Publications (69)
The Electronics and Data Acquisition System for the DarkSide-50 Veto Detectors
P. Agnes, L. Agostino, I. F. M. Albuquerque +155
DarkSide-50 is a detector for dark matter candidates in the form of weakly interacting massive particles (WIMPs). It utilizes a liquid argon time projection chamber (LAr TPC) for t…
Fermionic sub-GeV Dark Matter from evaporating Primordial Black Holes at DarkSide-50
50 Collaboration, P. Agnes, I. F. Albuquerque +125
We present a search for boosted dark matter from Primordial Black Holes (PBH) evaporation using the DarkSide-50 ionization-signal-only dataset corresponding to the experiment's ($1…
Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago
R. Genzel, N. M. Förster Schreiber, H. Ãbler +28
In cold dark matter cosmology, the baryonic components of galaxies are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the t…
A new hybrid gadolinium nanoparticles-loaded polymeric material for neutron detection in rare event searches
20k Collaboration, F. Acerbi, P. Adhikari +311
Experiments aimed at direct searches for WIMP dark matter require highly effective reduction of backgrounds and control of any residual radioactive contamination. In particular, ne…
Search for dark matter particle interactions with electron final states with DarkSide-50
50 Collaboration, P. Agnes, I. F. M. Albuquerque +140
We present a search for dark matter particles with sub-GeV/ masses whose interactions have final state electrons using the DarkSide-50 experiment's (12306 184) kg d low-…
The Electronics and Data Acquisition System of the DarkSide Dark Matter Search
The DarkSide Collaboration, P. Agnes, T. Alexander +143
It is generally inferred from astronomical measurements that Dark Matter (DM) comprises approximately 27\% of the energy-density of the universe. If DM is a subatomic particle, a p…
The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
R. Genzel, R. Schoedel, T. Ott +12
We analyze deep near-IR adaptive optics imaging as well as new proper motion data of the nuclear star cluster of the Milky Way. The surface density distribution of faint stars peak…
Characterization of spurious-electron signals in the double-phase argon TPC of the DarkSide-50 experiment
50 Collaboration, P. Agnes, I. F. Albuquerque +144
Spurious-electron signals in dual-phase noble-liquid time projection chambers have been observed in both xenon and argon Time Projection Chambers (TPCs). This paper presents the fi…
Benchmarking the design of the cryogenics system for the underground argon in DarkSide-20k
20k Collaboration, F. Acerbi, P. Adhikari +315
DarkSide-20k (DS-20k) is a dark matter detection experiment under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It utilises ~100 t of low radioactivity a…
Calibration of the liquid argon ionization response to low energy electronic and nuclear recoils with DarkSide-50
The DarkSide collaboration, P. Agnes, I. F. M. Albuquerque +136
DarkSide-50 has demonstrated the high potential of dual-phase liquid argon time projection chambers in exploring interactions of WIMPs in the GeV/c mass range. The technique, b…
Massive binaries in the vicinity of Sgr A*
O. Pfuhl, T. Alexander, S. Gillessen +5
A long-term spectroscopic and photometric survey of the most luminous and massive stars in the vicinity of the super-massive black hole Sgr A* revealed two new binaries; a long-per…
Search for dark matter annual modulation with DarkSide-50
50 Collaboration, P. Agnes, I. F. M. Albuquerque +142
Dark matter induced event rate in an Earth-based detector is predicted to show an annual modulation as a result of the Earth's orbital motion around the Sun. We searched for this m…
Constraints on Sub-GeV Dark Matter-Electron Scattering from the DarkSide-50 Experiment
The DarkSide Collaboration, P. Agnes, I. F. M. Albuquerque +193
We present new constraints on sub-GeV dark matter particles scattering off electrons in argon based on an analysis of ionization signal data from the DarkSide-50 detector.
