TESTING DAMA/LIBRA RESULT WITH ANAIS-112 EXPERIMENT

J. Amaré, I. Coarasa, S. Cebrián, E. García, M. Martínez, M.A. Oliván, Y. Ortigoza, A. Ortiz de Solórzano, J. Puimedón, A. Salinas, M.L. Sarsa, J.A. Villar✝, P. Villar

RENATA Thematic Meeting on Dark Matter @ LSC7th February 2018

Outlin

e

• ANAIS scientific case and experiment goals• Other experiments sharing these goals • ANAIS status• Summary and outlook

• Schedule and experimental planning• Staff (recent, present and projected)• Funding requirements

• Confirmation of DAMA-LIBRA modulation signal -> same target and technique / different experimental approach / different environmental conditions affecting systematics

• At Canfranc Underground Laboratory, @ SPAIN (under 2450 m.w.e.)

• 3x3 matrix of 12.5 kg cylindrical modules = 112.5 kg of active mass

Annual modulation with NAI Scintillators

AN

AIS e

xperim

ent

at LS

C

Dark M

atter A

nnua

lMod

ulationvorbital = 30 km/s

vsun = 230 km/s

Positive identification of WIMP against backgroundscould be allowed by analyzing DM signatures, as annualmodulation in the detection rate

Small effect (<7% of S0)

Inverse modulation at verylow energies

It depends strongly on the halo model

ω=2π/365 d-1

t0 ∼1st June

Dark M

atter A

nnua

lMod

ulationvorbital = 30 km/s

vsun = 230 km/s

Positive identification of WIMP against backgroundscould be allowed by analyzing DM signatures, as annualmodulation in the detection rate

Small effect (<7% of S0)

Inverse modulation at verylow energies

It depends strongly on the halo model

ω=2π/365 d-1

t0 ∼1st June

Expe

rimen

tal S

ituation

~250kg NaI(Tl) scintillators @ LNGS

Total exposure:DAMA/NaI (100 kg NaI, 7 years, completed in 2002)+ DAMA/LIBRA (250 kg NaI, 7 cycles, + ongoing)→ total exposure: 1.33 ton x year

DAMA/LIBRA experiment

Data taking ongoing after upgrading PMTs … Results probably released soon

Expe

rimen

tal S

ituation

DAMA/LIBRA experiment

Model Independent Result

Am = 0.0112 ±0.0012 cpd/kg/keVeeT = (0.998 ±0.002 ) yT0 = (144 ±7) d (2nd June=153)No modulation above 6 keV

Evidence (9.3 σ C.L.) of an annual modulation of the single-hit events in the (2–6) keVee energy region satisfying all the requests of a DM component in the galactic halo

SI interactions From N.J. Smith at TAUP 2017, Sudbury

Expe

rimen

tal S

ituation

Expe

rimen

tal S

ituation

One single experiment has reported evidence of a signal compatible with Dark Matterobserving a model independent annual modulation

Other much sensitive experiments do not have any hint, and in fact they are reachingthe limiting NEUTRINO FLOOR -> However, comparison is model – dependent

CONTROVERSIAL issue for more than a decadeIs possible a model independent confirmation or refutation?Can DAMA/LIBRA result be a door into new Physics or just systematics?

Many WIMP scenarios considering halo and particle models have been considered and reconciling all results seems very difficult, but there is discovery potential, may be in unexpected directions

Expe

rimen

tal S

ituation

Experiments aiming at testing the DAMA LIBRA signal

NaI scintillators (same target and technique)

NaI(Tl)

CsI

KIMS @ Y2L (2013 - …)

DM-ICE @ South Pole (2011 - …)

Joint in COSINE -100 project

Taking Data from September 2016 at Yang Yang Underground Lab106 kg of NaI(Tl) from same provider / quality ANAIS’s crystalsusing a Liquid Scintillator Veto System

Expe

rimen

tal S

ituation

Experiments aiming at testing the DAMA LIBRA signal

NaI scintillators (same target and technique)

Sodium-iodide with Active Background RejectionPlanning proof-of-principle with 5 kg of NaIData taking is planned in Gran Sasso Underground Laboratory (Italy) & Stawell Underground Physics Laboratory (SUPL), in Australia

KAMLAND-PICO @ KAMIOKA

SABRE project

AN

AIS e

xperim

ent

at LS

CAnnual modulation with NAI Scintillators

• Energy threshold at or below 2 keVee• High light collection per energy unit• Effective filtering protocols for non-bulk scintillation / robust estimates of

acceptance efficiencies

• Background as low as possible below 10 keVee (at or below a few cpd/kg/keV level)

