67 results match your criteria: "Institute of Particle and Nuclear Studies[Affiliation]"

If dark matter (DM) consists of primordial black holes (PBHs) and particles simultaneously, PBHs are generically embedded within particle DM halos. Such "dressed PBHs" (dPBHs) are subject to modified constraints compared to PBHs and can contribute to significant DM abundance in the mass range 10^{-1}-10^{2}M_{⊙}. We show that diffractive lensing of chirping gravitational waves from binary mergers can not only discover, but can also identify dPBH lenses and discriminate them from bare PBHs on the event-by-event basis, with potential to definitively establish the coexistence of subdominant PBHs and particle DM.

View Article and Find Full Text PDF

Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for the first time at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. New millisecond isomers have been identified at low excitation energies, 985.3(19) keV in ^{213}Tl and 874(5) keV in ^{215}Tl.

View Article and Find Full Text PDF

New insight into the exotic states strongly coupled with the DD‾ from the T.

Sci Bull (Beijing)

October 2024

School of Physics and Center of High Energy Physics, Peking University, Beijing 100871, China.

We have investigated the internal structure of the open- and hidden-charmed (DD/D¯D) molecules in the unified framework. We first fit the experimental lineshape of the T state and extract the DD interaction, from which the T is assumed to arise solely. Then we obtain the DD¯ interaction by charge conjugation.

View Article and Find Full Text PDF

Isotropy of Cosmic Rays beyond 10^{20}  eV Favors Their Heavy Mass Composition.

Phys Rev Lett

July 2024

High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112-0830, USA.

We report an estimation of the injected mass composition of ultrahigh energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-dependent sky distribution of UHECR events observed by the Telescope Array surface detector by comparing it to the Large Scale Structure of the local Universe. In the case of negligible extragalactic magnetic fields (EGMFs), the results are consistent with a relatively heavy injected composition at E∼10  EeV that becomes lighter up to E∼100  EeV, while the composition at E>100  EeV is very heavy.

View Article and Find Full Text PDF

The first results of the study of high-energy electron neutrino (ν_{e}) and muon neutrino (ν_{μ}) charged-current interactions in the FASERν emulsion-tungsten detector of the FASER experiment at the LHC are presented. A 128.8 kg subset of the FASERν volume was analyzed after exposure to 9.

View Article and Find Full Text PDF

Gravitational Wave Symphony from Oscillating Spectator Scalar Fields.

Phys Rev Lett

July 2024

Institut de Física d'Altes Energies (IFAE), The Barcelona Institute of Science and Technology (BIST), Campus UAB, 08193 Bellaterra, Barcelona, Spain.

We investigate a generic source of stochastic gravitational wave background due to the parametric resonance of oscillating scalar fields in the early Universe. By systematically analyzing benchmark models through lattice simulations and considering a wide range of parameters, we demonstrate that such a scenario can lead to detectable signals in gravitational wave detectors over a broad frequency range and potentially address the recent findings by pulsar timing array experiments. Furthermore, these models naturally yield ultralight dark matter candidates or dark radiation detectable by cosmic microwave background observatories.

View Article and Find Full Text PDF

Cosmic microwave background (CMB) experiments have deployed focal planes with transition edge sensor (TES) bolometers cooled to sub-Kelvin temperatures by multiplexing the readout of many TES channels onto a single pair of wires. Digital Frequency-domain Multiplexing (DfMux) is a multiplexing technique used in many CMB polarization experiments, such as the Simons Array, SPT-3 G, and EBEX. The DfMux system studied here uses LC filters with resonant frequencies ranging from 1.

View Article and Find Full Text PDF

Statistical Anisotropy of Primordial Gravitational Waves from Generalized δN Formalism.

Phys Rev Lett

June 2024

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba 305-0801, Japan; The Graduate University for Advanced Studies (SOKENDAI), Tsukuba 305-0801, Japan; International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP), High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan; and Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Chikusa-Ku, Nagoya, Aichi 464-8602, Japan.

In this Letter, we demonstrate how to use the generalized δN formalism, which enables us to compute the evolution of all the large-scale fluctuations, including gravitational waves, solely by solving the evolution of the background homogeneous Universe. Using the Noether charge density, we derive an analytic formula which describes the mapping between the fluctuations at the horizon crossing and the sourced gravitational waves at the end of inflation. This formula can apply also to an inflation model with an anisotropic background.

View Article and Find Full Text PDF

Development of silicon-on-insulator direct electron detector with analog memories in pixels for sub-microsecond imaging.

