Transcript Document 7262619

Comments on Neutrinoless
Double Beta Decay Experiments
Huan Zhong Huang (黄焕中)
Department of Physics and Astronomy
University of California, Los Angeles 90095
[email protected]
OCPA Underground Sciences Workshop
Hong Kong, July 21-23 2008
Thanks to F. Avignone, S.J. Freedman,
E. Fiorini, R. Maruyama
Neutrino Physics Program
Critical Questions for Future Neutrino Physics Program
1) Are neutrinos their own anti-particles?
Dirac or Majorana neutrinos
2) What are the scale of neutrino masses and the
hierarchy of the neutrino mass ordering?
3) What is the remaining neutrino mixing angle q13?
4) Do neutrinos violate the CP symmetry and
contribute to the matter-antimatter
asymmetry?
Massive Neutrinos: Majorana or Dirac?
Lorentz Invariance:
massive particle velocity < speed of light c
spin
Left-handed nLH
Momentum
Right-handed nRH
Majorana Neutrino
Neutrino=anti-neutrino
(Speed-of-light Frame)
Dirac Neutrino
Neutrino and anti-neut distinct
Boost
nLH
(Lab)
Boost
nRH
nLH
nRH
nLH
CPT
CPT
CPT
nRH
Double Beta Decay
2nbb
Even-even nucleus
(A,Z)
(A,Z+1)
bb
(A,Z+2)
(A,Z)
2nbb: T1/2 ≥ 1018y
ne
W
e–
1935

M. Goeppert-Mayer
e–
W
(A,Z+2)
ne
(A,Z)  (A,Z+2) + 2e– + 2ne
Dirac or Majorana Neutrinos?
0nbb
1937
(A,Z)
0nbb: T1/2 ≥ 1025y
W
ne
ne
W
(A,Z+2)
(A,Z)  (A,Z+2) + 2e–
Majorana  neutrino = anti-neutrino
Lepton Number violation !
e–
e–
Measuring Neutrino Masses
1) Direct Measurement
tritium decays
E0 = 18.6 keV
3
<mb> =
| U
i 1
2
ei
2
i
| m
2) Effective Majorana Mass
3
2
<mbb> =
ei
i i
i 1
i – CP phase for neutrinos
| U
| m
3) Precise Cosmological Measurement
3
<mS> =  mi
i 1
The actual range of mbb depends on the NME !
There is no clear issue identified regarding the
experimental data.
The Cuoricino experiment
• 62 TeO2 bolometers
• Total detector mass:
M ~ 11 kg 130Te ~ 5x1025 130Te nuclides
• Deep underground in the Gran Sasso
Laboratory (Italy) (3500 m.w.e.)
• Started in 2003, currently the largest
operated bolometric experiment
Cuoricino Results Neither Support Nor Rule
Out Heidelberg-Moscow Claim
60C
o
PRELIMINARY
Updated Aug 2007
Tot exposure = 15.53 kg y 130Te
bb0n
Background in bb region
0.18  0.01 c/keV/kg/y
Average resolution @
2615keV
~ 8keV
Results for 0nbb half life
and Majorana mass (90% c.l.):
T1/20n (130Te) > 3.1 x 1024 y
mbb < 200 - 680 meV (*)
(*) using NME from Rodin et al, Nucl.
Phys. A 776 (2006) and erratum
arXiv::nucl-th/0706.4304
Cuoricino demonstrates the feasibility of a large scale
bolometric
detector with good energy
resolution
The Constraint from Cosmology Competitive
Model Dependent !