First Nuclear Ultra-Heavy Dark Matter Search in Argon Time Projection Chambers with the DarkSide-50 Experiment
P. Agnes, I. F. Albuquerque, T. Alexander +125
We report the first search for nuclear ultra-heavy dark matter (UHDM) in a dual-phase liquid argon time projection chamber using the DarkSide-50 experiment. Unlike conventional wea…
Flow and thermal modelling of the argon volume in the DarkSide-20k TPC
20k Collaboration, F. Acerbi, P. Adhikari +300
The DarkSide-20k dark matter experiment, currently under construction at LNGS, features a dual-phase time projection chamber (TPC) with a ~50 t argon target from an underground wel…
Effective field theory interactions for liquid argon target in DarkSide-50 experiment
50 Collaboration, P. Agnes, I. F. M. Albuquerque +164
We reanalize data collected with the DarkSide-50 experiment and recently used to set limits on the spin-independent interaction rate of weakly interacting massive particles (WIMPs)…
Search for two-neutrino double electron capture in Ar with the DarkSide-50 detector
50 Collaboration, P. Agnes, I. F. M. Albuquerque +83
The DarkSide-50 experiment used low‑radioactivity liquid argon to search for the rare two‑neutrino double electron capture decay of ^36Ar, finding no signal and setting a half‑life…
SiPM-matrix readout of two-phase argon detectors using electroluminescence in the visible and near infrared range
The DarkSide collaboration, C. E. Aalseth, S. Abdelhakim +312
Proportional electroluminescence (EL) in noble gases is used in two-phase detectors for dark matter searches to record (in the gas phase) the ionization signal induced by particle…
DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS
C. E. Aalseth, F. Acerbi, P. Agnes +282
Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a tw…
Search for low-mass dark matter WIMPs with 12 ton-day exposure of DarkSide-50
50 Collaboration, P. Agnes, I. F. M. Albuquerque +139
We report on the search for dark matter WIMPs in the mass range below 10 GeV/c, from the analysis of the entire dataset acquired with a low-radioactivity argon target by the Da…
Evidence for Warped Disks of Young Stars in the Galactic Center
H. Bartko, F. Martins, T. K. Fritz +18
The central parsec around the super-massive black hole in the Galactic Center hosts more than 100 young and massive stars. Outside the central cusp (R~1") the majority of these O a…
Production, Quality Assurance and Quality Control of the SiPM Tiles for the DarkSide-20k Time Projection Chamber
F. Acerbi, P. Adhikari, P. Agnes +301
The DarkSide-20k dark matter direct detection experiment will employ a 21 m^2 silicon photomultiplier (SiPM) array, instrumenting a dual-phase 50 tonnes liquid argon Time Projectio…
Long-term temporal stability of the DarkSide-50 dark matter detector
50 Collaboration, P. Agnes, I. F. M. Albuquerque +142
The stability of a dark matter detector on the timescale of a few years is a key requirement due to the large exposure needed to achieve a competitive sensitivity. It is especially…
Stellar dynamics in the central arcsecond of our galaxy
R. Schoedel, R. Genzel, T. Ott +3
We present proper motions for 40 stars at projected distances from Sagittarius A* (Sgr A*). We find evidence on a level for radial anisotropy of the cluste…
First Results from the DarkSide-50 Dark Matter Experiment at Laboratori Nazionali del Gran Sasso
P. Agnes, T. Alexander, A. Alton +143
We report the first results of DarkSide-50, a direct search for dark matter operating in the underground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nucle…
Low-Mass Dark Matter Search with the DarkSide-50 Experiment
The DarkSide Collaboration, P. Agnes, I. F. M. Albuquerque +192
We present the results of a search for dark matter WIMPs in the mass range below 20 GeV/c^2 using a target of low-radioactivity argon. The data were obtained using the DarkSide-50…
Infrared spectroscopy of NGC 4151: ISO observations and NLR line profiles
E. Sturm, T. Alexander, D. Lutz +3
