neutrinoless double beta decay - taup conference · 2015. 9. 10. · -interacting boson model;...

Neutrinoless double beta decay

Oliviero CremonesiINFN, Sezione di Milano Bicocca

TAUP 2015 - September 7-11, 2015 - Turin, Italy

O. Cremonesi -‐ September 10, 2015 -‐ TAUP 2015, Turin, Italy

Outline

2

Phenomenology: • NLDBD and neutrinos• Exotic models

Nuclear Physics• Nuclear Matrix Elements• gA renormalization

Experiments• Status• Prospects

Conclusions

Nuclear Process


Neutrinoless Double Beta decay

3

Very rare nuclear decay

• Many possible (more or less exotic) mechanisms

Requires:• neutrino to be Majorana AND have non-zero mass- Any process that allows 0νββ to occur requires Majorana neutrinos with

non-zero mass (Schechter and Valle, 1982)

• Lepton number violation- No compelling evidence that Lepton number must be conserved (i.e.

allowed based on general SM principles, such as electroweak-isospin conservation and renormalizability)

A(Z) A(Z+2)

e e

NuclearProcess

(A,Z) → (A,Z+2) + 2e-

If ββ(0ν) decay is observed: → neutrinos are Majorana particles→ lepton number is violated

[T 0⌫1/2]

�1 = G0⌫ |M0⌫⌘ |2⌘2


Open Questions in ν Physics

4

What is the absolute neutrino mass scale? Is the lightest ν massless? Hierarchical or degenerate?

What is the neutrino mass ordering? Normal (m1<m2 ≪ m3) or inverted (m3 ≪ m1 <m2)?

Are neutrinos Dirac or Majorana particles?Lepton number violation, neutrinoless double beta decays

What is the origin of neutrino masses and flavor mixing? See saw mechanisms, flavor symmetries, ...

Is there CP violation in the lepton sector? What is the value of the Dirac CP-violating phase δ?

⌧�10⌫ = G0⌫(Q,Z)|M0⌫ |2|hmeei|2


0νββ: mass mechanism

5

RH antineutrino (L=1) is emitted at one vertexLH neutrino (L=-1) is absorbed at the other vertex

l Majorana particlel Helicity flip (neutrino mass dependence)

Exchange of a light Majorana neutrino (standard interpretation)

= c212c213m1 + s212c

213e

i↵m2 + s213ei�m3

< mee >=X

k

U2ekmk

NEUTRINOMIXING MATRIX

NEUTRINO MASS EIGENALUES

N.B.: Majorana phases make meecancellation possible (mee could be smaller than any of the mi).

Decay rate depends on:• nuclear processes• nature of lepton number violating interactions (η).

• Phase space, G0ν is calculable.• Nuclear matrix elements (NME) via

theory.• Effective neutrino mass, <mββ>,

depends directly on the assumed form of lepton number violating (LNV) interactions.

Half lifetime can be expressed as

PHASE SPACE FACTOR

NME EFFECTIVE MAJORANA MASS

FN: Nuclear Factor of merit

IH HDm2<0L

NH HDm2>0L

10-4 0.001 0.01 0.1 110-4

0.001

0.01

0.1

1

m lightest @eVD

mbb@eVD


Three light ν’s: the “standard” plot

6

• S.Pascoli, S.Petcov, Phys.Atom.Nucl. 66 (2003) 444, arxiv:0111203• R.Mohapatra et al., arXiv:0510213• A.Strumia and F.Vissani, IFUP-TH/2004-1; arXiv:0606054

S. Dell’Oro, S. Marcocci, F. Vissani, Phys. Rev. D90, 033005 (2014)

• G.L Fogli, et al, PRD 78 033010 (2008), arXiv:0805.2517v3

Experimental parameters are pictured as a function of the lightest mass eigenvalue:

Bands arise from specific experimental and theoretical uncertainties:

• darker: Majorana phases range

• light: mixing parameter uncertainties


Exotic interpretations

7

• The exchange of a light Majorana neutrino is the most standard interpretation of NLDBD

• Other more exotic mechanisms are however possible Beyond the Standard Model (BSM):

- heavy neutrinos- non standard Higgs- SUSY

• NLDBD can provide very competitive limits

SM+Higgs triplet SUSY


Nuclear Matrix Elements

8

• Nuclear Matrix Elements (NME) are essential to extract the Physics parameters BSM:

• NME are calculated using different approximate methods: - Nuclear Shell Model; - Quasi-random phase approximation (QRPA); - Interacting Boson Model; - Projected Hartree-Fock-Bogoliubov; - Generating co-ordinate method extension of PHFB; - Pseudo-SU(3) deformed shell model.

• Extracting an effective neutrino mass requires a good understanding of the nuclear matrix elements (NME).

• Recent progress NSM-QRPA:- 2005 within x 5- 2015 agree within x ~2

• Agreement between methods doesn’t necessarily provide an estimate of theoretical uncertainties or of actual values.

⌧�10⌫ = G0⌫(Q,Z)|M0⌫ |2|hmeei|2

IBM-2: J. Barea et al., PRC 91, 034304 (2015),QRPA-Tu: F. Simkovic et al. PRC 87, 045501 (2013),QRPA-Jy: Hyv¨arinen et al., PRC 91 024613 (2015),QRPA-def: J:L. Fang et al., PRC 83 034320 (2011), ISM: J. Menendez et al., NPA 818, 139 (2009),PHFB: P.K. Rath et al., PRC 82, 064310 (2010),EDF: T.R. Rodriguez et al., PRL 105, 252503 (2008)


NME status

9


Preferred isotopes

10

• In principle, isotopes with the best Nuclear Factor of Merit (G*M) should be favored• A surprising inverse correlation has been observed between phase space and the

square of the nuclear matrix element .

A.Robertson, Mod. Phys. Lett. A, Vol. 28, No. 8 (2013) 1350021, arXiv 1301.1323

• dots are the geometric mean of the squared matrix element range limits

• the phase-space factor is evaluated at gA=1

No preferred isotope... within a factor 2-3

hT 2⌫,exp1/2

i�1= G2⌫ |Meff

2⌫ |2


Quenching of gA

11

• Typically, the effective axial-vector coupling constant, gA, is incorporated in the phase space factor G0ν, or occasionally in the nuclear matrix elements M0ν:

• Calculated phase-space factors for 0νββ use the free-nucleon value gA = 1.269, or gA = 1.25, or gA = 1.

• M2ν,exp/M2ν,theor < 1 - Barea et al. and Ejiri have fit half-lives for ββ(2ν) and find gA of about 0.8 for shell-model calculations and 0.6 for the Interacting Boson Model (IBM).

