ANAIS-112
ANAIS (Annual modulation with NaI Scintillators) is a dark matter direct detection experiment located at the Canfranc Underground Laboratory (LSC), in Spain.
Legal status | Taking data since 03-08-2017 |
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Purpose | Testing the positive annual modulation signal reported by DAMA/LIBRA |
Headquarters | Canfranc Underground Laboratory, Spain |
Fields | Dark Matter search, Astroparticle Physics |
Website | https://gifna.unizar.es/anais/ |
ANAIS' goal is to confirm or refute in a model independent way the DAMA/LIBRA[1][2][3] experiment positive result: an annual modulation in the low-energy detection rate having all the features expected for the signal induced by weakly interacting dark matter particles (WIMPs) in a standard galactic halo. This modulation is produced as a result of the Earth rotation around the Sun. A modulation with all the characteristic of a Dark Matter (DM) signal has been observed for about 20 years by DAMA/LIBRA, but it is in strong tension with the negative results of other DM direct detection experiments.[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Compatibility among the different experimental results in most conventional WIMP-DM scenarios is actually disfavored,[20][21] but it is strongly dependent on the DM particle and halo models considered. A comparison using the same target material, NaI(Tl), is more direct and almost model-independent.
Experimental set up and performance[22]
ANAIS-112 experimental setup consists of 112.5 kg of NaI(Tl), distributed in 9 cylindrical modules, 12.5 kg each and built by Alpha Spectra Inc., arranged in a 3 × 3 configuration.
Among the most relevant features of ANAIS- 112 modules, it is worth highlighting its remarkable optical quality, which combined to using high quantum efficiency Hamamatsu photomultipliers (PMTs) results in a very high light collection, at the level of 15 photoelectrons (phe) per keV in all the nine modules.[23] The signals from the two PMTs coupled to each module are digitized at 2 GS/s in a 1.2 μs window with high resolution (14 bits). The trigger requires the coincidence of the two PMT trigger signals in a 200 ns window, while the PMT individual trigger is set at the single phe level.
Another interesting feature is a Mylar window in the middle of one of the lateral faces of the detectors, which allows to calibrate simultaneously the nine modules with external x-ray/gamma sources down to 10 keV in a radon-free environment. A careful low energy calibration of the region of interest (ROI), from 1 to 6 keV, is carried out by combining information from external calibrations and background. External calibrations with a 109Cd source are performed every two weeks, and every 1.5 months energy depositions at 3.2 and 0.87 keV from 40K and 22Na internal contaminations in one ANAIS module are selected by profiting from the coincidence with a high energy gamma in a second module.
The ANAIS-112 experiment is installed inside a shielding consisting of an inner layer of 10 cm of archaeological lead and an outer layer of 20 cm of low activity lead. This lead shielding is encased into an anti-radon box, tightly closed and kept under overpressure with radon-free nitrogen gas. The external layer of the shielding (the neutron shielding) consists of 40 cm of a combination of water tanks and polyethylene bricks. An active veto made up of 16 plastic scintillators is placed between the anti-radon box and the neutron shielding, covering the top and sides of the set-up allowing to effectively tag the residual muon flux onsite along the ANAIS-112 data taking. ANAIS-112 was commissioned during the spring of 2017 and it started the data-taking phase at the hall B of the LSC on 3 August 2017 under 2450 m.w.e. rock overburden. The "live time" of the experiment, useful for analysis, is more than 95%, allowing for the high duty cycle achieved. Down time is mostly due to the periodical calibration of the modules.