• Stability of operation and monitoring of possible systematics

AN

AIS S

tatus

• 12.5 kg cylindrical NaI(Tl) detectors built @ AS, Co (US) from NaI selected powder & developing specific radiopurity protocols

• housed in OFE copper @ AS• Mylar windows allow for LE calibration

Last three modules received at LSC in March 2017

2xHE PMT Ham12669SEL2 model coupled to each module at LSC clean room

• High Quantum Efficiency / Low dark current • Electroformed copper housing made at LSC facility• Voltage dividers made of Cuflon PCB• PMT Radioactivity screening at LSC

AN

AIS S

tatus

ANAIS-112 consists of a matrix of 3x3 modules and was installed in March 2017 after the reception of the last three AS modules

ANAIS-112 detectors testing and commissioning run started immediately and was fully operative by June-July 2017 for detector calibration and general assessment

AN

AIS S

tatus

ANAIS-112 scintillators veto system was installed in May 2017

ANAIS-112 neutron shielding was installed in July 2017. It consists of water tanks and polyethylene (40 cm)It allows partial periodic opening for calibrations

AN

AIS S

tatus

• DAQ hardware and software designed and tested with previous set-ups -> ROBUST &> SCALABLE

• Individual PMT signals digitized and fully processed• Trigger at phe level for each PMT• Logical AND coincidence in 200ns window for each module

triggering• Redundant energy conversion

• Preamplifiers designed at UZ• Electronics at air-conditioned-room to decouple from

temperature fluctuations in Hall B

AN

AIS S

tatus

Calibrations every 2 weeks at low energy

109Cd sources on flexible wires allowing the simultaneous calibration of the 9 modulesEnergies 11.9 keV, 22.6 keV and 88.0 keV

AN

AIS S

tatus

First 20 days of data taking in ANAIS-112 commissioning period

First six months of ANAIS-112DM run, from 03-08-17 until 30-01-18

159,12 days of live time accumulated

AN

AIS S

tatus

First 20 days of data taking in ANAIS-112 commissioning period

First six months of ANAIS-112DM run, from 03-08-17 until 30-01-18

159,12 days of live time accumulated

AN

AIS S

tatus

First 20 days of data taking in ANAIS-112 commissioning period

Liquid nitrogen supply shortcuts

First six months of ANAIS-112DM run, from 03-08-17 until 30-01-18

AN

AIS S

tatus

88.0 keV22.6 keV11.9 keV

Periodic 109Cd calibrations

They allow monitoring (and if necessary correcting) possible gain drifts in the modules.

Evolution of the positions of 109Cd lines along the six months of measurement.

Most of the modules have been very stable during this period of data taking.

AN

AIS S

tatus

Detector PMT/set-up Total Light Collection (phe/keV)

D0 Ham R12669 / ANAIS25Ham R12669 / ANAIS37Ham R12669 / A37D3

Ham R12669 /ANAIS112

15.6 ± 0.215.3 ± 0.115.1 ± 0.114.6± 0.1

D1 Ham R11065 / ANAIS25Ham R12669 / ANAIS25-III

Ham R12669 / ANAIS37Ham R12669 /ANAIS112

12.6 ± 0.115.2 ± 0.114.4 ± 0.114.7 ± 0.1

D2 Ham R12669 / ANAIS37Ham R12669 /ANAIS112

15.4 ± 0.114.6 ± 0.1

D3 Ham R12669 / A37D3Ham R12669 /ANAIS112

15.2 ± 0.514.6 ± 0.1

D4 Ham R12669 / A37D5Ham R12669 /ANAIS112

14 ± 114.5 ± 0.1

D5 Ham R12669 / A37D5Ham R12669 /ANAIS112

15 ± 114.3 ± 0.1

D6 Ham R12669 /ANAIS112 12.7 ± 0.1D7 Ham R12669 /ANAIS112 14.9 ± 0.1D8 Ham R12669 /ANAIS112 16.0 ± 0.1

Excellent light collection

A factor of 2 larger than thepublished light collection for

DAMA/LIBRA detectors

AN

AIS S

tatus

M.A. Oliván et al.,Astroparticle Physics 93 (2017) 86-95

Periodic monitoring of light collection along ANAIS-112 DM run.

Evolution of the light collection estimates per PMT and per module, using the periodic Cd-109 calibration (22.6 keV line) and the photoelectron area distribution derived from background runs.

It is to remark the stability of the total light collection per module along the data taking.

