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Fujii, Daisuke; Iwanaka, Akihiro*; Hosaka, Atsushi*
Physical Review D, 106(1), p.014010_1 - 014010_6, 2022/07
Times Cited Count：1 Percentile：0.01(Astronomy & Astrophysics)The Roper resonance, the first excited state of the nucleon, is one of the best established baryon resonates. Yet, its properties have not been consistently explained by effective models of QCD, such as the non-relativistic quark model. In this paper, we propose an alternative approach in the Sakai-Sugimoto model that is one of the holographic models of QCD. In particular, we analyze the helicity amplitude of the electromagnetic transitions at the leading of 't Hooft coupling 
. The model incorporates baryon structure at short distance by nonlinear mesons surrounded by meson clouds at long distance. We demonstrate that the recently observed data by CLAS are explained in the present approach.
Fujii, Daisuke*; Hosaka, Atsushi
Physical Review D, 104(1), p.014022_1 - 014022_6, 2021/07
Times Cited Count：4 Percentile：36.61(Astronomy & Astrophysics)Nagae, Daisuke*; Abe, Yasushi*; Okada, Shunsuke*; Omika, Shuichiro*; Wakayama, Kiyoshi*; Hosoi, Shun*; Suzuki, Shinji*; Moriguchi, Tetsuro*; Amano, Masamichi*; Kamioka, Daiki*; et al.
Nuclear Instruments and Methods in Physics Research A, 986, p.164713_1 - 164713_7, 2021/01
Times Cited Count：5 Percentile：64.12(Instruments & Instrumentation)
CsCl-supplemented diet to evaluate the effects of low dose-rate exposureTanaka, Sota; Kinouchi, Tadatoshi*; Fujii, Tsuguru*; Imanaka, Tetsuji*; Takahashi, Tomoyuki*; Fukutani, Satoshi*; Maki, Daisuke*; Notomi, Akihiro*; Takahashi, Sentaro*
Scientific Reports (Internet), 10, p.16055_1 - 16055_7, 2020/09
Times Cited Count：7 Percentile：53.13(Multidisciplinary Sciences)Since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, morphological abnormalities of the lepidopteran insects have been reported. However, it is unclear whether the abnormalities were caused directly by radiation because they did not study on absorbed dose and dose-effect relationship. In this study, we conducted an internal exposure experiment on silkworm using CsCl-supplemented artificial diet and estimated the absorbed dose to evaluate the morphological abnormalities in silkworm. The ratio of wing to whole body of pupae was compared between the CsCl-exposured and control groups and no significant differences were observed between the groups. This result suggest that morphological abnormalities in lepidopterans are unlikely due to direct radiation effects from Cs contamination after the FDNPP accident.
Nagai, Takayuki; Okamoto, Yoshihiro; Akiyama, Daisuke*; Uehara, Akihiro*; Fujii, Toshiyuki*; Sekimoto, Shun*
KURNS Progress Report 2019, P. 257, 2020/08
To understand the influence of glass structural change by neutron irradiation and boron isotope composition, glass samples were made from enrichment boric acid reagents and neutron irradiation of those samples was carried out in Pn-2 of KUR. The structural change of glass sample after the irradiation will be estimated in 2020FY. Before neutron irradiation test of glass samples, the Si-O bridging structure difference by boron isotope composition compared by using a Raman spectrometry.
Fujii, Daisuke*; Hosaka, Atsushi
Physical Review D, 101(12), p.126008_1 - 126008_10, 2020/06
Times Cited Count：4 Percentile：29.93(Astronomy & Astrophysics)
F from 
O
?Tang, T. L.*; Uesaka, Tomohiro*; Kawase, Shoichiro; Beaumel, D.*; Dozono, Masanori*; Fujii, Toshihiko*; Fukuda, Naoki*; Fukunaga, Taku*; Galindo-Uribarri, A.*; Hwang, S. H.*; et al.
Physical Review Letters, 124(21), p.212502_1 - 212502_6, 2020/05
Times Cited Count：14 Percentile：73.46(Physics, Multidisciplinary)The structure of a neutron-rich F nucleus is investigated by a quasifree (
) knockout reaction. The sum of spectroscopic factors of 
orbital is found to be 1.0 
0.3. The result shows that the O core of F nucleus significantly differs from a free O nucleus, and the core consists of 
35% O
, and 65% excited O. The result shows that the O core of F nucleus significantly differs from a free O nucleus. The result may infer that the addition of the 
proton considerably changes the neutron structure in F from that in O, which could be a possible mechanism responsible for the oxygen dripline anomaly.
