Publications
277 results found
Aalbers J, Akerib DS, Al Musalhi AK, et al., 2022, Cosmogenic production of 37Ar in the context of the LUX-ZEPLIN experiment, Physical Review D, Vol: 105, Pages: 1-8, ISSN: 2470-0010
We estimate the amount of 37Ar produced in natural xenon via cosmic-ray-induced spallation, an inevitable consequence of the transportation and storage of xenon on the Earth’s surface. We then calculate the resulting 37Ar concentration in a 10-tonne payload (similar to that of the LUX-ZEPLIN experiment) assuming a representative schedule of xenon purification, storage, and delivery to the underground facility. Using the spallation model by Silberberg and Tsao, the sea-level production rate of 37Ar in natural xenon is estimated to be 0.024 atoms/kg/day. Assuming the xenon is successively purified to remove radioactive contaminants in 1-tonne batches at a rate of 1 tonne/month, the average 37Ar activity after 10 tons are purified and transported underground is 0.058−0.090 μBq/kg, depending on the degree of argon removal during above-ground purification. Such cosmogenic 37Ar will appear as a noticeable background in the early science data, while decaying with a 35-day half-life. This newly noticed production mechanism of 37Ar should be considered when planning for future liquid-xenon-based experiments.
Akerib DS, Akerlof CW, Akimov DY, et al., 2022, The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs (vol 80, 1044, 2020), EUROPEAN PHYSICAL JOURNAL C, Vol: 82, ISSN: 1434-6044
Akerib DS, Al Musalhi AK, Alsum SK, et al., 2021, Projected sensitivities of the LUX-ZEPLIN experiment to new physics via low-energy electron recoils, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 104, Pages: 1-16, ISSN: 1550-2368
LUX-ZEPLIN is a dark matter detector expected to obtain world-leading sensitivity to weakly-interacting massive particles interacting via nuclear recoils with a ∼7-tonne xenon target mass. This paper presents sensitivity projections to several low-energy signals of the complementary electron recoil signal type: 1) an effective neutrino magnetic moment, and 2) an effective neutrino millicharge, both for pp-chain solar neutrinos, 3) an axion flux generated by the Sun, 4) axionlike particles forming the Galactic dark matter, 5) hidden photons, 6) mirror dark matter, and 7) leptophilic dark matter. World-leading sensitivities are expected in each case, a result of the large 5.6 t 1000 d exposure and low expected rate of electron-recoil backgrounds in the <100 keV energy regime. A consistent signal generation, background model and profile-likelihood analysis framework is used throughout.
Akerib DS, Al Musalhi AK, Alsum SK, et al., 2021, Projected sensitivity of the LUX-ZEPLIN experiment to the two-neutrino and neutrinoless double β decays of Xe134, Physical Review C, Vol: 104, Pages: 1-11, ISSN: 2469-9985
The projected sensitivity of the LUX-ZEPLIN (LZ) experiment to two-neutrino and neutrinoless double β decay of 134Xe is presented. LZ is a 10-tonne xenon time-projection chamber optimized for the detection of dark matter particles and is expected to start operating in 2021 at Sanford Underground Research Facility, USA. Its large mass of natural xenon provides an exceptional opportunity to search for the double β decay of 134Xe, for which xenon detectors enriched in 136Xe are less effective. For the two-neutrino decay mode, LZ is predicted to exclude values of the half-life up to 1.7×1024 years at 90% confidence level (CL) and has a three-sigma observation potential of 8.7×1023 years, approaching the predictions of nuclear models. For the neutrinoless decay mode LZ, is projected to exclude values of the half-life up to 7.3×1024 years at 90% CL.
Akerib DS, Akerlof CW, Akimov DY, et al., 2020, The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs, European Physical Journal C: Particles and Fields, Vol: 80, Pages: 1-52, ISSN: 1124-1861
LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above 1.4×10−48cm2 for a WIMP mass of 40GeV/c2 and a 1000days exposure. LZ achieves this sensitivity through a combination of a large 5.6t fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented.
Collaboration TLUX-ZEPLIN, Akerib DS, Akerlof CW, et al., 2020, Simulations of Events for the LUX-ZEPLIN (LZ) Dark Matter Experiment, Astroparticle Physics, ISSN: 0927-6505
The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to theWIMP-nucleon spin-independent cross-section down to (1-2) $\times$ $10^{-12}$pb at a WIMP mass of 40 GeV/$c^2$. This paper describes the simulationsframework that, along with radioactivity measurements, was used to support thisprojection, and also to provide mock data for validating reconstruction andanalysis software. Of particular note are the event generators, which allow usto model the background radiation, and the detector response physics used inthe production of raw signals, which can be converted into digitized waveformssimilar to data from the operational detector. Inclusion of the detectorresponse allows us to process simulated data using the same analysis routinesas developed to process the experimental data.