A background understanding has been achieved, except in the [1-2] keV energy region, where the background model underestimates the measured event rate.[24] Crystal bulk contamination is the dominant background source, being 210Pb, 40K, 22Na, 3H contributions the most relevant ones in the region of interest. Considering altogether the nine ANAIS-112 modules, the average background in the ROI is 3.6 cpd/kg/keV after three years of data taking,[25] while DAMA/LIBRAphase2 background is below 0.80 cpd/kg/keV in the[1–2] keV energy interval, below 0.24 cpd/kg/keV in the [2–3] keV energy interval, and below 0.12 cpd/kg/keV in the [3–4] keV energy interval.[3]
Annual modulation analysis and results
The development of filtering protocols based on the pulse shape and light sharing among the two PMTs has been crucial to fulfill the ANAIS-112 goal since the trigger rate in the ROI is dominated by non-bulk scintillation events. The determination of the corresponding efficiency is very important, and it is calculated using 109Cd, 40K and 22Na events. It is very close to 100% down to 2 keV, and then decreases steeply to about 15% at 1 keV, where the analysis threshold is set.[22]
A blind protocol for the annual modulation analysis of ANAIS-112 data has been applied: single-hit events in the ROI are kept blinded during the event selection. Up to now, three unblindings of the data have been carried out: at 1.5 years,[26] at 2 years,[27] and 3 years,[25] which correspond to exposures of 157.55, 220.69, and 313.95 kg×y, respectively. ANAIS-112 annual modulation search is performed in the same regions explored by DAMA/LIBRA collaboration, [1–6] keV and [2–6] keV, fixing the period to 1 year and the maximum of the modulation to 2 June.
To evaluate the statistical significance of a possible modulation in ANAIS–112 data, the events rate of the nine detectors is calculated in 10-days bins, and it is minimized χ2 = Σi (ni − μi)2/σ2i, where ni is the number of events in the time bin ti (corrected by live time and detector efficiency), σi is the corresponding Poisson uncertainty, accordingly corrected, and μi is the expected number of events at that time bin, that depends on the background model and can be written as: μi = [R0φbkg(ti) + Smcos(ω(ti − t0))]M∆E∆t.
Here, R0 represents the non-modulated rate in the experiment, is the probability distribution function (PDF) in time of any non-modulated component, Sm is the modulation amplitude, ω is fixed to 2π/365 d = 0.01721 rad d−1, t0 to −62.2 d (time origin has been taken on 3 August and then the cosine maximum is on 2 June), M is the total detector mass, ∆E is the energy interval width, and ∆t the time bin width. R0 is a free parameter, while Sm is either fixed to 0 (for the null hypothesis) or left unconstrained, positive or negative (for the modulation hypothesis).
The null hypothesis is well supported for the 3-years data in both energy regions, being the results for the two background models (a single exponential or a PDF based on the Monte Carlo background model) compatible. The standard deviation σ(Sm) is slightly lower when detectors are considered independently, as expected following a priori sensitivity analysis.[28] Therefore, this fit is chosen to quote the ANAIS-112 annual modulation final result and sensitivity for three-year exposure. The best fits are incompatible with the DAMA/LIBRA result at 3.3 and 2.6 σ in [1-6] and [2-6] keV energy regions, for a sensitivity of 2.5 (2.7)σ at [1–6] keV ([2–6] keV). ANAIS-112 results for 1.5,[26] 2[27] and 3 years[25] of data-taking fully confirm the sensitivity projection.
Sm (cpd/kg/keV) | |||
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Energy region | ANAIS-112[25] | DAMA/LIBRA[29] | COSINE-100[30] |
[1-6] keV | -0.0034 ± 0.0042 | 0.0105 ± 0.0011 | - |
[2-6] keV | 0.0003 ± 0.0037 | 0.0102 ± 0.0008 | 0.0092 ± 0.0067 |
ANAIS-112 results support the prospects of reaching a sensitivity above 3σ in 2022, within the scheduled 5 years of data taking.
Several consistency checks have been carried out (changing the number of detectors entering into the fit, considering only the first two years or the last two years, or changing the time bin size), concluding that there is no hint supporting relevant systematical uncertainties in the result. The performance of a large set of Monte Carlo pseudo-experiments sampled from the background model guarantees that the fit is not biased. A frequency analysis have also been conducted, and the conclusion is that there is no statistically significant modulation in the frequency range searched in the ANAIS-112 data.[25]
Future prospects
ANAIS-112 sensitivity limitation is mostly due to the high background in the ROI, but in particular in the region from 1 to 2 keV. In this context, the application of machine learning techniques based on Boosted Decision Trees (BDTs), under development at present, could improve the rejection of these non-bulk scintillation events. Preliminary results point to a relevant sensitivity improvement.[31] Extending the data taking for one more year, until August 2023, could allow testing DAMA/LIBRA at the 4σ level.