Kotila and Iachello, Phys. Rev. C85 034316

MeffX =

✓gA,eff

gA

◆2

MX

Calculated for the X isotope according to different models

→ gA,eff is essentially a way to rescale Mtheor


Quenching of gA

12

- In 2νββ only the 1+ (GT) multipole contributes. - In 0νββ all multipoles 1+, 2-,...; 0+, 1-,... contribute. Some of which could be

unquenched.

→ If not, how to estimate gA,eff? - Experiments: by measuring the matrix elements to and from the intermediate odd-odd

nucleus in 2νββ decayQuenching coming from other sources than size of the model space?

- Theoretical studies by using effective field theory (EFT) to estimate the effect of non-nucleonic degrees of freedom (two-body currents)

• gA,eff is a smooth function of A: gA,eff = 1.269A−γ

- IBM-2: γ = 0.18- QRPA: γ = 0.16- ISM: γ = 0.12

• Similar values found by analyzing β−/EC for IBM-2 and for QRPA (Ejiri, Soukouti and Suhonen, PLB 729, 27(2014)

J.Barea, J.Kotila, F.Iachello, Phys. Rev. C87, 014315 (2013)

ββ(2ν) data→ Assumed values of gA,eff can change calculated rate by ~20

→ Is the renormalization of gA the same in 2νββ as in 0νββ?


gA quenching

13

(Ge) > 3.0⋅1025 yr M. Agostini et al. (GERDA Collaboration), Phys. Rev. Lett. 111, 122503 (2013)(Xe) 2.6⋅1025 yr I. Shimizu, Results presented at Neutrino 2014, Boston

S. Dell’Oro et al., Phys. Rev. D 90, 033005 (2014)

gA = 1gA = 1.25

gA,phen


Experimental signature of ββ(0ν)

14

(A,Z) → (A,Z+2)++ + 2 e-l A new (ionised) isotope l Two electrons

Main signature: • 0νββ exhibits a peak at Q in the two

e- energy sum spectrum over 2νββ tail (and background contributions)

Additional informations:• Single electron energy spectrum• Angular correlation between the two electrons• Daughter nuclear species

→ Track and event topology→ Time Of Flight

• Can allow to disentangle decay modes• Can help reducing backgrounds

10.5

Moreover, to cure NME systematics:• study as many as possible different isotopes

NB = bkg ·�E ·M · tmeas

NB < 1

NB >> 1


Experimental sensitivity

15

Nnuclei number of active nuclei in the experiment

tmeas measuring time [y] M detector mass [kg]ε detector efficiencyi.a. isotopic abundanceA atomic numberΔE energy resolution [keV]bkg background [c/keV/y/kg]

Two cases are then possible depending on the extent of the background:

generally named “zero background” condition

The number of background events expected along the experiment lifetime is

S0⌫1/2 / ✏

i.a.

A

sM · tmeas

bkg ·�E

S0⌫1/2 / ✏

i.a.

AM · tmeas

1

S0⌫1/2(mee)

/qS0⌫1/2 ·G0⌫ |M0⌫ |

By inserting the proper nuclear factor of merit is then possible to get the sensitivity on the effective neutrino Majorana mass

Despite their simplicity these formula’s outline the dependence of the sensitivity on the critical experimental parameters: Mass, Measure Time, Energy resolution, Background and Isotope choice


Energy resolution

16

• Strong influence on• discovery power• background

- irreducible ββ(2ν)- background

disentanglement

0.5% 1%

3.5% 10%

Signal 50 events T1/2= 5⋅1025 yr t = 1 yr

M = 1tonB = 1 count/ton/keV/yr

from JJ Gomez-Cadenas


Background

17

“Brute force”: directly reduce intrinsic, extrinsic, & cosmogenic activities• Select and use ultra-pure materials• Minimize all passive (non “source”) materials• Avoid material re-contamination (machining, manipulation, storage)• Fabricate ultra-clean materials (underground fab if needed)• Go deep — reduced µ’s & related induced activities• Rank materials: build an accurate Background budget (MC model)

MethodsTPCs (liquid, gas) 136XeDoped Liquid Scintillators 136Xe,130TeSolid state detectors 76Ge, 116CdBolometers (+ enhancements) 130Te, 82Se,100Mo, 116CdFoils with tracking chambers 82Se, 150Nd, 100Mo

→Both approaches are generally needed→Specific and intense R&D’s needed

Discrimination techniques• Energy resolution• Active veto detector• Tracking (topology)• Particle ID, angular,

spatial,time correlations• Fiducial Fits• Granularity (arrays)• Pulse shape discrimination

(PSD)• Ion Identification

The background index in the ROI is the most critical of the parameters driving the sensitivity.

• Radioactivity • Cosmogenic activation• µ-induced reactions• 2 neutrino double beta decay• ...Strategies:


ββ(0ν) ongoing efforts

18

Experiment Isotope Technique Mass ββ(0ν) isotope Status

CUORICINO 130Te TeO2 Bolometer 10 kg CompleteNEMO3 100Mo/82Se Foils with tracking 6.9/0.9 kg CompleteGERDA I 76Ge Ge diodes in LAr 15 kg CompleteEXO200 136Xe Xe liquid TPC 160 kg OperatingKamLAND-ZEN 136Xe 2.7% in liquid scint. 380 kg OperatingCUORE-0 130Te TeO2 Bolometer 11 kg OperatingGERDA II 76Ge Point contact Ge in LAr 30+35 kg CommissioningMajorana D 76Ge Point contact Ge 30 kg CommissioningCUORE 130Te TeO2 Bolometer 206 kg ConstructionSNO+ 130Te 0.3% natTe suspended in Scint 55 kg ConstructionNEXT-100 136Xe High pressure Xe TPC 80 kg ConstructionSuperNEMO D 82Se Foils with tracking 7 kg ConstructionCANDLES 48Ca 305 kg of CaF2 crystals - liq. scint 0.3 kg ConstructionLUCIFER 82Se ZnSe scint. bolometer 18 kg Construction1TGe (GERDA+MJ) 76Ge Best technology from GERDA and MAJORANA ~ tonne R&DCUPID - Hybrid Bolometers ~ tonne R&DnEXO 136Xe Xe liquid TPC ~ tonne R&DSuperNEMO 82Se Foils with tracking 100 kg R&D

AMoRE 100Mo CaMoO4 scint. bolometer 50 kg R&DMOON 100Mo Mo sheets 200 kg R&DCOBRA 116Cd CdZnTe detectors 10 kg/183 kg R&DCARVEL 48Ca 48CaWO4 crystal scint. ~ tonne R&DDCBA 150Nd Nd foils & tracking chambers 20 kg R&D


