Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; Kim, S.; 七村 拓野; 佐甲 博之; 田村 裕和; 山本 剛史; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(12), p.123D01_1 - 123D01_17, 2022/12
被引用回数:0 パーセンタイル:0.01(Physics, Multidisciplinary) atomic X-ray spectroscopy is one of the most useful methods for investigation of the
-nucleus strong interaction. Since the X-ray energy is shifted and/or broadened due to the
-nucleus strong interaction compared to those calculated from electromagnetic interaction alone, the measurement of the energy shift,
E, and the width,
, give us information on the
-nucleus potential. A serious problem in the measurement is the significant background derived from in-flight
decay. A novel method of identifying stopped
events using the nuclear emulsion was developed to realize the first
atomic X-ray spectroscopy experiment as the J-PARC E07 experiment, which also aimed at searching for
and
hypernuclei in the emulsion. The X-rays emitted from
Br and
Ag atoms were measured using germanium detectors. No clear peaks were observed in the obtained spectra. However, we succeeded in reducing the background to 1/170 by this method employing coincidence measurements using nuclear emulsion and X-ray detectors.
山本 剛史; 藤田 真奈美; 後神 利志*; 原田 健志*; 早川 修平*; 細見 健二; 市川 裕大; 石川 勇二*; 鎌田 健人*; 叶内 萌香*; et al.
EPJ Web of Conferences, 271, p.03001_1 - 03001_5, 2022/11
X-ray spectroscopy of hadronic atoms give us various information on the strong interaction between hadrons and nuclei. At J-PARC, we are aiming for the world-first detection of the X rays from atoms with a doubly strange hyperon, . Recently, two experiments, J-PARC E07 and J-PARC E03, have been performed for the detection of X rays from
atoms. Overview and status of these measurements will be presented. We will also discuss future plan of X-ray spectroscopy on
-atoms, which can be performed together with high resolution
hyper nuclear spectroscopy using newly constructed S-2S spectrometer. Preparation status will be shown in this contribution.
藤田 真奈美; 細見 健二; 石川 勇二*; 叶内 萌香*; 小池 武志*; 小椋 裕*; 田村 裕和; 谷田 聖; 鵜養 美冬*; 山本 剛史
Nuclear Instruments and Methods in Physics Research A, 1042, p.167439_1 - 167439_9, 2022/11
被引用回数:1 パーセンタイル:71.47(Instruments & Instrumentation) atomic X-ray spectroscopy is a powerful method of studying the
N interaction, for which very limited experimental data are currently available. For this reason, we constructed a germanium (Ge) detector array referred to as Hyperball-X and conducted the first-ever
atomic X-ray measurements in 2016 and 2017 at J-PARC. We developed a novel method for in-beam energy calibration of Ge detectors. Three
rays (202 keV, 307 keV, and 511 keV) from
Lu in LSO scintillation counters and
Na source were used as reference. The
and
coincidence detection using the Ge detectors and LSO counters allows for continuous in-beam calibration with this new calibration method, and the calibration uncertainty is reduced to less than
100 eV for energies ranging from 202 to 511 keV.
山本 風海; 金正 倫計; 林 直樹; Saha, P. K.; 田村 文彦; 山本 昌亘; 谷 教夫; 高柳 智弘; 神谷 潤一郎; 菖蒲田 義博; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
被引用回数:1 パーセンタイル:71.47(Nuclear Science & Technology)J-PARC 3GeVシンクロトロン(RCS)は、最大1MWの大強度ビームを25Hzという早い繰り返しで中性子実験及び下流の主リングシンクロトロンに供給することを目的に設計された。2007年の加速器調整運転開始以降、RCSではビーム試験を通じて加速器の設計性能が満たされているかの確認を進め、必要に応じてより安定に運転するための改善を行ってきた。その結果として、近年RCSは1MWのビーム出力で連続運転を行うことが可能となり、共用運転に向けた最後の課題の抽出と対策の検討が進められている。本論文ではRCSの設計方針と実際の性能、および改善点について議論する。
七村 拓野; 藤田 真奈美; 長谷川 勝一; 市川 真也; 市川 裕大; 今井 憲一*; 成木 恵; 佐藤 進; 佐甲 博之; 田村 裕和; et al.