We present ISO-SWS and ISOPHOT-S spectroscopy of the Seyfert galaxy NGC 4151. We detect a total of 17 fine structure emission lines emitted by a wide range of low- and high-excitat…
Results from the first use of low radioactivity argon in a dark matter search
The DarkSide Collaboration, P. Agnes, L. Agostino +158
Liquid argon is a bright scintillator with potent particle identification properties, making it an attractive target for direct-detection dark matter searches. The DarkSide-50 dark…
Observation of the Dependence of Scintillation from Nuclear Recoils in Liquid Argon on Drift Field
T. Alexander, H. O. Back, H. Cao +27
We have exposed a dual-phase Liquid Argon Time Projection Chamber (LAr-TPC) to a low energy pulsed narrowband neutron beam, produced at the Notre Dame Institute for Structure and N…
The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
T. Paumard, R. Genzel, F. Martins +11
We report the definite spectroscopic identification of 41 OB supergiants, giants and main sequence stars in the central parsec of the Galaxy. Detection of their absorption lines ha…
Evidence for a Long-Standing Top-Heavy IMF in the Central Parsec of the Galaxy
H. Maness, F. Martins, S. Trippe +10
We classify 329 late-type giants within 1 parsec of Sgr A*, using the adaptive optics integral field spectrometer SINFONI on the VLT. These observations represent the deepest spect…
Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
R. Genzel, R. Schoedel, T. Ott +5
Recent measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a 3.6-million-solar-mass black hole. Sgr A*…
Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
S. Gillessen, F. Eisenhauer, S. Trippe +4
We present the results of 16 years of monitoring stellar orbits around the massive black hole in center of the Milky Way using high resolution NIR techniques. This work refines our…
Simulation of argon response and light detection in the DarkSide-50 dual phase TPC
The DarkSide Collaboration, P. Agnes, I. F. M. Albuquerque +147
A Geant4-based Monte Carlo package named G4DS has been developed to simulate the response of DarkSide-50, an experiment operating since 2013 at LNGS, designed to detect WIMP intera…
Inward Bound: Studying the Galactic Centre with NAOS/CONICA
T. Ott, R. Schoedel, R. Genzel +25
We report on the first results obtained using adaptive optics measurements of the Galactic Centre done with NAOS/CONICA.
First Commissioning of a Cryogenic Distillation Column for Low Radioactivity Underground Argon
H. O. Back, T. Alexander, A. Alton +11
We report on the performance and commissioning of a cryogenic distillation column for low radioactivity underground argon at Fermi National Accelerator Laboratory. The distillation…
The veto system of the DarkSide-50 experiment
The DarkSide Collaboration, P. Agnes, L. Agostino +158
Nuclear recoil events produced by neutron scatters form one of the most important classes of background in WIMP direct detection experiments, as they may produce nuclear recoils th…
Cosmogenic production of Ar and Ar in argon
R. Saldanha, H. O. Back, R. H. M. Tsang +6
We have experimentally determined the production rate of Ar and Ar from cosmic ray neutron interactions in argon at sea level. Understanding these production rates is…
The Electronics, Trigger and Data Acquisition System for the Liquid Argon Time Projection Chamber of the DarkSide-50 Search for Dark Matter
DarkSide Collaboration, P. Agnes, I. F. M. Albuquerque +177
The DarkSide-50 experiment at the Laboratori Nazionali del Gran Sasso is a search for dark matter using a dual phase time projection chamber with 50 kg of low radioactivity argon a…
Search for low mass dark matter in DarkSide-50: the bayesian network approach
50 Collaboration, P. Agnes, I. F. M. Albuquerque +140
We present a novel approach for the search of dark matter in the DarkSide-50 experiment, relying on Bayesian Networks. This method incorporates the detector response model into the…
An Extremely Top-Heavy IMF in the Galactic Center Stellar Disks
H. Bartko, F. Martins, S. Trippe +19
We present new observations of the nuclear star cluster in the central parsec of the Galaxy with the adaptive optics assisted, integral field spectrograph SINFONI on the ESO/VLT. O…