G.L. Fogli et al, hep-ph/0805.2517
Cosmological Data Set
CMB
CMB+HST+SN-Ia
CMB+HST+SN-Ia+BAO
CMB+HST+SN-Ia+BAO+Lya
S (at 2s)
< 1.19 eV
< 0.75 eV
< 0.60 eV
< 0.19 eV
CMB – WMAP 5-year, ACBAR, VSA, CBI, BOOMERANG
HST – Hubble Space Telescope h=0.75+-0.07
SN-Ia – SNLA (The SuperNova Legacy Survey)
BAO – Baryonic Acoustic Oscillation (WMAP)
Lya – Small Scale Primordial Spec from Lyman-a forest coulds
Candidate for Double beta Decays
Q (MeV) Abund.(%)
48Ca48Ti
4.271
0.187
76Ge76Se
2.040
7.8
82Se82Kr
2.995
9.2
96Zr96Mo
3.350
2.8
100Mo100Ru
3.034
9.6
110Pd110Cd
2.013
11.8
116Cd116Sn
2.802
7.5
124Sn124Te
2.228
5.64
130Te130Xe
2.533
34.5
136Xe136Ba
2.479
8.9
150Nd150Sm
3.367
5.6
Major 0nbb Experiments
(scalable to ~1 ton now or planned)
0nbb Experiments
-- CUORE 130Te
-- MAJORANA/GERDA 76Ge
-- EXO
136Xe
Essential to Measure 0nbb for Several
Elements !!
US-Italy Collaboration
CUORE @ LNGS
CUORE R&D (Hall C)
Underground National Laboratory
of Gran Sasso
L'Aquila – ITALY
3500 m.w.e.
CUORICINO CUORE
(Hall A)
CUORE
CUORE: Cryogenic Underground
Observatory for Rare Events will be a tightly
packed array of 988 Bolometers - M ~ 200 kg
of 130Te
80 cm
19 CUORICINOlike towers with 13
planes of 4 crystals
each
• Operated at Gran Sasso laboratory
• Special cryostat built w/ selected
materials
• Cryogen-free dilution refrigerator
• Shielded by several lead shields
Bolometer
TeO2 Bolometer: Source = Detector
Heat sink: ~8-10 mK
Thermal coupling: Teflon
Thermometer: NTD Ge thermistor
Absorber: TeO2 crystal
Signal from NTD Ge Thermistor
Energy resolution of a TeO2 crystal of
5x5x5 cm3 (~ 760 g )
210
@ 46 keV
@ 0.351 MeV
@ 0.911 MeV
@ 2.615 MeV
@ 5.407 MeV
Po a line
Counts
0.8 keV FWHM
1.4 keV FWHM
2.1 keV FWHM
2.6 keV FWHM
3.2 keV FWHM
the best a spectrometer
so far
Energy [keV]
Scaling CUORE from CUORICINO
Background Reduction is the Key
CUORICINO – Surface Related Background
CUORE -Crystal Production
-- TeO2 Material QA for Crystal Production
-- Crystal Processing QA
-- Improved Surface Cleaning Procedure
Crystal Support Structure (Cu)
-- New/Improved Surface Cleaning Procedure
Note – CUORICINO/CUORE Has Excellent
Shielding (Roman Lead)
Expected Sensitivity of the CUORE Experiment
APS Neutrino Study 2004
General Comments
CUORE-- 130Te
-- Excellent Energy Resolution (FWHM 0.3%)
-- Cost Effective
-- Background Elimination Challenging
-- Data-Taking Early 2011
GERDA/MAJORANA -- 76Ge
-- Ultra-Low Background Possible
-- Detector Segmentation and Pulse Shape
Analysis Possible
-- Very Costly !
EXO -- 136Xe
-- Easy to Scale Up
-- Ba+ Tagging Challenging / FWHM ~3.4%
Interdisciplinary Sciences
Three Overarching Themes
-- APS multidivisional neutrino study
Neutrino Matrix – physics/0411216
1) Neutrinos and the New Paradigm
-- neutrino masses, Dirac/Majorana and CP violation
beyond the Standard Model
2) Neutrinos and the Unexpected
-- Many discoveries in recent years, what surprises and
extraordinary properties ahead?
