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雨森 道紘*; 土屋 晴文; Tibet AS
Collaboration*; 他116名*
Astrophysical Journal, 954(2), p.200_1 - 200_7, 2023/09
被引用回数：1 パーセンタイル：50.15(Astronomy & Astrophysics)Gamma rays from HESS J1849-000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches 
and 
levels above 25 TeV and 100 TeV, respectively. The energy spectrum measured between 40 TeV 
E 320 TeV for the first time is described with a simple power-law function of dN/dE = 
. The gamma-ray energy spectrum from the sub-TeV to sub-PeV ranges including the results of previous studies can be modeled with the leptonic scenario, Inverse Compton Scattering by high-energy electrons accelerated by the PWN of PSR J1849-0001, but the scenario requires sophisticated theoretical modeling. On the other hand, the gamma-ray energy spectrum can be simply modeled with the hadronic scenario in which gamma rays are generated from the decay of neutral pions produced by collisions between accelerated cosmic-ray protons and the ambient molecular cloud found in the gamma-ray emitting region. The cutoff energy of cosmic-ray protons 
is estimated at 
, suggesting that protons are accelerated up to the PeV energy range. Our study proposes that HESS J1849-000 should be further investigated as a new candidate for a Galactic PeV cosmic-ray accelerator, or "PeVatron".
西 隆博*; 橋本 直; 他46名*
Nature Physics, 19(6), p.788 - 793, 2023/06
被引用回数：3 パーセンタイル：80.44(Physics, Multidisciplinary)According to quantum chromodynamics, vacuum is not an empty space, because it is filled with quark-antiquark pairs. The pair has the same quantum numbers as the vacuum and forms a condensate because the strong interaction of the quantum chromodynamics is too strong to leave the vacuum empty. This quark-antiquark condensation, the chiral condensate, breaks the chiral symmetry of the vacuum. The expectation value of the chiral condensate is an order parameter of the chiral symmetry, which is expected to decrease at high temperatures or high matter densities where the chiral symmetry is partially restored. Head-on collisions of nuclei at ultra-relativistic energies have explored the high-temperature regime, but experiments at high densities are rare. Here we measure the spectrum of pionic 
Sn atoms and study the interaction between the pion and the nucleus. We find that the expectation value of the chiral condensate is reduced at finite density compared to the value in vacuum. The reduction is linearly extrapolated to the nuclear saturation density and indicates that the chiral symmetry is partially restored due to the extremely high density of the nucleus.
(980) meson decaying into 
at 
2.4 GeV村松 憲仁*; 土川 雄介; LEPS2 BGOegg Collaboration*; 他61名*
Physical Review C, 107(4), p.L042201_1 - L042201_5, 2023/04
被引用回数：0 パーセンタイル：0.02(Physics, Nuclear)For the first time, differential cross sections and photon beam asymmetries were measured for the reaction 
by using a linearly polarized photon beam up to 2.4 GeV and a liquid hydrogen target. The (980) photoproduction signal was clearly observed owing to the absence of contributions from vector-meson photoproduction. The results indicate the 
-channel exchange of vector mesons as a mechanism of the (980) photoproduction at 
approximate to 2.1 GeV, putting constraints on the nature of (980).
decay of the 8
isomer in 
UZhang, M. M.*; Tian, Y. L.*; Wang, Y. S.*; Zhang, Z. Y.*; Gan, Z. G.*; Yang, H. B.*; Huang, M. H.*; Ma, L.*; Yang, C. L.*; Wang, J. G.*; et al.
Physical Review C, 106(2), p.024305_1 - 024305_6, 2022/08
被引用回数：2 パーセンタイル：52.69(Physics, Nuclear)The extremely neutron-deficient even-even uranium isotopes U were produced in the complete-fusion reactions induced by impinging 
Ar and Ca ions on 
W targets. Fusion evaporation residues were separated in flight by the gas-filled recoil separator SHANS (Spectrometer for Heavy Atoms and Nuclear Structure) and subsequently identified using the recoil--correlation method. In this paper, we report on new -decay activities with 
keV for 
U and 
keV for 
U, which decay from the 8 isomeric states of U into the 2 states of their daughter nuclei 
Th, respectively. The new results extend the systematics of the -decay fine structure for the 
= 124 and 126 even-even isotones.
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：6 パーセンタイル：78.27(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.
