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meson mass through 
decays佐甲 博之; 市川 真也; 成木 恵; 坂口 貴男; 佐藤 進; 他12名*
Journal of Subatomic Particles and Cosmology (Internet), 1-2, p.100012_1 - 100012_7, 2024/11
Experimental evidence for the mass and the chiral condensate of hadrons is still poor. To challenge this situation we aim to measure meson mass inside the nucleus through decays in proton-nucleus collisions at J-PARC. In this presentation we will show the experimental proposal (E88), and the status of preparation.
C
reaction at 1.8 GeV/
with the Superconducting Kaon spectrometer市川 裕大; 藤田 真奈美; 長谷川 勝一; 今井 憲一*; 七村 拓野; 成木 恵; 佐藤 進; 佐甲 博之; 田村 裕和; 谷田 聖; et al.
Progress of Theoretical and Experimental Physics (Internet), 2024(9), p.091D01_1 - 091D01_13, 2024/09
被引用回数：0 パーセンタイル：0.00(Physics, Multidisciplinary)We conducted a measurement of the inclusive missing-mass spectrum in the C
reaction at an incident beam momentum of 1.8 GeV/. This measurement was carried out utilizing the Superconducting Kaon Spectrometer (SKS) and the K1.8 beamline spectrometer at the Hadron Experimental Hall in J-PARC. Remarkably, our experimental setup yielded an exceptionaly good energy resolution of 8.2 MeV (FWHM), enabling us to observe significant enhancements in the vicinity of the 
Be threshold region. In order to estimate the spectrum information, we employed several fitting parameters assumptions. The best agreement with the spectrum shape was obtained with combining quasi-free (QF) component and two-Gaussian functions, with the experimental resolution 
being held constant. The peak positions were obtained to be 
(stat.) 
(syst.) MeV and 
(stat.) 
(syst.) MeV. Another model assumption, utilizing quasi-free (QF) and one Breit-Wigner function with 
(stat.) 
(syst.) MeV and 
(stat.) 
(syst.) MeV, also yielded a similar 
value.
H hypernucleus using in-flight 
He
H reaction赤石 貴也; 橋本 直; 谷田 聖; 他35名*
Physics Letters B, 845, p.138128_1 - 138128_4, 2023/10
被引用回数：1 パーセンタイル：26.66(Astronomy & Astrophysics)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.
measured in 
reactions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：9 パーセンタイル：77.17(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：105 パーセンタイル：99.79(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.
佐久間 史典*; 田村 裕和; 谷田 聖; 山本 剛史; 他39名*
EPJ Web of Conferences, 271, p.11001_1 - 11001_7, 2022/11
The J-PARC Hadron Experimental Facility was constructed with an aim to explore the origin and evolution of matter in the universe through experiments with intense particle beams. In the past decade, many results from particle and nuclear physics experiments have been obtained at the present facility. To expand the physics programs to as yet unexplored regions, the extension project of the Hadron Experimental Facility has been extensively discussed. This contribution presents the physics of the extension of the Hadron Experimental Facility to resolve issues related to strangeness nuclear physics, hadron physics, and flavor physics.
三輪 浩司*; 藤田 真奈美; 原田 健志; 長谷川 勝一; 細見 健二; 市川 真也; 今井 憲一*; 佐甲 博之; 佐藤 進; 田村 裕和; et al.
EPJ Web of Conferences, 271, p.04001_1 - 04001_7, 2022/11
A new hyperon-proton scattering experiment, dubbed J-PARC E40, was performed to measure differential cross sections of the 
, 
elastic scatterings and the 
scattering by identifying a lot of 
particles in the momentum ranging from 0.4 to 0.8 GeV/ produced by the 
reactions. We successfully measured the differential cross sections of these three channels with a drastically improved accuracy with a fine angular step. These new data will become important experimental constraints to improve the theories of the two-body baryon-baryon interactions. Following this success, we proposed a new experiment to measure the differential cross sections and spin observables by using a highly polarized 
beam for providing quantitative information on the 
interaction. The results of three 
channels and future prospects of the 
scattering experiment are described.
atoms (J-PARC E03, E07 and future)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.
後神 利志*; 江端 健悟; 藤田 真奈美; 原田 健志; 長谷川 勝一; 細見 健二; 市川 裕大; 今井 憲一*; Kim, S.; 七村 拓野; et al.
EPJ Web of Conferences, 271, p.11002_1 - 11002_7, 2022/11
In the K1.8 beam-line at Hadron Experimental Facility of J-PARC, a new magnetic spectrometer S-2S is being installed. S-2S was designed to achieve a high momentum resolution of 
in FWHM. Several strangeness-physics programs which require the high resolution will be realized by S-2S. The present article introduces J-PARC E70 (missing-mass spectroscopy of 
Be) and E94 (missing-mass spectroscopy of 
Li, 
B, and 
C) experiments.
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：16 パーセンタイル：83.44(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.
bound-state observation in E15 and future prospects佐久間 史典*; 谷田 聖; 他73名*
EPJ Web of Conferences, 262, p.01008_1 - 01008_7, 2022/04
The possible existence of deeply-bound 
-nuclear bound states, kaonic nuclei, has been widely discussed as products of the strongly attractive 
interaction in 
channels. Investigations of those exotic states will provide us unique information of the interaction below the threshold, which is still not fully understood so far. Recently, we observed the simplest kaonic nuclei, 
, having a much deeper binding energy than normal nuclei via inflight 
reactions at the J-PARC E15 experiment. For further studies, we have proposed a series of experimental programs for the systematic investigation of light kaonic nuclei, from () to 
. We will measure the 
(
) system at the new experiment approved as J-PARC E80, as a first step toward a comprehensive study.
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：11 パーセンタイル：73.92(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.
reaction in momentum range 470-650 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; 佐甲 博之; 佐藤 進; 田村 裕和; et al.
Physical Review Letters, 128(7), p.072501_1 - 072501_6, 2022/02
被引用回数：18 パーセンタイル：86.92(Physics, Multidisciplinary)The differential cross sections of the reaction were measured accurately for the 
momentum 
ranging from 470 to 650 MeV/ at the J-PARC Hadron Experimental Facility. Precise angular information about the reaction was obtained for the first time by detecting approximately 100 reaction events at each angular step of 
. The obtained differential cross sections show slightly forward-peaking structure in the measured momentum regions. The cross sections integrated for 
were obtained as 
mb and 
mb for 
(MeV/c) 
and 
(MeV/c)
, respectively. These results show a drastic improvement compared to past measurements of the hyperon-proton scattering experiments. They will play essential roles in updating the theoretical models of the baryon-baryon interactions.
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：19 パーセンタイル：89.84(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.
-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：20 パーセンタイル：81.57(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, .
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.
scattering experiment at J-PARC赤澤 雄也*; 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.011134_1 - 011134_6, 2021/03
We are performing a scattering experiment between a 
hyperon and a proton (J-PARC E40) at the K1.8 beamline in the J-PARC Hadron Hall. The purpose of this experiment is to investigate the 
interaction by measuring the differential cross sections of the , elastic scatterings and inelastic scattering. The experimental data gives a strong constraint on the theoretical models of the interaction. The identification of scattering event with a high statistics is important by overcoming the difficulties in the hyperon proton scattering experiment. We have introduced a new identification method of the scattering event, which does not need to detect particles directly. We used a new detector system called CATCH and two spectrometer systems installed at the upstream and the downstream of a liquid hydrogen target. A high intensity 
beam of 20 M/spill was used to produce particle. The momenta of beam and scattered 
were measured by the spectrometers to reconstruct the momentum of a beam produced via the 
reactions. The scattering angle and the kinetic energy of recoil protons from the scattering were measured by CATCH for the identification of the scattering events by checking the kinematic consistency. A part of the experiment was performed in 2018 and 2019 in J-PARC. As a result of analyzing the collected data, the production and the scattering reaction have been identified. It means that our new measurement and analysis method are successfully working well. Analysis for deriving the differential cross section of the scattering is on going.
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：44 パーセンタイル：93.52(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.
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：13.63(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.