Progress of Theoretical and Experimental Physics (Internet), 2022(9), p.093D01_1 - 093D01_35, 2022/09
被引用回数:0 パーセンタイル:0.01(Physics, Multidisciplinary)We performed a novel scattering experiment at the J-PARC Hadron Experimental Facility. Approximately 2400
elastic scattering events were identified from
tagged
particles in the
momentum range 0.44 - 0.80 GeV/c. The differential cross sections of the
elastic scattering were derived with much better precision than in previous experiments. The obtained differential cross sections were approximately 2 mb/sr or less, which were not as large as those predicted by the fss2 and FSS models based on the quark cluster model in the short-range region. By performing phase-shift analyses for the obtained differential cross sections, we experimentally derived the phase shifts of the
and
channels for the first time. The phase shift of the 3S1 channel, where a large repulsive core was predicted owing to the Pauli effect between quarks, was evaluated to be
. If the sign of
is assumed to be negative, the interaction in this channel is moderately repulsive, as the Nijmegen extended-sort-core models predicted.
吉本 雅浩*; 藤田 真奈美; 橋本 直; 早川 修平; 市川 裕大; 市川 真也; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Progress of Theoretical and Experimental Physics (Internet), 2021(7), p.073D02_1 - 073D02_19, 2021/07
被引用回数:6 パーセンタイル:77.07(Physics, Multidisciplinary)Bound-systems of -
are studied via
capture at rest followed by emission of a twin single-
hypernucleus in the emulsion detectors. Two events forming extremely deep
bound states were obtained by analysis of a hybrid method in the E07 experiment at J-PARC and reanalysis of the E373 experiment at KEK-PS. The decay mode of one event was assigned as
+
+
+
. Since there are no excited states for daughter particles, the binding energy of the
hyperon,
, in
nucleus was uniquely determined to be 6.27
0.27 MeV. Another
-
system via the decay
+
+
brings a
value, 8.00
0.77 MeV or 4.96
0.77 MeV, where the two possible values of
correspond to the ground and the excited states of the daughter
nucleus, respectively. Because the
values are larger than those of the previously reported events (KISO and IBUKI), which are both interpreted as the nuclear
state of the
-
system, these new events give the first indication of the nuclear
state of the
hypernucleus,
.
奥野 浩; 佐藤 宗平; 川上 剛; 山本 一也; 田中 忠夫
Journal of Radiation Protection and Research, 46(2), p.66 - 79, 2021/06
東京電力福島第一原子力発電所の事故は、最大級の地震とそれに伴う津波により、原子力発電所周辺の住民の避難を誘発した被害の典型的なものであった。本論文は、東京電力福島第一原子力発電所の敷地外緊急事態に対する日本原子力研究開発機構(JAEA)の原子力緊急時支援・訓練センター(NEAT)の初期対応についてまとめたものである。本論文では、東京電力福島第一原子力発電所に関連した2011年以前のNEATの緊急時対応活動、2011年3月11日のNEATの状況、東京電力福島第一原子力発電所の事故を含むオフサイト緊急事態への早期対応について論じた。また、複雑な災害の問題点についても論じた。
山本 風海; 長谷川 和男; 金正 倫計; 小栗 英知; 林 直樹; 山崎 良雄; 内藤 富士雄*; 吉井 正人*; 外山 毅*
JPS Conference Proceedings (Internet), 33, p.011016_1 - 011016_7, 2021/03
J-PARC施設は量子ビームを用いた様々な科学実験を行うために建設された。施設はリニアック, 3GeVシンクロトロン(RCS),主リング(MR)の3つの加速器とRCSおよびMRからビームを受ける実験施設群で構成される。J-PARCは、物質生命科学実験施設(MLF)において中性子を用いたユーザー利用運転を2008年12月より開始し、東日本大震災やハドロン実験施設における放射能の管理区域外へのリーク、中性子ターゲットの破損などによる比較的長期の中断を挟みながらも現在まで10年以上運転を継続してきた。これまでの加速器の運転統計データから、特に大きなトラブルが無ければ、MLFの運転稼働率は90%程度、MRがビームを供給するハドロン実験およびニュートリノ実験は85%程度の稼働率が確保できていることを確認した。また、近年ではイオン源の寿命が延びたことでその保守日数が低減され、その分運転日数に余裕を持つことができるようになった。そのため、トラブル発生時にその予備日を運転に回すことができ、稼働率はさらに改善している。運転中の停止頻度も、2018年夏にリニアックのビームロスモニタの設定を見直すことで劇的に低減することができた。
坂尾 珠和*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
JPS Conference Proceedings (Internet), 33, p.011133_1 - 011133_6, 2021/03
The reaction is an important elementary process to produce
from a proton target and is a key for a
scattering experiment where the momentum of
should be tagged from the missing momentum of the
reaction. However, the
spectroscopy method has not been established yet due to the difficulty of the
detection. Therefore, we have proposed a new
detection method where
and
from the
decay are measured by a forward magnetic spectrometer and a detector cluster surrounding the target, respectively. The feasibility of the
detection method was confirmed by analyzing the J-PARC E40 data taken with such a detector system. In the analysis,
's were successfully identified in the missing mass spectrum of the
reaction.
