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MOON Double beta decays for neutrinos and dark matter Hiro Ejiri Osaka /JASRI /ICU

MOON Double beta decays for neutrinos and dark matter Hiro Ejiri Osaka /JASRI /ICU I. Neutrino studies by bb and MOON II. MOON detector and MOON 1 for bb III. Dark matter WIMP’s by MOON IV. Comcluding remarks.

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MOON Double beta decays for neutrinos and dark matter Hiro Ejiri Osaka /JASRI /ICU

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  1. MOON Double beta decays for neutrinos and dark matter Hiro Ejiri Osaka /JASRI /ICU I. Neutrino studies by bb and MOON II. MOON detector and MOON 1for bb III. Dark matter WIMP’s by MOON IV. Comcluding remarks. Erice 05 Sep. 2005. Neutrinos in cosmology and astro particle nucl. Phys.

  2. Neutrino studies by bb and MOON Neutrino study in nuclear micro laboratories • 1. Nuclei , being consist of nucleons in quantum states, are • excellent micro-laboratories to study fundamental particles & interactions. • 2. bb decays in nuclei, where n-exchange between 2 n is enhanced by 107, and • BG single b is forbidden, are used to study the n nature and the absolute mass . • 3. Inverse b decays by astro-n’s are used to study low-enrgy astro-n’s. n nuclear responses are crucial for n study in nuclei. • H. Ejiri, n studies in nuclei. Phys. Rep. 338 2000 265 n bb

  3. Neutrino studies by bb decaysA. Faessler abd F. Simcovic J. Phys. G24 98 2139S.R.Elliott and P. Vogel Ann Rev. Nucl. Part. Sci. 52 02 115H. Ejiri, Invited Review bb and n. JPSJ 74, 2101, Aug.05 . 2nbbDL=0 T2n = G2n |M2n|2 M2n =M(tsts) 0nbb DL=2 T0n = G0n |M0n|2 |<m>| 2 RHC, SUSY, Majoron, Majorana effective mass <m> = S ki exp(i fi) mi is expressed by using kidms, dma given by n oscillations

  4. bb & n masses bb exps. With I. 0.1~ 0.2 eV QD, m1 > 0.1 eV II. 20 ~ 30 meV give the mass spectrum and m1 in case of IH • III. 1~ 2 meV give mass spectrum in case of NH and m1 • Note s2 = sin q13 is crucial for NH. 2

  5. Energy and angular correlations of 0nbb raysH. Ejiri, Phys. Rep. 338 2000 265

  6. MOON objectives and Unique features A.bb decay spectroscopy with mn~30 meV. B. Charged current 7Be solar neflux within 10%. • 1. Large Q = 3.034 MeV leads to the large 0nbb phase space and large signals well above most RI BG . • 2. Excited 0+ by g-g , less BG’s of 2nbb, RI. • 3. bb angular correlations to identify the mnterm . • 4. Localization in space and time to select signals and reject BG • 5. Multi-use with other bb nuclei as 82Se, 150Nd etc and solar-n • MOON : Mo Observatory Of Neutrinos can be Multi-use Observatory Of n . H.Ejiri, H.Robertson, et al. PRL, 85, 2917; H.Ejiri, J. Engel, et al., PL B 530, 27

  7. 100Mo: Large Q value, large phase volume G, and large transition rate T. Ground and excited 0+ states in 76Ge, 82Se, 100Mo, and 136XeQRPA matrix elements by Simkovic et al ‘04

  8. MOON sensitivitySignal T = SN mn2 : SN ~ 1.3 10 -24 / (eV)2 with M0n ~3, Y0nwith signal efficiency of 0.3 is 6 per ton year for 50 meV 2s peak requires Y0n > 2 (BG)1/2, BG = Y2n ~ 8 t y (s / 3%)6 Energy resolution s=3%(FWHM7 %) s= 2,3 % 5 t y with s= 3% (FWHM7 %) gives 35 meV s= 2,3 %(FWHM 5 %) 19 meV

  9. M0n for excited 0+ depend on 0nbb mechanisms,light n, heavy n , SUSY.Simkovic, Faessler et al.Good exp. with good M0n ratios for the g & excited 0+clarifies the process. T = SN m2

  10. Unique features for solar n • 1. Large CC rates withlow Eth • 2. GS: pp-n and 7Be-n, • B(GT) from EC. • 3. Real time studies of CC • 4. The two b (charged particles) • coincidence to localize signals • in space & time to cut RI, bb BG. .