-ray spectroscopy of low-lying yrast and non-yrast states in neutron-rich 
KrGerst, R.-B.*; Blazhev, A.*; Moschner, K.*; Doornenbal, P.*; Obertelli, A.*; Orlandi, R.; 他62名*
Physical Review C, 105(2), p.024302_1 - 024302_11, 2022/02
被引用回数：6 パーセンタイル：82.52(Physics, Nuclear)The neutron rich krypton isotopes Kr (
=36, =58,59,60 respectively) were investigated at the Radioactive Isotope Beam Facility Facility (RIBF) at RIKEN. The nuclei of interest were produced in nuclear reactions induced by radioactive Kr and Rb beams, prduced via in-flight fission of 
U, impinging onto the liquid hydrogen target MINOS. The main reactions occurring were (p,pn), (p,p') and (p,2p). The isotopes of interest were separated in the fragment separator BigRIPS, and their rays detected using the DALI2 -ray spectrometer. The Kr provide insights onto the sudden onset of deformation occurring in Zr and Mo isotopes at =60, which is also associated with shape coexistence. In this experiment the level scheme of these isotopes could be extended, and new yrast and non-yrast states were identified. The results were compared with predictions of the "beyond-mean-field" model and the IBM model, and indications of prolate-oblate shape coexistence at =60 in the Kr isotopes was found.
Gilbert, M. R.*; 荒河 一渡*; 鈴土 知明; 都留 智仁; 他26名*
Journal of Nuclear Materials, 554, p.153113_1 - 153113_31, 2021/10
被引用回数：33 パーセンタイル：90.46(Materials Science, Multidisciplinary)核融合炉環境における材料性能の予測において、計算科学モデリングが重要な役割を果たしており、第一世代の核融合発電所が稼働し長期的な挙動の観察が可能になるまで継続することが予定されている。2019年に、主要な専門家のグループがIEAの傘下の会合に参加し、核融合材料のモデル化における現在の位置と進行中の課題、および高度な実験特性評価がモデルの改善にどのように役立つかについて議論した。本論文は、そのワークショップ中に行われた議論から得られたレビューとして報告するものである。照射誘発欠陥の生成と基本特性のモデリング、ガスの挙動、クラスタリング、欠陥成長と相互作用、新しいマルチスケールシミュレーション、および高度な実験によるモデリングと実験の連携に関する取り組みについて議論した。
collisions at 
=200 GeVAcharya, U. A.*; 長谷川 勝一; 今井 憲一*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他306名*
Physical Review Letters, 127(16), p.162001_1 - 162001_8, 2021/10
被引用回数：9 パーセンタイル：72.45(Physics, Multidisciplinary)Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in collisions at =200 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a fifty-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.
AuHarding, R. D.*; Andreyev, A. N.; Barzakh, A. E.*; Cubiss, J. G.*; Van Duppen, P.*; Al Monthery, M.*; Althubiti, N. A.*; Andel, B.*; 他26名*
Physical Review C, 104(2), p.024326_1 - 024326_16, 2021/08
被引用回数：5 パーセンタイル：46.8(Physics, Nuclear)A detailed nuclear spectroscopy study of Au was performed at ISOLDE, CERN. This work provides new insights into the low-lying levels in the daughter nuclei 
Ir. For 
Au, the nuclear magnetic moments of a high spin and low spin state were determined and used to predict the most likely configuration of each level. Their -decay branching ratios were also extracted: a 58(5)% branching for the low-spin state, and 29(5)% for the high-spin state.
decays with hadronic taggingCao, L.*; 谷田 聖; Belle Collaboration*; 他236名*
Physical Review D, 104(1), p.012008_1 - 012008_32, 2021/07
被引用回数：10 パーセンタイル：65.5(Astronomy & Astrophysics)We present measurements of partial branching fractions of inclusive semileptonic decays using the full Belle data set of 711 fb
of integrated luminosity at the 
resonance and for 
. Inclusive semileptonic decays are CKM suppressed and measurements are complicated by the large background from CKM-favored 
transitions, which have a similar signature. Using machine learning techniques, we reduce this and other backgrounds effectively, whilst retaining access to a large fraction of the phase space and high signal efficiency. We measure partial branching fractions in three phase-space regions covering about 
to 
of the accessible phase space. The most inclusive measurement corresponds to the phase space with lepton energies of 
GeV, and we obtain 
from a two-dimensional fit of the hadronic mass spectrum and the four-momentum-transfer squared distribution, with the uncertainties denoting the statistical and systematic error. We find 
from an average of four calculations for the partial decay rate with the third uncertainty denoting the average theory error. This value is higher but compatible with the determination from exclusive semileptonic decays within 1.3 standard deviations.
, 
, and 
decays at BelleJia, S.*; 谷田 聖; Belle Collaboration*; 他186名*
Journal of High Energy Physics (Internet), 2021(6), p.160_1 - 160_13, 2021/06
被引用回数：4 パーセンタイル：37.94(Physics, Particles & Fields)Using a data sample of 980 fb collected with the Belle detector at the KEKB asymmetric-energy 
collider, we study the processes of , , and for the first time. The relative branching ratios to the normalization mode of 
are measured to be 
where the uncertainties are statistical and systematic, respectively. We obtain the branching fractions of , , and to be 
where the uncertainties are statistical, systematic, and from 
, respectively. The asymmetry parameters 
and 
are 
and 
, respectively, where the uncertainties are statistical followed by systematic.
