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rays from a neutron-induced 
-wave resonance of 
Xe奥平 琢也*; 谷 結以花*; 遠藤 駿典; Doskow, J.*; 藤岡 宏之*; 広田 克也*; 亀田 健斗*; 木村 敦; 北口 雅暁*; Luxnat, M.*; et al.
Physical Review C, 107(5), p.054602_1 - 054602_7, 2023/05
被引用回数：1 パーセンタイル：68.16(Physics, Nuclear)
波共鳴と波共鳴の混合に起因するParity violationの増幅が観測されている
Xe+nにおける3.2eV共鳴からのガンマ線の中性子エネルギーに依存する角度分布を測定した。波共鳴からのガンマ線の遷移を同定し、1807keVの終状態に遷移する7132keVガンマ線の角度分布を評価した。この角度分布は波共鳴と波共鳴の干渉による結果と考えられており、複合核におけるParity violationの増幅メカニズムの理解に役立つ。
rays in the 
Sn(
)
Sn reaction遠藤 駿典; 奥平 琢也*; 安部 亮太*; 藤岡 宏之*; 広田 克也*; 木村 敦; 北口 雅暁*; 奥 隆之; 酒井 健二; 嶋 達志*; et al.
Physical Review C, 106(6), p.064601_1 - 064601_7, 2022/12
被引用回数：2 パーセンタイル：52.69(Physics, Nuclear)熱外中性子入射により形成される複合核において観測された、空間反転対称性の破れの大きな増幅は、今のところ複合核状態の入射チャネルにおけるパリティの異なる部分波の混合の結果として説明されている。さらに時間反転対称性の破れも同様のメカニズムで増幅されることが示唆されている。この入射チャネルにおける混合は、複合核共鳴から放出される個々のガンマ線のエネルギー依存なスピン-角相関を引き起こす。本研究ではJ-PARC・MLF・ANNRIにて偏極熱外中性子ビームを用い、Sn()Sn反応におけるガンマ線強度分布が、中性子の偏極方向に依存することを確認した。
atomic X-ray spectroscopy using a counter-emulsion hybrid method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.
elastic scattering in the momentum range 0.44-0.80 GeV/c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：5 パーセンタイル：67.44(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.
rays from the -wave resonance of Sn古賀 淳*; 高田 秀佐*; 遠藤 駿典; 藤岡 宏之*; 広田 克也*; 石崎 貢平*; 木村 敦; 北口 雅暁*; 新實 裕大*; 奥平 琢也*; et al.
Physical Review C, 105(5), p.054615_1 - 054615_5, 2022/05
被引用回数：3 パーセンタイル：66.85(Physics, Nuclear)J-PACR MLFのパルス中性子源及びBL04 ANNRIに設置されたゲルマニウム検出器を用いて、Sn(n,)反応により生じるガンマ線の中性子エネルギー依存する角度分布を測定した。Snの複合核状態からSnの基底状態への遷移で発生する9327keVのガンマ線に関して、角度によって1.33eVの波共鳴の形状が変わることが明らかに確認できた。この共鳴の低エネルギー側の積分値と高エネルギー側の積分値をそれぞれ
で表したとき、非対称性
は
cos
という角度依存をし、それぞれのパラメータ値が
、
であることがわかった。
elastic scattering in momentum range 470 to 850 MeV/
三輪 浩司*; 藤田 真奈美; 長谷川 勝一; 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.
Physical Review C, 104(4), p.045204_1 - 045204_20, 2021/10
被引用回数：12 パーセンタイル：89.15(Physics, Nuclear)A high statistics 
scattering experiment is performed at the J-PARC Hadron Experimental Facility. Momentum-tagged 
s running in a liquid hydrogen target are accumulated by detecting the reaction with a high intensity 
beam of 20 M/spill. The differential cross sections of the elastic scattering were derived with a drastically improved accuracy by identifying approximately 4,500 events from 1.72 
10
. The derived differential cross section shows a clear forward-peaking angular distribution for a momentum range from 470 to 850 MeV/. The accurate data will impose a strong constraint on the theoretical models of the baryon-baryon interactions.
rays in the 
La(
)
La
reaction奥平 琢也*; 遠藤 駿典; 藤岡 宏之*; 広田 克也*; 石崎 貢平*; 木村 敦; 北口 雅暁*; 古賀 淳*; 新實 裕大*; 酒井 健二; et al.
Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07
被引用回数：4 パーセンタイル：57.13(Physics, Nuclear)Neutron energy-dependent angular distributions were observed for individual rays from the 0.74 eV -wave resonance of La+
to several lower excited states of La. The -ray signals were analyzed in a two dimensional histogram of the -ray energy, measured with distributed germanium detectors, and neutron energy, determined with the time-of-flight of pulsed neutrons, to identify the neutron energy dependence of the angular distribution for each individual rays. The angular distribution was also found for a photopeak accompanied with a faint -wave resonance component in the neutron energy spectrum. Our results can be interpreted as interference between - and -wave amplitudes which may be used to study discrete symmetries of fundamental interactions.
-state of a hypernucleus, 
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：13 パーセンタイル：81.3(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, .
酒井 健二; 奥 隆之; 奥平 琢也; 甲斐 哲也; 原田 正英; 廣井 孝介; 林田 洋寿*; 加倉井 和久*; 清水 裕彦*; 広田 克也*; et al.
JPS Conference Proceedings (Internet), 33, p.011116_1 - 011116_6, 2021/03
中性子基礎物理学において、パリティ非保存(PNC)項や時間反転非保存項と干渉する中性子スピン
と標的核スピン
の相関項
は重要な研究テーマである。中性子共鳴ピーク付近でPNC項の増大が測定され、スピン交換光ポンピング(SEOP)法により
の偏極が得られるキセノン(Xe)は、本研究にとって興味深い原子核である。我々は小型SEOPシステムを用いた偏極Xe標的を開発し、核破砕中性子源で得られる大強度の熱外中性子ビームを利用した項の研究を計画している。その第一段階として、我々は
Xeの9.6eV共鳴ピーク付近でのXe偏極時と非偏極時の中性子透過率比の変化
を捕らえることで、項に起因する中性子偏極能力の測定をJ-PARC物質・生命科学実験施設(MLF)のBL10で試みた。実験では、本測定系がドップラーブロードニングの影響(
)を検知できることを実証した上で、初期結果として有意なの値を得ている。現在はをより詳細に評価するために、核磁気・電子スピン共鳴法によるXe偏極度の導出を進めている。
吉田 純也; 赤石 貴也; 藤田 真奈美; 長谷川 勝一; 橋本 直; 細見 健二; 市川 真也; 市川 裕大; 今井 憲一*; Kim, S.; et al.
JPS Conference Proceedings (Internet), 33, p.011112_1 - 011112_8, 2021/03
J-PARC E07 is the most ambitious and complex emulsion experiment to date investigating double hypernuclei with Hybrid emulsion method. The physics run at the K1.8 beam line in the J-PARC hadron experimental facility have been completed in 2017. The emulsion sheets are presently being analyzed with dedicated optical microscopes. Current statistics are estimated to be more 3 times than that of previous experiments. Quantitative data on the 
and 
interaction are being accumulated successfully via analysis of double and hypernuclei. Multiple hypernucleus candidates suggests several features about hypernucleus that the identification efficiency of 
C is significantly higher than other mode, many daughters of C are identified as He or Be, and multiple bound states of exist in the 
N nucleus. An analysis of X-ray spectroscopy of hyperatoms are ongoing.
identification method by the 
reaction for a 
scattering experiment at J-PARC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.
-N system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：34 パーセンタイル：95.34(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.
hypernuclear spectroscopy with the 
reaction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：2 パーセンタイル：84.57(Astronomy & Astrophysics)We 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.
interaction from the scattering experiment at J-PARC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：84.57(Astronomy & Astrophysics)A 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.
He neutron spin filter at J-PARC奥平 琢也; 奥 隆之; 猪野 隆*; 林田 洋寿*; 吉良 弘*; 酒井 健二; 廣井 孝介; 高橋 慎吾*; 相澤 一也; 遠藤 仁*; et al.
Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10
被引用回数：10 パーセンタイル：79.13(Instruments & Instrumentation)We are developing a neutron polarizer with polarized He gas, referred to as a He spin filter, based on the Spin Exchange Optical Pumping (SEOP) for polarized neutron scattering experiments at Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). A He gas-filling station was constructed at J-PARC, and several He cells with long spin relaxation times have been fabricated using the gas-filling station. A laboratory has been prepared in the MLF beam hall for polarizing He cells, and compact pumping systems with laser powers of 30 W and 110 W, which can be installed onto a neutron beamline, have been developed. A He polarization of 85% was achieved at a neutron beamline by using the pumping system with the 110 W laser. Recently, the first user experiment utilizing the He spin filter was conducted, and there have been several more since then. The development and utilization of He spin filters at MLF of J-PARC are reported.
rays from neutron-induced compound states of La山本 知樹*; 奥平 琢也; 遠藤 駿典; 藤岡 宏之*; 広田 克也*; 猪野 隆*; 石崎 貢平*; 木村 敦; 北口 雅暁*; 古賀 淳*; et al.
Physical Review C, 101(6), p.064624_1 - 064624_8, 2020/06
被引用回数：9 パーセンタイル：73.66(Physics, Nuclear)An sp-mixing model, which describes a compound nuclear reaction by mixing partial waves, predicts a correlation term in this reaction. The correlation term 
(
) in the La(n,) reaction has been studied by measuring -ray and neutron energies utilizing epithermal polarized neutrons and germanium detectors. The transverse asymmetry for single -ray transition was measured to be 0.60 0.19 in the p-wave resonance.
-rays after neutron capture by La for a T-violation search奥平 琢也; 清水 裕彦*; 北口 雅暁*; 広田 克也*; Haddock, C. C.*; 伊藤 維久也*; 山本 知樹*; 遠藤 駿典*; 石崎 貢平*; 佐藤 匠*; et al.
EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12
原子核が熱外中性子を共鳴吸収する反応において、弱い相互作用起因のパリティ対称性の破れが核子間相互作用の最大10
倍増幅される現象が観測されている。この反応では時間反転対称性の破れにも同様の増幅効果があることが理論的に予言されており、全く新しい手法で未知の時間反転対称性の破れを世界最高感度で探索できる可能性がある。しかし、その増幅率は全ての核種で未知であり、この手法がもつ可能性を具体的に議論できていなかった。本研究ではJ-PARC, MLF, BL04のGe検出器群を用いて、La(n,)反応の角度分布測定を行い、世界で初めてLaで時間反転対称性の破れの増幅率を求めることに成功した。この結果を用いて、実験に必要な測定時間を見積もると、偏極率40%のLa核偏極技術、偏極率70%, 79atm・cmのHe Spin Filterを用意すれば、1.4日の測定で世界最高感度で時間反転対称性の破れ探索実験が可能であることが判明した。現在原子力機構では高性能なHe Spin Filterの開発を行なっており、本発表では線の角度分布測定の結果、及び共用ビームラインに適用するためのHe Spin Filterの開発の現状について発表する。
奥平 琢也; 奥 隆之; 酒井 健二; 猪野 隆*; 林田 洋寿*; 廣井 孝介; 篠原 武尚; 加倉井 和久*; 相澤 一也; 清水 裕彦*; et al.
Proceedings of Science (Internet), 356, p.029_1 - 029_5, 2019/12
共通技術開発セクションでは、J-PARC物質・生命科学実験施設の大強度中性子を活用するために、偏極中性子デバイスの一つである
Heスピンフィルターの開発を行なっている。Heスピンフィルターの性能評価の一つの手段に、基礎物理分野での応用・評価があり、基礎物理実験も活用している。現在の物質優勢宇宙を説明するためには時間反転対称性の破れが不可欠であり、世界中で時間反転対称性の破れの探索実験が行われている。その一つに偏極中性子と原子核を使用して対称性の破れを測定する方法があり、J-PARCの大強度中性子を用いた時間反転対称性の破れ探索が計画されている。本計画では1eV程度のエネルギーの高い中性子を偏極するための従来にない巨大なHeスピンフィルターを開発する必要があり、原子力機構にて開発が行われているHeスピンフィルターの性能評価の良い検証となる。現在、偏極率の精度の良い評価システムやHeスピンフィルター製作のための真空システムの構築を行い、熱外中性子偏極のための大型スピンフィルターの開発を継続している。本発表ではHeスピンフィルターの開発の現状について発表する。
scattering experiment at J-PARC and the analysis status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.
in nuclei through C
spectrum at 1.8 GeV/ in the J-PARC E05 experiment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.