ββ(0ν) present and near past

19

HDM & IGEX @ LNGS

NEMO-3 @ LSM

EXO-200 @ WIPP

KamLAND-ZEN @ Kamioka

Cuoricino@ LNGS

CUORE-0@ LNGS

GERDA-I@ LNGS


Current results

20

Isotope T2ν1/2 (1019 y) T0ν1/2 (1024 y)48Ca NEMO-3 4.4 ± 0.5 (stat) ± 0.4 (syst) ELEGANT VI > 0.05876Ge KKDC 22.3+4.4-3.1*76Ge GERDA-I 184 ± 10 GERDA-I > 21 (30 comb.)82Se NEMO-3 9.6 ± 0.1 (stat) ± 1.0 (syst) NEMO-3 > 0.3296Zr NEMO-3 2.35 ± 0.14 (stat) ± 0.16 (syst) NEMO-3 > 0.0092

100Mo NEMO-3 0.716 ± 0.001 (stat) ± 0.054(syst)) NEMO-3 > 1.0

116Cd NEMO-3 2.88±0.04(stat)±0.16(syst) Solotvina > 0.17130Te NEMO-3 70±9(stat)±11(syst) CUORE-0 > 2.8 (4 comb.)

136Xe EXO-200KamLAND-Zen 217.2 ± 1.7 (stat) ± 6(syst) EXO-200

KamLAND-Zen > 19 (34 comb.)

150Nd NEMO-3 0.911±0.025(stat)±0.063(syst) NEMO-3 > 0.018

IH HDm232<0L

NH HDm232>0L

10-4 10- 3 10-2 10-1 110-4

10- 3

10-2

10-1

1

m lightest @eVD

»m ee»@eVD


Status: present

21

Ge claim GERDA-I EXO+KamLAND-Zen

Cuoricino+CUORE-0


CUORE-0

22

1 CUORE tower• 52 TeO2 5x5x5 cm3 bolometers • 13 floors of 4 crystals each • total mass: 39 kg (11 kg of 130Te)

Goals:• Proof of concept of CUORE detector in all

stages• Test and debug of the CUORE towerxq

assembly line• Test of the CUORE DAQ and analysis

framework• Operating as independent experiment while

CUORE is under construction• Demonstrate potential for DM detection

A successful program: all goals accomplished!• Achieved energy resolution and background level

objectives. • Long term stable operation. Good live time

fraction.• Cuoricino sensitivity surpassed in ~ half the time.• Confirmed that CUORE sensitivity goal is within

reach.• Did not find evidence of 0νDBD decay. • 0νDBD paper published in PRL. Other papers in

preparation.


CUORE-0: calibration energy resolution

23

The 5 keV CUORE goal has been reached!

Reconstructed Energy (keV)2560 2570 2580 2590 2600 2610 2620 2630 2640 2650

Cou

nts /

(0.5

keV

)

05000

1000015000200002500030000350004000045000 Summed calibration data

Projected fitγTl 208

2560 2570 2580 2590 2600 2610 2620 2630 2640 2650

)σ

Res

idua

l (

-6-4-20246

FWHMfit = 4.8 keV

Total fit on the 2615 keV line

AVGT/T0.75 0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 1.25

Entries/0.02

0

2

4

6

8

10

12

14

16

18 Cuoricino

CUORE-0

CUORE-0 preliminary

Temperature distribution

The narrower distribution of CUORE-0 temperatures compared to Cuoricino shows the improvement in the reproducibility of the detector construction

Cuoricino RMS: 9%CUORE-0 RMS: 2%

Energy [keV]2600 2800 3000 3200 3400 3600 3800

Even

t Rat

e [c

ount

s/keV

/kg/

y]

-210

-110

1

10

Cuoricino

CUORE-0

CUORE-0 Preliminary208Tl

190Pt

O. Cremonesi -‐ September 10, 2015 -‐ TAUP 2015, Turin, Italy 24

CUORE-0 background

ROI 2.7-3.9 MeV effCUORE-0

Cuoricino (II)

0.058 ± 0.004 0.016 ± 0.001 81 ± 1

0.153 ± 0.006 0.110 ± 0.001 83 ± 1

Factor 6 reduction in the alpha continuum region

ββ

counts/(keV⋅kg⋅y)


CUORE-0: ββ0ν result

25

• The background index in the ROI is:�0⌫ = 0.01± 0.12 (stat.)± 0.01 (syst.)⇥ 10�24yr�1

0.058± 0.004 (stat.)± 0.002 (syst.) c/keV/kg/yr

• The best fit value of the 0νDBD decay rate is

• N90 = 11 (9 after efficiency correction)• We set a 90% C.L. Bayesian lower limit of: T1/2 > 2.7 × 1024

• Combining CUORE-0 result with the existing 19.75 kg · yr of 130Te exposure from Cuoricino we get: T0ν > 4.0 × 1024 yr (90% C.L.)

Phys. Rev. Lett. 115, 102502

→ C.Bucci talk → Posters: L.Canonica, G.Piperno


KamLAND-Zen

26

• Double beta decay search using the KamLAND detector

• “Inner balloon” deployed inside the detector and filled with LS loaded with 136Xe

Visible Energy (MeV)1 2 3 4

Ev

ents

/0.0

5M

eV

-110

1

10

210

310

410

510 (a) DS-1 + DS-2 Bi208

Y88

Ag110m

Th 232U + 238

Kr85Bi + 210 +

IB/External

Spallation

Data

Total

ββνXe 2136

Total

U.L.)ββν(0

ββνXe 0136

(90% C.L. U.L.)

Exposure 89.5 kg-yr • T1/20ν > 1.9⋅1025 yr • when combined with EXO-200:

- T1/20ν > 3.4⋅1025 yr- 〈mββ〉 < 120-250 meV

• large background signal in the ROI

PRL 110 062502 (2013)

Xe-LS383 kg

Xe loaded

Outer-LS1 kton Inner Balloon

(3.08 m ø)


KamLAND-Zen progress (phase 2)

27

• Background identified as 110mAg• 110mAg background reduction: ~ 1/10• Primary background:

- 214Bi at balloon- spallation 10C- remaining 110mAg

Days0 50 100 150 200

Even

ts/D

ay/T

on

0

0.1

0.2

0.3DS-1 DS-2

= 2.222χAg, 110m

= 8.062χBi, 208

= 10.162χY, 88

T2ν1/2 = 2.32 ± 0.05(stat) ± 0.08(syst) x1021 yr

Dec. 11, 2013 - May 1, 2014 (114.8days) r < 1.0m0νββ improved limits

• phase-1- T0ν1/2 > 1.9×1025 yr (90%CL)

• phase-2 (114.8days)- < 17.0 events/day/kton-LS (90%C.L.)- T0ν1/2 > > 1.3×1025 yr

• combined- T0ν1/2 > 2.6×1025 yr - <mββ> < 0.14 – 0.28 eV (90%)

