MOONDouble beta decays for neutrinos and dark matter

Hiro Ejiri Osaka /JASRI /ICU

I. Neutrino studies by and

II. MOON detector and MOON 1 　 for

III. Dark matter WIMP’s by MOON

IV. Comcluding remarks.

　　　

Erice 05 Sep. 2005. Neutrinos in cosmology and astro particle nucl. Phys.

I. Neutrino studies by 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 decays in nuclei, where -exchange between 2 n is enhanced by 107, and BG single is forbidden, are used to study the nature and the absolute mass

. • 3. Inverse decays by astro-’s are used to study low-enrgy astro-’s.

nuclear responses 　　 are crucial for study in nuclei.

• H. Ejiri, studies in nuclei. Phys. Rep. 338 2000 265

Neutrino studies by decaysA. Faessler abd F. Simcovic J. Phys. G24 98 2139S.R.Elliott and P. Vogel Ann Rev. Nucl. Part. Sci. 52 02 115

H. Ejiri, Invited Review and JPSJ 74, 2101, Aug.05 .

2 L=0 T = G |M|2 M=M() 0L=2 T = G0n |M|2 |<m>| 2 RHC, SUSY, Majoron, Majorana effective mass <m> = ki exp(i i) mi is expressed by using ki ms, ma given by oscillations

& masses

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 = sin13 is crucial for NH.

2

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

MOON objectives and Unique features

A. decay spectroscopy with m~30 meV.

B. Charged current 7Be solar e flux within 10%. 　

•

• 1. Large Q = 3.034 MeV leads to the large phase space and large signals well above most RI BG .• 2. Excited 0+ by , less BG’s of , RI.

• 3. angular correlations to identify the m term .

• 4. Localization in space and time to select signals and reject BG

• 5. Multi-use with other nuclei as 82Se, 150Nd etc and solar• MOON : Mo Observatory Of Neutrinos can be Multi-use Observatory Of .

H.Ejiri, H.Robertson, et al. PRL, 85, 2917; H.Ejiri, J. Engel, et al., PL B 530, 27

100Mo: Large Q value, large phase volume G, and large transition rate T.

Ground and excited 0+ states in 76Ge, 82Se, 100Mo, and 136Xe QRPA matrix elements by Simkovic et al ‘04

MOON sensitivity

Signal T = SN m2 : SN ~ 1.3 10 -24 / (eV)2 with M0 ~3,

Y with signal efficiency of 0.3 is 6 per ton year for 50 meV 2 peak requires Y0 > 2 (BG)1/2, BG = Y2 ~ 8 t y ( / 3%)6

1

10

100

1000

0.01 0.1 1 10 100 isotopes ton*year

Energy resolution=3%(FWHM7 %) = 2,3 %

5 t y with= 3% (FWHM7 %) gives 35 meV= 2,3 %(FWHM 5 %) 19 meV

for excited 0+ depend on 0 mechanisms,　 light , heavy , SUSY. Simkovic, Faessler et al.

Good exp. with good M ratios for the g & excited 0+clarifies the process.

T = SN m2

Unique features for solar • 1. Large CC rates with　 low Eth

• 2. GS: pp- and 7Be-, • B(GT) from EC.

• 3. Real time studies of CC• 4. The two (charged particles)• coincidence to localize signals • in space & time to cut RI,

BG.

.