One possible systematics affecting the comparison between DAMA/LIBRA and ANAIS result is a possible different detector response to nuclear recoils, because both experiments are calibrated using x-rays/gammas. It is well known that scintillation is strongly quenched for energy deposited by nuclear recoils with respect to the same energy deposited by electrons. Measurements of Quenching Factors (QF) in NaI scintillators are affected by strong discrepancies. ANAIS-112 detectors QF are being determined after measurements at TUNL.[32] In addition, a complete calibration program for the experiment using neutron sources onsite is being developed.
ANAIS-112 data are available upon request. After the scheduled five-year data taking, data will be released.
External links
References
- Bernabei, R.; Belli, P.; Bussolotti, A.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Dai, C. J.; d'Angelo, A.; Di Marco, A. (1 September 2020). "The DAMA project: Achievements, implications and perspectives". Progress in Particle and Nuclear Physics. 114: 103810. Bibcode:2020PrPNP.11403810B. doi:10.1016/j.ppnp.2020.103810. ISSN 0146-6410. S2CID 225281419. Retrieved 19 April 2022.
- Bernabei, R.; Belli, P.; Caracciolo, V.; Cerulli, R.; Merlo, V.; Cappella, F.; d'Angelo, A.; Incicchitti, A.; Dai, C. J. (10 October 2021). "The dark matter: DAMA/LIBRA and its perspectives". arXiv:2110.04734 [astro-ph, physics:hep-ex, physics:hep-ph, physics:physics]. arXiv:2110.04734.
- Bernabei, Rita; Belli, Pierluigi; Bussolotti, Andrea; Cappella, Fabio; Caracciolo, Vincenzo; Cerulli, Riccardo; Dai, Chang-Jiang; D'Angelo, Annelisa; Di Marco, Alessandro (6 November 2018). "First Model Independent Results from DAMA/LIBRA–Phase2". Universe. 4 (11): 116. Bibcode:2018Univ....4..116B. doi:10.3390/universe4110116. ISSN 2218-1997.
- PandaX-II Collaboration; Cui, Xiangyi; Abdukerim, Abdusalam; Chen, Wei; Chen, Xun; Chen, Yunhua; Dong, Binbin; Fang, Deqing; Fu, Changbo (30 October 2017). "Dark Matter Results from 54-Ton-Day Exposure of PandaX-II Experiment". Physical Review Letters. 119 (18): 181302. arXiv:1708.06917. Bibcode:2017PhRvL.119r1302C. doi:10.1103/PhysRevLett.119.181302. PMID 29219592. S2CID 29716579. Retrieved 19 April 2022.
- PandaX-4T Collaboration; Meng, Yue; Wang, Zhou; Tao, Yi; Abdukerim, Abdusalam; Bo, Zihao; Chen, Wei; Chen, Xun; Chen, Yunhua (23 December 2021). "Dark Matter Search Results from the PandaX-4T Commissioning Run". Physical Review Letters. 127 (26): 261802. arXiv:2107.13438. Bibcode:2021PhRvL.127z1802M. doi:10.1103/PhysRevLett.127.261802. PMID 35029500. S2CID 236469421. Retrieved 19 April 2022.
- XENON Collaboration; Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser, L.; Amaro, F. D.; Antochi, V. C.; Angelino, E. (17 December 2019). "Light Dark Matter Search with Ionization Signals in XENON1T". Physical Review Letters. 123 (25): 251801. arXiv:1907.11485. Bibcode:2019PhRvL.123y1801A. doi:10.1103/PhysRevLett.123.251801. PMID 31922764. S2CID 198953427. Retrieved 19 April 2022.
- XENON Collaboration 7; Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser, L.; Amaro, F. D.; Anthony, M.; Arneodo, F. (12 September 2018). "Dark Matter Search Results from a One Ton-Year Exposure of XENON1T". Physical Review Letters. 121 (11): 111302. arXiv:1805.12562. Bibcode:2018PhRvL.121k1302A. doi:10.1103/PhysRevLett.121.111302. hdl:11245.1/4e39d67c-7ddb-4254-aa30-ab2430abc279. PMID 30265108. S2CID 51681150. Retrieved 19 April 2022.
