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-ray emitter 
Al in massive stars; Study of the key Al(n,
) reactionLederer-Woods, C.*; 原田 秀郎; 木村 敦; 他123名*
Physical Review C, 104(3), p.L032803_1 - L032803_6, 2021/09
被引用回数：8 パーセンタイル：67.39(Physics, Nuclear)Neutron destruction reactions of the cosmic -ray emitter Al are of importance to determine the amount of Al ejected into our galaxy by supernova explosions and for Al production in asymptotic giant branch stars. We performed a new measurement of the Al(n,) reaction up to 160-keV neutron energy at the neutron time-of-flight facilities n_TOF at CERN and GELINA at EC-JRC. We provide strengths for ten resonances, six of them for the first time. We use our data to calculate astrophysical reactivities for stellar temperatures up to 0.7 GK. Our results resolve a discrepancy between the two previous direct measurements of this reaction, and indicate higher stellar destruction rates than the most recently recommended reactivity.
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：13 パーセンタイル：60.53(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.
Sahoo, D.*; 谷田 聖; Belle Collaboration*; 他223名*
Physical Review D, 102(11), p.111101_1 - 111101_9, 2020/12
被引用回数：7 パーセンタイル：38.66(Astronomy & Astrophysics)We search for lepton-number- and baryon-number-violating decays 
, 
, 
, 
, 
, and 
using 921 fb of data, equivalent to 
events, recorded with the Belle detector at the KEKB asymmetric-energy 
collider. In the absence of a signal, 90% confidence-level upper limits are set on the branching fractions of these decays in the range 
-
. We set the world's first limits on the first four channels and improve the existing limits by an order of magnitude for the last two channels.
collisions at 
= 510 GeVKim, M. H.*; 谷田 聖; RHICf Collaboration*; 他23名*
Physical Review Letters, 124(25), p.252501_1 - 252501_6, 2020/06
被引用回数：6 パーセンタイル：42.59(Physics, Multidisciplinary)Transverse single-spin asymmetries of very forward neutral pions generated in polarized 
collisions allow us to understand the production mechanism in terms of perturbative and non-perturbative strong interactions. During 2017 the RHICf Collaboration installed an electromagnetic calorimeter in the zero-degree region of the STAR detector at the Relativistic Heavy Ion Collider (RHIC) and measured neutral pions produced at pseudorapidity larger than 6 in polarized 
+ collisions at = 510 GeV. The large non-zero asymmetries increasing both in longitudinal momentum fraction 
and transverse momentum 
have been observed at low transverse momentum 
GeV/
for the first time at this collision energy. The asymmetries show an approximate scaling in the region where non-perturbative processes are expected to dominate. A non-negligible contribution from soft processes may be necessary to explain the nonzero neutral pion asymmetries.
for forward 
production in polarized 
collisions at 
GeVAdare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他423名*
Physical Review D, 98(3), p.032007_1 - 032007_14, 2018/08
被引用回数：17 パーセンタイル：60.02(Astronomy & Astrophysics)We have measured the cross section and single spin asymmetries from forward production in longitudinally polarized collisions at GeV using the PHENIX detector at the Relativistic Heavy Ion Collider. The cross sections are consistent with previous measurements at this collision energy, while the most forward and backward longitudinal single spin asymmetries provide new insights into the sea quark helicities in the proton. The charge of the 
bosons provides a natural flavor separation of the participating partons.
hadrons in nucleus-nucleus collisions at 
from 62.4 GeV to 2.76 TeVAdare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他623名*
Physical Review C, 93(2), p.024911_1 - 024911_20, 2016/02
被引用回数：19 パーセンタイル：75.67(Physics, Nuclear)Measurements of the fractional momentum loss (
) of high-transverse-momentum-identified hadrons in heavy-ion collisions are presented. Using 
in Au+Au and Cu+Cu collisions at = 62.4 and 200 GeV measured by the PHENIX experiment at the Relativistic Heavy Ion Collider and and charged hadrons in Pb+Pb collisions measured by the ALICE experiment at the Large Hadron Collider, we studied the scaling properties of 
as a function of a number of variables: the number of participants, 
, the number of quark participants, 
, the charged-particle density, 
, and the Bjorken energy density times the equilibration time, 
. We find that the , where has its maximum, varies both with centrality and collision energy. Above the maximum, tends to follow a power-law function with all four scaling variables. The data at = 200 and 2.76 TeV, for sufficiently high particle densities, have a common scaling of with and , lending insight into the physics of parton energy loss.