Nagai, Takayuki; Kobayashi, Hidekazu; Okamoto, Yoshihiro; Akiyama, Daisuke*; Sato, Nobuaki*; Uehara, Akihiro*; Fujii, Toshiyuki*; Sekimoto, Shun*
KURNS Progress Report 2018, P. 105, 2019/08
To understand this structural change of a borosilicate glass by a neutron irradiation in detail, the irradiation test was carried out in KUR in 2017FY. The glass structure was estimated by using Raman spectrometry in 2018FY. Comparing with the Raman spectra of glass samples before and after irradiation, it could be observed the change of peak height of Si-O bridging structure by the irradiation.
Yamada, Katsunori; Fujii, Katsutoshi; Kanda, Hiroshi; Higashi, Daisuke; Kobayashi, Toshiaki; Nakagawa, Masahiro; Fukami, Tomoyo; Yoshida, Keisuke; Ueno, Yumi; Nakajima, Junya; et al.
JAEA-Review 2013-033, 51 Pages, 2013/12
JAEA-Review-2013-033.pdf:2.73MB
After the accident at Fukushima Dai-ichi Nuclear Power Plant, various numerical criteria relevant to radiation protection were defined. We surveyed these criteria through internet. As a result of survey, the following 13 items were identified: (1) criteria for taking stable iodine tablets, (2) criteria for the screening of surface contamination, (3) evacuation area, sheltering area, etc., (4) activity concentrations in food, drinking water, etc., (5) dose limit for radiation workers engaged in emergency work, (6) guideline levels of radioactive substances in bathing areas, (7) criteria for use of school buildings and schoolyards, (8) restriction on planting rice, (9) acceptable activity concentrations in feedstuff, (10) acceptable activity concentrations in compost, (11) criteria for export containers and ships, (12) criteria for contaminated waste, (13) standards for radiation workers engaged in decontamination work. In this report, the basis of and issues on these criteria are summarized.
Ogura, Koichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Yogo, Akifumi; Nishiuchi, Mamiko; Orimo, Satoshi; Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.
Japanese Journal of Applied Physics, 51(4), p.048003_1 - 048003_2, 2012/04
Times Cited Count：2 Percentile：8.9(Physics, Applied)A proton beam driven by a repetitive high-intensity-laser is utilized to induce a 
Li(p,n)Be nuclear reaction. The total activity of Be are evaluated by two different methods. The activity obtained measuring the decay 
-rays after 1912 shots at 1 Hz is 1.70.2 Bq. This is in good agreement with 1.60.3 Bq evaluated from the proton energy distribution measured using a time-of-flight detector and the nuclear reaction cross-sections. We conclude that the production of activity can be monitored in real time using the time-of-flight-detector placed inside a diverging proton beam coupled with a high-speed signal processing system.
Nishiuchi, Mamiko; Daito, Izuru; Ikegami, Masahiro; Daido, Hiroyuki; Mori, Michiaki; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Pirozhkov, A. S.; et al.
Applied Physics Letters, 94(6), p.061107_1 - 061107_3, 2009/02
Times Cited Count：59 Percentile：87.41(Physics, Applied)A pair of conventional permanent magnet quadrupoles is used to focus a 2.4 MeV laser-driven proton beam at a 1 Hz repetition rate. The magnetic field strengths are 55 T/m and 60 T/m for the first and second quadrupoles respectively. The proton beam is focused to a spot size (full width at half maximum) of 2.7
8 mm
at a distance of 650 mm from the source. This result is in good agreement with a Monte Carlo particle trajectory simulation.
Fujii, Toshiyuki*; Suzuki, Daisuke; Yamana, Hajimu*
Solvent Extraction and Ion Exchange, 26(2), p.100 - 112, 2008/00
Times Cited Count：5 Percentile：26.25(Chemistry, Multidisciplinary)Chromium isotopes were fractionated by continuous extraction using dicyclohexano-18-crown-6 as an extractant. This system was designed for accumulating isotope effect into the aqueous phase. After a long period operation, the Cr isotope ratios in the residual aqueous phase were precisely measured by using a multi-collector thermal ionization mass spectrometer with the total evaporation technique. The analytical results showed a clear mass-independent isotope fractionation. The mass-independent property was consistent with that obtained from a batch extraction. The isotopic mass balance was verified to be preserved in the continuous extraction. The Bigeleisen's 1996 theory gave the consistent explanation on the Cr isotope effect, in which the mass-independent isotope effect was identified to be the nuclear field shift effect.
