Publications

Order by: publication date number of citations

• Analysis of radiation damage in silicon charge-coupled devices used for dark matter searches

  Steven J. Lee

  SciPost Phys. Proc. 12, 030 (2023) · published 4 July 2023 | Toggle abstract · pdf

  Nuclear recoils in crystal detectors generate radiation damage in the form of crystal defects that can be measured in scientific-grade CCDs as local hot spots of leakage current stimulated by temperature increases in the devices. In this proceeding, we use a neutron source to generate defects in DAMIC-M CCDs, and using increases in leakage current at different temperatures, we demonstrate a procedure for identifying crystal defects in the CCDs of the DAMIC-M experiment. This is the first time that individual defects generated from nuclear recoils have been studied. This technique could be used to distinguish nuclear recoils from electron recoils in some energy ranges, which would improve the ability of CCD detectors to search for weakly interacting dark matter.

  1 citation

• Direct searches of dark matter with the SABRE South experiment

  Madeleine J. Zurowski on behalf of the SABRE South Collaboration

  SciPost Phys. Proc. 12, 029 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The SABRE (Sodium-iodide with Active Background REjection) South experiment is a direct dark matter detector, made of radio-pure NaI(Tl) crystals surrounded by a liquid scintillator veto. The achievement of ultra-low background rate is essential to provide a model independent test of the signal observed by the DAMA/LIBRA experiment whose claim has not been verified yet. The SABRE South experiment will be located at the Stawell Underground Physics Laboratory (SUPL), Australia, the first deep underground laboratory in the Southern Hemisphere. The laboratory will not only house rare event physics searches but also measurement facilities to support low background physics experiments and applications like radiobiology and quantum computing. The SABRE South detector commissioning is expected to occur in 2023. This paper details the setup and projections for the experiment, and a brief description of the underground laboratory.

  1 citation

• Quenching Factor estimation of Na recoils in NaI(Tl) crystals using a low-energy pulsed neutron beam measurement

  Mukund Raghunath Bharadwaj, G. Angloher, P. S. Barbeau, I. Dafinei, N. Di Marco, L. Einfalt, F. Ferroni, S. Fichtinger, A. Filipponi , T. Frank , M. Friedl , A. Fuss, Z. Ge , S. Hedges, M. Heikinheimo, K. Huitu, M. Kellermann, R. Maji, M. Mancuso, L. Pagnanini, F. Petricca, S. Pirro, F. Pröbst , G. Profeta, A. Puiu, F. Reindl , K. Schäffner, J. Schieck, D. Schmiedmayer , C. Schwertner , M. Stahlberg , A. Stendahl, M. Stukel , F. Wagner, S. Yue, V. Zema, Y. Zhu

  SciPost Phys. Proc. 12, 028 (2023) · published 4 July 2023 | Toggle abstract · pdf

  NaI(Tl) based scintillation detectors have become a staple in the field of direct dark matter searches, with the DAMA-LIBRA experiment being the standout for its reported observation of an annually modulating WIMP-like signal which is in direct contrast with other results. In order to accurately calibrate the energies of WIMP-induced nuclear recoil signals, precise measurements of the quenching factor of the NaI crystals are essential for each of these experiments, as it is well established that electron recoils and nuclear recoils have dissimilar scintillation light yields. In this contribution, we present first preliminary results of an ongoing systematic study that has been carried out by the COSINUS collaboration and Duke University to measure the quenching factor of Na recoils. Five ultra-pure NaI crystals, manufactured by the Shanghai Institute for Ceramics, each of which have varying Tl dopant concentrations, were irradiated with a mono-energetic neutron beam at the Triangle Universities National Laboratory, North Carolina, USA to extract the quenching factor values in the low recoil energies of 1-30keV$_{nr}$.

  2 citations

• Hidden dependencies in model independent tests of DAMA

  Madeleine J. Zurowski

  SciPost Phys. Proc. 12, 027 (2023) · published 4 July 2023 | Toggle abstract · pdf

  For nearly two decades the DAMA Collaboration has been observing a modulating signal compatible with that expected from a dark matter presence in our galaxy. However, interpretations of this with the standard assumptions for dark matter particles are strongly ruled out by a large number of other experiments. This tension can be relaxed somewhat by making more tailored choices for the dark matter model and properties of interest, but expanding the models of interest in such a way makes it impossible to test the DAMA modulation conclusively. In order to understand the exact nature of this signal, we need to use a detector based on the same target (NaI(Tl)), which would be sensitive to exactly the same particle interaction models as DAMA. There are a number of such experiments in the data taking or commissioning stages designed to do just this, two of which (ANAIS and COSINE) recently released their results after 3 years of data taking. Interestingly, the modulation observed by the two experiments deviate from each other by 2$\sigma$, while being within 3$\sigma$ of the DAMA result. This paper addresses potential differences between NaI(Tl) based detectors that could lead to the differing results to date, with a particular focus on the quenching factor

  1 citation

• Status and prospects of SABRE North

  Ambra Mariani on behalf of the SABRE North Collaboration

  SciPost Phys. Proc. 12, 026 (2023) · published 4 July 2023 | Toggle abstract · pdf

  We present the characterization of a low background NaI(Tl) crystal for the SABRE North experiment. The crystal NaI-33, was studied in two different setups at Laboratori Nazionali del Gran Sasso, Italy. The Proof-of-Principle (PoP) detector was equipped with a liquid scintillator veto and collected data for about one month (90 kg$\times$days). The PoP-dry setup consisted of NaI-33 in a purely passive shielding and collected data for almost one year (891 kg$\times$days). The average background in the energy region of interest (1-6 keV) for dark matter search was 1.20 $\pm$ 0.05 and 1.39 $\pm$ 0.02 counts/day/kg/keV within the PoP and the PoP-dry setup, respectively. This result opens to a new shielding design for the physics phase of the SABRE North detector, that does not foresee the use of an organic liquid scintillator external veto, in compliance with the new safety and environmental requirements of Laboratori Nazionali del Gran Sasso.