The Galactic Center: A Laboratory for Fundamental Astrophysics and Galactic Nuclei
A. Ghez, M. Morris, J. Lu +24
As the closest example of a galactic nucleus, the Galactic center presents an exquisite laboratory for learning about supermassive black holes (SMBH) and their environs. Detailed s…
Measurement of the ion fraction and mobility of Po produced in Rn decays in liquid argon
P. Agnes, I. F. M. Albuquerque, T. Alexander +163
We report measurements of the charged daughter fraction of Po as a result of the Rn alpha decay, and the mobility of Po ions, using radon-polonium coinc…
SINFONI in the Galactic Center: young stars and IR flares in the central light month
F. Eisenhauer, R. Genzel, T. Alexander +18
We report 75 milli-arcsec resolution, near-IR imaging spectroscopy within the central 30 light days of the Galactic Center [...]. To a limiting magnitude of K~16, 9 of 10 stars in…
The origin of variability of the intermediate-mass black-hole ULX system HLX-1 in ESO 243-49
J. -P. Lasota, T. Alexander, G. Dubus +5
The ultra-luminous intermediate-mass black-hole system HLX-1 in the ESO 243-49 galaxy exhibits variability with a possible recurrence time of a few hundred days. Finding the origin…
Design and construction of a new detector to measure ultra-low radioactive-isotope contamination of argon
The DarkSide Collaboration, C. E. Aalseth, S. Abdelhakim +328
Large liquid argon detectors offer one of the best avenues for the detection of galactic weakly interacting massive particles (WIMPs) via their scattering on atomic nuclei. The liq…
Sensitivity to low-mass WIMPs with an improved liquid argon ionization response model within the DarkSide programme
F. Acerbi, P. Adhikari, P. Agnes +294
Dark matter detection experiments using liquid argon rely on a precise characterization of the ionization response to nuclear recoils, especially in the keV energy range relevant f…
Quality Assurance and Quality Control of the SiPM production for the DarkSide-20k dark matter experiment
F. Acerbi, P. Adhikari, P. Agnes +289
DarkSide-20k is a novel liquid argon dark matter detector currently under construction at the Laboratori Nazionali del Gran Sasso (LNGS) of the Istituto Nazionale di Fisica Nuclear…
Separating Ar from Ar by cryogenic distillation with Aria for dark matter searches
DarkSide Collaboration, P. Agnes, S. Albergo +309
The Aria project consists of a plant, hosting a 350 m cryogenic isotopic distillation column, the tallest ever built, which is currently in the installation phase in a mine shaft a…
Effect of Low Electric Fields on Alpha Scintillation Light Yield in Liquid Argon
P. Agnes, I. F. M. Albuquerque, T. Alexander +158
Measurements were made of scintillation light yield of alpha particles from the Rn decay chain within the DarkSide-50 liquid argon time projection chamber. The light yield…
Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel
P. Agnes, I. Ahmad, S. Albergo +296
Dark matter lighter than 10 GeV/c encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50…
A Geometric Determination of the Distance to the Galactic Center
F. Eisenhauer, R. Schoedel, R. Genzel +5
We report new astrometric and spectroscopic observations of the star S2 orbiting the massive black hole in the Galactic Center, which were taken at the ESO VLT with the adaptive op…
DarkSide-50 532-day Dark Matter Search with Low-Radioactivity Argon
The DarkSide Collaboration, P. Agnes, I. F. M. Albuquerque +172
The DarkSide-50 direct-detection dark matter experiment is a dual-phase argon time projection chamber operating at Laboratori Nazionali del Gran Sasso. This paper reports on the bl…
A search for broad infrared recombination lines in NGC 1068
D. Lutz, R. Genzel, E. Sturm +12
We report infrared spectroscopy of the prototypical Seyfert 2 galaxy NGC 1068, aiming at detection of broad components of hydrogen recombination lines that originate in the obscure…
Search for dark matter-nucleon interactions via Migdal effect with DarkSide-50