Sagisaka, Akito; Utsumi, Takayuki*; Daido, Hiroyuki; Ogura, Koichi; Orimo, Satoshi; Takai, Mamiko; Hayashi, Yukio; Mori, Michiaki; Yogo, Akifumi; Kado, Masataka; et al.
Journal of Plasma Physics, 72(6), p.1281 - 1284, 2006/12
Times Cited Count：0 Percentile：0.01(Physics, Fluids & Plasmas)no abstracts in English
Fujii, Toshiyuki*; Suzuki, Daisuke; Yamana, Hajimu*
no journal, ,
no abstracts in English
Ogura, Koichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Orimo, Satoshi; Sagisaka, Akito; Nishiuchi, Mamiko; Mori, Michiaki; Yogo, Akifumi; Pirozhkov, A. S.; Sugiyama, Hironori*; et al.
no journal, ,
Protons with energies up to 3 MeV have been generated by the irradiation of a 7.5 
m thickness target by a 1 Hz table top laser with intensity of 700mJ. These protons were used to induce the nuclear reaction 7Li(p,n)7Be. Simultaneously, energy of proton was detected by a time of flight method.
Mori, Michiaki; Ogura, Koichi; Yogo, Akifumi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Tampo, Motonobu; Daito, Izuru; et al.
no journal, ,
Experimental studies of laser-driven ion acceleration aimed at ion therapy for cancer treatment are being conducted at the PMRC of JAEA using the J-KAREN Ti:Sapphire laser system at JAEA's APRC. In recent experiments thin foil targets have been irradiated with focused 38 fs laser pulses at the 1.8J laser energy. The energy spectrum of the proton beam is observed to extend to a cut-off value in excess of 7-MeV. Our results expose the prospects and challenges associated with developing a laser-driven ion therapy facility.
Mori, Michiaki; Ogura, Koichi; Yogo, Akifumi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Tampo, Motonobu; Daito, Izuru; et al.
no journal, ,
no abstracts in English
Ogura, Koichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Orimo, Satoshi; Sagisaka, Akito; Nishiuchi, Mamiko; Mori, Michiaki; Yogo, Akifumi; Pirozhkov, A. S.; Sugiyama, Hironori*; et al.
no journal, ,
Ultrashort and high intensity laser can induce high energy protons. Proton beams have a wide range of applications such as in the production of radioisotopes and proton therapy. An energy of the proton beam has a wide distribution. The distribution of activity in depth is calculated while laser induced protons are injected into an iron plate.
Fujii, Daisuke; Iwanaka, Akihiro*; Suenaga, Daiki*; Kitazawa, Masakiyo*
no journal, ,
The Matsubara formalism for the thermal quantum field theory introduces temperature into the theory as a boundary condition along the imaginary time direction of Euclidean spacetime. In this study, we consider the pure Yang-Mills theory on , which further imposes boundary conditions on the spatial direction, and discuss thermodynamic quantities and phase structures. Results from lattice QCD simulations show that anisotropic effects are suppressed until the spatial directional spread becomes significantly smaller near the critical temperature. By constructing the model to reproduce the lattice QCD results, it becomes clear that the system suggests the existence of a very rich phase structure.
Fujii, Daisuke; Iwanaka, Akihiro*
no journal, ,
The form factor is an important physical quantity for the elucidation of the internal structure of hadrons because it incorporates information about the internal structure of the extended particles. Recently, the gravitational form factor, which characterizes the matrix element of the energy-momentum tensor, has been experimentally observed, and its theoretical understanding has been attracting much attention. In this presentation, we will present our recent results on the gravitational form factor of vector mesons and the stress distribution obtained from it using the Sakai-Sugimoto model, which is a top-down approach to holographic QCD. We are the first to formulate the gravitational form factor of a vector meson using the Sakai-Sugimoto model. As a result, we succeeded in finding a deep relationship between the stability condition of the stress distribution of the vector meson and the glueball spectra.