  11. II. MOON detector and MOON 1

  12. III. MOON R&D Key elements for IH-L 25 meV bb spectrum for 10 t y 100Mo with s ~3% 1/mn = k M0n (Nbb/BG)1/4 A. M0n nuclear matrix element ? B. Signal rate ? 100Mo Nbb ~ 0.5 -1 ton ? C. BG per Mo ton 1. BG in bb = 2nbb / E-resolution ? BG ~ [10 / ton year ] (s / 3%)6 2. BG in solar n is accidental 2nbb , Position resolution order of 10-9 ton = mg 3. RI-BG rates: RI impurity ? Modest 10 m Bq/ton leads to negligible RI-BG 2nbb 1/100 0nbb 0.05 eV 2.8 3.0 3.2 MeV

  13. MOON signal selection and RI-BG rejectionby localization of signals in 4-dimentional space-time in detector • MOON: multi-layer modules with good position resolution 10-8 are excellent • self-shielded detectors by requiring anti-coincidence with each other. • Tracking detector for two b-ray correlation study. • Option 1. Multi-layer PL scintillators with multi-PM and fiber for positions. • Option 2. Liq. Ar with multi-wires for position read-out. UW • A. SSSC :Signal Selection by Spatial Correlation rejects most b-g BG’s, • which are associated with g rays. • B. SSTC :Signal Selection by Tim Correlation rejects most b-a BG’s , • which are associated with pre- and/or post decay. s b g b b a bb T

  14. B’ B’B B” T B T’ • SSTC Signal Selection by Time Correlation • B • S Single site for bb • 2 sites within 30 sec for solar b followed by b • Time correlated pre- and post decay signals, B’ and B’’. • Time window T ’ < < eventinterval / unit cell detector: • H.Ejiri, Czechoslovak Journal Physics 54 (2004) Suppl. MEDEX Proc. T T’ Time coordinate B’’

  15. MOON detector concept A Supermodule of Mo films and fiber/plate scintillators*. 1. Position read-out by fibers with 4 mm - 0.4 mm 2. Energy read-out by plate scintillators with E resolution s ~ 2.5 % including the Mo film (20 mg / cm2). 3. Modest volume with enriched Mo and modest cost of MPA / PM 4. Enriched 100Mo 0.5~ 1 ton by centrifugal separation of MoF6 gas 5. Detector / 100Mo ratio in a module is ~ 8 mm / 20 mg = 40. One unit:100Mo 0.1 ton is 4 ton PL (XYZ =1.4 m 1.4 m 2m). B.Liq.Ar with Mo filmUW.Ionizations and lights give better E resolutin Fiber XY plane Mo film One module Fiber XY Scintillator plate 6 mm

  16. Scintilation Fiber MOON Plastic fiber-Mo Ensemble Mo 0.02g/cm2 2 sets of x- y fiber planes Mo(20mg) Plate scintillator

  17. R&D C. BG rate / E resolution C1. BG(2nbb)/t y ~ 10 (s/3 %)6 Goal : Energy Resolution s ~ 2-3 %(FWHM ~ 5-7 %) CIA. Test of a small PL with 207Bi conversion electrons PL (0.06 m 0.06 m 0.01 m) Counts/Time 207Bi 976 keV 8.9%(FWHM) 207Bi 1048 keV ADC-Channel • Measured values are • Np=10K photons / MeV, • QE =24% photo-electron efficiency, • T = 78% photon collection efficiency, • Ne= 1830 photo-electrons / MeV. • Statistical s = 2.3 % . Non-stat. s = 3 % • Over-all s = 3.8 %(FWHM8.9 %)@975keV • s =3.6 % @ b1=1.5 MeV • if non-stat remains constant 3 % • s = 2.5 % ( FWHM 6 %) @ 3 MeV • 1.3 % stat. and 2 % non-stat.