Akerib DS, Akerlof CW, Alsum SK, et al., 2020, Projected WIMP sensitivity of the LUX-ZEPLIN dark matter experiment, Physical Review D: Particles, Fields, Gravitation and Cosmology, Vol: 101, Pages: 1-17, ISSN: 1550-2368
LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 1.4×10−48 cm2 for a 40 GeV/c2 mass WIMP. Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 2.3×10−43 cm2 (7.1×10−42 cm2) for a 40 GeV/c2 mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020.
Abramishvili R, Adamov G, Akhmetshin RR, et al., 2020, COMET phase-I technical design report, Progress of Theoretical and Experimental Physics, Vol: 2020, ISSN: 2050-3911
The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus (μ–e conversion, μ−N→e−N); a lepton flavor-violating process. The experimental sensitivity goal for this process in the Phase-I experiment is 3.1×10−15, or 90% upper limit of a branching ratio of 7×10−15, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the μ–e conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.
Akerib DS, Akerlof CW, Akimov DY, et al., 2020, The LUX-ZEPLIN (LZ) experiment, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment, Vol: 953, Pages: 1-22, ISSN: 0168-9002
We describe the design and assembly of the LUX-ZEPLIN experiment, a direct detection search for cosmic WIMP dark matter particles. The centerpiece of the experiment is a large liquid xenon time projection chamber sensitive to low energy nuclear recoils. Rejection of backgrounds is enhanced by a Xe skin veto detector and by a liquid scintillator Outer Detector loaded with gadolinium for efficient neutron capture and tagging. LZ is located in the Davis Cavern at the 4850’ level of the Sanford Underground Research Facility in Lead, South Dakota, USA. We describe the major subsystems of the experiment and its key design features and requirements.
Bauer D, Colling D, Fayer S, et al., 2019, An open source data transfer tool kit for research data, 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP), Publisher: E D P SCIENCES, ISSN: 2100-014X
Abreu Y, Bauer D, Fayer S, et al., 2019, Data management for the SoLid experiment, 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP), Publisher: E D P SCIENCES, ISSN: 2100-014X
Bauer D, Colling D, Fayer S, et al., 2019, The LZ UK Data Centre, 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP), Publisher: E D P SCIENCES, ISSN: 2100-014X
Bauer D, 2018, Distributed computing for small experiments, EPJ Web of Conferences, ISSN: 2101-6275
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0. The large Large Hadron Collider experiments have successfully used distributed computing for years. The same infrastructure yields large opportunistic resources for smaller collaborations. In addition, some national grid initiatives make dedicated resources for small collaborations available. This article presents an overview of the services available and how to access them, including an example of how small collaborations have successfully incorporated distributed computing into their workflows.
Bauer D, Fayer S, 2017, Stealth Cloud: How not to waste CPU during grid to cloud transitions, 22nd International Conference on Computing in High Energy and Nuclear Physics (CHEP2016), ISSN: 1742-6588
© Published under licence by IOP Publishing Ltd. UKI-LT2-IC-HEP is a WLCG tier-2 comprising around 4000 job slots and 3.7 PB of storage supporting LHC and non-LHC VOs. When first looking at converting a part of our site's grid infrastructure into a cloud based system in late 2013 we needed to ensure the continued accessibility of all of our resources during a potentially lengthy transition period. To accomplish this we brought together a number of existing middleware and cloud tools. This proved to be a viable long-term solution to maintain resource usage during extended periods of transition.
Bauer D, Fayer S, 2017, GridPP DIRAC: Supporting non-LHC VOs on LHC centric resources, 22nd International Conference on Computing in High Energy and Nuclear Physics (CHEP2016), ISSN: 1742-6588
© Published under licence by IOP Publishing Ltd. To allow non-LHC communities access to the primarily LHC dominated resources of the grid, the GridPP consortium in the UK maintains a multi-VO DIRAC service for this user-base. After an extensive testing phase, this service has been in production for the last two years and has been fully integrated into the user communities' workflows. We report on the approaches taken by the VOs and the insights gained from these.