- LUX Collaboration; Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P. (11 January 2017). "Results from a Search for Dark Matter in the Complete LUX Exposure". Physical Review Letters. 118 (2): 021303. arXiv:1608.07648. Bibcode:2017PhRvL.118b1303A. doi:10.1103/PhysRevLett.118.021303. hdl:10044/1/45091. PMID 28128598. S2CID 206284055. Retrieved 19 April 2022.
- DEAP Collaboration; Ajaj, R.; Amaudruz, P.-A.; Araujo, G. R.; Baldwin, M.; Batygov, M.; Beltran, B.; Bina, C. E.; Bonatt, J. (24 July 2019). "Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB". Physical Review D. 100 (2): 022004. arXiv:1902.04048. Bibcode:2019PhRvD.100b2004A. doi:10.1103/PhysRevD.100.022004. S2CID 119342085. Retrieved 19 April 2022.
- DarkSide Collaboration; Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Araujo, G. R.; Asner, D. M.; Ave, M.; Back, H. O. (23 August 2018). "Low-Mass Dark Matter Search with the DarkSide-50 Experiment". Physical Review Letters. 121 (8): 081307. arXiv:1802.06994. Bibcode:2018PhRvL.121h1307A. doi:10.1103/PhysRevLett.121.081307. hdl:2434/631601. PMID 30192596. S2CID 52173907. Retrieved 19 April 2022.
- SuperCDMS Collaboration; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Basu Thakur, R.; Bauer, D. A.; Beaty, J.; Billard, J. (20 June 2014). "Search for Low-Mass Weakly Interacting Massive Particles with SuperCDMS". Physical Review Letters. 112 (24): 241302. arXiv:1402.7137. Bibcode:2014PhRvL.112x1302A. doi:10.1103/PhysRevLett.112.241302. hdl:1721.1/88645. PMID 24996080. S2CID 119066853. Retrieved 19 April 2022.
- SuperCDMS Collaboration; Agnese, R.; Aralis, T.; Aramaki, T.; Arnquist, I. J.; Azadbakht, E.; Baker, W.; Banik, S.; Barker, D. (15 March 2019). "Search for low-mass dark matter with CDMSlite using a profile likelihood fit". Physical Review D. 99 (6): 062001. arXiv:1808.09098. Bibcode:2019PhRvD..99f2001A. doi:10.1103/PhysRevD.99.062001. S2CID 119215767. Retrieved 19 April 2022.
- EDELWEISS Collaboration; Armengaud, E.; Augier, C.; Benoît, A.; Benoit, A.; Bergé, L.; Billard, J.; Broniatowski, A.; Camus, P. (17 April 2019). "Searching for low-mass dark matter particles with a massive Ge bolometer operated above ground". Physical Review D. 99 (8): 082003. arXiv:1901.03588. Bibcode:2019PhRvD..99h2003A. doi:10.1103/PhysRevD.99.082003. S2CID 91184022. Retrieved 19 April 2022.
- CRESST Collaboration; Abdelhameed, A. H.; Angloher, G.; Bauer, P.; Bento, A.; Bertoldo, E.; Bucci, C.; Canonica, L.; D'Addabbo, A. (25 November 2019). "First results from the CRESST-III low-mass dark matter program". Physical Review D. 100 (10): 102002. Bibcode:2019PhRvD.100j2002A. doi:10.1103/PhysRevD.100.102002. S2CID 90261775. Retrieved 19 April 2022.
- Adhikari, Govinda; Souza, E. Barbosa de; Carlin, N.; Choi, J.J.; Choi, S.; Djamal, M.; Ezeribe, Anthony C.; Franca, L.E.; Ha, C.; Hahn, I.S.; Jeon, E.J. (23 April 2021). "Strong constraints from COSINE-100 on the DAMA dark matter results using the same sodium iodide target". doi:10.21203/rs.3.rs-429107/v1. S2CID 233181853.