  18. CI Test of medium size PL with 0.53 m 0.53m 0.01 m. Medium PL (0.53 m 0.53 m 0.01 m) with 32 Hamamatsu 60 mm sq. R6236-01 PM s ~ 4.5 % (FWHM 11%) @1MeV N=10 K / MeV, T = 65 %, QE=30 %. s ~ 3% (FWHM 7%） @ 3MeV with s ~1.35 % stat., ~2.7% non-stat. 2 % is realistic with 1.35 % stat., 1.5 % non-stat. Left/right photon yield ratio gives position. 2.5 % / 20 cm can be corrected with 2 cm

  19. MOON 1 Proto type MOON in operation since April 2005 Plate sintillator ensemble inside the ELEGANT V Pb-Cu NaI shield • 6-layers of PL 53×53×1cm3Mo-Foil160g @20mg/cm2×2 2-PL Energy sum spectrum Test run 0 count per 0.5 kg keV year Side View

  20. 60 km south of Osaka, near Int. Airport Oto Cosmo Observatory Oto Nishiyoshino Lab.II Lab.I To Osaka Unused tunnel 1400 m we Cosmic m 4 10-3 /m2/s Neutron 4 10-1/m2/s Rn 10 Bq/m3 ELEGANT VI Double beta decays of 48Ca and dark matter ELEGANT V Double beta decays of 100Mo and dark matter

  21. Event selection Signals from PL3 and PL 4 No signals from other PL’s No signals from NaI. ROI (Region Of Interest) Double layer hit event : bb counts/50keV/year At the ROI of 2.7-3.2MeV, 60 gr 100Mo 0 counts for 11 days. PMT1 PMT2 PMT3 Selected layer keV PMT4 PMT5 PMT6 0 / 500 keV / 60 gr / 11 days ~ 0 / keV / kg / year H. Nakamura et al., Each PMT combination is PMT1,6<200keV, PMT2,5>200keV, PMT3,4>500keV

  22. Nuclear matrix elementT1/2 y m(BC) eV m(DEF) eV MOON 1.6 1027 0.015-0.018 0.043-0.047 B:Rodin-03 QRPA,C:Rodin-03 RQRPA, D:Simkovis01 QRPAE:Suhonen02 QRPA F:Faessler98 RQRPA

  23. Nuclear response M2n for 2nbb.LSD (Low-lying State Dominance) H.Ejiri, PR 338, 265, JPSJ 65 ’96 7. H. EjiriPR 338 02 GR cancels because G includes S with + sign and S includes G with - sign M2n ~ S M S(+) M S(+) / DS low-lying matrix elements with effective gA derived from exps. Frekers ; Charge exchange reactions

  24. Nuclear Responses (M0n) for 0nbb H. Ejiri, PR 338 263 • Single (3He,t, t,3He)and double CE ( 11B, 11Li) at RCNP

  25. Charge exchange reactions with medium energy hadrons. RCNPOsaka Univ. High E-resolution analyzer DE ~ 50 keV for 0.5 GeV : 10-4 n-responses for low lying state

  26. Double charge exchangespin-flip reaction (11B, 11Li) ~ (p+, p-)K. Takahisa, H.Ejiri, et alRCNP 0.76 GeV 13C(11B, 11Li) 13O

  27. Photons : Neutral & charged weak currents g + A = A’ for n + A = n + A’, <f |g Mb| i> = g /e <f | emg | i> = g/e (2T)1/2 <IAS | emg | i> LEPS Laser Electron Photon Sources give pol. GeV-MeV g for E/M. HIGS High Intensity g Source (Duke) 2~5 MeV g by 0.3 ~ 4 GeV e Spring-8 Multi-GeV-MeV from 8-1.5 GeV electrons. T,Tz=5,4 T_=IAS T,Tz=5,5 g T,Tz=6,6 b T,Tz = 6,6 bb T,Tz=4,4 H. Ejiri, PRL 21 ’68, H. Ejiri, PR 38 ‘78

  28. R&D B. Enriched100Mo isotopes • VNIIEF is ready to produce 1 Kg immediately, and 0.1 t / y soon. • Rate 0.5 t 100Mo(90 %) / 5 y with 6 K centrifuges and 40 processes.

  29. III. Dark matter WIMP’s search by MOON (Multi-module Observatory Of Neutralinos)

  30. Dark matter WIMP’s (Neutralinos) detection • Dark energy 65%, DM 30 %, baryonic matter 5 %. • DM : mainly of cold DM WIMP’s : LSP Lightest SUSY Particle. • Detection of WIMP’s is extremely hard. • Cross sections – fluxes (event rates) are small. s(coherent) = A2 • Energy signals of recoil nuclei are low and smooth as BG/noise. • Recoil E ~ 50-100 keV. Detected E ~ 2-5 KeV with quenching. • Annular modulation of E-spectra : • Small ( % order) and subject to annular BG modulation. • MOONMulti-Modular Observatory Of Neutrinos • Multi-layer NaI plates with ~300 mm in thickness. • A. Nuclear inelastic g. • B. Atomic electrons & X-rays with nuclear recoils