J. Phys. G 39 124006 (2012)


DBD future

28

GERDA-II @ LNGS

CUORE@LNGS

MAJORANA-Demonstrator@ SURF

KAMLAND-Zen @ Kamioka

SNO+ @ Sudbury

nEXO @ SNOLab

SuperNEMO D @ LSM

NEXT/BEXT @LSC

IH HDm232<0L

NH HDm232>0L

10-4 10- 3 10-2 10-1 110-4

10- 3

10-2

10-1

1

m lightest @eVD

»m ee»@eVD


Status: near future

29

τ0ν > 1026-‐1027 yCUORE, MJD, GERDA-‐II, KamLAND-‐Zen


Synopsis

30

GERDA&II

MJDModule/1

Module/2

EXO&200

CUORE

SNO+

NEXT NEXT/NewNEXT&100

SuperNEMO/D

KamLAND&Zen

2019

2013 2014 2015 2016 2017 2018 2019

2013 2014 2015 2016 2017 2018


GERDA-II

31

Improvements wrt GERDA-I:• mass increase: 30 enriched BEGe detectors (20.1 kg)

- produced at Canberra Olen- commissioned at Hades (Belgium)- First BEGe sample already used in GERDA-I- all 30 BEGe's delivered to LNGS and being commissioned

• background reduction: factor ~10 wrt GERDA-I- new HV and signal cables (less radioactive)- new FE (less radioactive), optimized for new detectors- PSA discrimination- LAr veto instrumentation- new lock


GERDA-II: LAr veto

32

suppression of 228Th with LAr veto (7 out 15 fiber channels, 14 out 16 PMTs)and Ge pulse shape discrimination

LAr veto suppression factor ~45, total suppression factor ~90 at 2039 keV


GERDA-II commissioning

33

April 2015:• LAr veto is working, will exchange in June broken PMTs• Germanium detectors:

- solved problems with cable connectionsback to a ”phase 1 like readout”

- some solved problems with detectors leakage current → etching

May 2015:• test all detectors in transport container for leakage current

and do etching either at LNGS or ship detectors back to Belgium for repair

• complete set of cables arrived

June 2015:• start mounting detectors into holder• when 2 strings (out of 7) are ready, install them in

GERDA, then add more strings as they become available

TAUP 2015:• first background spectrum

→ K.Gusev talk → Poster: B. Lehnert


GERDA-II First bkg spectrum @ TAUP 2015

34

Commissioning 2nd step: 5 string assembly


MJD: Majorana Demonstrator

35

Goals: • Demonstrate backgrounds low enough to justify building a tonne

scale experiment.• Establish feasibility to construct & field modular arrays of Ge

detectors.• Searches for additional physics beyond the standard model

• Located underground at 4850’ Sanford Underground Research Facility (Homestake mine)

• Background Goal in the 0νββ peak region of interest (4 keV at 2039 keV)

- 3 counts/ROI/t/y (after analysis cuts) - Assay U.L. currently ≤ 3.1 (scales to 1 count/ROI/t/y for a tonne

experiment)• 40-kg of Ge detectors

- 29 kg of 87% enriched 76Ge crystals- 11 kg of natGe- Detector Technology: P-type, point-contact.

• 2 independent cryostats- ultra-clean, electroformed Cu- 20 kg of detectors per cryostat- naturally scalable

• Compact Shield- low-background passive Cu and Pb- shield with active muon veto

→ M.Green talk


MJD background budget

36

Very careful assay of all the component materials


MJD: background

37

• Prototype Module: - 3 strings of natGe

detectors - Taking Data since

Spring ’14- in shield since July

’14

• Electroformed Copper- < 0.06 µBq/kg 232Th,- < 0.1 µBq/kg 238U

• Accounts for < 0.23 counts / t / yr / ROI• EFCu machined in underground machine

shop to prevent cosmogenic isotopes

• Module 1: - 16.8 kg (20) enrGe- 5.7 kg (9) natGe

• Module 2: - 12.6 kg (14) enrGe- 9.4 kg (15) natGe

Summary:• MJD Prototype module taking data in

shield since July 2014. Simulations and analysis of data underway

• Module 1 with enriched detectors is being commissioned

• Assembly of strings for Module 2 is underway.

• Significant progress in quantifying low energy backgrounds.


CUORE @ LNGS

38

Cryogenic Underground Observatory for Rare Events

Complex cryogenic set-up• Fully cryogen-free system:

- custom cryostat- 5 pulse tubes- a powerful dilution refrigerator and

• ~10 mK operating temperature• Independent suspension of the detector array• An embedded detector calibration system• Radio-pure materials• Heavy low temperature shield

CUORE detector• 988 TeO2 crystals run as a bolometer array

- 5x5x5 cm3 crystal, 750 g each• 19 Towers; 13 floors; 4 modules per floor

- 741 kg total - 206 kg 130Te- 1027 130Te nuclei

• Excellent energy resolution of bolometers • Radio-pure material and clean assembly to achieve low

background at ROI- strict radiopurity control protocol to limit bulk and surface

contaminations in crystal production - transportation at sea level to LNGS - bolometric test to check performances and radio-purity- TECM protocol (Tumbling, Electropolishing, Chemical etching,

and Magnetron plasma etching) for copper surface cleaning - limited exposure to cosmic rays: underground storage of the

copper parts in between production and cleaning


CUORE sensitivity

39

Design sensitivity goal:• background rate of 10-2 counts/(keV kg y)• 5 keV FWHM• 5 years of live time

CUORE projected sensitivity (90% C.L.)• S1/2(0νββ) = 9.5 x 1025 y

or equivalently in terms of effective Majorana mass down to • <mee> ~ 50-130 meV

• 0νββ• Dark matter• Rare nuclear decays

→ C.Bucci talk → Poster: V.Singh

Live time [y]0 1 2 3 4 5 6 7

[y] 9

0% C

.L. S

ensit

ivity

1/2ν0 T 2410

2510

2610

Cuoricino y)× kg ×CUORE-0 - bkg: 0.063 events/(keV

y)× kg ×CUORE - bkg: 0.01 events/(keV


CUORE: status

40

• Phased commissioning program of the cryogenic system• Phase I: system tests down to 4K

- Vacuum tightness- Cooling devices (PT’s) characterization

• Phase II: full cryogenic system check- 3 series of cooldowns at increasing complexity- 2 successfully completed: Tbase < 6 mK!- last cooldowns at full load (all but the detector): are

ongoing

• Detector tower assembly completed by summer 2014

• Detector installation: fall 2015

• Start data taking: early 2016

IH HDm232<0L

NH HDm232>0L

10-4 10- 3 10-2 10-1 110-4

10- 3

10-2

10-1

1

m lightest @eVD

»m ee»@eVD


Future challenge

41

τ0ν > 1027-‐1028 y

Tonne size detector(s)Zero Background


Future challenge

42

Active international collaborations aiming at a next generation experiment with sensitivities T1/2 ~ 1027-1028 yr (→ multi-ton, low background)

