9,575 research outputs found
Dark Matter directional detection: comparison of the track direction determination
Several directional techniques have been proposed for a directional detection
of Dark matter, among others anisotropic crystal detectors, nuclear emulsion
plates, and low-pressure gaseous TPCs. The key point is to get access to the
initial direction of the nucleus recoiling due to the elastic scattering by a
WIMP. In this article, we aim at estimating, for each method, how the
information of the recoil track initial direction is preserved in different
detector materials. We use the SRIM simulation code to emulate the motion of
the first recoiling nucleus in each material. We propose the use of a new
observable, D, to quantify the preservation of the initial direction of the
recoiling nucleus in the detector. We show that in an emulsion mix and an
anisotropic crystal, the initial direction is lost very early, while in a
typical TPC gas mix, the direction is well preserved.Comment: 9 pages, 5 figure
Low Energy Electron and Nuclear Recoil Thresholds in the DRIFT-II Negative Ion TPC for Dark Matter Searches
Understanding the ability to measure and discriminate particle events at the
lowest possible energy is an essential requirement in developing new
experiments to search for weakly interacting massive particle (WIMP) dark
matter. In this paper we detail an assessment of the potential sensitivity
below 10 keV in the 1 m^3 DRIFT-II directionally sensitive, low pressure,
negative ion time projection chamber (NITPC), based on event-by-event track
reconstruction and calorimetry in the multiwire proportional chamber (MWPC)
readout. By application of a digital smoothing polynomial it is shown that the
detector is sensitive to sulfur and carbon recoils down to 2.9 and 1.9 keV
respectively, and 1.2 keV for electron induced events. The energy sensitivity
is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy
resolution is sufficient to identify the escape peak. The effect a lower energy
sensitivity on the WIMP exclusion limit is demonstrated. In addition to recoil
direction reconstruction for WIMP searches this sensitivity suggests new
prospects for applications also in KK axion searches
The ALICE Experiment Upgrades
The ALICE experiment profited of the Long Shutdown during 2019-2021 in order
to expand its physics capabilities and fully profit from the increased LHC
luminosity in Run 3. The Inner Tracking System has been replaced with a new
silicon tracker based on MAPS technology, and a new tracking device has been
added in front of the Muon Spectrometer to improve its vertexing capabilities.
The wire chambers for TPC readout have been replaced with new GEM detectors
which will minimize ion backflow and allow for continuous data taking:
moreover, a new detector array dedicated to fast triggering has been installed.
On the software side, a new first pass reconstruction was added in order to
handle and reduce the data flow and storage. These upgrades will be presented
together with an outlook of the future ALICE upgrades in view of the LHC Run 4,
which will include the replacement of the ITS inner tracking layers with
upgraded silicon devices and a high-granularity electromagnetic and hadronic
calorimeter in the forward direction (FOCAL)Comment: 4 pages, 1 Figure. Proceedings of 32nd Rencontres de Blois
conference, October 17-22, 202
NEWSdm Collaboration
Direct Dark Matter searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nuclear recoils induced by the scattering of Weakly Interactive Massive Particles (WIMPs). Detectors able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also prove the galactic origin of Dark Matter with an unambiguous signal-to-background separation. Indeed, the angular distribution of recoiled nuclei is centered around the direction of the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we present the discovery potential of a directional experiment based on the use of a solid target made of newly developed nuclear emulsions and of optical read-out systems reaching unprecedented nanometric resolution
Colorado--The Changing Landscape of Land Use Law and Regulations Impacting the Colorado Oil and Gas Industry: From the Colorado Oil and Gas Conservation Act of 1951 to Senate Bill 181 of 2019
When Colorado Democratic Governor Jared Polis approved Senate Bill 181, this new law significantly redirected the historical focus of Colorado oil and gas regulation. This provided a significant delegation of land use related authority to local government for the first time since the passage of this Act in 1951. This new law moved away from the traditional notion of statewide regulation based upon exclusive jurisdiction by the Colorado Oil and Gas Conservation Commission (“COGCC”). While this change of legislative focus is significant, this latest direction is probably a natural continuation of a general trend that has been emerging in Colorado since certain Supreme Court Opinions were announced in 1992, as explained later in this Article. As the State of Colorado has, among other things, grown in population, residential housing now significantly finds itself competing with oil and gas development in the same geographical areas, especially the suburbs of the “Front Range.” Simultaneously, the political sentiment of Colorado has trended into a more significantly Democratic direction from a historically Republican majority. The law as to the governance of the oil and gas industry has now changed as a result of the passing of SB 181—from fostering the development of oil and gas industry to a new paradigm requiring the weighing of interests, including environmental concerns. This Article provides a historic explanation to allow the reader to better understand how this transition has come about. That which is observed in Colorado might also be seen as a potential harbinger of future change that could be noted in other oil and gas states
Direct Dark Matter Searches
For many working in particle physics and cosmology successful discovery and
characterisation of the new particles that most likely explain the non-baryonic
cold dark matter, known to comprise the majority of matter in the Universe,
would be the most significant advance in physics for a century. Reviewed here
is the current status of direct searches for such particles, in particular the
so-called Weakly Interacting Massive Particles (WIMPs), together with a brief
overview of the possible future direction of the field extrapolated from recent
advances. Current best limits are at or below 10-7 pb for spin-independent
neutralino coupling, sufficient that experiments are already probing SUSY
models. However, new detectors with tonne-scale mass and/or capability to
correlate signal events to our motion through the Galaxy will likely be needed
to determine finally whether WIMPs exist.Comment: Submitted to JPSJ, 20 pages, 5 figure
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The Pandora multi-algorithm approach to automated pattern recognition in LAr TPC detectors
The development and operation of Liquid Argon Time Projection Chambers (LAr TPCs) for neutrino physics has created a need for new approaches to pattern recognition, in order to fully exploit the superb imaging capabilities offered by this technology. The Pandora Software Development Kit provides functionality to aid the process of designing, implementing and running pattern recognition algorithms. It promotes the use of a multi-algorithm approach to pattern recognition: individual algorithms each address a specific task in a particular topology; a series of many tens of algorithms then carefully builds-up a picture of the event. The input to the Pandora pattern recognition is a list of 2D Hits. The output from the chain of over 70 algorithms is a hierarchy of reconstructed 3D Particles, each with an identified particle type, vertex and direction
Reasoning about Qualitative Direction and Distance between Extended Objects using Answer Set Programming
In this thesis, we introduce a novel formal framework to represent and reason
about qualitative direction and distance relations between extended objects
using Answer Set Programming (ASP). We take Cardinal Directional Calculus (CDC)
as a starting point and extend CDC with new sorts of constraints which involve
defaults, preferences and negation. We call this extended version as nCDC. Then
we further extend nCDC by augmenting qualitative distance relation and name
this extension as nCDC+. For CDC, nCDC, nCDC+, we introduce an ASP-based
general framework to solve consistency checking problems, address composition
and inversion of qualitative spatial relations, infer unknown or missing
relations between objects, and find a suitable configuration of objects which
fulfills a given inquiry.Comment: In Proceedings ICLP 2019, arXiv:1909.0764
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