinguished chief of Oto, Mr. Toshihiro. Kitamura for great, timely , & crucial supports for our science proje
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