Microscopy (Oxf)

December 2024

Institute of Materials and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.

We have developed a high-speed recordable direct electron detector based on silicon-on-insulator technology. The detector has 16 analog memories in each pixel to record 16 images with sub-microsecond temporal resolution. A dedicated data acquisition system has also been developed to display and record the results on a personal computer.

View Article and Find Full Text PDF

Direct Measurement of the Spectral Structure of Cosmic-Ray Electrons+Positrons in the TeV Region with CALET on the International Space Station.

Phys Rev Lett

November 2023

Department of Physics and McDonnell Center for the Space Sciences, Washington University, One Brookings Drive, St. Louis, Missouri 63130-4899, USA.

Detailed measurements of the spectral structure of cosmic-ray electrons and positrons from 10.6 GeV to 7.5 TeV are presented from over 7 years of observations with the CALorimetric Electron Telescope (CALET) on the International Space Station.

View Article and Find Full Text PDF

A half-wave plate (HWP) is often used as a modulator to suppress systematic error in the measurements of cosmic microwave background (CMB) polarization. A HWP can also be used to measure circular polarization (CP) through its optical leakage from CP to linear polarization. The CP of the CMB is predicted from various sources, such as interactions in the Universe and extension of the standard model.

View Article and Find Full Text PDF

First Direct Observation of Collider Neutrinos with FASER at the LHC.

Phys Rev Lett

July 2023

Département de Physique Nucléaire et Corpusculaire, University of Geneva, CH-1211 Geneva 4, Switzerland.

We report the first direct observation of neutrino interactions at a particle collider experiment. Neutrino candidate events are identified in a 13.6 TeV center-of-mass energy pp collision dataset of 35.

View Article and Find Full Text PDF

Signatures of a High Temperature QCD Transition in the Early Universe.

Phys Rev Lett

June 2023

Department of Physics, University of California, San Diego, La Jolla, California 92093, USA.

Beyond-Standard-Model extensions of QCD could result in quark and gluon confinement occurring well above at temperature around the GeV scale. These models can also alter the order of the QCD phase transition. Therefore, the enhanced production of primordial black holes (PBHs) that can accompany the change in relativistic degrees of freedom at the QCD transition could favor the production of PBHs with mass scales smaller than the Standard Model QCD horizon scale.

View Article and Find Full Text PDF

Charge-Sign Dependent Cosmic-Ray Modulation Observed with the Calorimetric Electron Telescope on the International Space Station.

Phys Rev Lett

May 2023

Department of Physics and McDonnell Center for the Space Sciences, Washington University, One Brookings Drive, Saint Louis, Missouri 63130-4899, USA.

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate.

View Article and Find Full Text PDF

Enhanced Gravitational Waves from Inflaton Oscillons.

Phys Rev Lett

May 2023

Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS The University of Tokyo, Kashiwa, Chiba 277-8583, Japan.

In broad classes of inflationary models the period of accelerated expansion is followed by fragmentation of the inflaton scalar field into localized, long-lived, and massive oscillon excitations. We demonstrate that matter dominance of oscillons, followed by their rapid decay, significantly enhances the primordial gravitational wave (GW) spectrum. These oscillon-induced GWs, sourced by second-order perturbations, are distinct and could be orders of magnitude lower in frequency than the previously considered GWs associated with oscillon formation.

View Article and Find Full Text PDF

Direct Measurement of the Cosmic-Ray Helium Spectrum from 40 GeV to 250 TeV with the Calorimetric Electron Telescope on the International Space Station.

Phys Rev Lett

April 2023

Department of Physics and McDonnell Center for the Space Sciences, Washington University, One Brookings Drive, St. Louis, Missouri 63130-4899, USA.

We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument in operation on the International Space Station since 2015. The observation period covered by this analysis spans from October 13, 2015, to April 30, 2022 (2392 days). The very wide dynamic range of CALET allowed for the collection of helium data over a large energy interval, from ∼40  GeV to ∼250  TeV, for the first time with a single instrument in low Earth orbit.

View Article and Find Full Text PDF

The new isotope ^{241}U was synthesized and systematic atomic mass measurements of nineteen neutron-rich Pa-Pu isotopes were performed in the multinucleon transfer reactions of the ^{238}U+^{198}Pt system at the KISS facility. The present experimental results demonstrate the crucial role of the multinucleon transfer reactions for accessing unexplored neutron-rich actinide isotopes toward the N=152 shell gap in this region of nuclides.