PMT0PMT1PMT0+PMT1

AN

AIS S

tatus

Monitoring of environmental parameters was ongoing by the start of ANAIS-112 DM run.

It consists of several windows for monitoring LN2 flux; temperatures at electronics, inner shielding, laboratory, preamplifiers, etc.; radon content in laboratory air; relative humidity; HV supply to every PMT; muon rates; etc. All the data are saved every few minutes and alarms have been set on the most relevant parameters sending an alarm message to ANAIS GLIMOS through Telegram.

AN

AIS S

tatus

Monitoring of environmental parameters was ongoing by the start of ANAIS-112 DM run.

It consists of several windows for monitoring LN2 flux; temperatures at electronics, inner shielding, laboratory, preamplifiers, etc.; radon content in laboratory air; relative humidity; HV supply to every PMT; muon rates; etc. All the data are saved every few minutes and alarms have been set on the most relevant parameters sending an alarm message to ANAIS GLIMOS through Telegram.

AN

AIS S

tatus

Monitoring of environmental parameters was ongoing by the start of ANAIS-112 DM run.

It consists of several windows for monitoring LN2 flux; temperatures at electronics, inner shielding, laboratory, preamplifiers, etc.; radon content in laboratory air; relative humidity; HV supply to every PMT; muon rates; etc. All the data are saved every few minutes and alarms have been set on the most relevant parameters sending an alarm message to ANAIS GLIMOS through Telegram.

AN

AIS S

tatus

Monitoring of environmental parameters was ongoing by the start of ANAIS-112 DM run.

It consists of several windows for monitoring LN2 flux; temperatures at electronics, inner shielding, laboratory, preamplifiers, etc.; radon content in laboratory air; relative humidity; HV supply to every PMT; muon rates; etc. All the data are saved every few minutes and alarms have been set on the most relevant parameters sending an alarm message to ANAIS GLIMOS through Telegram.

AN

AIS S

tatus

Spectra at low energy in coincidence with a high-energy gamma at 1460.5 keV (1274.5 keV) in another module for all the modules in the ANAIS-112 set-up. These spectra have been used for the determination of the potassium contents, but also for calibrating down to the threshold our experiment.

AN

AIS S

tatusWe are triggering

down to 1 keVee

PMT noise filtering:

C. Cuesta et al., EPJ C 74 (2014) 3150

Multiparametric cuts on:− Number of peaks in the pulse (n>2 in each PMT)− Temporal parameters of the pulse − Asymmetry in light sharing

Acceptance efficiency curvesfrom external calibration data

AN

AIS S

tatus

Good linearity in all the modulesA

NA

IS S

tatus

The ANAIS-112 data taken in the commissioning run up to July, 2017, have been analysed to understand the relevant background sources.Background spectra at the low energy region in ANAIS-112 commissioning run; first and latest data are compared, showing the decay of cosmogenics in the last received detectors.

First 29.2 days (March-April)

Last 30.1 days (June-July)

AN

AIS S

tatus

Preliminary background models considering the measured crystal activities and the ANAIS-112 configuration, point to equivalent relevant background sources in the very low energy region:

40K and 22Na peaks and 210Pb (bulk+surface) and 3H continua are the most significantcontributions in the very low energy region

Backgroundsources wellunderstood

AN

AIS S

tatus

J. Amaré et al.Astrop. Phys. 97

(2018) 96-105

J. Amaré et al.Eur. Phys. Journal C

76 (2016) 1-15

J. Amaré et al.JCAP02 (2015) 046

S. Cebrián et al,Astrop. Phys. 37

(2012) 60-69

(Talk by Susana Cebrián yesterday)

0.20 mBq/kg 3H

0.09 mBq/kg 3H

0.09 mBq/kg 3H

AN

AIS S

tatus

AN

AIS-112 S

ensitivity

Detection limit at 90% C.L. for a critical limit at 90% C.L. for ANAIS-112• Estimated average background from D0-D5 measured levels (corrected for cutefficiency)• 2-6 keVee region• 5 years

Dark matter hypothesisDAMA region: JCAP04(2009)10

ANAIS-112 can detect the annual modulation in the 3σ region compatible with the

DAMA/LIBRA result

90% probability of detectingan annual modulation signal at

90% C.L.

https://arxiv.org/pdf/1704.06861.pdf /

AN

AIS-112 S

ensitivity

Detection limit at 90% C.L. for a critical limit at 90% C.L. for ANAIS-112• Estimated average background from D0-D5 measured levels (corrected for cutefficiency)• 2-6 keVee region• 5 years