3) Neutrinos and Cosmos
-- # of neutrinos, neutrino masses – large structures
CP violation – matter/anti-matter asymmetry
CUORE Collaboration
Universita’ di Milano-Bicocca5
C. Arnaboldi, C. Brofferio, S. Capelli, M. Carrettoni, M. Clemenza,
E. Fiorini, S. Kraft, C. Maiano, C. Nones, A. Nucciotti, M. Pavan,
D. Schaeffer, M. Sisti, L. Zanotti
Sezione di Milano dell’INFN
F. Alessandria, L. Carbone, O. Cremonesi, L. Gironi, G. Pessina,
S. Pirro, E. Previtali
Politecnico di Milano
R. Ardito, G. Maier
Laboratori Nazionali del Gran Sasso
M. Balata, C. Bucci, P. Gorla, S. Nisi, E. L. Tatananni, C. Tomei, C. Zarra
Universita’ di Firenze and Sezione di Firenze dell’INFN
M. Barucci, L. Risegari, G. Ventura
Universita’ dell’Insubria5
University of California at Berkeley
A. Bryant2, M.P. Decowski2 , M.J. Dolinski3 , S.J. Freedman2,
E.E. Haller2, L. Kogler2, Yu.G. Kolomensky2
University of South Carolina
E. Andreotti, L. Foggetta, A. Giuliani, M. Pedretti, C. Salvioni
Universita di Genova
S. Didomizio6, A. Giachero7, P. Ottonello6, M. Pallavicini6
Laboratori Nazionali di Legnaro
F.T. Avignone III, I. Bandac, R. J. Creswick, H.A. Farach,
C. Martinez, L. Mizouni, C. Rosenfeld
G. Keppel, P. Menegatti, V. Palmieri, V. Rampazzo
Lawrence Berkeley National Laboratory
Universita di Roma La Sapienza and Sezione di Roma dell’INFN
J. Beeman, E. Guardincerri, R.W. Kadel, A.R. Smith, N. Xu
F. Bellini, C. Cosmelli, I. Dafinei, R. Faccini, F. Ferroni, C. Gargiulo,
E. Longo, S. Morganti, M. Olcese, M. Vignati
Lawrence Livermore National Laboratory
Universita’ di Bologna and Sezione di Bologna dell’INFN
K. Kazkaz, E.B. Norman4, N. Scielzo
M. M. Deninno, N. Moggi, F. Rimondi, S. Zucchelli
University of California, Los Angeles
University of Zaragoza
H. Z. Huang, S. Trentalange, C. Whitten Jr.
M. Martinez
University of Wisconsin, Madison
Kammerling Onnes Laboratory, Leiden University
L.M. Ejzak, K.M. Heeger, R.H. Maruyama, S. Sangiorgio
A. de Waard, G. Frossati
California Polytechnic State University
Shanghai Institute of Applied Physics
(Chinese Academy of Sciences)
T.D. Gutierrez
X. Cai, D. Fang, Y. Ma, W. Tian, H. Wang
2also
LBNL
3also LLNL
4also UC Berkeley
5also
6also
Sezione di Milano dell’INFN
Sezione di Genova dell’INFN
7also LNGS
Full estimated range of M0n within QRPA framework and comparison with NSM
(higher order currents now included in NSM) – P. Vogel
Double Beta Decay Candidates
Normal beta-decay is energetically forbidden, while
double beta-decay from (A,Z)  (A, Z+2) is energetically
allowed:
(A=even, Z=even)
A, Z+1
A, Z+3
0+
A, Z
bb
0+
A, Z+2
Some candidates:
48Ca, 70Zn, 76Ge, 80Se, 86Kr, 96Zr, 100Mo, 116Cd, 130Te, 136Xe, 150Nd
CUORE
Array of 988 TeO2 crystals
• 19 Cuoricino-like “towers”
• 13 levels, 4 crystals each
• 5x5x5 cm3 (750 g each)
• Low conductance Teflon insulators
• OFHC Cu structure
• Crystals equipped with NTDs
• Suspended from cold stage
• Mechanically isolated
OGHC-Oxygen Free High Conductivity
NTD-Neutron Transmutation Doped
Neutrino Masses and Hierarchy
Normal
Inverted
Cosmogenic Co from Te