activity
19982026
most citedExtension of the Cosmic-Ray Energy Spectrum Beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff

674 citations · 4.7k across the 58 of their papers we have counts for

collaborators

59 papers

astro-ph.IM2026

Investigation of magnetic-field effects on photomultiplier tubes for the first Large-Sized Telescope of the Cherenkov Telescope Array Observatory

Yukiho Kobayashi, Dai Tateishi, Yuji Sunada +28

Photomultiplier tubes (PMTs) are widely used in imaging atmospheric Cherenkov telescopes. Their response can depend on the telescope pointing direction through changes in their ori…

astro-ph.IM2026

The performance of the TA4 surface detector array: 4.3 years of the first-half expansion

Telescope Array Collaboration, R. U. Abbasi, T. Abu-Zayyad +126

The Telescope Array (TA) experiment aims to reveal the origin of ultra-high-energy cosmic rays (UHECRs) by observing air showers using surface detectors (SDs), which spread over an…

astro-ph.IM2026

Mechanism for reduction of the afterpulsing rate of PMTs

Kai Morita, Mitsunari Takahashi, Habib Ahammad Mondal +7

Photomultiplier tubes (PMTs) are used in Imaging Atmospheric Cherenkov Telescopes (IACTs) to detect Cherenkov light produced by air showers induced by gamma rays in the atmosphere.…

astro-ph.GA2025

Searching for EeV photons with Telescope Array Surface Detector and neural networks

Telescope Array Collaboration, R. U. Abbasi, T. Abu-Zayyad +126

Ultra-high-energy photons play an important role in probing astrophysical models and beyond-Standard-Model scenarios. We report updated limits on the diffuse photon flux using Tele…

astro-ph.IM2025★ 5 cited

Development and Quality Control of PMT Modules for the Large-Sized Telescopes of the Cherenkov Telescope Array Observatory

T. Saito, M. Takahashi, Y. Inome +56

The camera of the Large-Sized Telescopes (LSTs) of the Cherenkov Telescope Array Observatory (CTAO) consists of 1855 pixels that are grouped into 265 high-performance photomultipli…

astro-ph.IM2025

Competition between Increasing and Decreasing Effects of the Afterpulsing Rate of PMTs during Night-Sky Observations

Takuto Kiyomoto, Tsutomu Nagayoshi, Shunsuke Sakurai +13

Photomultiplier tubes (PMTs) have been widely used in imaging atmospheric Cherenkov telescopes (IACTs). The Large-Sized Telescopes (LSTs) of the Cherenkov Telescope Array Observato…

astro-ph.HE2024★ 1 cited

Isotropy of cosmic rays beyond eV favors their heavy mass composition

Telescope Array Collaboration, R. U. Abbasi, Y. Abe +138

We report an estimation of the injected mass composition of ultra-high energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-depend…

astro-ph.HE2024

Mass composition of ultra-high energy cosmic rays from distribution of their arrival directions with the Telescope Array

Telescope Array Collaboration, R. U. Abbasi, Y. Abe +138

We use a new method to estimate the injected mass composition of ultrahigh cosmic rays (UHECRs) at energies higher than 10 EeV. The method is based on comparison of the energy-depe…

astro-ph.HE2024★ 1 cited

Observation of Declination Dependence in the Cosmic Ray Energy Spectrum

The Telescope Array Collaboration, R. U. Abbasi, T. Abu-Zayyad +122

We report on an observation of the difference between northern and southern skies of the ultrahigh energy cosmic ray energy spectrum with a significance of . We use measu…

physics.ao-ph2022★ 21 cited

First High-speed Video Camera Observations of a Lightning Flash Associated with a Downward Terrestrial Gamma-ray Flash

R. U. Abbasi, M. M. F. Saba, J. W. Belz +146

In this paper, we present the first high-speed video observation of a cloud-to-ground lightning flash and its associated downward-directed Terrestrial Gamma-ray Flash (TGF). The op…

astro-ph.IM2022★ 1 cited

Calibration and performance of the readout system based on switched capacitor arrays for the Large-Sized Telescope of the Cherenkov Telescope Array

Seiya Nozaki, Kyosuke Awai, Aya Bamba +59

The Cherenkov Telescope Array (CTA) is the next-generation ground-based very-high-energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA is designed to detect gamma r…

astro-ph.HE2021★ 4 cited

Observation of Variations in Cosmic Ray Single Count Rates During Thunderstorms and Implications for Large-Scale Electric Field Changes

