Dark matter with Planck-scale mass (≃10^{19} GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from ...supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19} GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18} cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.
Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through ...the study of a polarization state of emitted photons. Starting from the basic principles of quantum mechanics we show that the models of symmetric dark matter are indiscernible by the photon polarization. However, we find that the asymmetric dark matter consisted of Dirac fermions is a source of circularly polarized photons, calling for the experimental determination of the photon state.
We present the results of a search for dark matter weakly interacting massive particles (WIMPs) in the mass range below 20 GeV/c^{2} using a target of low-radioactivity argon with a 6786.0 kg d ...exposure. The data were obtained using the DarkSide-50 apparatus at Laboratori Nazionali del Gran Sasso. The analysis is based on the ionization signal, for which the DarkSide-50 time projection chamber is fully efficient at 0.1 keVee. The observed rate in the detector at 0.5 keVee is about 1.5 event/keVee/kg/d and is almost entirely accounted for by known background sources. We obtain a 90% C.L. exclusion limit above 1.8 GeV/c^{2} for the spin-independent cross section of dark matter WIMPs on nucleons, extending the exclusion region for dark matter below previous limits in the range 1.8-6 GeV/c^{2}.
Liquid argon detectors are ubiquitous in particle, astroparticle, and applied
physics. They reached an unprecedented level of maturity thanks to more than 20
years of R&D and the operation of ...large-scale facilities at CERN, Fermilab, and
the Gran Sasso laboratories. This article reviews such an impressive advance -
from the grounding of the experimental technique up to cutting-edge
applications. We commence the review by describing the physical and chemical
properties of liquid argon as an active and target medium for particle
detection, together with advantages and limitations compared with other
liquefied noble gases. We examine the opportunities and challenges of liquid
argon detectors operated as calorimeters, scintillators, and time projection
chambers. We then delve into the core applications of liquid argon detectors at
colliders (ATLAS), accelerator neutrino beams (SBN, DUNE), and underground
laboratories (DarkSide, DEAP, ICARUS) for the observation of rare events. We
complete the review by looking at unconventional developments (pixelization,
combined light-charge readout, Xe-doped devices, all-optical readout) and
applications in medical and applied physics to extend this technology's scope
toward novel research fields.
We present new constraints on sub-GeV dark-matter particles scattering off electrons based on 6780.0 kg d of data collected with the DarkSide-50 dual-phase argon time projection chamber. This ...analysis uses electroluminescence signals due to ionized electrons extracted from the liquid argon target. The detector has a very high trigger probability for these signals, allowing for an analysis threshold of three extracted electrons, or approximately 0.05 keVee. We calculate the expected recoil spectra for dark matter-electron scattering in argon and, under the assumption of momentum-independent scattering, improve upon existing limits from XENON10 for dark-matter particles with masses between 30 and 100 MeV/c^{2}.
In the direct searches for Weakly Interacting Massive Particles (WIMPs) as Dark Matter candidates, the sensitivity of the detector to the incom- ing particle direction could provide a smoking gun ...signature for an interesting event. The SCENE collaboration firstly suggested the possible directional de- pendence of a dual-phase argon Time Projection Chamber through the columnar recombination effect. The Recoil Directionality project (ReD) within the Global Argon Dark Matter Collaboration aims to characterize the light and charge re- sponse of a liquid Argon dual-phase TPC to neutron-induced nuclear recoils to probe for the hint by SCENE. In this work, the directional sensitivity of the de- tector in the energy range of interest for WIMPs (20-100 keV) is investigated with a data-driven analysis involving a Machine Learning algorithm.
Elastic neutrino-electron scattering represents a powerful tool to investigate key neutrino properties. In view of the recent results released by the LUX-ZEPLIN collaboration, we provide a first ...determination of the limits achievable on the neutrino magnetic moment and neutrino millicharge, whose effect becomes non-negligible in some beyond the Standard Model theories. In this context, we evaluate and discuss the impact of different approximations to describe the neutrino interaction with atomic electrons. The new LUX-ZEPLIN data allows us to set a very competitive limit on the neutrino magnetic moment when compared to the other laboratory bounds, namely \(\mu_{\nu}^{\rm{eff}} < 1.1 \times 10^{-11} \, \mu_{\text{B}}\) at 90\(\%\) C.L., which improves by a factor of 2.5 the Borexino collaboration limit and represents the second best world limit after the recent XENONnT result. Moreover, exploiting the so-called equivalent photon approximation, we obtain the most stringent limit on the neutrino millicharge, namely \(|q_{\nu}^{\rm{eff}}| < 1.5 \times 10^{-13} e_0\) at 90\(\%\) C.L., which represents a great improvement with respect to the previous laboratory bounds.
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 blind analysis of a ...(16 660±270) kg d exposure using a target of low-radioactivity argon extracted from underground sources. We find no events in the dark matter selection box and set a 90% C.L. upper limit on the dark matter–nucleon spin-independent cross section of 1.14×10−44 cm2 (3.78×10−44 cm2, 3.43×10−43 cm2) for a WIMP mass of 100 GeV/c2 (1 TeV/c2, 10 TeV/c2).
Flavor physics of leptons and dipole moments Raidal, M.; van der Schaaf, A.; Bigi, I. ...
European physical journal. C, Particles and fields,
09/2008, Volume:
57, Issue:
1-2
Journal Article, Conference Proceeding
Peer reviewed
Open access
This chapter of the report of the “Flavor in the era of the LHC” Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector ...and in flavor conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
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