STUDY OF ELECTRON ANTI-NEUTRINOS ASSOCIATED WITH GAMMA-RAY BURSTS USING KamLAND

We search for electron anti-neutrinos ([bar over ν][subscript e]) from long- and short-duration gamma-ray bursts (GRBs) using data taken by the Kamioka Liquid Scintillator Anti-Neutrino Detector (KamLAND) from 2002 August to 2013 June. No statistically significant excess over the background level is found. We place the tightest upper limits on [bar over ν][subscript e] fluence from GRBs below 7 MeV and place first constraints on the relation between [bar over ν][subscript e] luminosity and effective temperature

A SEARCH FOR ELECTRON ANTINEUTRINOS ASSOCIATED WITH GRAVITATIONAL-WAVE EVENTS GW150914 AND GW151226 USING KAMLAND

We present a search, using KamLAND, a kiloton-scale anti-neutrino detector, for low-energy anti-neutrino events that were coincident with the gravitational-wave (GW) events GW150914 and GW151226, and the candidate event LVT151012. We find no inverse beta-decay neutrino events within ±500 s of either GW signal. This non-detection is used to constrain the electron anti-neutrino fluence and the total integrated luminosity of the astrophysical sources.United States. Department of Energy (Grant DE-FG03-00ER41138)United States. Department of Energy (Grant DE-AC02- 05CH11231)United States. Department of Energy (Grant DE-FG02-01ER41166

Report of the Topical Group on Wave Dark Matter for Snowmass 2021

There is a strong possibility that the particles making up the dark matter in the Universe have a mass below 1 eV and in many important situations exhibit a wave-like behavior. Amongst the candidates the axion stands out as particularly well motivated but other possibilities such as axion-like particles, light scalars and light vectors, should be seriously investigated with both experiments and theory. Discovery of any of these dark matter particles would be revolutionary. The wave-like nature opens special opportunities to gain precise information on the particle properties a well as astrophysical information on dark matter shortly after a first detection. To achieve these goals requires continued strong support for the next generations of axion experiments to probe significant axion parameter space this decade and to realize the vision of a definitive axion search program in the next 20 years. This needs to be complemented by strong and flexible support for a broad range of smaller experiments, sensitive to the full variety of wave-like dark matter candidates. These have their own discovery potential but can also be the test bed for future larger scale searches. Strong technological support not only allows for the optimal realization of the current and near future experiments but new technologies such as quantum measurement and control can also provide the next evolutionary jump enabling a broader and deeper sensitivity. Finally, a theory effort ranging from fundamental model building over investigating phenomenological constraints to the conception of new experimental techniques is a cornerstone of the current rapid developments in the search for wave-like dark matter and should be strengthened to have a solid foundation for the future.Comment: First arXiv version for community feedbac

Light Yield of Perovskite Nanocrystal-Doped Liquid Scintillator

Future generations of liquid scintillator neutrino experiments will require stably loading tons of candidate isotopes into kiloton-scale detectors, representing a significant chemical challenge. Nanoparticles containing the candidate isotopes provide a promising method for this loading. Additionally, the unique optical properties of nanoparticles can enhance detection and background discrimination. Perovskite nanocrystals are particularly attractive due to the reliability of their crystal structure and their easily-scalable synthesis. We present here the first study of lead-based perovskite nanocrystals for this application.Comment: 14 pages, 10 figures, submitted for publication in JINST. arXiv admin note: substantial text overlap with arXiv:1807.0663

The search for low-mass axion dark matter with ABRACADABRA-10cm

Two of the most pressing questions in physics are the microscopic nature of the dark matter that comprises 84% of the mass in the universe and the absence of a neutron electric dipole moment. These questions would be resolved by the existence of a hypothetical particle known as the quantum chromodynamics (QCD) axion. In this work, we probe the hypothesis that axions constitute dark matter, using the ABRACADABRA-10cm experiment in a broadband configuration, with world-leading sensitivity. We find no significant evidence for axions, and we present 95% upper limits on the axion-photon coupling down to the world-leading level $g_{a\gamma\gamma}<3.2 \times10^{-11}$ GeV$^{-1}$, representing one of the most sensitive searches for axions in the 0.41 - 8.27 neV mass range. Our work paves a direct path for future experiments capable of confirming or excluding the hypothesis that dark matter is a QCD axion in the mass range motivated by String Theory and Grand Unified Theories.Comment: 17 pages, 12 figure

Design and Implementation of the ABRACADABRA-10 cm Axion Dark Matter Search

The past few years have seen a renewed interest in the search for light particle dark matter. ABRACADABRA is a new experimental program to search for axion dark matter over a broad range of masses, $10^{-12}\lesssim m_a\lesssim10^{-6}$ eV. ABRACADABRA-10 cm is a small-scale prototype for a future detector that could be sensitive to QCD axion couplings. In this paper, we present the details of the design, construction, and data analysis for the first axion dark matter search with the ABRACADABRA-10 cm detector. We include a detailed discussion of the statistical techniques used to extract the limit from the first result with an emphasis on creating a robust statistical footing for interpreting those limits.Comment: 12 pages, 8 figure

US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure