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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.
meson properties in nuclear matter from dilepton and 
decaysGubler, P.; Bratkovskaya, E.*
EPJ Web of Conferences, 271, p.09004_1 - 09004_4, 2022/11
There is presently no consensus on how the meson mass and width will change once it is put in a dense environment such as nuclear matter. While many theoretical works exist, connecting them with experimental measurements remains non-trivial task, as the meson in nuclear matter is usually produced in high-energy pA reactions, which are generally non-equilibrium processes. In this presentation I will report on an ongoing project, attempting to simulate pA reactions in which the meson is produced in nuclei, making use of a transport approach. Results of simulations of 12 GeV/30 GeV p+C and p+Cu reactions will be presented and comparisons between obtained dilepton spectra and experimental data of the E325 experiment at KEK will be made. Furthermore, predictions for the ongoing J-PARC E16 experiment for both dilepton and 
spectra will be given and discussed.
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.
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.
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.
岡 眞
no journal, ,
クォーク2個の相関を表すダイクォークのカイラル有効理論を構成し、これを用いてヘビーバリオン,ヘビーテトラクォークのスペクトルと崩壊を解析した。
atomic X-ray measurement at J-PARC E07藤田 真奈美
no journal, ,
原子X線分光はS=-2体系における強い相互作用を理解するために有用な実験手法である。実験の非常に難しい点は、生成したハイペロンの崩壊に起因して大量にバックグラウンドが生じる事である。そこで我々は、原子核乾板(エマルション)を用いた静止選択法を開発した。この手法の導入により信号雑音比の良いクリーンなX線スペクトルの取得が期待された。我々は、J-PARC K1.8ビームラインにおいてカウンター-エマルションハイブリット法を用いた原子X線測定を実施した。ハイペロンは
反応により生成し、磁気スぺクトロメータとシリコンストリップ検出器を用いて、反応分光と生成ハイペロンの飛跡を解析した。この飛跡解析により、エマルション表面のハイペロン入射地点を予測でき、短時間での効率の良い解析を実現した。原子X線は、ゲルマニウム検出器アレイ(Hyperball-X)により測定した。本講演では、銀と臭素の原子X線測定の最終結果を報告する。
bound state in the 
final states of the in-flight 
reaction on 
He橋本 直
no journal, ,
In recent years, the possible existence of deeply-bound 
nuclear bound states has been widely discussed as a consequence of the strongly attractive 
interaction in I = 0 channels. Very recently, J-PARC E15 experiment reported an observation of the simplest kaonic nuclei, 
, in the invariant-spectrum of the in-flight reaction on helium-3. Observation of other kaonic nuclei would provide a further support for the existence of such exotic states. Furthermore, mass-number dependence of kaonic nuclear systems would be of great importance to study interplay between the attraction and the 
repulsion at short distances. We collected -induced data on helium-4 as a feasibility test of a lifetime measurement of light hypernuclei (J-PARC T77) in June 2020. In this contribution, we would like to present the latest results of the analysis, and discuss future prospects towards more comprehensive investigation of the system.
N cusp" at J-PARC (J-PARC P90)市川 裕大
no journal, ,
Recently, we have proposed a new experiment (J-PARC P90 experiment) to measure the missing-mass spectrum around the 
threshold in the d(K
, 
) reaction at 1.4 GeV/c. A clear enhancement was observed near the N threshold, so called "N cusp", for a long time ago. However, the dynamical origin of this enhancement remains unclear as yet. Especially, whether "N cusp", is cusp or unstable bound state has not been determined yet. One of the key to make it clear is to improve the missing-mass resolution and statistics. In this experiment, we can achieve the missing-mass resolution of 0.4 MeV in 
by using K1.8 beam line and S-2S spectrometers at J-PARC. Moreover, we will additionally install the time projection chamber (HypTPC), which was developed for the other J-PARC experiment (E42: H-dibaryon search), to suppress quasi-free backgrounds by detecting the charged tracks of the decay products. We can deduce the scattering length of N system with isospin T = 1/2 and spin triplet channel in this experiment.
谷田 聖
no journal, ,
Belle and Belle II are B-factory experiments using electron-positron collisions. Not only particle physics, but also hadron spectroscopy is actively pursued in the experiments. In this talk, we will present recent results on exotic (and conventional) hadrons from the Belle experiment and on the status and prospects of the Belle II experiment.