Isotope Experiment Description

76Ge GERDA & MAJORANA Large Scale Ge, O(tonne) HPGE crystals

82Se SuperNEMO Se foils, tracking and calorimeter, 100 kg scale

136Xe nEXO Liquid TPC, 5 tonnes

NEXT/BEXT High pressure gas TPC, tonne scale

KamLAND2-Zen 136Xe in scintillator

130Te CUPID Bolometers with light sensor (also 82Se, 116Cd, 100Mo)

SNO+ II 130Te in scintillator

• Additional efforts underway: AMoRE, CANDLES, PandaX III, CDEX 1T, COBRA• In most cases a phased approach is proposed (stepwise increments)• Isotope enrichment requires time and money

• Potential underground lab sites (increasing number): SNOLAB, JingPing, Gran Sasso, SURF, CanFranc, Frejus, Kamioka, ANDES, Y2L


MAGE

43

MJD:• Modules of enrGe housed in high-purity• electroformed copper cryostat• Shield: electroformed copper / lead• Initial phase: R&D demonstrator module:• Total 40 kg (29 kg enr.)

GERDAMAJORANA

GERDA:• ‘Bare’ enrGe array in liquid argon • Shield: high purity liquid Argon / H2O • Phase I (2013): 21.6 kg⋅yr • Phase II (2015): add ~20 kg new detectors -

Total ~40 kg• Joint Cooperative Agreement:• Open exchange of knowledge &

technologies (e.g. MaGe, R&D)Intention is to merge for Large Scale Ge. Select best techniques developed and tested in GERDA and MAJORANA

Thermometer(

Light(

Energy(release(

Scin4lla4ng(bolometer(

Light(Detector(


CUPID: CUORE Upgrade with Particle IDentification

44

•White papers: arXiv:1504.03599, arXiv:1504.03612•Artusa, D.R. et al. Eur.Phys.J. C74 (2014) 10, 3096, arXiv:1404.4469

• Next-generation bolometric tonne-scale experiment• Based on the CUORE design and CUORE cryogenics

- Largest cryostat and DU built; mature technology- 988 enriched (90%) crystals, PID with light

detection• 4 options considered:

- 130TeO2 : phonons + Cherenkov detector- Zn82Se, Zn100MoO4, 116CdWO4 : phonons

+scintillation• Aim for zero-background measurement• Sensitivity to entire IH region

- CUORE geometry and background model- 99.9% α rejection @ >90% signal efficiency (5σ

separation of α and β)- 5 keV FWHM resolution- Challenge: nearly zero background

measurement: background goal <0.02 events / (ton-year)

- Half-life sensitivity (2-5)×1027 years in 10 years (3σ) - mßß sensitivity 6-20 meV (3σ)

-


CUPID group of interest

45

High Energy Physics Division, Argonne National Laboratory, Argonne, IL, USAMaterials Science Division, Argonne National Laboratory, Argonne, IL, USA!INFN - Laboratori Nazionali del Gran Sasso, Assergi (AQ), Italy!Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USADepartment of Nuclear Engineering, University of California, Berkeley, CA, USADepartment of Physics, University of California, Berkeley, USAUniversità di Bologna and INFN Bologna, Bologna, ItalyMassachusetts Institute of Technology, Cambridge, MA, USADepartment of Physics and Astronomy, University of South Carolina, Columbia, SC, USATechnische Universität München, Physik-Department E15, Garching, GermanyDipartimento di Fisica, Università di Genova and INFN - Sezione di Genova, Genova, ItalyInstitute for Nuclear Research, Kyiv, UkraineINFN - Laboratori Nazionali di Legnaro, Legnaro, ItalyLawrence Livermore National Laboratory, Livermore, CA, USADepartment of Physics and Astronomy, University of California, Los Angeles, CA, USAINFN sez. di Milano Bicocca and Dipartimento di Fisica, Università di Milano Bicocca, ItalyState Scientific Center of the Russian Federation - Institute of Theoretical and Experimental Physics(ITEP), Moscow, RussiaMax-Planck-Institut für Physik, D-80805 München, GermanyNikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk, RussiaSobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk, RussiaCentre de Sciences Nuclèaires et de Sciences de la Matière (CSNSM), CNRS/IN2P3, Orsay, FranceINFN - Sezione di Padova, Padova, ItalyInstitut de Chimie de la Matière Condensè de Bordeaux (ICMCB), CNRS, 87, Pessac, FranceDipartimento di Fisica, Università di Roma “La Sapienza” and INFN - Sezione di Roma, Roma, ItalyIFN-CNR, Via Cineto Romano, I-00156 Roma, Italy!Service de Physique des Particules, DSM/IRFU, CEA-Saclay, France!Physics Department, California Polytechnic State University, San Luis Obispo, CA, USAShanghai Institute of Applied Physics (SINAP), ChinaInstitut de Physique Nuclèaire de Lyon, Universitè Claude Bernard, Lyon 1, Villeurbanne, FranceWright Laboratory, Department of Physics, Yale University, New Haven, CT, USA!Laboratorio de Fisica Nuclear y Astropartculas, Universidad de Zaragoza, Zaragoza, Spain)


nEXO

46

Concept• Large ultra-pure volume of enriched liquid 136Xenon• Contaminants removed by filtering• Use ultra-low radioactivity material around the LXe• Then rely on self-shielding

• Measure ionization e-• Reconstruct position on segmented anode (wires or

pads/strips)• Excellent multi-pulse separation

• Measure scintillation photons• Timing for drift direction position reconstruction• Achieve excellent energy resolution combining with

charge measurement

Based on the successful operation of EXO-200

EXO-200:• ~150 kg enriched LXe detector • operation 2011-2014 @ WIPP

nEXO:• ~5,000kg LXe detector • pre-conceptual stage• based @ SNOLAB


nEXO

47

• Vertical barrel (~130cm diameter)• Single drift volume (~130cm long)• Charge collection on anode plane• Photo-detector around the barrel

• T1/2 = 6 x 1027 yr in 5 years of counting• Majorana neutrino mass <mββ> sensitivity of

7-18 meV

Limit cosmogenic background by going deep WIPP → SNOLAB (tbc)

Limit material radioactivity by assaying every piece of material No changes

Self shielding by selecting events in the middle of the detector

2.5 MeV att. Length / radius: 0.43 → 0.13

Reject gamma-ray by identifying multiple interaction points

improved segmentation and lower charge noise (cold electronics)