早川 修平; 藤田 真奈美; 長谷川 勝一; 橋本 直; 細見 健二; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Physical Review Letters, 126(6), p.062501_1 - 062501_6, 2021/02
被引用回数:27 パーセンタイル:97.14(Physics, Multidisciplinary)In an emulsion-counter hybrid experiment performed at J-PARC, a absorption event was observed which decayed into twin single-
hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as
N
Be +
He. For the binding energy of the
hyperon in the
-
N system a value of
MeV was deduced. The energy level of
is likely a nuclear
state which indicates a weak
-
coupling.
後神 利志*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 今井 憲一*; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; 佐藤 進; et al.
Journal of Physics; Conference Series, 1643, p.012133_1 - 012133_6, 2020/12
被引用回数:0 パーセンタイル:0.09We performed hypernuclear spectroscopy with the
reaction at J-PARC to investigate the
interaction (J-PARC E05). A new experiment (J-PARC E70) in which a better energy resolution could be achieved is now being prepared. In this article, an analysis status of J-PARC E05 and a preparation status of J-PARC E70 are described.
三輪 浩司*; 藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; 七村 拓野; 成木 恵; 佐甲 博之; et al.
Journal of Physics; Conference Series, 1643, p.012174_1 - 012174_6, 2020/12
被引用回数:2 パーセンタイル:88.4A high statistics scattering experiment has been performed at the K1.8 beamline in the J-PARC Hadron Experimental Facility. Data for momentum-tagged
beam running in a liquid hydrogen target were accumulated by detecting the
reaction with a high intensity
beam of 20 M/spill. The number of the
beam was about
in total. The
elastic scattering and the
inelastic scattering events were successfully observed with about 100 times larger statistics than that in past experiments.
中田 祥之*; 長谷川 勝一; 早川 修平*; 細見 健二; 市川 裕大; 今井 憲一; 七村 拓野*; 成木 恵*; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 26, p.023024_1 - 023024_5, 2019/11
J-PARC E40 aims to measure the differential cross sections of the elastic scatterings and the
conversion. A clear peak of
was observed in a missing mass spectrum of the
reaction and recoil protons from the
elastic scattering were successfully observed in the data taken in the summer 2018. The rest of data taking is coming in the spring 2019.
Yang, S. B.*; 長谷川 勝一; 早川 修平*; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 田村 裕和*; 谷田 聖; et al.
JPS Conference Proceedings (Internet), 26, p.023015_1 - 023015_5, 2019/11
We performed a gamma-ray spectroscopy of at J-PARC Hadron Experimental Facility in 2015. It is the first measurement of
rays emitted from
-shell hypernuclei. In this experiment, we determined the energy spacing between the ground state spin doublet,
and
states, as 316 keV. The excitation energies of
and
states are also determined to be 895 and 1266 keV, respectively. The energy spacing is found to be well reproduced by shell-model calculations which describe
- and
-shell
hypernuclei well. The results show that the present theories of the
interaction describe not only the light hypernuclei but also a heavier hypernucleus.
本多 良太郎*; 長谷川 勝一; 早川 修平; 細見 健二; 今井 憲一; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 26, p.023014_1 - 023014_4, 2019/11
We measured the reaction spectra at 1.8 GeV/
for the graphite and the polyethylene targets in the J-PARC E05 pilot experiment. By comparing the spectra for these two targets, it was found that
in the
B nucleus is quite broadened. Furthermore, we also compared broadness of
with
obtained in the
spectrum.
seems to be much more broadened in nuclei than
. We gave a possible interpretation, which is related to compositeness of decuplet baryons, for this situation.
