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赤石 貴也; 橋本 直; 谷田 聖; 他35名*
Physics Letters B, 845, p.138128_1 - 138128_4, 2023/10
We present a new measurement of the H hypernuclear lifetime using in-flight + He H + reaction at the J-PARC hadron facility. We demonstrate, for the first time, the effective selection of the hypernuclear bound state using only the -ray energy decayed from . This opens the possibility for a systematic study of isospin partner hypernuclei through comparison with data from (, ) reaction. As the first application of this method, our result for the H lifetime, , is one of the most precise measurements to date. We are also preparing to measure the lifetime of the hypertriton (H) using the same setup in the near future.
相川 脩*; 橋本 直; 谷田 聖; 他73名*
Physics Letters B, 837, p.137637_1 - 137637_8, 2023/02
被引用回数:0 パーセンタイル:0.02(Astronomy & Astrophysics)We measured a set of , , and invariant mass spectra below and above the mass threshold in -induced reactions on deuteron. We deduced the -wave and scattering amplitudes in the isospin 0 channel in the framework of a and coupled channel. We find that a resonance pole corresponding to is located at 1417.7(fitting errors)(systematic errors) + (fitting errors)(systematic errors)] MeV/, closer to the mass threshold than the value determined by the Particle Data Group.
Wei, D.*; Gong, W.; 都留 智仁; Lobzenko, I.; Li, X.*; Harjo, S.; 川崎 卓郎; Do, H.-S.*; Bae, J. W.*; Wagner, C.*; et al.
International Journal of Plasticity, 159, p.103443_1 - 103443_18, 2022/12
被引用回数:12 パーセンタイル:98.45(Engineering, Mechanical)Face-centered cubic single-phase high-entropy alloys (HEAs) containing multi-principal transition metals have attracted significant attention, exhibiting an unprecedented combination of strength and ductility owing to their low stacking fault energy (SFE) and large misfit parameter that creates severe local lattice distortion. Increasing both strength and ductility further is challenging. In the present study, we demonstrate via meticulous experiments that the CoCrFeNi HEA with the addition of the substitutional metalloid Si can retain a single-phase FCC structure while its yield strength (up to 65%), ultimate strength (up to 34%), and ductility (up to 15%) are simultaneously increased, owing to a synthetical effect of the enhanced solid solution strengthening and a reduced SFE. The dislocation behaviors and plastic deformation mechanisms were tuned by the addition of Si, which improves the strain hardening and tensile ductility. The present study provides new strategies for enhancing HEA performance by targeted metalloid additions.
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.
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:1 パーセンタイル:61.09(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.
橋本 直; 谷田 聖; 他68名*
Physical Review Letters, 128(11), p.112503_1 - 112503_6, 2022/03
被引用回数:4 パーセンタイル:79.93(Physics, Multidisciplinary)We have measured the transition X-rays of kaonic He and He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be (stat) (syst) eV and (stat) (syst) eV, and widths to be (stat) (syst) eV and (stat) (stat) eV, for kaonic He and He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach, and agree with calculations based on optical-potential models.
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:9 パーセンタイル:88.26(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.
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:8 パーセンタイル:80.33(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, .
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:28 パーセンタイル:95.73(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 NBe + 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.
佐甲 博之
Nuclear Physics A, 1005, p.121916_1 - 121916_4, 2021/01
被引用回数:1 パーセンタイル:19.67(Physics, Nuclear)We are planning a future heavy-ion beam program at J-PARC (J-PARC-HI), where we explore dense baryonic matter and multi-strangeness production. In this presentation, we show physics of J-PARC-HI, the experimental plans, and the strategy starting from proton-nucleus collisions towards heavy-ion experiments.
中島 宏
JAEA-Conf 2020-001, p.69 - 74, 2020/12
J-PARC(日本陽子加速器研究施設)は、世界最高のビーム出力の高エネルギー陽子加速器施設である。非常に高いビーム出力と高エネルギー及び大規模な加速器複合体であることから、放射線の安全設計に関するいくつかの非常に困難な問題があった。これらを克服するために、かつて、様々な対策が行われた。この論文ではこれらについて紹介する。また、完成後10年の間における研究開発により、新たな様々な知見も得ており、これらについても述べている。
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:85.05We 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:85.05A 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.
山我 拓巳*; 橋本 直; 谷田 聖; 他66名*
Physical Review C, 102(4), p.044002_1 - 044002_14, 2020/10
被引用回数:13 パーセンタイル:87.6(Physics, Nuclear)We have performed an exclusive measurement of the reaction at an incident kaon momentum of . In the invariant mass spectrum, a clear peak was observed below the mass threshold of , as a signal of the kaonic nuclear bound state, . The binding energy, decay width, and -wave Gaussian reaction form-factor of this state were observed to be , , and , respectively. The total production cross-section of , determined by its decay mode, was . We estimated the branching ratio of the state to the and decay modes as , by assuming that the physical processes leading to the final states are analogous to those of .
佐久間 史典*; 橋本 直; 谷田 聖; 他66名*
AIP Conference Proceedings 2249, p.020005_1 - 020005_10, 2020/07
被引用回数:1 パーセンタイル:69.41The bound system, symbolically denoted as "", is the simplest -nuclear bound system which has been widely discussed as a consequence of the strongly attractive interaction in channels. Many theoretical works have pointed out the existence of the "" bound system, but the calculated properties such as the binding energy and the width spread out due to the uncertainty of the interaction below the mass threshold. Experimentally, there are several reports on observation of a "" candidate with the binding energy of around 100 MeV, however, no definitive evidence was available so far. At J-PARC, we conducted a experimental search for the "" bound system using He reaction at 1.0 GeV/ where the "" is expected to be directly produced via the reaction. We finally observed a bound state below the mass threshold in the final state, which can be interpreted as the "" bound state. The possible existence of the "" state is discussed from both aspects of production and decay.
佐久間 史典*; 橋本 直; 谷田 聖; 他66名*
JPS Conference Proceedings (Internet), 32, p.010088_1 - 010088_8, 2020/07
-nuclear bound states have been widely discussed as a consequence of the strongly attractive interaction in channels. Especially, the simplest -nuclear bound state of (denoted as "") has attracted the strong interest both of theoretical and experimental studies. We observed a bound state below the mass threshold with in-flight induced reactions on He target, which can be interpreted as the "" bound state. The possible existence of the "" state is discussed from both aspects of production and decay: "" and productions, and non-mesonic and mesonic decays, respectively.
Vu, TheDang; 西村 和真*; 宍戸 寛明*; 原田 正英; 及川 健一; 宮嶋 茂之*; 日高 睦夫*; 奥 隆之; 曽山 和彦; 相澤 一也; et al.
Journal of Physics; Conference Series, 1590, p.012036_1 - 012036_9, 2020/07
被引用回数:0 パーセンタイル:0.01Our CB-KID neutron imager detects high spatial resolution neutrons transmission images by using a delay-line technique. We found that the number of events was remarkably increased with increasing the detector temperature until close to the critical temperature Tc. We investigated the properties of CB-KID at near Tc. We observed systematic changes of neutron signals as a function of the detector temperature from 4 K to Tc. The simulations modeled the sequential physical processes for B(n,)Li reactions and energy deposition by particles within CB-KID, including neutrons, He particles, Li particles, photon and electron transport.
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.