Excellent energy resolution by combining light and charge

1-2% with APDs & warm electronics → <1% with SiPMs & cold electronics

Barium tagging Beyond this phase of nEXO

• Radioactive background budget assessed by simulations• Assay all material with highly sensitive techniques

- Nuclear Activation- ICPMS → Talks: I.Ostrovski


KamLAND-Zen program

48

• 2014: KamLAND-Zen w/ lower 110mAg- Just resumed with 380 kg

• 2017: KamLAND-Zen 700 kg - with clean mini-balloon

• Future: KamLAND-Zen2 - high QE PMT- high yield LS- light concentrator - σE(2.6 MeV) < 2.5%

• Super-KamLAND-Zen


SNO+

49

• SNO heavy water replaced by 780 tonnes of liquid scintillator - ~9500 PMTs - 1700 + 5700 tonnes ultra-pure water

shielding - New rope net to hold down the 6m

radius acrylic vessel- 6800’ underground in SNOLAB

• Stable loading of aqueous Te(OH)6 in SNO+ scintillator with good optical properties achieved by BNL

• 780 tonne detector and high 130Te isotopic abundance gives large isotope mass - 0.3 – 0.5% Te (by weight) in SNO+

Phase I is 2.34 – 3.9 tonnes of Te or 800 – 1333 kg of 130Te

- Percent level loading is feasible - 3% Te in SNO+ Phase II would give 8

tonnes of 130Te

•


SNO+: plan

50

2016:• Scintillator runs • Measure most background• Verify detector response models • 0.3% Te loading

2017:• Stringent 0νββ limits for 130Te • T1/2>9.4x1025 y (90% CL) • 3σ detection at T1/2= 6.9⋅1025 y • Verify purification techniques

Total background target = 21.3 events/yearPhase I

• 3% loading of Te (already demonstrated)• Plug-in replacement of SNO+ PMTs with

R5912-HQE’s• Additional wavelength-shifter/loading R&D

could further improve this• Containment bag could reduce amount of

isotope, improve cleanliness Can leverage KamLAND-Zen and BOREXINO knowledge- T1/2 > 7x1026 y (90% CL)- 3σ detection for T1/2> 4x1026 y

Phase II

→ Talk: J.Maneira


NEXT

51

• High Pressure Xenon (HPXe) TPC operating in EL mode.

• Filled with 100 kg of Xenon enriched at 90% in 136Xe (in stock) at a pressure of 15 bar.

• Event energy is integrated by a plane of radiopure PMTs located behind a transparent cathode (energy plane), which also provide t0.

• Event topology is reconstructed by a plane of radiopure silicon pixels (MPPCs) (tracking plane).

NEXT @ LSCStart operation

2nd half 2016


BEXT

52

Improve the tracking resolution• Resolution is dominated by longitudinal and transverse

diffusion. Addition of 0.3 % of CO2 reduce diffusion to ~1.5 mm/√m and improves reconstruction

Add a magnetic field• Measurement of the average curvature of the track,

separating single from double electrons

Replace PMTs by SiPMs• PMTs do not work in a magnetic field. SiPM's with

improved dark currents are presently available

Construction parameters• B field ~0.5 - 1 Tesla • L = 2 m, R = 1.5 m.• ~70,000 SiPMs in anode and 70,000

SiPMs in cathode • P = 10 bar: —> 815 kg• P = 15 bar: —> 1220 kg

DEMO++ ready by 2016

→ Talk: A.Laing


Sensitivity revisited

53

By generalizing:• n’ = M⋅z• B’ = B/z

and re-defining1. x’ ≡ n’⋅T ≡ S(cale)2. y’ ≡ B’⋅Δ ≡ P(erformance)

we completely get rid of the “z” block and get an effective and objective comparison

The conditionNB = (B’⋅ΔE)⋅(n’⋅T) = x’ ⋅y’ = P⋅S

is a lin in log-log scaleMeaning:

n’ ≡ number of “effective” moles of ββ isotopeB’ ≡ background rate normalized to the number of “effective” moles of ββ isotope

T ≡ tmeasB ≡ bkgΔ ≡ ΔEη ≡ a.i.S0⌫

1/2 / ✏i.a.

A

sM · tmeas

bkg ·�E

S0⌫1/2 / ✏

i.a.

AM · tmeas

NB >> 1

NB ≤ O(1) → “zero background”

z = η⋅ε/A

Biassoni et al., arXiv:1310.3870

• Sensitivity estimates depend obviously on the assumptions for the the expected performance and scale of the experiments.

• For the major upcoming experiments, in some cases they are measured with pilot experiments, in others they are modeled through Monte Carlo simulations

• In all cases the actual values will be soon measured when the experiments will start taking data.


90% sensitivities

54NME’s from J. Barea and F. Iachello, Phys. Rev. C 79 (2009) 044301

- NME- construction time and cost

Still missing ingredients:

Isotope Q FWHM Biso Performance Scale/time counts[1y]

Sensitivity[90% CL]

<mββ>[meV]

CUORE0 130Te 2527 5.0 1.70E-01 1.60E-01 7.30E+01 11.7 9.20E+24 290CUORE 130Te 2527 5.0 2.90E-02 2.67E-02 1.40E+03 37.1 9.82E+25 89GERDA-I 76Ge 2039 4.5 2.30E-02 1.09E-02 1.20E+02 1.4 4.59E+25 237GERDA-I up 76Ge 2039 3.0 4.10E-02 1.27E-02 2.90E+01 0.4 2.05E+25 354GERDA-II 76Ge 2039 3.0 1.20E-03 3.63E-04 2.90E+02 0.1 2.62E+26 99K-Zen 136Xe 2458 243.2 9.80E-03 3.23E-01 1.00E+03 332.9 2.43E+25 213K-Zen 2 136Xe 2458 243.2 3.10E-04 1.04E-02 1.20E+03 12.4 1.46E+26 87EXO-200 136Xe 2458 80.9 2.80E-03 4.36E-02 4.10E+02 17.7 4.14E+25 163EXO-200 2 136Xe 2458 57.8 1.20E-03 1.37E-02 4.10E+02 5.6 7.39E+25 122MJD 76Ge 2039 3.0 1.20E-03 3.68E-04 2.40E+02 0.1 2.22E+26 108SuperNEMO D 82Se 2997 138.6 1.10E-04 4.21E-03 2.30E+01 0.1 2.09E+25 209SNO+ 130Te 2527 267.3 3.70E-04 1.29E-02 1.30E+03 16.2 1.35E+26 76NEXT 136Xe 2458 19.7 8.00E-04 8.56E-03 1.70E+02 1.4 5.98E+25 136CUPID(TeO2) 130Te 2527 5.0 1.10E-03 1.03E-03 3.59E+03 3.7 8.03E+26 31CUPID(ZnMoO4) 100Mo 3034 5.0 1.10E-03 1.46E-03 2.50E+03 3.7 5.69E+26 38CUPID(Li2MoO4) 100Mo 3034 5.0 1.10E-03 1.12E-03 3.30E+03 3.7 7.37E+26 33CUPID(CdWO4) 116Cd 2814 5.0 1.10E-03 2.34E-03 1.60E+03 3.7 3.54E+26 63K-Zen II 136Xe 2458 243.2 2.00E-04 6.56E-03 1.90E+03 12.4 2.31E+26 69nEXO 136Xe 2458 57.8 3.80E-05 4.19E-04 1.30E+04 5.3 2.36E+27 22SNO+ 2 150Nd 3367 229.0 1.80E-03 1.18E-01 4.30E+02 50.4 2.59E+25 224SuperNEMO 82Se 2997 138.6 1.10E-04 4.21E-03 4.60E+02 1.9 1.42E+26 80