中川 真菜美*; 長谷川 勝一; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 田村 裕和; 谷田 聖; et al.
JPS Conference Proceedings (Internet), 26, p.023005_1 - 023005_3, 2019/11
The interaction is not much studied than the
interaction. To understand the
interaction, we study
hypernuclei. As for the
hypernucleus, only the ground state of
has been observed. To obtain more information about the
interaction, the excited state should be studied. Therefore, we measure the missing-mass of the
He
reaction at
GeV/
and
2-14
at the J-PARC K1.8 beam line. The ground state of
is observed whereas a peak of the excited states is not observed. We also observe suppression of the
quasi-free process at smaller angles.
小池 武志*; 長谷川 勝一; 早川 修平*; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 杉村 仁志; 田村 裕和; et al.
AIP Conference Proceedings 2130, p.020011_1 - 020011_9, 2019/07
被引用回数:1 パーセンタイル:53.97Experimental results from the J-PARC E13 experiments are summarized. A new experimental set up of E13 has established a platform for the future -ray hypernuclear spectroscopy at J-PARC using kaon beams. New
rays are identified in
He and
F. The energy of 1.406 MeV for the
He
transition confirmed a sizable effect of Charge Symmetry Breaking (CSB) in
interaction in the
hypernuclear system. The identification of four
rays in
F is made for the first time in
shell hypernuclei. Especially, energy spacing of the ground state doublet is found to be 315.5 keV. A good agreement with two theoretical calculations suggests that the theoretical formalism used in
shell hypernuclei is also applicable to heavier hypernuclei. Lastly, an overview of the future J-PARC E63 experiment is given.
永江 知文*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 金原 慎二; 七村 拓野*; 成木 恵; et al.
AIP Conference Proceedings 2130, p.020015_1 - 020015_9, 2019/07
被引用回数:11 パーセンタイル:99.02For the full understanding of baryon-baryon interactions in flavor , the
interaction is the last missing piece of information. So far, we have revealed the
interaction to be attractive (
MeV), and
interaction to be repulsive in the medium to heavy mass-number region. The
bonding energy is weakly attractive. While we have a few experimental observations suggesting the
interaction would be attractive, there still exist large theoretical ambiguities weather it is attractive or not. Experimental determinations on the existence of bound states of
hypernuclei by observing bound-state peaks are strongly awaited. In this report, a new preliminary result on the missing-mass spectrum of a
C
reaction, which strongly suggests the existence of
-hypernuclear bound states, is presented.
長谷川 和男; 金正 倫計; 小栗 英知; 山本 風海; 林 直樹; 山崎 良雄; 内藤 富士雄*; 吉井 正人*; 外山 毅*; 山本 昇*; et al.
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (インターネット), p.1235 - 1239, 2019/07
J-PARCでは2018年の夏季メンテナンス終了後、3GeVシンクロトロン(RCS)からビームを供給する物質・生命科学実験施設(MLF)での利用運転を10月下旬から再開した。出力は夏前の500kWと同じであるが、リニアックのピークビーム電流値を、夏前の40mAから定格の50mAに上げた。一方、スーパーカミオカンデの改修やハドロン実験施設の保守や整備などもあり、30GeVのメインリング(MR)のビーム運転は休止したが、利用運転は2月中旬からハドロン実験施設向けに51kWで再開した。しかし3月18日、MRへの入射ビームラインでの偏向電磁石1台に不具合が発生し、仮復旧で4月5日に利用運転を再開したが、再度不具合が発生し4月24日に夏前の利用運転を終了した。2018年度の稼働率は、リニアック, RCSともに安定でMLF向けは94%、ニュートリノとハドロン実験施設向けは86%、74%であった。ここでは、こうした1年間の運転経験を報告する。
江川 弘行; 足利 沙希子; 長谷川 勝一; 橋本 直; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 金原 慎二*; 七村 拓野; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.021D02_1 - 021D02_11, 2019/02
被引用回数:19 パーセンタイル:83.3(Physics, Multidisciplinary)A double- hypernucleus,
, was observed by the J-PARC E07 collaborationin nuclear emulsions tagged by the
reaction. This event was interpreted as a production and decay of
,
, or
via
capture in
.By assuming the capture in the atomic 3D state, the binding energy of two
hyperons
(
)of these double-
hypernuclei are obtained to be
,
, and
, respectively. Based on the kinematic fitting,
is the most likely explanation for the observed event.