Explanipedia

Direct observation of the superallowed α decay of 104Te Open

I. Cox, K. P. Rykaczewski, S. Nishimura, R. Yokoyama, N. Fukuda , et al. · 2025

Alpha particle radioactivity is one of the most striking evidence for the existence of cluster structures in atomic nuclei. During the decay process, a preexisting α particle tunnels through the potential barrier formed by the residual nuc…

Discovery of Proton-Rich Radioactive Isotopes in the Z = 60 Region Produced by the Projectile Fragmentation of a 345-MeV/Nucleon 238U Beam Open

Hideyuki Suzuki, Nobuo Fukuda, H. Takeda, Y. Shimizu, Masahiro Yoshimoto , et al. · 2025

We report proton-rich new isotopes obtained in the region of atomic number $Z$ = 60 produced by the projectile fragmentation of a 345-MeV/nucleon $^{238}$U beam at the RI Beam Factory, RIKEN. Based on the evaluation shown in the National N…

Binding Energy of 3ΛH and 4ΛH via Image Analyses of Nuclear Emulsions Using Deep-Learning Open

A. Kasagi, T. Saito, Vadym Drozd, H. Ekawa, S. Escrig , et al. · 2025

Subatomic systems are pivotal for understanding fundamental baryonic interactions, as they provide direct access to quark-level degrees of freedom. In particular, the inclusion of a strange quark introduces strangeness as a new dimension, …

State-of-the-art beam loss minimization at high-intensity beam operation of the 3 GeV rapid cycling synchrotron at the Japan Proton Accelerator Research Complex Open

Pranab Saha, Hiroyuki Harada, Fumihiko Tamura, Kota Okabe, Masahiro Yoshimoto , et al. · 2025

At the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex, we have minimized the beam loss at high-intensity beam operation up to the designed beam power of 1 MW. This was accomplished through systematic…

Xenon-Gas Ionization Chamber to Improve the Z Identification of Heavy-Ion Beams with Z > 70 Open

Masahiro Yoshimoto, N. Fukuda, Riku Matsumura, D. Nishimura, H. Otsu , et al. · 2025

An ionization chamber (IC) is employed in nuclear experiments to measure energy deposits and provide crucial information for identifying nuclei in flight after undergoing nuclear reactions or decay. In ICs using P-10 (Ar+CH$_4$) gas, the a…

Measurement of Cross Sections and Momentum Distributions of Proton-Rich Radioactive Isotopes Produced from a 345-MeV/Nucleon 78Kr Beam Open

Hajime Suzuki, N. Fukuda, H. Takeda, Y. Shimizu, T. Sumikama , et al. · 2025

We measured the production cross sections and momentum distributions of proton-rich radioactive isotopes (RIs) whose atomic numbers were 18–37. These isotopes were produced by the projectile fragmentation of a 345-MeV/nucleon $^{78}$Kr bea…

Study of proton–nucleus interactions in the DsTau/NA65 experiment at the CERN-SPS Open

S. Aoki, A. Ariga, T. Ariga, N. Charitonidis, Sergey Dmitrievsky , et al. · 2025

Candidate for the Double Gamow–Teller Giant Resonance in 48Ca Studied by the (12C, 12Be(0+2)) Reaction at 250 MeV/Nucleon Open

A. Sakaue, K. Yako, S. B. Ota, H. Baba, T. Chillery , et al. · 2024

A new experimental method to search for the double Gamow–Teller giant resonance using the double charge exchange ($^{12}$C, $^{12}$Be(0$^{+}_{2}$)) reaction is proposed and applied, for the first time, to a ${}^{48}$Ca target at 250 MeV/nu…

New high-precision measurement system for electron–positron pairs from sub-GeV/GeV gamma-rays in the emulsion telescope Open

Yuya Nakamura, Shigeki Aoki, T Hayakawa, A. Iyono, Ayaka Karasuno , et al. · 2024

Discovery of Neutron-Rich Silicon Isotopes 45,46Si Open

Masahiro Yoshimoto, Hiroshi Suzuki, N. Fukuda, H. Takeda, Y. Shimizu , et al. · 2024

New isotopes $^{45,46}$Si, which extend beyond the most neutron-rich Si isotopes confirmed thus far, have been discovered at the RI Beam Factory at the RIKEN Nishina Center. The isotopes were produced by the in-flight fragmentation reactio…