• Dark Matter: DAMA/LIBRA and its perspectives

  R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, R. Cerulli, C.J. Dai, A. d'Angelo, A. Incicchitti, A. Leoncini, X.H. Ma, V. Merlo, F. Montecchia, X.D. Sheng, Z.P. Ye

  SciPost Phys. Proc. 12, 025 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The long-standing model-independent annual modulation effect measured by DAMA deep underground at Gran Sasso Laboratory with different experimental configurations is summarized and perspectives will be highlighted. DAMA/LIBRA-phase2 set-up, $\simeq$ 250 kg highly radio-pure NaI(Tl) confirms the evidence of a signal that meets all the requirements of the model independent Dark Matter annual modulation signature at high C.L.; the full exposure is 2.86 ton $\times$ yr over 22 annual cycles. The experiment is currently collecting data in the DAMA/LIBRA-phase2 empowered configuration with an even lower software energy threshold. Other recent claims are shortly commented.

  1 citation

• Status and future prospects of the NEWS-G experiment

  P. Knights on behalf of the NEWS-G Collaboration

  SciPost Phys. Proc. 12, 024 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The NEWS-G collaboration is searching for light dark matter using spherical proportional counters. Access to the mass range from 50 MeV to 10 GeV is enabled by the combination of low energy threshold, light gaseous targets (H, He, Ne), and highly radio-pure detector construction. Several of the recent developments that have paved the way for the operation of a new 140 cm in diameter, spherical proportional counter are presented. Constructed and commissioned at LSM using 4N copper with a 500$\mu$xm electroplated inner layer, the detector is now installed in SNOLAB, where it has begun data taking. Building on the electroplating of the current detector, the collaboration construct its next detector directly in the underground laboratory, using ultra-pure copper electroforming. The design and construction of ECUME, a 140 cm in diameter spherical proportional counter fully electroformed underground is discussed, along with the potential to achieve sensitivity reaching the neutrino floor in light Dark Matter searches with a next-generation detector.

• The Scintillating Bubble Chamber Experiment

  Ben Broerman

  SciPost Phys. Proc. 12, 023 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The Scintillating Bubble Chamber (SBC) collaboration is combining the well-established liquid argon and bubble chamber technologies to search for low-mass, GeV-scale dark matter. Liquid-noble bubble chambers benefit from the excellent electron-recoil insensitivity inherent in bubble chambers with the addition of energy reconstruction provided from the scintillation signal for background rejection. The projected sensitivity with a quasi-background-free 10-kg-year exposure at a 100 eV nuclear recoil threshold is approximately 10$^{-43}$ cm$^2$ for a 1 GeV/c$^2$ dark matter mass.

• Search for low mass WIMP dark matter with DarkSide-50

  Masato Kimura on behalf of DarkSide-50 Collaboration

  SciPost Phys. Proc. 12, 022 (2023) · published 3 July 2023 | Toggle abstract · pdf

  DarkSide-50 is a direct dark matter detection experiment at Laboratori Nazionali del Gran Sasso that uses argon as the target material. Exploiting the ionization signal from a dual-phase time projection chamber filled with low-radioactivity argon, it has set the most stringent exclusion limit on WIMPs with a mass of few $\mathrm{GeV}/c^2$. A new analysis has recently been carried out with a larger exposure, profiting from an improved understanding of the detector response and background model. An improvement of about a factor 10 in sensitivity is expected for a WIMP mass of 2 GeV/c$^2$.

• Dark matter directionality approach using ZnWO$_4$ crystal scintillators

  Vincenzo Caracciolo, Volodymyr Yakovych Degoda, Pierluigi Belli, Rita Bernabei, Y. A. Borovlev, Fabio Cappella, Riccardo Cerulli, Fedor A. Danevich, Antonella Incicchitti, Alice Leoncini, Vittorio Merlo, N. Cherubini, Dmytro V. Kasperovych, Y. P. Kogut, G. P. Podust, Oksana G. Polischuk, A. G. Postupaeva, V. N. Shlegel, Volodymyr I. Tretyak

  SciPost Phys. Proc. 12, 021 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The development of low-background anisotropic detectors can offer a unique way to study those Dark Matter (DM) candidate particles able to induce nuclear recoils through the directionality technique. Among the anisotropic scintillators, the ZnWO$_{4}$ has unique features and is an excellent candidate for the purposes. Both the light output and the scintillation pulse shape depend on the impinging direction of heavy particles with respect to the crystallographic axes and can supply two independent modes to study the directionality and discriminate $\gamma/\beta$ radiation. Measurements to study the anisotropic and scintillation performances of ZnWO$_4$ are reported.