Double%20Beta%20Decays%20and%20Majorana%20Neutrinos

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Double Beta Decays and Majorana Neutrinos A
brief review of DBD experiments and MOON (Mo
Observatory Of Neutrinos) Hiro Ejiri Thanks
Cristina and Baha for Invitation ECT June
07
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1. Neutrino-less bb decay and Majorana
n-masses 2. DBD experiments, the present and
future. 3. DBD nuclear matrix elements 4. MOON
Mo Observatory Of Neutrinos 5. Concluding
remarks H. Ejiri, J. Phys. Soc. Japan, Invited
Review, 74 (2005) 2101.
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• Neutrino-less bb decays (0nbb) and
• Majorana n-masses

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1.Neutrino-less bb decays
A B b b Lepton number DL2 beyond
SM. .
Part. n physics Majorana n, mn CP

T0n G0n M0n mn2
Nucl. micro-lab. to selectively enhance .
n-exchange
Cosmology DM Leptogenesis
Nucl. physics. pp,ph, tensor interactions t s
correlation
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0nbb and effective Majorana n mass 0nbb is the
sensitive and realistic probe for studying
Majoranan-mass suggested by n oscillation

• .

m3 m2 m1
ne nm nt
m2 m1 m3
DmS 9 meV
DmA 45meV
ne nm nt
NH IH
Absolute mass scale
T0n G0n M0n2 ltmgt 2 Effective Majorana mass
lt mngt S ki exp(i fi) mi is given by using
ki DmS, DmA from by n oscillation.
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• Effective masses

KKDC 440meV
NEMO3 CUORITINO Phase 1 100-150 meV QD Phase
2 100-50 meV QD-IH Phase 3 50-30 meV
IH New Phase 4-2 meV
QD Cosmo. Sm lt 680 meV Single b
200 meV
(q13)2 mA 1.125 for sin 22q13 0.1
Phase /- 2 IH/NH 10 mn k/M0n M0n
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Leptogenesis
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0nbb by RHC, Heavy n, SUSY, and others
A0n LHC RHC ltmgt
SUSY ltlgt k(ML/MR)2 LHC / RHC
Q21 and E12 correlations

LHC m / SUSY mn M0n kMS different
isotopes different M
A2nGM2n AM ltgMgt M Energy
spectra 4,3,2 body

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2. DBD experiments, the present and future
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0nbb status
CUORITINO 130Te Tgt3.0 1024 y
mlt0.2 1 eV
NEMOIII 100Mo gt4.6 1023 y lt0.66 2.81 eV
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Mass sensitivities and nuclear sensitivity ltmngt
13 meV (0.01 A/SN)1/2 (e0n N)-1/2 d1/2 SN GM
2 M3 except M3/2 for Nd
d 2.3 1.5 (BN)1/2 B/t y N ton
BB(RI) 4.2(e2n/t2n1/2) (100/A), e2n 10-7
and t2n1/2 1020
Isotope (0.01 A/SN)1/2 Exp.
76Ge 2.25 GERDA/Majorana
82Se 100Mo 1.10 0.95 MOON MOON
130Te 1.05 CUORE
136Xe 1.15 EXO
150Nd 1.15 S-NEMO
IH mass of 30 meV if e0n N 1, (0.01 A/SN)1/2
1, d 4.
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Signal of 0nbb and RI BG schematic spectra
Calorimetric. 76Ge low Q, low Y0n, high RI-BG,
Sharp-peak
Spectroscopic MOON high Q, high Y0n, low RI,
Broad-peak
KKDC
Resolution
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Future experiments for QD-IH
Transition amplitude A(0nbb) mn SN
SD SN G1/2 M0n Qbb5/2 Nucl.
Sensitivity Large M 0n Qbb SD Nbb /
NBG1/4 Detector Sensitivity Nbb ton NBG 1/t y
Detector not bb source,
one multi-purpose detector
SNO
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Calorimetric detector Detector bb source
High resolution/efficiency, low Qbb, BGRI76Ge


MAJORANA
nbb 0.0180.04 t, 2008 - 2010 nbb
0.06/0.12 t 0.5 t B 50 - 5 /t y
B 1/ t y PSD.
Segmentation, SSTC. Purification.
Joint work for 1 ton B1/t y exps.
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48Ca (CANDLES)
Signal rate A 0.2 laser ton scale BG
2nbb 150Nd (SNO Q 3.368 50 meV 1k ton
detector with 0.1 of 56 enriched 150Nd
Prof.E.Fiorini B 200 20 / t y 24120 1466
meV
500 Xal, 100 kg 2007 construction
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COBRA
K. Zuber, Phys. Lett. B 519,1 (2001)
Use large amount of CdZnTe Semiconductor
Detectors
4x4x4 array at LNGS in 2006, 0.5 kg . 64K
crystals may reach 50 meV if BG 1/t/y
Array of 1cm3 CdZnTe detectors
Major isotopes of interest 64Zn,106Cd 116Cd,
130Te
Currently about 20 people (UK, Germany, Italy)
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EXO for 136Xe
EXO
LXe TPC Laser tagging 136Ba,
200 kg 136Xe TPC
M(RQRPA) 1.02
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• Spectroscopic detectors
• ELEGANT- MOON, DCBA
• NEMOIII - Super NEMO
• 1. E12-Q12 identify mn term
• 2. Detector ? source
• Select bb nuclide by
• Qbb, Z, Enrichment, 2nbb
• 3. Small RI-BG E(RI) lt Qbb
• b/a,g separation
• Major BG 2nbb tail in onbb window.
  E-resolution !