New high-precision measurement system for electron-positron pairs from sub-GeV/GeV gamma-rays in the emulsion telescope Open

Yuya Nakamura, Shigeki Aoki, T Hayakawa, A. Iyono, Ayaka Karasuno , et al. · 2024

The GRAINE project observes cosmic gamma-rays, using a balloon-borne emulsion-film-based telescope in the sub-GeV/GeV energy band. We reported in our previous balloon experiment in 2018, GRAINE2018, the detection of the known brightest sou…

Correction to: Nuclear-moment measurement using highly spin-aligned RI beams: Recent activities at RIBF Open

Y. Ichikawa, Y. Shinohara, S. Go, H. Nıshıbata, S. Ando , et al. · 2024

Xenon-gas ionization chamber to improve particle identification of heavy ion beams with Z>70 Open

Masahiro Yoshimoto, N. Fukuda, Riku Matsumura, D. Nishimura, H. Otsu , et al. · 2024

In conventional ionization chambers (ICs) using P-10 (Ar+CH4) gas, as the atomic number (Z) of the ion beams increases in the energy region of 200-300 MeV/u, the Z resolution deteriorates rapidly when Z>70. This degradation is attributed t…

Development of new synchronized data system for J-PARC RCS Open

Hiroki Takahashi, Pranab Saha, Masahiro Yoshimoto, Yuki Sawabe · 2024

In J-PARC 3 GeV Rapid Cycling Synchrotron, the synchronized data system with reflective memory was constructed. However, this system has been operated for more than 10 years, it is essential to take countermeasures against deterioration ov…

First Emulsion γ-Ray Telescope Imaging of the Vela Pulsar by the GRAINE 2018 Balloon-borne Experiment Open

Satoru Takahashi, Shigeki Aoki, A. Iyono, Ayaka Karasuno, Kohichi Kodama , et al. · 2023

We are developing the Gamma-Ray Astro-Imager with Nuclear Emulsion project, designed for 10 MeV–100 GeV cosmic γ -ray observations with a high angular resolution (5′/0.°08 at 1–2 GeV) and a polarization-sensitive large-aperture (∼10 m 2 ) …

Development of proton beam irradiation system for the NA65/DsTau experiment Open

S. Aoki, A. Ariga, T. Ariga, N. Charitonidis, Sergey Dmitrievsky , et al. · 2023

Tau neutrino is the least studied lepton of the Standard Model (SM). The NA65/DsTau experiment targets to investigate D s , the parent particle of the ν τ , using the nuclear emulsion-based detector and to decrease the systematic uncertain…

Hypernuclear event detection in the nuclear emulsion with Monte Carlo simulation and machine learning Open

A. Kasagi, Wenrui Dou, V. Drozd, H. Ekawa, S. Escrig , et al. · 2023

Studies of three-and four-body hypernuclei with heavy-ion beams, nuclear emulsions and machine learning Open

Takehiko Saito, P. Achenbach, H. Alibrahim Alfaki, F. Amjad, M. Armstrong , et al. · 2023

Interests on few-body hypernuclei have been increased by recent results of experiments employing relativistic heavy ion beams. Some of the experiments have revealed that the lifetime of the lightest hypernucleus, hypertriton, is significan…

Developments of the next-generation nuclear emulsion readout system “HTS2(Hyper Track Selector 2)” Open

Hideyuki Minami, A. Iyono, Hiroki Rokujo, Ikuya Usuda, Koichi Kodama , et al. · 2023

GRAINE project aims at precise observations of cosmic gamma rays from sub-GeV to GeV, especially on the Galactic plane or central region, using a balloon-borne nuclear emulsion telescope with a large sensitive area, high angular resolution…

New high-precision measurement system for emulsion gamma ray telescope in sub-GeV/GeV Open

Yuya Nakamura, Shigeki Aoki, A. Iyono, Ayaka Karasuno, Kohichi Kodama , et al. · 2023

The Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE) project is aimed at the precise observation of astronomical gamma-ray sources in the energy range of 10 MeV-100 GeV using a balloon-borne telescope utilizing a nuclear emulsion, whi…

