Improving ANAIS-112 sensitivity to DAMA/LIBRA signal with machine learning techniques

Abstract

The DAMA/LIBRA observation of an annual modulation in the detection rate compatible with that expected for dark matter particles from the galactic halo has accumulated evidence for more than twenty years. It is the only hint of a direct detection of the elusive dark matter, but it is in strong tension with the negative results of other very sensitive experiments, requiring ad-hoc scenarios to reconcile all the present experimental results. Testing the DAMA/LIBRA result using the same target material, NaI(Tl), removes the dependence on the particle and halo models and is the goal of the ANAIS-112 experiment, taking data at the Canfranc Underground Laboratory in Spain since August 2017 with 112.5 kg of NaI(Tl). At very low energies, the detection rate is dominated by non-bulk scintillation events and careful event selection is mandatory. This article summarizes the efforts devoted to better characterize and filter this contribution in ANAIS-112 data using a boosted decision tree (BDT), trained for this goal with high efficiency. We report on the selection of the training populations, the procedure to determine the optimal cut on the BDT parameter, the estimate of the efficiencies for the selection of bulk scintillation in the region of interest (ROI), and the evaluation of the performance of this analysis with respect to the previous filtering. The improvement achieved in background rejection in the ROI, but moreover, the increase in detection efficiency, push the ANAIS-112 sensitivity to test the DAMA/LIBRA annual modulation result around 3$\sigma$ with three-year exposure, being possible to reach 5$\sigma$ by extending the data taking for a few more years than the scheduled 5 years which were due in August 2022.

References in corpus (62)

• Dark Matter Search Results from a One Tonne$\times$Year Exposure of XENON1T
• Results from a search for dark matter in the complete LUX exposure
• A History of Dark Matter
• First results from DAMA/LIBRA and the combined results with DAMA/NaI
• Dark Matter Results From 54-Ton-Day Exposure of PandaX-II Experiment
• New results from DAMA/LIBRA
• TMVA - Toolkit for Multivariate Data Analysis
• First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment
• Final model independent result of DAMA/LIBRA-phase1
• Search for Low-Mass WIMPs with SuperCDMS
• Light Dark Matter Search with Ionization Signals in XENON1T
• First results from the CRESST-III low-mass dark matter program
• Dark Matter Search Results from the PandaX-4T Commissioning Run
• Direct Detection of WIMP Dark Matter: Concepts and Status
• Low-Mass Dark Matter Search with the DarkSide-50 Experiment
• Dark Matter Search Results from the Complete Exposure of the PICO-60 C${}_3$F${}_8$ Bubble Chamber
• DarkSide-50 532-day Dark Matter Search with Low-Radioactivity Argon
• Migdal Effect in Dark Matter Direct Detection Experiments
• Current status of direct dark matter detection experiments
• Searching for low-mass dark matter particles with a massive Ge bolometer operated above-ground
• First model independent results from DAMA/LIBRA-phase2
• Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB
• Search for Low-Mass Dark Matter with CDMSlite Using a Profile Likelihood Fit
• First results on dark matter annual modulation from ANAIS-112 experiment
• The SABRE project and the SABRE PoP
• Annual modulation results from three-year exposure of ANAIS-112
• Search for dark matter at colliders
• The COSINUS project - perspectives of a NaI scintillating calorimeter for dark matter search
• Indirect dark matter searches in Gamma- and Cosmic Rays
• Quenching and Channeling of Nuclear Recoils in NaI[Tl]: Implications for Dark Matter Searches
• First search for a dark matter annual modulation signal with NaI(Tl) in the Southern Hemisphere by DM-Ice17
• Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data
• Strong constraints from COSINE-100 on the DAMA dark matter results using the same sodium iodide target
• Three-year annual modulation search with COSINE-100
• Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold
• 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
• Analysis of backgrounds for the ANAIS-112 dark matter experiment
• Modulations of the Cosmic Muon Signal in Ten Years of Borexino Data
• Optimizing EDELWEISS detectors for low-mass WIMP searches
• Measurement of the quenching factor of Na recoils in NaI(Tl)
• Performance of ANAIS-112 experiment after the first year of data taking
• Lowering the energy threshold in COSINE-100 dark matter searches
• Search for Low-Mass Dark Matter with CsI(Tl) Crystal Detectors
• ANAIS-112 sensitivity in the search for dark matter annual modulation
• Convolutional Neural Networks for Direct Detection of Dark Matter
• Development of highly radiopure NaI(Tl) scintillator for PICOLON dark matter search project
• Search for sub-GeV dark matter by annual modulation using XMASS-I detector
• Improving sensitivity to low-mass dark matter in LUX using a novel electrode background mitigation technique
• Quenching factor measurements of sodium nuclear recoils in NaI:Tl determined by spectrum fitting
• Light yield determination in large sodium iodide detectors applied in the search for dark matter
• High sensitivity characterization of an ultra-high purity NaI(Tl) crystal scintillator with the SABRE proof-of-principle detector
• ANAIS-112 status: two years results on annual modulation
• A semi-supervised approach to dark matter searches in direct detection data with machine learning
• Measurement of the cosmic ray muon flux seasonal variation with the OPERA detector
• Limits on Interactions between Weakly Interacting Massive Particles and Nucleons Obtained with NaI(Tl) crystal Detectors
• Probing spin-dependent dark matter interactions with ${}^6$Li
• Quenching Factor consistency across several NaI(Tl) crystals
• Pulse-shape discrimination between electron and nuclear recoils in a NaI(Tl) crystal
• Design, scale-up and characterization of the data acquisition system for the ANAIS dark matter experiment
• Improved Sensitivity of the DRIFT-IId Directional Dark Matter Experiment using Machine Learning
• Machine-learning techniques applied to three-year exposure of ANAIS-112
• Long term measurement of the ${}^{222}$Rn concentration in the Canfranc Underground Laboratory

Cited by in corpus (10)

• Nonproportionality of NaI(Tl) Scintillation Detector for Dark Matter Search Experiments
• Combined Annual Modulation Dark Matter Search with COSINE-100 and ANAIS-112
• The SABRE South Technical Design Report Executive Summary
• Towards a Robust Model-Independent Test of the DAMA/LIBRA Dark Matter Signal: ANAIS-112 Results with Six Years of Data
• Progress in End-to-End Optimization of Detectors for Fundamental Physics with Differentiable Programming
• Insights into Dark Matter Direct Detection Experiments: Decision Trees versus Deep Learning
• Bayesian technique to combine independently-trained Machine-Learning models applied to direct dark matter detection
• Characterisation of Hamamatsu R11065-20 PMTs for use in the SABRE South NaI(Tl) Crystal Detectors
• State of the Art in Direct Dark Matter Detectors: Technologies, Performance, and Future Directions
• Photomultiplier Requirements and Pre-Calibration for the SABRE South Liquid Scintillator Veto