II. MOON detector and MOON 1

spectrum for 10 t y 100Mo with ~3% eV

0.05 eV

III. MOON R&D Key elements for IH-L 25 meV

1/m = k M (NBG)1/4

A. M nuclear matrix element ? B. Signal rate ? 100Mo N~ 0.5 -1 ton ?

C. BG per Mo ton 1. BG in= 2 / E-resolution ? BG ~ [10 / ton year ] (/ 3%)6

2. BG in solar is accidental Position resolution order of 10-9 ton =

mg

3. RI-BG rates: RI impurity ? Modest 10 m Bq/ton leads to negligible RI-BG

MOON signal selection and RI-BG rejection by 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 -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 BG’s, • which are associated with rays.• B. SSTC :Signal Selection by Tim Correlation rejects most BG’s , • which are associated with pre- and/or post decay.

s

T

• SSTC Signal Selection by Time Correlation

• B

• S Single site for

• 2 sites within 30 sec for solar followed by

• • Time correlated pre- and post decay signals, B’ and B’’. • Time window T ’ < < 　 event 　 interval / unit cell detector:

• H.Ejiri, Czechoslovak Journal Physics 54 (2004) Suppl. MEDEX Proc.

•

Time coordinate T T’

T’

B’

B

B’’

’”

MOON detector concept

o film

Scintillator plate 6 mm

Fiber XY

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 ~ 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 film 　 UW. 　 Ionizations and lights give better E resolutin

Fiber XY plane

One module

MOON Plastic fiber-Mo Ensemble

Scintilation 　　 Fiber

Mo 0.02g/cm2 2 sets of x- y fiber planes Mo(20mg)

Plate scintillator

R&D 　 C. BG rate / E resolution C1. BG(2)/t y ~ 10 (/3 %)6

Goal : Energy Resolution ~ 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)

207Bi 1048 keV

207Bi 976 keV8.9%(FWHM)

ADC-Channel

Cou

nts

/Tim

e•Measured values are •Np=10K photons / MeV,•QE =24% photo-electron efficiency,•T = 78% photon collection efficiency, •Ne= 1830 photo-electrons / MeV. • Statistical = 2.3 % . Non-stat. = 3 %

•Over-all = 3.8 %(FWHM8.9 %)@975keV =3.6 % @ 1=1.5 MeV if non-stat remains constant 3 %= 2.5 % ( FWHM 6 %) @ 3 MeV 1.3 % stat. and 2 % non-stat.

•

CI Test of medium size PL with 0.53 m 0.53m 0.01 m.

Left/right photon yield ratio gives position. 2.5 % / 20 cm can be corrected with 2 cm

Medium PL (0.53 m 0.53 m 0.01 m) with 32 Hamamatsu 60 mm sq. R6236-01 PM

N=10 K / MeV, T = 65 %, QE=30 %. ~ 3% (FWHM 7% ） @ 3MeV with ~1.35 % stat., ~2.7% non-stat.

2 % is realistic with 1.35 % stat., 1.5 % non-stat.

~ 4.5 % (FWHM 11%) @1MeV

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 53×53×1cm3　Mo-Foil　 160g @20mg/cm2×2

Side View

2-PL Energy sum spectrum

Test run 0 countper 0.5 kg keV year　

Oto Cosmo Observatory

Unused tunnel 140

0 m we

Cosmic

4 10-3 /m2/s Neutron

4 10-1/m2/s Rn

10 Bq/m3

Lab.II Lab.INishiyoshino

Oto

ToOsaka

ELEGANT VI Double beta decays of 48Ca and dark matter

ELEGANT VDouble beta decays of

100Mo and dark matter

60 km south of Osaka, near Int. Airport

Double layer hit event :

• Event selection• Signals from PL3 and PL 4

• No signals from other PL’s

• No signals from NaI.

ROI (Region Of Interest)

keV

At the ROI of 2.7-3.2MeV, 60 gr 1

00Mo 0 counts for 11 days.

PMT3PMT4

PMT6PMT5

PMT2PMT1

Selectedlayer

coun

ts/5

0keV

/ye

ar

Each PMT combination isPMT1,6<200keV, PMT2,5>200keV, PMT3,4>500keV

0 / 500 keV / 60 gr / 11 days ~ 0 / keV / kg / year H. Nakamura et al.,

Nuclear matrix element T1/2 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 QRPA E:Suhonen02 QRPA F:Faessler98 RQRPA

Nuclear response M2n for LSD (Low-lying State Dominance)

H. EjiriPR 338 02

low-lying matrix elements with effective gA derived from exps.