R. U. Abbasi, T. Abu-Zayyad, M. Allen +160

We present the first observation by the Telescope Array Surface Detector (TASD) of the effect of thunderstorms on the development of cosmic ray single count rate intensity over a 7…

astro-ph.HE2021★ 11 cited

Indications of a Cosmic Ray Source in the Perseus-Pisces Supercluster

Telescope Array Collaboration, R. U. Abbasi, T. Abu-Zayyad +155

The Telescope Array Collaboration has observed an excess of events with in the data which is centered at (RA, dec) = (, ). This is n…

astro-ph.IM2021★ 18 cited

Surface detectors of the TAx4 experiment

Telescope Array Collaboration, R. U. Abbasi, M. Abe +145

Telescope Array (TA) is the largest ultrahigh energy cosmic-ray (UHECR) observatory in the Northern Hemisphere. It explores the origin of UHECRs by measuring their energy spectrum,…

astro-ph.HE2020★ 47 cited

The Cosmic-Ray Composition between 2 PeV and 2 EeV Observed with the TALE Detector in Monocular Mode

Telescope Array Collaboration

We report on a measurement of the cosmic ray composition by the Telescope Array Low-Energy Extension (TALE) air fluorescence detector (FD). By making use of the Cherenkov light sig…

physics.ao-ph2020★ 64 cited

Observations of the Origin of Downward Terrestrial Gamma-Ray Flashes

J. W. Belz, P. R. Krehbiel, J. Remington +137

In this paper we report the first close, high-resolution observations of downward-directed terrestrial gamma-ray flashes (TGFs) detected by the large-area Telescope Array cosmic ra…

astro-ph.HE2020★ 28 cited

Search for Large-scale Anisotropy on Arrival Directions of Ultra-high-energy Cosmic Rays Observed with the Telescope Array Experiment

Telescope Array Collaboration, R. U. Abbasi, M. Abe +141

Motivated by the detection of a significant dipole structure in the arrival directions of ultrahigh-energy cosmic rays above 8 EeV reported by the Pierre Auger Observatory (Auger),…

astro-ph.HE2020★ 4 cited

Evidence for a Supergalactic Structure of Magnetic Deflection Multiplets of Ultra-High Energy Cosmic Rays

Telescope Array Collaboration, R. U. Abbasi, M. Abe +140

Evidence for a large-scale supergalactic cosmic ray multiplet (arrival directions correlated with energy) structure is reported for ultra-high energy cosmic ray (UHECR) energies ab…

astro-ph.HE2020★ 21 cited

Measurement of the Proton-Air Cross Section with Telescope Array's Black Rock Mesa and Long Ridge Fluorescence Detectors, and Surface Array in Hybrid Mode

R. U. Abbasi, M. Abe, T. Abu-Zayyad +140

Ultra high energy cosmic rays provide the highest known energy source in the universe to measure proton cross sections. Though conditions for collecting such data are less controll…

astro-ph.HE2019★ 9 cited

Search for Ultra-High-Energy Neutrinos with the Telescope Array Surface Detector

R. U. Abbasi, M. Abe, T. Abu-Zayyad +133

We present an upper limit on the flux of ultra-high-energy down-going neutrinos for $E > 10^{18}\ \mbox{eV}$ derived with the nine years of data collected by the Telescope Array su…

astro-ph.HE2018★ 68 cited

Constraints on the diffuse photon flux with energies above eV using the surface detector of the Telescope Array experiment

Telescope Array Collaboration, R. U. Abbasi, M. Abe +139

We present the results of the search for ultra-high-energy photons with nine years of data from the Telescope Array surface detector. A multivariate classifier is built upon 16 rec…

astro-ph.HE2018★ 53 cited

Testing a reported correlation between arrival directions of ultrahigh-energy cosmic rays and a flux pattern from nearby starburst galaxies using Telescope Array data

Telescope Array Collaboration, R. U. Abbasi, M. Abe +138

The Pierre Auger Collaboration (Auger) recently reported a correlation between the arrival directions of cosmic rays with energies above 39 EeV and the flux pattern of 23 nearby st…

astro-ph.HE2018★ 59 cited

Mass composition of ultra-high-energy cosmic rays with the Telescope Array Surface Detector Data

Telescope Array Collaboration, R. U. Abbasi, M. Abe +139

The results on ultra-high-energy cosmic rays (UHECR) mass composition obtained with the Telescope Array surface detector are presented. The analysis employs the boosted decision tr…

astro-ph.IM2018★ 11 cited

A Technique for Estimating the Absolute Gain of a Photomultiplier Tube

M. Takahashi, Y. Inome, S. Yoshii +26

Detection of low-intensity light relies on the conversion of photons to photoelectrons, which are then multiplied and detected as an electrical signal. To measure the actual intens…