  31. A. Nuclear inelastic g.H.Ejiri, K. Fushimi, H. Ohsumi, Phys. Lette. B317 1993 14 J.D. Vergados, P. Quentin, D. Strottmann, hep-ph/041151.1. Larger signals~ 50 keV than quenched recoil signals 2. Sharp peak at Eg=57 keV in case of 127I. 3. Incoherent and thus smaller cross-section. Spin-coupled DM

  32. Muliti-layers of thin NaI plate modulesK. Fushimi et al Tokushima Osaka • NaI 500 mm x 50 mm x 5 mm • LG 500 mm x 60 mm x 60 mm • ESR reflector • 16 modules (phase 1 present) • 256 modules (phase 2) • Sensitivity ~ 1 GeV /cc • one order improvement. 57 keV g efficiency at n+1 th NaI when recoil at n th NaI

  33. K and L X-rays from LSP-nuclear interaction H. Ejiri, Ch. C. Moustakidis, J.D. Vergados, 2005. Ch. C. Moustakidis, J.D. Vergados, H. Ejiri, Nucl. Phys. 2005, hep-ph/0507123 J.D. Vergados and H. Ejiri, PL B606 (2005) 305. 1. Large number of inner-shell holes/X-rays, K:0.2 and L:5 for Xe /I isotopes.2. Large flight pass, K: 0.1 gr, L: 0.01 gr.3. Coincidence measurements of X-rays and nuclear recoils.

  34. ConcludingRemarks

  35. ConcludingRemarks MOON for mn ~ 25 meV and 7Be n’s with different isotope and different method (spectroscopic) is interesting and realistic. . 1. Nuclear matrix elements are checked/adjusted by 1+, 2-, etc strengths by (3He,t) and (d,2He), and (IAS, g) 2. 100Mo of 0.5 -1 ton can be obtained with 6K centrifuges of MoF6 3. PL’s data have shown A: the photo-electrons of 2 K/ MeV, and E-resolution of s=2.5~3 % to separate 0nbb peak from 2nbb tail. 4. RI impurity simulations with NEMO data are promising. 5. MOON 1 , MOON proto-type at Oto lab. proves overall MOON sensitivity ( resolution & BG). Liq. Ar in UW. 6. MOON with external bb source can be used for Se, Nd, and others. • One MOON-type multi-use detector should be build. • B. MOON (Multi-layer Observatory Of Neutralinos) is used to WIMP’s/LSP by exclusive measurements of X-rays following WIMP’s nuclear scatterings.

  36. MOON collaboration • P.J.Doe, R.G.H.Robertson*, D.E.Vilches, J.F.Wilkerson、D. I. Will. CENPA, Univ. Washington. • H.Ejiri*, R. Hazama, K.Ichihara, Y.Ikegami, H. Ishii, T.Itahashi N.Kudomi, K.Matsuoka, H. Nakamura, M.Nomachi+,T. Ogama, T. Shima, Y.Sugaya, S.Yoshida. • RCNP, and Physics OULNS, Osaka Univ. • S.R.Elliott, LANL • J.Engel. Phys.Astronomy, Univ. North Carolina. • M.Finger, and K. Kuroda, Phys. Charles Univ.Prague • K.Fushimi, K. Ichihara, GAS, Tokushima Univ.Tokushima • M. Greenfield, ICU, Tokyo. • A.Gorin, I.Manouilov, A.Rjazantsev.High Energy Physics, Protvino. • A. Para FNAL • A. Sissakian, V. Kekelidze, V. Voronon, G. Shirkov A. Titov, JINR • V. Vatulin, V. Kutsalo, VNIIEF • * Contact persons, + Osaka MOOM1 group head MOON 1 students

  37. NNR05 Workshop Neutrino Nuclear Responses inbb and Low-energy Astro-n’sII. Date and placeDec. 2-4, 2005.CAST (Center for Advanced Science and Technology) andJASRI (Japan Synchrotron Radiation Research Institute) SPring-8120 km west of Osaka Univ. and 120 km west of Kansai air-port. 1. Nuclear responses for bb-n 2. Charge exchange reactions for bb-n’s 3. Astro n nuclear interactions 4. Nuclear EM and weak probes for n nuclear responses. 5. DM and Related subjects. http://www.spring8.or.jp/e/conference/appeal/nnr05/ ,

  38. Thank you for attention Welcome to MOON to give rise to

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