{{cite journal}}
: Cite journal requires|journal=
(help) - XENON Collaboration; Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P. (6 March 2017). "Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data". Physical Review Letters. 118 (10): 101101. Bibcode:2017PhRvL.118j1101A. doi:10.1103/PhysRevLett.118.101101. hdl:10316/80088. PMID 28339273. S2CID 206287497. Retrieved 19 April 2022.
- LUX Collaboration; Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A. (27 September 2018). "Search for annual and diurnal rate modulations in the LUX experiment". Physical Review D. 98 (6): 062005. arXiv:1807.07113. Bibcode:2018PhRvD..98f2005A. doi:10.1103/PhysRevD.98.062005. hdl:10400.26/27687. S2CID 51805286. Retrieved 19 April 2022.
- CDEX Collaboration; Yang, L. T.; Li, H. B.; Yue, Q.; Ma, H.; Kang, K. J.; Li, Y. J.; Wong, H. T.; Agartioglu, M. (25 November 2019). "Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory". Physical Review Letters. 123 (22): 221301. arXiv:1904.12889. Bibcode:2019PhRvL.123v1301Y. doi:10.1103/PhysRevLett.123.221301. PMID 31868422. S2CID 140212171. Retrieved 19 April 2022.
- Sarsa, M.L (December 1995). Experimento Para la Detección Directa de Materia Oscura Galáctica fría con Detectores de Centelleo Mediante la búsqueda de Señales Distintivas. Ph.D. Thesis, Universidad de Zaragoza, Zaragoza, Spain.
{{cite book}}
: CS1 maint: location missing publisher (link) - Baum, Sebastian; Freese, Katherine; Kelso, Chris (10 February 2019). "Dark Matter implications of DAMA/LIBRA-phase2 results". Physics Letters B. 789: 262–269. arXiv:1804.01231. Bibcode:2019PhLB..789..262B. doi:10.1016/j.physletb.2018.12.036. ISSN 0370-2693. S2CID 119398561. Retrieved 20 April 2022.
- Kang, Sunghyun; Scopel, Stefano; Tomar, Gaurav; Yoon, Jong-Hyun (6 July 2018). "DAMA/LIBRA-phase2 in WIMP effective models". Journal of Cosmology and Astroparticle Physics. 2018 (7): 016. arXiv:1804.07528. Bibcode:2018JCAP...07..016K. doi:10.1088/1475-7516/2018/07/016. ISSN 1475-7516. S2CID 119100672. Retrieved 20 April 2022.
- Amaré, J.; Cebrián, S.; Coarasa, I.; Cuesta, C.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; de Solórzano, A. Ortiz; Puimedón, J.; Salinas, A. (12 March 2019). "Performance of ANAIS-112 experiment after the first year of data taking". The European Physical Journal C. 79 (3): 228. arXiv:1812.01472. Bibcode:2019EPJC...79..228A. doi:10.1140/epjc/s10052-019-6697-4. ISSN 1434-6052. S2CID 119492260.
- Oliván, M. A.; Amaré, J.; Cebrián, S.; Cuesta, C.; García, E.; Martínez, M.; Ortigoza, Y.; Ortiz de Solórzano, A.; Pobes, C.; Puimedón, J.; Sarsa, M. L. (1 July 2017). "Light yield determination in large sodium iodide detectors applied in the search for dark matter". Astroparticle Physics. 93: 86–95. arXiv:1703.01262. Bibcode:2017APh....93...86O. doi:10.1016/j.astropartphys.2017.06.005. ISSN 0927-6505. S2CID 119349144.
- Amaré, J.; Cebrián, S.; Coarasa, I.; Cuesta, C.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Puimedón, J.; Salinas, A. (15 May 2019). "Analysis of backgrounds for the ANAIS-112 dark matter experiment". The European Physical Journal C. 79 (5): 412. arXiv:1812.01377. Bibcode:2019EPJC...79..412A. doi:10.1140/epjc/s10052-019-6911-4. ISSN 1434-6052. S2CID 119201136.
