112 research outputs found
A Factorization Law for Entanglement Decay
We present a simple and general factorization law for quantum systems shared
by two parties, which describes the time evolution of entanglement upon passage
of either component through an arbitrary noisy channel. The robustness of
entanglement-based quantum information processing protocols is thus easily and
fully characterized by a single quantity.Comment: 4 pages, 5 figure
DM-like anomalies in neutron multiplicity spectra
Publisher Copyright: © 2022 Institute of Physics Publishing. All rights reserved.A new experiment collects data, since November 2019, at a depth of 210 m.w.e. in the Callio Lab in the Pyhasalmi mine in Finland. The setup, called NEMESIS (New Emma MEasurementS Including neutronS), incorporates infrastructure from the EMMA experiment with neutron and large-area plastic scintillator detectors. The experiment's primary aim is to combine muon tracking with position-sensitive neutron detection to measure precision yields, multiplicities, and lateral distributions of high-multiplicity neutron events induced by cosmic muons in various materials. The data are relevant for background evaluation of the deep-underground searches for Dark Matter (DM), neutrino-less double beta decay, etc. Preliminary analysis revealed anomalies in muon-suppressed neutron multiplicity spectra collected during a 344-day run (live time) with a 565 kg Pb target. The spectra, otherwise well described by an exponential fit, show three peaks at high multiplicities. Although still at a low statistical significance, these small excesses match the outcome of an earlier measurement. The nature of the anomalies remains unclear, but, in principle, they may be a signature of self-annihilation of a WIMP with a mass close to 13 GeV/c2. With that assumption, the expected cross-section would be around 10-42 cm2 for Spin-Dependent or 10-46 cm2 for Spin Independent interactions. We propose verifying this hypothesis with an upgraded NEMESIS experiment, able to collect an order of magnitude more data than this measurement. Based on the statistical uncertainty, analysis of the event rate indicates that cross-section limits for DM mass range of approximately 3-40 GeV/c2 can be investigated with such a setup.Peer reviewe
New NEMESIS Results
Funding Information: This work has been supported in part by the EU INTERREG for the Baltic Sea programme within the BSUIN project, and by the Polish Ministry of Science and Higher Education (Grant no. Funding Information: This work has been supported in part by the EU INTERREG for the Baltic Sea programme within the BSUIN project, and by the Polish Ministry of Science and Higher Education (Grant no. 3988/INTERREG BSR/2018/2). Publisher Copyright: © Copyright owned by the author(s) under the terms of the Creative Commons.Preliminary results from a 349-day run (live time) with a 565 kg Pb target and a 166-day background measurement are presented. Three minor anomalies were detected in muon-suppressed neutron multiplicity spectra. The multiplicities of these small excesses match the outcome of an earlier, similar but independent measurement. The nature of the anomalies remains unclear, but, in principle, they may be a signature of self-annihilation of a Weakly Interacting Massive Particle (WIMP) with a mass around 10 GeV/c2. If our interpretation is correct, the expected cross section would be of the order of 10-42 cm2 for Spin Dependent and 10-46 cm2 for Spin Independent interactions. Analysis of the event rate, based on the statistical uncertainty, indicates that cross-section limits for Dark Matter (DM) mass range of approximately 3-40 GeV/c2 can be investigated with an upgraded NEMESIS setup.Peer reviewe
NEMESIS setup for Indirect Detection of WIMPs
We summarize the evidence for DM-like anomalies in neutron multiplicity spectra collected underground with Pb targets by three independent experiments: NEMESIS (at 210 m.w.e.) NMDS (at 583 m.w.e.), and ZEPLIN-II (at 2850 m.w.e.). A new analysis shows small but persistent anomalies at high neutron multiplicities. Adjusted for differences in detection efficiencies, the positions of the anomalies are consistent between the three systems. Also, the intensities match when corrected for the acquisition time and estimated detection efficiency. While the three measurements are inconclusive when analyzed separately, together, they exclude a statistical fluke to better than one in a million. To prove the existence of the anomalies above the 5-sigma discovery threshold, we propose to upgrade the current NEMESIS setup. The upgrade concept and the critical components of the new experiment are described. The upgraded setup would already acquire the needed data sample during the first year of operation. Additional information, vital for the physics interpretation of the analysis, will be obtained with a Cu target.Peer reviewe
The BSUIN project
Baltic Sea Underground Innovation Network (BSUIN) is an European Union funded project that
extends capabilities of underground laboratories. The aim of the project is to join efforts in making
the underground laboratories in the Baltic Sea Region’s more accessible for innovation, business
development and science by improving the availability of information about the underground
facilities, service offerings, user experience, safety and marketing.The development of standards
for the characterization of underground laboratories will allow to compared them with each other.
This will help you choose the best places for physical measurements such as neutrino physics or
searching for dark matter. The project concerns laboratories where so far no measurements have
been made, and even undergrounds where there are no organized laboratories yet.The description
of the BSUIN project and the first results of characterization of natural radioactive background in
underground laboratories will be presented ˙ The BSUIN Project is funded by Interreg Baltic Sea
funding cooperation [2]
Cosmic Ray Extremely Distributed Observatory: a global network of detectors to probe contemporary physics mysteries
In the past few years, cosmic-rays beyond the GZK cut-off ( eV) have been detected by leading collaborations such as Pierre Auger
Observatory. Such observations raise many questions as to how such energies can
be reached and what source can possibly produce them. Although at lower
energies, mechanisms such as Fermi acceleration in supernovae front shocks seem
to be favored, top-down scenarios have been proposed to explain the existence
of ultra-high energy cosmic-rays: the decay of super-massive long-lived
particles produced in the early Universe may yield to a flux of ultra-high
energy photons. Such photons might be presently generating so called
super-preshowers, an extended cosmic-ray shower with a spatial distribution
that can be as wide as the Earth diameter. The Cosmic Ray Extremely Distributed
Observatory (CREDO) mission is to find such events by means of a network of
detectors spread around the globe. CREDO's strategy is to connect existing
detectors and create a worldwide network of cosmic-ray observatories. Moreover,
citizen-science constitutes an important pillar of our approach. By helping our
algorithms to recognize detection patterns and by using smartphones as
individual cosmic-ray detectors, non-scientists can participate in scientific
discoveries and help unravel some of the deepest mysteries in physics.Comment: excited QCD Conference, CREDO Collaboration, 7 pages, 3 figure
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