The sensitivity hill

55

Direction of maximum increase of F0ν

“Zero background” region

“Finite background” regionTransition region

Biassoni et al., arXiv:1310.3870

=


Fixed budget

56

Bkg FWHM Miso T1/20v (ZB) <mββ> a.i. Cost(iso) Prod. Cost(nat) Mtot

[c/keV/kg/y] [keV] [ton] [yr] [meV] [%] [€/g] [ton/y] €/g [ton]

MAGE 76Ge 8.40E-‐05 3 0.71 6.99E+27 19 7.8 70 165 1.20 0.79

CUPID ZnSe 82Se 1.56E-‐05 10 0.71 6.32E+27 12 9.2 70 2275 0.80 1.28

CUPID ZnMO4 100Mo 1.94E-‐05 9 0.50 3.63E+27 15 7.6 100 266000 0.02 1.15

CUPID CdWO4 116Cd 3.19E-‐05 6 0.33 2.09E+27 26 9.6 150 22200 0.06 1.05

CUPID TeO2 130Te 8.35E-‐06 5 3.85 2.34E+28 6 34.2 13 150 0.03 4.79

SNO++ 130Te 1.93E-‐07 270 3.85 5.37E+27 12 34.2 13 150 0.03 3.85

nEXO+ 136Xe 5.52E-‐07 58 6.25 2.09E+28 7 8.9 8 50 1.20 6.25

Kam-Zen 136Xe 1.28E-‐07 250 6.25 1.25E+28 9 8.9 8 50 1.20 6.25

BEXT 136Xe 2.13E-‐06 15 6.25 1.25E+28 9 8.9 8 50 1.20 6.25

• On a large scale, factors like cost and time can become important.• Enrichment is a common request. Let’s assume it accounts for half of the cost.• Let’s also assume gA=1.25 and request a background level such to maintain each

isotope in the ZB condition.• What is the reach of a 100M € experiment?


Fixed <mββ> sensitivity

57

Bkg FWHM Miso T1/20v (ZB) Cost(iso) a.i. Cost(iso) Prod. Cost(nat) Mtot

[c/keV/kg/y] [keV] [ton] [yr] [M€] [%] [€/g] [ton/y] €/g [ton]

MAGE 76Ge 2.29E-05 3 2.62 2.57E+28 184 7.8 70 165 1.20 2.92

CUPID ZnSe 82Se 9.68E-06 10 1.03 9.16E+27 72 9.2 70 2275 0.80 2.07

CUPID ZnMO4 100Mo 7.73E-06 9 1.13 8.19E+27 113 7.6 100 266000 0.02 2.88

CUPID CdWO4 116Cd 4.27E-06 6 2.24 1.40E+28 336 9.6 150 22200 0.06 7.81

CUPID TeO2 130Te 2.27E-05 5 1.27 7.72E+27 17 34.2 13 150 0.03 1.76

SNO++ 130Te 1.21E-07 270 5.53 7.72E+27 72 34.2 13 150 0.03 6.15

nEXO+ 136Xe 9.36E-07 58 3.32 1.11E+28 27 8.9 8 50 1.20 3.68

Kam-Zen 136Xe 1.30E-07 250 5.53 1.11E+28 44 8.9 8 50 1.20 6.14

BEXT 136Xe 2.17E-06 15 5.53 1.11E+28 44 8.9 8 50 1.20 6.14

• Let’s revers our argument and design an experiment with a sensitivity <mββ>=10 meV (gA=1.25 and a background level such to maintain each isotope in the ZB condition )

• What is its scale and cost?


Conclusions

58

• Neutrino physics has still a number of urgent open questions: ββ(0ν) is our probe of the Majorana/Dirac nature of neutrinos

• NME uncertainties are still an issue. Ongoing effort to understand the origin

• We are entering a very exciting period in which new sensitive experiments are starting operation

• New important informations are expected from the new group of experiments

• For future generation experiments the technical challenge is becoming daunting

• The effort will require always larger collaborations and presumably only few challenging experiments

• Preparation (contest) for future program has started

O.Cremonesi -‐ 08/05/2012 CCM @ LNGS 59


Neutrino oscillations

60

• neutrinos are massive fermions• there are 3 active neutrino flavors (να)• neutrino flavor states are mixtures of mass

states (νk)Atmospheric /Accelerator

Reactor /Accelerator

Solar /Reactor

|⌫↵i =X

k

U↵k|⌫ki

Precision measurements of neutrino parameters:

Provide most of our knowledge on neutrino mixing parameters and masses


Neutrino absolute mass scale

61

Cosmology (CMB+LSS+...)

Neutrinoless Double Beta decay

Beta decay end-point

Present sensitivity ≈ 0.1 eV ≈ 0.1 eV 2 eVFuture sensitivity 0.01 eV 0.01 eV 0.2 eV

Observable

Model dependency ↓ yes ↓ yes ↑ no

Three complementary methods• Different sensitivities• Complementary pro and cons


Cosmological bounds

62

Σ (eV) method ref.

0.17 CMB WMAP+Lyman-α SDSS U. Seljak et al. (SDSS), Phys. Rev. D 71, 103515 (2005)

0.18 Planck and WiggleZ galaxy clustering data

S. Riemer-SSørensen, D. Parkinson, and T. Davis, Phys. Rev. D 89, 103505 (2014)

0.14 Lyman-α SDSS + Planck M. Costanzi, B. Sartoris, M. Viel, and S. Borgani, JCAP 1410, 081 (2014)

0.153 Planck 2015 + Supernovae + BAO P. Ade et al. (Planck), (2015), arXiv:1502.01589 [astro-ph.CO].

0.14 SDSS-III+BAO+neutrino non-linearities N. Palanque-Delabrouille et al., JCAP 1502, 045 (2015)

• Cosmology is making impressive progress and is producing more and more stringent bounds on Σ (≡mΣ)

• The bound is pushed down to hundreds or tens of meV• All the predictions are strongly model dependent. • Complementary measurements needed!