Han, Y.*; 長谷川 勝一; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 杉村 仁志; 谷田 聖; J-PARC E42 Collaboration*; 他23名*
JPS Conference Proceedings (Internet), 8, p.021002_1 - 021002_5, 2015/09
The famed yet elusive H-dibaryon, an exotic quark state (
), was predicted several decades ago and also supported by recent Lattice QCD calculations. The E42 experiment has been approved at J-PARC to search for the H-dibaryon with high statistics. A large acceptance hyperon spectrometer with a time projection chamber (TPC) will be used for searching the H-dibaryon from 
reaction off nuclei via its possible following decays such as 
. The E42 experiment has high sensitivity both above and below threshold and will be the definitive experiment on the existence of the H-dibaryon, once and for all. Recent progress and achievements of the E42 collaboration will be presented, which include simulations on estimation of TPC performance in the electric field and the magnetic field, testing and optimization of a prototype TPC, and preparation of various detectors.
He + Au collisions at = 200 GeVAdare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他623名*
Physical Review Letters, 115(14), p.142301_1 - 142301_9, 2015/09
被引用回数：117 パーセンタイル：96.02(Physics, Multidisciplinary)We present the first measurement of elliptic (
) and triangular (
) flow in high-multiplicity He + Au collisions at = 200 GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in He + Au and in collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the He + Au system. The collective behavior is quantified in terms of elliptic and triangular anisotropy coefficients measured with respect to their corresponding event planes. The values are comparable to those previously measured in 
+ Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.
斎藤 伸三; 田中 利幸; 数土 幸夫; 馬場 治; 新藤 雅美; 塩沢 周策; 茂木 春義; 大久保 実; 伊藤 昇; 新藤 隆一; et al.
JAERI 1332, 247 Pages, 1994/09
現在原研は、高温ガス炉技術基盤の確立と高度化、高温における先端的基礎研究の実施を主な目的として、高温工学試験研究炉(HTTR)の建設を進めている。HTTRは、熱出力30MW、原子炉出口冷却材温度が定格運転時850
C、高温試験運転時950Cであり、燃料・材料の各種照射試験、安全性実証試験、核熱利用に関する試験研究を行うことが計画されている。本報は、平成2年11月にHTTRの安全審査が終了し、設置許可を受けたことから、主要機器の設計の概要をまとめるとともに、関連するR&D、安全評価等について報告するものである。
関 有沙*; 多田 隆治*; 入野 智久*; 松崎 賢史*; 吉岡 純平*; 奈良 郁子; 他20名*; ReC23-03 members*
no journal, ,
リポジトリコア再解析プログラム(ReCoRD)は、高知コアセンター(KCC)に保管されている、過去のDSDP・ODP・IODPで採取されたコア(リポジトリコア)を活用して、通常のサンプルリクエストよりも大きなチームで組織的に研究を行うプログラムである(https://j-desc.org/record/)。このReCoRDの3番目のプロジェクトとして、「中新世日本海の古気候と古海洋(ReC23-03)」が採択され、2024年度、非破壊分析とサンプリングパーティーを実施した。ReC23-03では、現在よりも温暖であった中新世の古気候・古海洋復元を目的とし、特に(1)平行葉理が観察される堆積物に記録された短周期の気候変動、(2)10.8Maの急激な温暖化時期の日本海における海洋環境復元、の2点に着目して研究を行っている。ReC23-03では再検証・改訂した年代モデルを用いて、異なる水深から採取した上記5地点のコアを正確に対比することにより、鉛直構造まで含めた過去の海洋環境を高時間解像度で復元することを目的としている。発表では、ReC23-03に提出された20件のサンプルリクエストを紹介し、リクエスト間の協力関係や進捗について紹介する。合わせて、ReCoRDの特徴でもある、XRFコアスキャナーやX線CTを用いた非破壊分析の結果を参照しながらサンプリングパーティーを行うことで得られた利点についても紹介する。