Andronis A, Bauer D, Chaze O, et al., 2015, The Diverse use of Clouds by CMS, 21st International Conference on Computing in High Energy and Nuclear Physics (CHEP2015), Publisher: IOP Publishing, ISSN: 1742-6588
Bauer D, Coiling D, Currie R, et al., 2015, The GridPP DIRAC project - DIRAC for non-LHC communities, 21st International Conference on Computing in High Energy and Nuclear Physics (CHEP2015), Publisher: IOP Publishing, ISSN: 1742-6588
Bauer D, Colling D, Currie R, et al., 2015, The GridPP DIRAC project: Implementation of a multi-VO DIRAC service, 21st International Conference on Computing in High Energy and Nuclear Physics (CHEP2015), Publisher: IOP Publishing, ISSN: 1742-6588
Coiling D, Huffman A, McCrae A, et al., 2014, Using the CMS High Level Trigger as a Cloud Resource, 20th International Conference on Computing in High Energy and Nuclear Physics (CHEP), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
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Cohen J, Filippis I, Woodbridge M, et al., 2013, RAPPORT: running scientific high-performance computing applications on the cloud, Philos Transact A Math Phys Eng Sci, Vol: 371, ISSN: 1364-503X
Cloud computing infrastructure is now widely used in many domains, but one area where there has been more limited adoption is research computing, in particular for running scientific high-performance computing (HPC) software. The Robust Application Porting for HPC in the Cloud (RAPPORT) project took advantage of existing links between computing researchers and application scientists in the fields of bioinformatics, high-energy physics (HEP) and digital humanities, to investigate running a set of scientific HPC applications from these domains on cloud infrastructure. In this paper, we focus on the bioinformatics and HEP domains, describing the applications and target cloud platforms. We conclude that, while there are many factors that need consideration, there is no fundamental impediment to the use of cloud infrastructure for running many types of HPC applications and, in some cases, there is potential for researchers to benefit significantly from the flexibility offered by cloud platforms.
Chatrchyan S, Khachatryan V, Sirunyan AM, et al., 2012, A New Boson with a Mass of 125 GeV Observed with the CMS Experiment at the Large Hadron Collider, SCIENCE, Vol: 338, Pages: 1569-1575, ISSN: 0036-8075
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CMS Collaboration, 2012, Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC, Phys. Lett. B
Aaij R, Abellan Beteta C, Adeva B, et al., 2012, Measurement of the B-+/- production cross-section in pp collisions at root s=7 TeV, JOURNAL OF HIGH ENERGY PHYSICS, ISSN: 1029-8479
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- Citations: 15
Abazov VM, Abbott B, Abolins M, et al., 2011, Publisher's Note: Search for CP violation in B-s(0) -> mu+Ds-X decays in p(p)over bar collisions at square s = 1.96 TeV (vol 82, 012003, 2010), PHYSICAL REVIEW D, Vol: 83, ISSN: 1550-7998
Abazov VM, Abbott B, Abolins M, et al., 2010, Dependence of the t(t)over-bar production cross section on the transverse momentum of the top quark, PHYSICS LETTERS B, Vol: 693, Pages: 515-521, ISSN: 0370-2693
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- Citations: 33
Antonelli M, Asner DM, Bauer D, et al., 2010, Flavor physics in the quark sector, PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, Vol: 494, Pages: 197-414, ISSN: 0370-1573
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- Citations: 169
Abazov VM, Abbott B, Abolins M, et al., 2010, Measurement of the t(t)over-bar cross section using high-multiplicity jet events, PHYSICAL REVIEW D, Vol: 82, ISSN: 1550-7998
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- Citations: 14
Abazov VM, Abbott B, Abolins M, et al., 2010, Search for CP violation in B-s(0) -> mu(+) D-s(-) X decays in p(p)over-bar collisions at root s=1.96 TeV, PHYSICAL REVIEW D, Vol: 82, ISSN: 1550-7998
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- Citations: 32
Abazov VM, Abbott B, Abolins M, et al., 2010, Search for single top quarks in the tau plus jets channel using 4.8 fb(-1) of p(p)over-bar collision data, PHYSICS LETTERS B, Vol: 690, Pages: 5-14, ISSN: 0370-2693
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Abazov VM, Abbott B, Abolins M, et al., 2010, Search for the Associated Production of a b Quark and a Neutral Supersymmetric Higgs Boson that Decays into tau Pairs, PHYSICAL REVIEW LETTERS, Vol: 104, ISSN: 0031-9007
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- Citations: 25
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