ANAIS is an experiment developed by the Nuclear and Astroparticle Physics group of the University of Zaragoza which pursues this elusive dark matter detection by looking at the annual modulation of the expected interaction rates in a target of sodium iodide, material which produces small scintillations when a particle interacts and deposits some energy. This modulation is a distinctive feature stemming from the Earth revolution around the Sun which changes periodically the relative velocity of the incoming Dark Matter particles to the detector and, because of that, the energy deposited. DAMA-LIBRA experiment at Gran Sasso Underground Laboratory has reported the presence of modulation in its data with a high statistical significance; ANAIS could confirm it and help to understand the different systematics involved.
ANAIS is the large scale conclusion of previous studies carried out with different prototypes by the University of Zaragoza group at the Canfranc Underground Laboratory, Spain. ANAIS-112 is using 112.5 kg of NaI(Tl) crystals to study the expected annual modulation in the galactic dark matter signal distributed in 9 modules of 12.5 kg each.
ANAIS-112 is taking data at the Canfranc Underground Laboratory since 3 August 2017. In 2019 first results, corresponding to 1.5 years of data, and in 2021 the results of 3 years were published. They are compatible with the absence of modulation and incompatible with the DAMA/LIBRA positive modulation with a sensitivity of 2.5-2.7 sigma for the 3 years result, confirming the sensitivity estimates. Recently, a new data release consisting of the reanalysis of the first 3 years of data using machine-learning techniques for the low-energy event selection has been presented. These results also support the absence of modulation and are incompatible with DAMA/LIBRA, but the sensitivity has been improved to 2.8 sigma. DAMA/LIBRA result is at reach with 5 sigmas of significance with a total data collection of 8 years.
ANAIS experiment operation is presently financially supported by MICIU/AEI/10.13039/501100011033 (Grants No. PID2022-138357NB-C21 and PID2019-104374GB-I00), and Unión Europea NextGenerationEU/PRTR (AstroHEP) and the Gobierno de Aragón. Funding from Grant FPA2017-83133-P, Consolider-Ingenio 2010 Programme under grants MULTIDARK CSD2009-00064 and CPAN CSD2007-00042, the Gobierno de Aragón and the LSC Consortium made possible the setting-up of the detectors. The technical support from LSC and GIFNA staff as well as from Servicios de Apoyo a la Investigación de la Universidad de Zaragoza (SAIs) is warmly acknowledged.
We list here the available datasets from the ANAIS experiment. The data can be downloaded for use or dynamically visualised within the repository. Please note the appropriate sources listed for citation when using data from the ANAIS Collaboration.