Cosmological bounds

63

• Taken at the face value, these bounds show a tension with the inverted hierarchy scenario and indicate a preference for the direct neutrino mass hierarchy

• On the ββ(0ν) side this would strengthen the request of ton or multi-ton scale detectors to probe the range of mββ allowed by cosmology.

• However these results have to be taken with the needed care. • It is likely that on the cosmological side, other progress will be made soon.

It is possible to include the new constraints on Σ → S. Dell’Oro talk

Dell’Oro et al. arXiv:1505.02722


Quenching of gA in 0νββ

64

• In 0νββ many (higher order) multipoles contribute and q ~ 100-200 MeV. - Weak processes with other multipolarities:

- µ capture is not quenched- forbidden β decays provide both possible answers but average quenching is ~0.8

• NME evaluations miss some important ingredient?- missing correlations in the nuclear wave functions- single-particle model truncation - renormalization of the Gamow-Teller operator, including the inclusion of the two-body

currents- Adding more single-particle states reduced 2νββ NME of 136Xe (M. Horoi and

B.A.Brown, arXiv:1301.0256)- Inclusion of 2 body currents brings less quenching in M0ν than in M2ν (Engel,

Simkovic, Vogel, PRC89, 064308 (2014))

• NME Summary:• The calculated M0ν by different methods are within the factor 2-3 of each other,• There is, at present, no convincing way to decide which is more realistic and which is

not.• In all methods the M0ν change relatively slowly from one nucleus to another. Hence

from that point of view there are no preferred nuclei.• The problem of gA quenching needs to be studied further. If the main explanation of

quenching are the two-body axial currents, the M0ν will be reduced only by 20-30%.

•


Requirements

65

Half life Signal rate[yr] [cts/(ton yr)]

~1025 ~500

5×1026 ~10

5×1027 ~1

>1029 <0.05

Present exp. sensitivities

Goal of next generation exp.

• Large exposure (ε f MT) of ββ-isotope• Background-free operaration in 0νββ region• Best possible energy resolution to discriminate 0νββ from 2νββ• Several isotopes

~T ~T1/2


GERDA-II: LAr veto

66

E resolution at 2.6 MeV PSD survival of FEP

Phase II readout 2.8 keV (2.6 keV with ZAC) 12%

Phase I readout 3.3 keV (2.9 keV with ZAC) 11%


Cryogenic set-up

67

Sub-systems: • Cryostat• Pulse tubes• Dilution unit

• Fast cooling system• Platforms• Suspensions

• Lifting system• Wiring• Low T shields

• Calibration system

Size:300K Shield: ∅1.7 x h 3.1

Weight:Detector: ~1 tonPbshields: ~10 tonsCu shields/flanges: ~8 tons

Main Support Plate (MSP)

Hoist system (winch)

Y beam

DCS motion system

Detector suspension

Dilution Unit

Pulse tube

Cold lead shield (top)

Cold roman lead shield (side)

Detector~

3 m

eter

s

300 K40 K4 K

600 mK50 mK10 mK


CUPID roadmap

68

A number of ongoing R&D’s has already demonstrated the feasibility of the proposed new detector technologies (arXiv:1504.03612).

• Improvements and scalability are the new goals

CUPID

TeO2

NO TeO2

Surface effects

Al Film

Scintillating foil

ZnSe

ZnMoO4 / Li2MoO4

CdWO4

Enrichment

Cherenkov

Luke effect

TES

MKID

MMC

Sensitivity to bulk / surface

alphas

Sensitivity to surface

alphas / betas ROI

< 2615 keV

ROI > 2615 keV

Scintillation

Isotope/technology selection criteria:• Dedicated experimental tests and verifiable simulations for the background target• Energy resolution not worse than that achieved in CUORE (5 keV FWHM)

• Readiness for construction: 2018 (technical limit)• Construction time: 5 years

• Keep scalability shown by CUORE: from single-module devices, to a full-tower demonstrator prototypes, to the full CUORE-sized array

• Reproducibility tested with an array of at least 8 modules operated underground in conditions similar to those expected in CUPID

• Cost and schedule of the enrichment process and of the crystal production compatible with a timely realization of the experiment.

• Compatibility of the CUPID technology with the existing CUORE infrastructure (mechanics, cryogenics, electronics)

→ Talks: M.Vignati, L.Pattavina→ Posters: F.Danevich


CUPID Sensitivity goal

69

Detector mass (kg)

Isotope fiducial

mass (kg)

T1/2(90%) [1027 y]

(@10 years)

mββ (90%)[meV]

(@10 years)

T1/2 discovery sensitivity (3σ) (@10 years)

mββ discovery sensitivity (3σ)(@10 years)

130TeO2 750 543 5.1 6-15 4.9 6-15

Zn100MoO4 540 212 2.2 6-17 2.1 7-17

Zn82Se 670 335 4.2 6-19 4.0 6-19

116CdWO4 980 283 3.0 8-15 2.9 8-15

Energy resolution at endpoint (FWHM) < 5 keV

Event selection efficiency in fiducial volume 75-90%

Background within FWHM of endpoint < 0.02 counts/(ton·year)


THEIA

70

• Advanced scintillation detector (arXiv/1409.5864)• 50-100 kton Water Based Liquid Scintillator target

• High coverage with ultra-fast high efficiency photon sensors• 4800 mwe underground (Homestake)• Comprehensive low-energy program: solar neutrinos,

supernovae, DSNB, proton decay, geo-neutrinos, NLDBD• In the LBNF beam: long baseline program complementary to

proposed LAr detector

• Directional resolution for different Cherenkov light yields

• 50 kt detector• 50% reduction of 8B• Particle ID / coincidence tags for int r/a • Rfit > 5.5 m from PMT's (30 kt fid)• 0.5% loading (natTe) in 50kt → 50t

130Te

• Future sensitivity into NH region- 3σ discovery in 10 y (mββ=15 meV)


Backgrounds

71

Mod. Phys. Lett. A 21, 1547 (2006).

KKDC-06 50 c/ROI/t/y

Phys. Lett. B 586, 198 (2004).

KKDC-04 360 c/ROI/t/y

PRD 65, 092007 (2002); 70, 078302 (2004)

IGEX 960 c/ROI/t/y

Cuoricino 1440 c/ROI/t/y

PRL. 95, 142501


Hot cases

72

To optimize the experimental conditions to open a new and challenging research field, experimental campaigns using, as probe, few targets of interest as candidate nuclei for the 0νββ decay such as 76Se, 76Ge, 116Cd, 130Te have been proposed


CEX reactions factorization

73

neutrinoless double beta decay - taup conference · 2015. 9. 10. · -interacting boson model;...

Documents