Frekers ; Charge exchange reactions

SSS

H.Ejiri, PR 338, 265, JPSJ 65 ’96 7.

GR cancels because G GR cancels because G includes S with + sign and includes S with + sign and S includes G with - signS includes G with - sign

Nuclear Responses (M0) for H. Ejiri, PR 338 263

• Single (3He,t, t,3He)　 and double CE ( 11B, 11Li) at RCNP

Charge exchange reactions with medium energy hadrons.

RCNP　Osaka Univ. 　High E-resolution analyzer 　E ~ 50 keV for 0.5 GeV : 10-4

-responses for low lying state

Double charge exchange spin-flip reaction (11B, 11Li) ~ () K. Takahisa, H.Ejiri, et al

RCNP 0.76 GeV 13C(11B, 11Li) 13O

Photons : Neutral & charged weak currents

z=6,6

z=5,5

,Tz=5,4

z=4,4

S

+ A = A’ for + A = + A’, <f |g M| i> = g /e <f | em | i> = g/e (2T)1/2 <IAS | em | i>

H. Ejiri, PRL 21 ’68, H. Ejiri, PR 38 ‘78

T,Tz = 6,6

LEPS Laser Electron Photon Sources give pol. GeV-MeV for E/M.HIGS High Intensity Source (Duke) 2~5 MeV by 0.3 ~ 4 GeV eSpring-8 Multi-GeV-MeV from 8-1.5 GeV electrons.

R&D B. Enriched 100Mo 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.

Production rate of Мо100

0

20

40

60

80

100

120

10 20 30 40 50 60 70 80 90 100 110 120

number of stages (separators)iz

otop

e ou

tput

(%)

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

prod

uctio

n ra

te o

f one

sep

arat

or (g

/day

)

III. Dark matter WIMP’s search by

MOON (Multi-module Observatory Of Neutralinos)

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. (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.• • MOON Multi-Modular Observatory Of Neutrinos • Multi-layer NaI plates with ~300 m in thickness.• A. Nuclear inelastic . • B. Atomic electrons & X-rays with nuclear recoils

•

A. Nuclear inelastic . 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 E=57 keV in case of 127I. 3. Incoherent and thus smaller cross-section. Spin-coupled DM

Muliti-layers of thin NaI plate modulesK. Fushimi et al Tokushima Osaka

• NaI 500 m x 50 mm x 5 mm • LG 500 m 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 efficiency at n+1 th NaI when recoil at n th NaI

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.

Concluding　 Remarks

. 1. Nuclear matrix elements are checked/adjusted by 1+, 2-, etc strengths by (3He,t) and (d,2He), and (IAS, )

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 2.5~3 % to separate 0 peak from 2 tail. 4. RI impurity simulations with NEMO data are promising. 5. MOON 1 , MOON proto-type at Oto lab. proves overall MOO

N sensitivity ( resolution & BG). Liq. Ar in UW. 6. MOON with external 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.

Concluding　 Remarks

MOON for m ~ 25 meV and 7Be ’s with different isotope and different method (spectroscopic) is interesting and realistic.

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

NNR05 WorkshopNeutrino Nuclear Responses in and Low-energy Astro-’s

II. Date and placeDec. 2-4, 2005.

CAST (Center for Advanced Science and Technology) andJASRI (Japan Synchrotron Radiation Research Institute) SPring-8

120 km west of Osaka Univ. and 120 km west of Kansai air-port.

1. Nuclear responses for 2. Charge exchange reactions for ’s

3. Astro nuclear interactions4. Nuclear EM and weak probes for nuclear responses.

5. DM and Related subjects.

http://www.spring8.or.jp/e/conference/appeal/nnr05/ ,

Thank you for attentionWelcome to MOON to give rise to