skip to main content

Search for: All records

Creators/Authors contains: "Hasegawa, T."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. International Ocean Discovery Program (IODP) Expedition 369 recovered pelagic sediments spanning the Albian to Pleistocene at Sites U1513, U1514, and U1516. The cores provide an opportunity to determine paleoclimatic and paleoceanographic dynamics from a hitherto poorly sampled mid-high-latitude location across an ~110 My interval, beginning during the Cretaceous supergreenhouse when eastern Gondwana was still largely assembled and ending during the modern icehouse climate after the final breakup of Gondwana. Here we present ~650 bulk carbonate carbon and oxygen stable isotope data points and plot them alongside shipboard data sets to present a first broad documentation of chemostratigraphic data that reveal the stratigraphic position of key climatic transitions and events at Sites U1513, U1514, and U1516. These records show a pronounced long-term δ13C decrease and δ18O increase from the Albian/Cenomanian through the Pleistocene. Superimposed on this long-term trend are transient δ13C and δ18O events correlated with Oceanic Anoxic Event 2, peak Cretaceous warmth during the Turonian, Santonian to Maastrichtian cooling, the Cretaceous/Paleogene boundary, the Paleocene/Eocene Thermal Maximum, the Early Eocene Climatic Optimum, the Middle Eocene Climatic Optimum, and the Eocene–Oligocene transition. Recognizing these isotopic events confirms and refines shipboard interpretations and, more importantly, demonstrates the suitability of Sites U1513, U1514, andmore »U1516 for future high-resolution paleoceanographic works aimed at illuminating the links between tectonic and oceanographic dynamics and global versus local environmental changes.« less
    Free, publicly-accessible full text available May 20, 2023
  2. Free, publicly-accessible full text available June 1, 2023
  3. Free, publicly-accessible full text available March 1, 2023
  4. Free, publicly-accessible full text available December 1, 2022
  5. Free, publicly-accessible full text available April 1, 2023
  6. Abstract The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, U.S.A. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of 7 × 6 × 7.2 m 3 . The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. ProtoDUNE-SP's successful operation between 2018 and 2020 demonstrates the effectiveness of the single-phase far detector design. This paper describes the design, construction, assembly and operation of the detector components.
    Free, publicly-accessible full text available January 1, 2023
  7. null (Ed.)
    Abstract The Deep Underground Neutrino Experiment (DUNE), a 40-kton underground liquid argon time projection chamber experiment, will be sensitive to the electron-neutrino flavor component of the burst of neutrinos expected from the next Galactic core-collapse supernova. Such an observation will bring unique insight into the astrophysics of core collapse as well as into the properties of neutrinos. The general capabilities of DUNE for neutrino detection in the relevant few- to few-tens-of-MeV neutrino energy range will be described. As an example, DUNE’s ability to constrain the $$\nu _e$$ ν e spectral parameters of the neutrino burst will be considered.
  8. Abstract The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE’s sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.