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DCBA Drift Chamber Beta ray Analyzer N. Ishihara

Points E-resolution Large volume DCBA-T3
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Spectroscopy DBD E12-Q12 Detector
? source
SuperNEMO 14 m 14m 14m 3Km3 5kg
20module 0.1 t
MOON 4-units, 0.1 t 2.6 m 2.6m 4m 30 m3
Detector modules V
m3/t MOON Multi-layer 100 0.3
K S-NEMO Single 20
30 K
factor 100
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Neutrino mass ltmgt in meV with 90 CL
for M0n 3
meV
76Ge B 1/t y 82Se s1.3 100Mo s 1.3
130Te B 20/ty 150Nd s 1.3
QD IH
N ton year
IH MOON (Se 2 ty Mo-Nd 4 ty) , CUORE(3 ty),
Majorana 8 ty QD CUORE (0.1 ty), MOON(0.2
ty), Majorana (0.4 ty)
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Normal hierarchy NH with 2-4 meV Bltlt1
100Mo 82Se 76Ge
NH
Y0n 1 for 0nbb, M4, e0n 0.15 for Se
and 0.85 for Ge A 82Se 5 t - 10 y
BG(2nbb) 0.5 for s 1.3 E cut.
Bi 0.004 / t y with 1.25 m Bq / t
and good position R. B. 76Ge 20 t - 10 y
BG ltlt 0.003, BG 1 / t y at present
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3 . Nuclear matrix elements
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Nuclear matrix element

• .
• mn A
  3/M0n B/nbb1/4 5/T ¼ in case of Bgtgt1
  
• M0n is crucial for extracting mn , for
  designing exps.
• M0n is smaller by a factor 2, need 10 times
  more nbb .
• Sensitive to nuclear structures, effective gA
  short-range force,
• higher-shell, isobars, pions, deformations,
  interactions.
• QRPA, RQRPA, Shell model
• Experimental inputs to help/check theoretical
  calculations.
• H.Ejiri, P R 338 00 NIM 503 03
• CER (Charge exchange reactions) ts
  Akimune,Frekers Zegers,
• RCNP (3He, t), (p,n), MSU (t, 3He),
  KVI (d,2He),
• Theory K.Amos OK for (p,n), but not for (n,p)
  radial dep. Transfer U2/V2 Transfer
  reactiona ( Schiffer), b decays.
• EC. TITANEC Triumf, UM/Jyuvaskyla.

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J.Suhonen MEDEX07
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Excited 0 states

• bb-g-g reduce BGs 2nbb, RI.
• Cancellation, but not at both.
• GRS and EXS
• T0n G Mn mn Ms l 2
• Mn M(1) M(Jgt1)

Isotope State 100Mo GRS 100Mo EXS 150Nd GRS 150Nd EXS
Qbb (MeV) 3.034 1.903 3.368 2.113
SN/0.01A 10-24 1.1 0.27 0.76 0.31
ltmgt meV 37-59 57-74 41-66 52-68
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150Nd -- 150Sm deformation
150Nd E(2) 0.13 MeV
Q MeV G0n 150Sm GS 0 E(2) 0.334
MeV 3.36 13.4 0.74 MeV E(2)
0.34 MeV 2.63 3 E0
1.255 MeV E(2) 0.16 MeV 2.11
1.3 E2
M0n due to change of deformation is 1/3? M0n to
the excited, but same deformation is 1
RCNP/MSU 3He,t t, 3He Zergers R
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RCNP Osaka High DE t- s response at low and
high 1 2- statesD. Freckers, R. Zegers,
MSU/RCNP/KVI
Charge exchange reactions
H. Akimune et al., PL B 394 97
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Photon probes
T,Tz5,4
Polarized GeV-MeV photons from laser scattered
off GeV electronsfor electric and magneic
trasitions.
T_IAS
g
T,Tz5,5
T,Tz5,5
T,Tz6,6
b
H. Ejiri PRL 21 68, H. Ejiri PR 38 78
T,Tz6,6
bb
T,Tz4,4
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Neutrino Weak probes
C.Volpe
p Hg ? n p, p ? m nm m ?e ne
anti-nm
SNS 1 6 1015 7 1014
J-PARC 3 1.2 1015 3 1014

• .

3 GeV-p p n
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4.MOON Mo Observatory Of Neutrinos
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MOON objectives and Unique features for bb

• bb spectroscopy mn30 meV.

• 1. Large Q 3.034 MeV,
• large phase space,
• large signals above most RI BG .
• 2. Excited 0 by g-g ,
• less BGs of 2nbb, RI.
• 3. bb angular correlations
• to identify the mn term .
• 4. Localization in space and time
• to get good S/N.
• 5. Multi-use for other bb nuclei as 82Se, 150Nd
  etc and 7Be solar-n

H. Ejiri, et al., PRL, 85, 2000, 2917. H. Ejiri
et al., Czech. J. Phsy. 54, 2004, 317.
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MOON detector conceptional sketch

• Multi-layers, 2 for bb and all others active
  shields
• Each with 1PL2PS 1.3 m-1.3 m- 4 cm 25 kg
• One unit 100 mod., bb30 kg, 1.3m1.3m4m,
• 4-units 120 kg 3
  m3m4 m
• 16 units 480 kg
  6m6m4m

Based on ELEGANT V
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Source thickness T , E-res. s, efficiency
e(0nbb) e(2nbb)
Source T effect is neg. at the higher sides of
0nbb and 2nbb. 30-100 mg Ds0.1 0.3
IH NH
s 1.3
ROI 250 keV from Ep-65 keV(1.6 s at 1.3
) e(0nbb) 0.26 for IH 0.15
for NH decrease slowly with T, the yield
increase. Optimum T 6080 mg e(2nbb)
remains same as T
s 2.2
T.Shima
E for 30 mg 130 keV
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Efficiencies of 0nbb 2nbb
ROI
10-7
T.Shima
e(0nbb) 0.27 0.24, e(2nbb) k s4
0.1 - 2 10-7 E2.865 3.025, E, Egt 0.5
MeV, emitted opposite,
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Oto underground Laboratory
MOON 1 prototype PL 6 layers, 53x53x1cm3
BC408. equ. 100Mo, 142g 40mg, 3 layers 56
PMTs HAMA. R6236-01. H.Nakamura et al.
ELEGANT V
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E-resolution
T 78 photon collection. E-resolution s 3.8
1 MeV s 2.2 _at_ Qbb 1.3 sta. and 1.7
non-sta.
s 2.9 for MOON 1 s 2.2 Position defined
s 1.3 Statistical limit Other
scintillators under consideration
H. Ejiri, Czeck. J. Physics, 56 (2006)
No 5, 459. H. Nakamura, et al.,http//arxiv.or
g/abs/nucl-ex/0609008
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Response for 214Bi single b
20mBq/ton 214Bi in 100Mo
Gate condition Counts /ton/yr
E1E2 gt 0keV 713
E1, E2 gt 500keV 0.91
Veto by other PL 0.83
MWPC coin. 0.002
1 track for each MWPC 0.002
ltlt 1 for 1 tonyr T.Shima
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82Se BG B(RI) B(n) B(2nbb)
BG origin Case A BG(A)/t y Case B BG(B)/t y
2nbb s2.2 4.6 s1.3 0.6
208Tl 60 mBq/t 0.3 20 mBq 0.1
214Bi 300mBq/t 0.01 100mBq 0.003
Cosmic n 2000 m w.e 0.01 2450 m w.e 0.007
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Run plan (possible option) in case of 82Se M3,
s1.3
Phase Ni nbb t - y S Ni n-mass meV
A I 0.03 - 2 0.06 - 1 0.06 0.12 165 119
II 0.12 - 3 0.48 63
III 0.48 3 1.92 32
Phase II - III / NEMO III
nbb
17.1 - 69 BG 2nbb
s4 (1.3 /3.3)-4 41 Efficiency
e0n 0.3 / 0.08
4 S/N e0n nbb /s4
1/2 100 210 n-mass
0.1 0.07

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4. Concluding Remarks
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• 0nbb is a unique and realistic probe for ns
  beyond SM. The Majorana nature and the absolute
  mass in QD/IH by DBD with 0.1/1 ton exps. and
  those in NH with 10t exps in future.
• 2. Signals are low E rare events and sensitive to
  nuclear structures
• and SUSY/heavy n interference, which depend
  on nuclei and states . Need experiments with
  different bb nuclides, the GR/EX 0 states and
  methods( calorimetric and spectroscopic).
• 3. Current GERDA/MAJORANA CUORE, EXO, S-NEMO will
  study QD 100 meV, and IH 50 meV by 0.1 and 1
  ton-scale detectors
• MOON is a realistic bb correlation exp. with
  0.06/0.5 ton 82Se-100Mo for QD/IH
  masses. Excited states and solar-n can be studied
  as well.
• Nuclear, photon, EC, n probes provide
  information on nuclear structures in a wide E and
  J ranges relevant to M0n calculations.

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INTERNATIONAL STATEMENT ON NEUTRINOLESS
DOUBLE-BETA DECAY http//www.rcnp.osaka-u.ac.jp
ejiri/DBD-Lett Form an international DBD
network in order to endorse a coordinated
approach to executing next-generation DBD probes
and to encourage internationl collaborations for
future large-scale experiments and extensive
theoretical calculations. MAJORANA/GERDA,
MOON/SuperNEMO , etc are encouraged 
Neutrino Nuclear Responses in bb Durham
Osaka-Spring-8, Open Letter RCNP, KVI, MSU and
others provide unique opportunities for the
experimental studies of the bb matrix
elements. H.Ejiri, D. Frekers, M. Harakeh, K.
Zuber, R. Zegers, others.
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Thank you for your attention