View Article and Find Full Text PDF

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110  MeV/c^{2} and 210-240  MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

View Article and Find Full Text PDF

The atomic masses of ^{55}Sc, ^{56,58}Ti, and ^{56-59}V have been determined using the high-precision multireflection time-of-flight technique. The radioisotopes have been produced at RIKEN's Radioactive Isotope Beam Factory (RIBF) and delivered to the novel designed gas cell and multireflection system, which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For ^{56,58}Ti and ^{56-59}V, the mass uncertainties have been reduced down to the order of 10 keV, shedding new light on the N=34 shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species ^{58}Ti and ^{59}V.

View Article and Find Full Text PDF

Cosmic-Ray Boron Flux Measured from 8.4  GeV/n to 3.8  TeV/n with the Calorimetric Electron Telescope on the International Space Station.

Phys Rev Lett

December 2022

Department of Physics and McDonnell Center for the Space Sciences, Washington University, One Brookings Drive, St. Louis, Missouri 63130-4899, USA.

Article Synopsis
  • The study measures how the boron flux in cosmic rays changes with energy and compares it to carbon flux using data from the Calorimetric Electron Telescope (CALET) over approximately 6.4 years.
  • The researchers found a hardening in the boron spectrum beginning at around 200 GeV/n, indicating that boron and carbon have different energy dependences despite the observed similarities at certain transition energies.
  • They also suggest that the B/C ratio, along with their findings, supports recent observations indicating that secondary cosmic rays like boron experience more significant energy hardening than primary ones.
View Article and Find Full Text PDF

Analytic Map of Three-Channel S Matrix: Generalized Uniformization and Mittag-Leffler Expansion.

Phys Rev Lett

November 2022

Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Osaka 567-0047, Japan.

We explore the analytic structure of the three-channel S matrix by generalizing uniformization and making a single-valued map for the three-channel S matrix. First, by means of the inverse Jacobi's elliptic function we construct a transformation from eight Riemann sheets of the center-of-mass energy complex plane onto a torus, on which the three-channel S matrix is represented single-valued. Second, we show that the Mittag-Leffler expansion, a pole expansion, of the three-channel scattering amplitude includes not only topologically trivial but also nontrivial contributions and is given by the Weierstrass zeta function.

View Article and Find Full Text PDF

Observation of Spectral Structures in the Flux of Cosmic-Ray Protons from 50 GeV to 60 TeV with the Calorimetric Electron Telescope on the International Space Station.

Phys Rev Lett

September 2022

Department of Physics and McDonnell Center for the Space Sciences, Washington University, One Brookings Drive, St. Louis, Missouri 63130-4899, USA.

A precise measurement of the cosmic-ray proton spectrum with the Calorimetric Electron Telescope (CALET) is presented in the energy interval from 50 GeV to 60 TeV, and the observation of a softening of the spectrum above 10 TeV is reported. The analysis is based on the data collected during ∼6.2  years of smooth operations aboard the International Space Station and covers a broader energy range with respect to the previous proton flux measurement by CALET, with an increase of the available statistics by a factor of ∼2.

View Article and Find Full Text PDF

Cryptoasset networks: Flows and regular players in Bitcoin and XRP.

PLoS One

August 2022

Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, Kyoto, Japan.

Cryptoassets flow among players as recorded in the ledger of blockchain for all the transactions, comprising a network of players as nodes and flows as edges. The last decade, on the other hand, has witnessed repeating bubbles and crashes of the price of cryptoassets in exchange markets with fiat currencies and other cryptos. We study the relationship between these two important aspects of dynamics, one in the bubble/crash of price and the other in the daily network of crypto, by investigating Bitcoin and XRP.

View Article and Find Full Text PDF

Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8  GeV/n to 240  GeV/n with CALET on the International Space Station.

Phys Rev Lett

April 2022

Department of Physics and McDonnell Center for the Space Sciences, Washington University, One Brookings Drive, St. Louis, Missouri 63130-4899, USA.

Article Synopsis
  • The abundance of cosmic ray nickel nuclei compared to iron is significant, making it a good candidate for studying cosmic ray spectra with low background noise.
  • Measurements of cosmic ray nickel above 3 GeV/n are limited, highlighting the importance of new data for understanding cosmic sources and heavy nucleus propagation.
  • The CALET instrument, operational on the International Space Station, provided precise measurements of the nickel spectrum from 8.8 to 240 GeV/n, revealing a spectral index of -2.51±0.07 in the energy range of 20 to 240 GeV/n.
View Article and Find Full Text PDF