Hypernuclear event detection in the nuclear emulsion with Monte Carlo simulation and machine learning Open

A. Kasagi, Wenrui Dou, V. Drozd, H. Ekawa, S. Escrig , et al. · 2023

This study developed a novel method for detecting hypernuclear events recorded in nuclear emulsion sheets using machine learning techniques. The artificial neural network-based object detection model was trained on surrogate images created…

Development of proton beam irradiation system for the NA65/DsTau experiment Open

Shigeki Aoki, A. Ariga, T. Ariga, N. Charitonidis, Sergey Dmitrievsky , et al. · 2023

Tau neutrino is the least studied lepton of the Standard Model (SM). The NA65/DsTau experiment targets to investigate $D_s$, the parent particle of the $ν_τ$, using the nuclear emulsion-based detector and to decrease the systematic uncerta…

Measurements of radiation fields from a ceramic break Open

Yoshihiro Shobuda, Takeshi Toyama, Masahiro Yoshimoto, Shuichiro Hatakeyama · 2023

Ceramic breaks are used in synchrotrons for many purposes. For example, they are inserted between the Multi-Wire Profile Monitor (MWPM) on the injection line at the Rapid Cycling Synchrotron (RCS) in J-PARC to completely prevent the wall c…

Recent results of beam loss mitigation and extremely low beam loss operation of J-PARC RCS Open

Pranab Saha, Kota Okabe, Takamitsu Nakanoya, Yoshihiro Shobuda, Hiroyuki Harada , et al. · 2023

In the 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC (Japan Proton Accelerator Research Complex), multi-turn H − charge-exchange injection is performed by using a thin stripped foil. The residual radiation at the injection area caused by…

Ξ − atomic X-ray spectroscopy using a counter-emulsion hybrid method Open

Masaya Fujita, H. Ekawa, Yuichi Endo, R. Goto, Shoichi Hasegawa , et al. · 2022

Ξ− atomic X-ray spectroscopy is one of the most useful methods for investigation of the Ξ–nucleus strong interaction. Since the X-ray energy is shifted and/or broadened due to the Ξ–nucleus strong interaction compared to those calculated f…

Measurements of protons and charged pions emitted from charged-current interactions on iron at a mean neutrino energy of 1.49 GeV using a nuclear emulsion detector Open

H. Oshima, T. Matsuo, A. Ali, S. Aoki, L. Berns , et al. · 2022

This study conducted an analysis of muons, protons, and charged pions emitted from $\nu_{\mu}$ charged-current interactions on iron using a nuclear emulsion detector. The emulsion detector with a 65$\,$kg iron target was exposed to a neutr…

Wide angle acceptance and high-speed track recognition in nuclear emulsion Open

Y. Suzuki, T. Fukuda, H. Kawahara, Ryosuke Komatani, Mikito Naiki , et al. · 2022

A nuclear emulsion film is a three-dimensional tracking device that is widely used in cosmic-ray and high-energy physics experiments. Scanning with a wide angle acceptance is crucial for obtaining track information in emulsion films. This …

Measurements of protons and charged pions emitted from $ν_μ$ charged-current interactions on iron at a mean neutrino energy of 1.49$\,$GeV using a nuclear emulsion detector Open

H. Oshima, Tetsuya MATSUO, A. Ali, S. Aoki, L. Berns , et al. · 2022

This study conducted an analysis of muons, protons, and charged pions emitted from $ν_μ$ charged-current interactions on iron using a nuclear emulsion detector. The emulsion detector with a 65$\,$kg iron target was exposed to a neutrino be…

Design and actual performance of J-PARC 3 GeV rapid cycling synchrotron for high-intensity operation Open

Kazami Yamamoto, Michikazu Kinsho, N. Hayashi, Pranab Saha, Fumihiko Tamura , et al. · 2022

In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, th…

Unique approach for precise determination of binding energies of hypernuclei with nuclear emulsion and machine learning Open

Manami Nakagawa, A. Kasagi, E. Liu, H. Ekawa, Junya Yoshida , et al. · 2022

Hypertriton is the lightest hypernucleus and a benchmark in hypernuclear physics. However, it has recently been suggested that its lifetime and binding energy values may differ from the established values. To solve this puzzle, it is neces…

Masahiro Yoshimoto YOU? Author Swipe