- Amaré, J.; Cebrián, S.; Cintas, D.; Coarasa, I.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; de Solórzano, A. Ortiz (27 May 2021). "Annual modulation results from three-year exposure of ANAIS-112". Physical Review D. 103 (10): 102005. arXiv:2103.01175. Bibcode:2021PhRvD.103j2005A. doi:10.1103/PhysRevD.103.102005. Retrieved 31 March 2022.
- Amaré, J.; Cebrián, S.; Coarasa, I.; Cuesta, C.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; de Solórzano, A. Ortiz (16 July 2019). "First Results on Dark Matter Annual Modulation from the ANAIS-112 Experiment". Physical Review Letters. 123 (3): 031301. arXiv:1903.03973. Bibcode:2019PhRvL.123c1301A. doi:10.1103/PhysRevLett.123.031301. ISSN 0031-9007. PMID 31386454. S2CID 119254901. Retrieved 31 March 2022.
- Amaré, J.; Cebrián, S.; Cintas, D.; Coarasa, I.; García, E.; Martínez, M.; Oliván, M.A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Puimedón, J.; Salinas, A. (1 February 2020). "ANAIS-112 status: two years results on annual modulation". Journal of Physics: Conference Series. 1468 (1): 012014. arXiv:1910.13365. Bibcode:2020JPhCS1468a2014A. doi:10.1088/1742-6596/1468/1/012014. ISSN 1742-6588. S2CID 204950148.
- Coarasa, I.; Amaré, J.; Cebrián, S.; Cuesta, C.; García, E.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; de Solórzano, A. Ortiz; Puimedón, J.; Salinas, A. (13 March 2019). "ANAIS-112 sensitivity in the search for dark matter annual modulation". The European Physical Journal C. 79 (3): 233. arXiv:1812.02000. Bibcode:2019EPJC...79..233C. doi:10.1140/epjc/s10052-019-6733-4. ISSN 1434-6052. S2CID 119034993.
- Bernabei, R.; Belli, P.; Bussolotti, A.; Cappella, F.; Caracciolo, V.; Cerulli, R.; Dai, C. J.; d'Angelo, A.; Di Marco, A.; Ferrari, N.; Incicchitti, A. (1 September 2020). "The DAMA project: Achievements, implications and perspectives". Progress in Particle and Nuclear Physics. 114: 103810. Bibcode:2020PrPNP.11403810B. doi:10.1016/j.ppnp.2020.103810. ISSN 0146-6410. S2CID 225281419.
- Adhikari, G.; Adhikari, P.; de Souza, E. Barbosa; Carlin, N.; Choi, S.; Djamal, M.; Ezeribe, A. C.; Ha, C.; Hahn, I. S. (16 July 2019). "Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment". Physical Review Letters. 123 (3): 031302. arXiv:1903.10098. Bibcode:2019PhRvL.123c1302A. doi:10.1103/PhysRevLett.123.031302. ISSN 0031-9007. PMID 31386435. S2CID 85501650. Retrieved 1 April 2022.
- Coarasa, I; Apilluelo, J; Amaré, J; Cebrián, S; Cintas, D; García, E; Martínez, M; Oliván, M A; Ortigoza, Y (1 December 2021). "Machine-learning techniques applied to three-year exposure of ANAIS–112". Journal of Physics: Conference Series. 2156 (1): 012036. arXiv:2110.10649. Bibcode:2021JPhCS2156a2036C. doi:10.1088/1742-6596/2156/1/012036. ISSN 1742-6588. S2CID 239050108. Retrieved 31 March 2022.
- Cintas, D.; An, P.; Awe, C.; Barbeau, P. S.; Barbosa de Souza, E.; Hedges, S.; Jo, J. H.; Martínez, M.; Maruyama, R. H. (1 December 2021). "Quenching Factor consistency across several NaI(Tl) crystals". Journal of Physics: Conference Series. 2156 (1): 012065. arXiv:2111.09590. Bibcode:2021JPhCS2156a2065C. doi:10.1088/1742-6596/2156/1/012065. ISSN 1742-6588. S2CID 244345782. Retrieved 31 March 2022.