1. |
- Ballan, M., et al.
(författare)
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Nuclear physics midterm plan at Legnaro National Laboratories (LNL)
- 2023
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Ingår i: European Physical Journal Plus. - 2190-5444. ; 138:8, s. 3-26
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Tidskriftsartikel (refereegranskat)abstract
- The next years will see the completion of the radioactive ion beam facility SPES (Selective Production of Exotic Species) and the upgrade of the accelerators complex at Istituto Nazionale di Fisica Nucleare – Legnaro National Laboratories (LNL) opening up new possibilities in the fields of nuclear structure, nuclear dynamics, nuclear astrophysics, and applications. The nuclear physics community has organised a workshop to discuss the new physics opportunities that will be possible in the near future by employing state-of-the-art detection systems. A detailed discussion of the outcome from the workshop is presented in this report.
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2. |
- Abdelhameed, A. H., et al.
(författare)
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Cryogenic characterization of a LiAlO2 crystal and new results on spin-dependent dark matter interactions with ordinary matter: CRESST Collaboration
- 2020
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 80:9
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a first cryogenic characterization of a scintillating LiAlO2 single crystal is presented. The results achieved show that this material holds great potential as a target for direct dark matter search experiments. Three different detector modules obtained from one crystal grown at the Leibniz-Institut fur Kristallzuchtung (IKZ) have been tested to study different properties at cryogenic temperatures. Firstly, two 2.8 g twin crystals were used to build different detector modules which were operated in an above-ground laboratory at the Max Planck Institute for Physics (MPP) in Munich, Germany. The first detector module was used to study the scintillation properties of LiAlO2 at cryogenic temperatures. The second achieved an energy threshold of (213.02 +/- 1.48) eV which allows setting a competitive limit on the spin-dependent dark matter particle-proton scattering cross section for dark matter particle masses between 350 MeV/c2 and 1.50 GeV/c2. Secondly, a detector module with a 373 g LiAlO2 crystal as the main absorber was tested in an underground facility at the Laboratori Nazionali del Gran Sasso (LNGS): from this measurement it was possible to determine the radiopurity of the crystal and study the feasibility of using this material as a neutron flux monitor for low-background experiments.
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3. |
- Abdelhameed, A. H., et al.
(författare)
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First results on sub-GeV spin-dependent dark matter interactions with Li-7
- 2019
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 79:7
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we want to highlight the potential of lithium as a target for spin-dependent dark matter search in cryogenic experiments, with a special focus on the low-mass region of the parameter space. We operated a prototype detector module based on a Li2MoO4 target crystal in an above-ground laboratory. Despite the high background environment, the detector sets a competitive limit on spin-dependent interactions of dark matter particles with protons and neutrons for masses between 1.5 GeV/c(2).
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4. |
- Bertoldo, E., et al.
(författare)
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Lithium-Containing Crystals for Light Dark Matter Search Experiments
- 2020
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Ingår i: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 199:1-2, s. 510-518
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Tidskriftsartikel (refereegranskat)abstract
- In the current direct dark matter search landscape, the leading experiments in the sub-GeV mass region mostly rely on cryogenic techniques which employ crystalline targets. One attractive type of crystals for these experiments is those containing lithium, due to the fact that 7Li is an ideal candidate to study spin-dependent dark matter interactions in the low mass region. Furthermore, 6Li can absorb neutrons, a challenging background for dark matter experiments, through a distinctive signature which allows the monitoring of the neutron flux directly on site. In this work, we show the results obtained with three different detectors based on LiAlO 2, a target crystal never used before in cryogenic experiments.
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5. |
- Abdelhameed, A. H., et al.
(författare)
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First results from the CRESST-III low-mass dark matter program
- 2019
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 100:10
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Tidskriftsartikel (refereegranskat)abstract
- The CRESST experiment is a direct dark matter search which aims to measure interactions of potential dark matter particles in an Earth-bound detector. With the current stage, CRESST-III, we focus on a low energy threshold for increased sensitivity towards light dark matter particles. In this paper we describe the analysis of one detector operated in the first run of CRESST-III (05/2016-02/2018) achieving a nuclear recoil threshold of 30.1 eV. This result was obtained with a 23.6 g CaWO4 crystal operated as a cryogenic scintillating calorimeter in the CRESST setup at the Laboratori Nazionali del Gran Sasso (LNGS). Both the primary phonon (heat) signal and the simultaneously emitted scintillation light, which is absorbed in a separate silicon-on-sapphire light absorber, are measured with highly sensitive transition edge sensors operated at similar to 15 mK. The unique combination of these sensors with the light element oxygen present in our target yields sensitivity to dark matter particle masses as low as 160 MeV/c(2).
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6. |
- Abdelhameed, A. H., et al.