50 Collaboration, P. Agnes, I. F. M. Albuquerque +141
Dark matter elastic scattering off nuclei can result in the excitation and ionization of the recoiling atom through the so-called Migdal effect. The energy deposition from the ioni…
CALIS - a CALibration Insertion System for the DarkSide-50 dark matter search experiment
P. Agnes, I. F. M. Albuquerque, T. Alexander +162
This paper describes the design, fabrication, commissioning and use of a CALibration source Insertion System (CALIS) in the DarkSide-50 direct dark matter search experiment. CALIS…
ISO-SWS spectroscopy of NGC 1068
D. Lutz, E. Sturm, R. Genzel +4
We present ISO-SWS spectroscopy of NGC 1068 for the wavelength range 2.4 to 45um, detecting a total of 36 emission lines. Most of the observed transitions are fine structure and re…
The Effects of Dissolved Methane upon Liquid Argon Scintillation Light
B. J. P. Jones, T. Alexander, H. O. Back +6
In this paper we report on measurements of the effects of dissolved methane upon argon scintillation light. We monitor the light yield from an alpha source held 20 cm from a cryoge…
Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon
H. Cao, T. Alexander, A. Aprahamian +32
We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time proje…
Directionality of nuclear recoils in a liquid argon time projection chamber
20k Collaboration, P. Agnes, I. Ahmad +264
The direct search for dark matter in the form of weakly interacting massive particles (WIMP) is performed by detecting nuclear recoils (NR) produced in a target material from the W…
Electroluminescence pulse shape and electron diffusion in liquid argon measured in a dual-phase TPC
P. Agnes, I. F. M. Albuquerque, T. Alexander +163
We report the measurement of the longitudinal diffusion constant in liquid argon with the DarkSide-50 dual-phase time projection chamber. The measurement is performed at drift elec…
Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way
R. Schodel, T. Ott, R. Genzel +20
Measurements of stellar velocities and variable X-ray emission near the centre of the Milky Way have provided the strongest evidence so far that the dark mass concentrations seen i…
DarkSide-20k sensitivity to light dark matter particles
20k Collaboration, F. Acerbi, P. Adhikari +310
The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV/c. This was demons…
A study of events with photoelectric emission in the DarkSide-50 liquid argon Time Projection Chamber
50 Collaboration, P. Agnes, I. F. M. Albuquerque +135
Finding unequivocal evidence of dark matter interactions in a particle detector is a major objective of physics research. Liquid argon time projection chambers offer a path to prob…
Light Yield in DarkSide-10: a Prototype Two-phase Liquid Argon TPC for Dark Matter Searches
T. Alexander, D. Alton, K. Arisaka +119
As part of the DarkSide program of direct dark matter searches using liquid argon TPCs, a prototype detector with an active volume containing 10 kg of liquid argon, DarkSide-10, wa…
Cryogenic Characterization of FBK RGB-HD SiPMs
C. E. Aalseth, F. Acerbi, P. Agnes +268
We report on the cryogenic characterization of Red Green Blue - High Density (RGB-HD) SiPMs developed at Fondazione Bruno Kessler (FBK) as part of the DarkSide program of dark matt…
The structure of the nuclear stellar cluster of the Milky Way
R. Schoedel, A. Eckart, T. Alexander +8
We present high-resolution seeing limited and AO NIR imaging observations of the stellar cluster within about one parsec of Sgr A*, the massive black hole at the centre of the Milk…
Sensitivity of future liquid argon dark matter search experiments to core-collapse supernova neutrinos
P. Agnes, S. Albergo, I. F. M. Albuquerque +273
Future liquid-argon DarkSide-20k and ARGO detectors, designed for direct dark matter search, will be sensitive also to core-collapse supernova neutrinos, via coherent elastic neutr…
Near-infrared scintillation of liquid argon
T. Alexander, C. O. Escobar, W. H. Lippincott +1
Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 m < ; < 1.5m). More controversial has been the que…