DAMA region: JCAP04(2009)10Model-independent annual modulation

Detection Limit for annual modulation amplitude: forANAIS-112 parameters

Factor of Merit: from the variance of the estimator of themodulated amplitude

ANAIS-112 has a detection limit forannual modulation lower than the

measured amplitude by DAMA/LIBRA: 0.0112 ± 0.0012 cpd/kg/keVee

https://arxiv.org/pdf/1704.06861.pdf /

SU

MM

AR

Y A

ND

OU

TLO

OK

ANAIS-112 has been installed successfully at LSC:112.5 kg (3x3 crystals matrix) of NaI(Tl) built at AS

-outstanding light collection-good background understanding

Electronics/Acquisition has been fine-tunedDark matter run started data taking by August, 3rd, 2017Data taking expected to go on in these conditions during the next two years

Control populations (muon-related events, blank module…) in preparationBlind annual modulation analysis foreseen after one year data taking

Good sensitivity prospects for exploring the DAMA/LIBRA signal:5 years data taking needed for a 3 sigma significant result

SU

MM

AR

Y A

ND

OU

TLO

OK

Scintillation Quenching Factor measurement for nuclear recoils: we want to investigate the possible dependence of this parameter on the crystal quality (impurities content for instance). We have three small AS crystals of different quality, and an agreement with Phil Barbeau, at Duke University, to carry out such measurements @ TUNL laboratories.

ANAIS + COSINE112.5 kg 55 kg 52 kg

Canfranc

Boulby

Yangyang

COMBINED ANALYSIS of 220 kg NaI(Tl) with present background levels

112.5 kg at Canfranc, Spain

+

107 kg at Yangyang, South Corea

Data taking of both set-ups started in 2016/17

Two years of data taking could explore the whole DAMA-LIBRA singled out parameter space

SU

MM

AR

Y A

ND

OU

TLO

OK

SU

MM

AR

Y A

ND

OU

TLO

OK

Installation of a blank module besides ANAIS-112 using similar PMTs, electronics and acquisition program in order to have a population of events without DM signal. It could be installed by spring 2018 at LSC. We are still considering this issue.

We plan to start researching the possibilities of applying Si PMs to the light readout of NaI(Tl) scintillator modules. Our present experiment is strongly limited by the rejection of PMT events down to 1 keVee, that we believe could be overcome by moving to a different light detection approach. We are considering possible collaborations.

LSV System could be faced as second phase depending on the achieved results. We are considering possible collaborations.

Making ANAIS data public after use to allow forindependent analysis

AN

AIS S

CH

ED

ULE

ANAIS schedule: Phase 1

2017 2018 2019

ANAIS-112 DM Run started on August 3rd

ANAIS-112 DM Run will end by the first week of August 2019BLIND analysis searching for modulation

R+D on application of Si PMs for the light readout of ANAIS-112 modules

ANAIS-112 DM Run first 2 years

AN

AIS S

CH

ED

ULE

ANAIS schedule: Phase 1 / Phase 2

2019 2020 2021 2022 2023

ANAIS-112 DM Run Phase 1 will continue for one year

ANAIS-112 DM Run Phase 2 will last for at least two more years

UPGRADING of ANAIS-112 detectors(still to be decided and funded)

ANAIS-112 DM Run last 2 years

AN

AIS S

TA

FF

ANAIS research team consists presently:

5 Permanent Researchers working full time in ANAIS

1 Permanent Researcher working at half time (working in T-REX)1 Permanent Researcher working at half time just incorporated by 2018, February 1st (working in CUORE)

1 Technical Engineer working at half time in ANAIS

1 PhD funded by Aragon Government Fellowship Program1 PhD to be hired by FPI program (next future)

We have lost in the last year: 1 Permanent, 1 Post-doc, and 2 Technical Positions (hired within the previous MINECO project)1 half-time Technician will be hired with the present MINECO project (next future)

No important changes are

foreseen in the next five years

AN

AIS F

UN

DIN

G

FUNDING allocated for 2018-2019: 80.000 €Project FPA-2017-83133P “Testing DAMA/LIBRA with ANAIS-112 experiment”Scarce, but we'll make for running the first two years plus some R+D on Si PMs

FUNDING required for 2020-2023: 120.000 € for running in similar conditionsAdditional funding for UPGRADING, if considered: either Si PMs light readout or Liquid Scintillator Veto System could imply an investment of about 100.000 € to be confirmed in the next two years, along the R+D phase, both the convenience of the upgrading and the funding required

FUNDING only via MINECO research project calls

Thank you for your attention