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.
= 82Moon, B.*; Jungclaus, A.*; Na
dja, H.*; Gargano, A.*; Lozeva, R.*; Moon, C.-B.*; Orlandi, R.; 他66名*
Physical Review C, 103(3), p.034320_1 - 034320_15, 2021/03
被引用回数：7 パーセンタイル：76.16(Physics, Nuclear)At RIKEN RIBF facility, the beta decay of 
Sb and 
Sb were studied and several new excited states were assigned to the level schemes of Te and Te. The structure of these Te isotopes deduced from the level scheme is compared with state-of-the-art shell-model calculations using different effective interactions. The comparison with calculations permits to determine the spectroscopic factors and deformation of these isotopes close to doubly magic 
Sn.
Hg isotopes; Illuminating the kink and odd-even staggering in charge radii across the = 126 shell closureDay Goodacre, T.*; Afanasjev, A. V.*; Barzakh, A. E.*; Marsh, B. A.*; Sels, S.*; Ring, P.*; 中田 仁*; Andreyev, A. N.; 他36名*
Physical Review Letters, 126(3), p.032502_1 - 032502_7, 2021/01
被引用回数：35 パーセンタイル：94.61(Physics, Multidisciplinary)The charge radii of Hg have been studied for the first time and those of 
Hg remeasured by laser spectroscopy at ISOLDE (CERN). The characteristic kink in the charge radii at the = 126 shell closure has been revealed, providing the first information on its behavior below the = 82 shell closure. By a theoretical analysis, it is demonstrated, contrary to previous interpretations, that both the kink at = 126 and the odd-even staggering can be described predominantly at the mean-field level and that pairing does not need to play a crucial role in their origin.
bound state in the 
He 
reaction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：17 パーセンタイル：88.31(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 
.
decay of 
Ni and the systematics of the low-lying level structure of neutron-rich odd-
Cu isotopesBello Garrote, F. L.*; Sahin, E.*; 角田 佑介*; 大塚 孝治*; G
rgen, A.*; Orlandi, R.; 他61名*
Physical Review C, 102(3), p.034314_1 - 034314_13, 2020/09
被引用回数：4 パーセンタイル：45.12(Physics, Nuclear)Detailed spectroscopy of neutron-rich odd- Cu isotopes is of great importance for studying the shell evolution in the region of 
Ni. Excited states in Cu were populated in the decay of Ni isotopes, which were produced by the in-flight fission at RIBF, RIKEN. The Ni isotopes were separated, identified, and implanted in a highly segmented Si detector array for the detection of the -decay electrons, while the delayed rays were detected by an array of HPGe cluster detectors. A level scheme of Cu was built up to 
4 MeV, from which the location of the two previously known low-lying isomeric states was clarified. The level structure below 2 MeV was interpreted based on the results of the shell-model calculations and the systematics of odd- Cu isotopes, revealing the evolution of single-particle states in this region.
bound system at J-PARC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：69.1(Physics, Applied)The 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.
-nuclear bound state at J-PARC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.
) two-proton knockout from neutron-rich nucleiFrotscher, A.*; G
mez-Ramos, M.*; Obertelli, A.*; Doornenbal, P.*; Authelet, G.*; 馬場 秀忠*; Orlandi, R.; 他86名*
Physical Review Letters, 125(1), p.012501_1 - 012501_7, 2020/07
被引用回数：5 パーセンタイル：38.78(Physics, Multidisciplinary)Twenty-one two-proton () knock-out cross sections of neutron-rich radioactive isotopes were measured in inverse kinematics using the MINOS time-projection chamber at RIBF, RIKEN. The proton angular distributions, measured for the first time, reveal that the reaction kinematics of the () reaction is consistent with sequential proton collisions within the projectile nucleus.
Seidl, R.*; 谷田 聖; Belle Collaboration*; 他136名*
Physical Review D, 101(9), p.092004_1 - 092004_13, 2020/05
被引用回数：5 パーセンタイル：36.79(Astronomy & Astrophysics)We report new measurements of the production cross sections of pairs of charged pions and kaons as a function of their fractional energies using various fractional-energy definitions. Two different fractional-energy definitions were used and compared to the conventional fractional-energy definition reported previously. The new variables aim at either identifying dihadron cross sections in terms of single-hadron fragmentation functions, or to provide a means of characterizing the transverse momentum created in the fragmentation process. The results were obtained applying the updated initial-state radiation correction used in other recent Belle publications on light-hadron production cross sections. In addition, production cross sections of single charged pions, kaons, and protons were also updated using this initial-state radiation correction. The cross sections are obtained from a 558 fb data sample collected at the resonance with the Belle detector at the KEKB asymmetric-energy 
collider.