(författare)
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Geant4-based electromagnetic background model for the CRESST dark matter experiment
- 2019
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 79:10
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Tidskriftsartikel (refereegranskat)abstract
- The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) dark matter search experiment aims for the detection of dark matter particles via elastic scattering off nuclei in CaWO4 crystals. To understand the CRESST electromagnetic background due to the bulk contamination in the employed materials, a model based on Monte Carlo simulations was developed using the Geant4 simulation toolkit. The results of the simulation are applied to the TUM40 detector module of CRESST-II phase 2. We are able to explain up to (68 +/- 16)% of the electromagnetic background in the energy range between 1 and 40 keV.
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7. |
- Kluck, H., et al.
(författare)
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Latest results of CRESST-III's search for sub-GeV/c(2) dark matter
- 2020
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 1468:1
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Konferensbidrag (refereegranskat)abstract
- The CRESST-III experiment searches for direct interactions of dark matter with ordinary matter. The main event signature would be a nuclear recoil inside one of the scintillating CaWO4 crystals. Operating the crystals as cryogenic calorimeters provides a phonon signal as measure of the deposited energy. The simultaneous readout of both signals is used to actively discriminate backgrounds. CRESST-III focuses on the sub-GeV/c(2) mass region where the sensitivity is driven by the threshold. In the first data taking campaign of CRESST-III from 2016-2018 an unprecedented low threshold of 30.1 eV for nuclear recoils was obtained. In this contribution, we will report the status of the experiment and the latest results. [GRAPHICS]
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8. |
- Mancuso, M., et al.
(författare)
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Searches for Light Dark Matter with the CRESST-III Experiment
- 2020
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Ingår i: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 199:1-2, s. 547-555
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Tidskriftsartikel (refereegranskat)abstract
- Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) is a long-standing direct dark matter detection experiment with cryogenic detectors located at the underground facility Laboratori Nazionali del Gran Sasso in Italy. CRESST-III, the third generation of CRESST, was specifically designed to have a world-leading sensitivity for low-mass dark matter (DM) (less than 2 GeV/c 2) to probe the spin-independent DM-nucleus cross section. At present, a large part of the parameter space for spin-independent scattering off nuclei remains untested for dark matter particles with masses below few GeV/c 2 although many motivated theoretical models having been proposed. The CRESST-III experiment employs scintillating CaWO 4 crystals of ∼ 25 g as target material for dark matter interactions operated as cryogenic scintillating calorimeters at ∼ 10 mK. CRESST-III first data taking was successfully completed in 2018, achieving an unprecedented energy threshold for nuclear recoils. This result extended the present sensitivity to DM particles as light as ∼ 160 MeV/c 2. In this paper, an overview of the CRESST-III detectors and results will be presented.
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9. |
- Angloher, G., et al.
(författare)
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Limits on dark matter effective field theory parameters with CRESST-II
- 2019
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 79:1
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Tidskriftsartikel (refereegranskat)abstract
- CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3–4 GeV/c2) are presented.
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10. |
- Davidsson, Joel, et al.
(författare)
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Absorption versus adsorption: high-throughput computation of impurities in 2D materials
- 2023
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Ingår i: npj 2D Materials and Applications. - 2397-7132. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Doping of a two-dimensional (2D) material by impurity atoms occurs via two distinct mechanisms: absorption of the dopants by the 2D crystal or adsorption on its surface. To distinguish the relevant mechanism, we systematically dope 53 experimentally synthesized 2D monolayers by 65 different chemical elements in both absorption and adsorption sites. The resulting 17,598 doped monolayer structures were generated using the newly developed ASE DefectBuilder—a Python tool to set up point defects in 2D and bulk materials—and subsequently relaxed by an automated high-throughput density functional theory (DFT) workflow. We find that interstitial positions are preferred for small dopants with partially filled valence electrons in host materials with large lattice parameters. In contrast, adatoms are favored for dopants with a low number of valence electrons due to lower coordination of adsorption sites compared to interstitials. The relaxed structures, characterization parameters, defect formation energies, and magnetic moments (spins) are available in an open database to help advance our understanding of defects in 2D materials.
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11. |
- Rizzo, G., et al.
(författare)
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The predictive power of brain mRNA mappings for in vivo protein density: a positron emission tomography correlation study
- 2014
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 34:5, s. 827-835
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Tidskriftsartikel (refereegranskat)abstract
- Substantial efforts are being spent on postmortem mRNA transcription mapping on the assumption that in vivo protein distribution can be predicted from such data. We tested this assumption by comparing mRNA transcription maps from the Allen Human Brain Atlas with reference protein concentration maps acquired with positron emission tomography (PET) in two representative systems of neurotransmission (opioid and serotoninergic). We found a tight correlation between mRNA expression and specific binding with 5-HT1A receptors measured with PET, but for opioid receptors, the correlation was weak. The discrepancy can be explained by differences in expression regulation between the two systems: transcriptional mechanisms dominate the regulation in the serotoninergic system, whereas in the opioid system proteins are further modulated after transcription. We conclude that mRNA information can be exploited for systems where translational mechanisms predominantly regulate expression. Where posttranscriptional mechanisms are important, mRNA data have to be interpreted with caution. The methodology developed here can be used for probing assumptions about the relationship of mRNA and protein in multiple neurotransmission systems.
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