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$$Xi^-$$ atomic X-ray spectroscopy using a counter-emulsion hybrid method

藤田 真奈美; 長谷川 勝一; 細見 健二; 市川 真也; 市川 裕大; Kim, S.; 七村 拓野; 佐甲 博之; 田村 裕和; 山本 剛史; et al.

Progress of Theoretical and Experimental Physics (Internet), 2022(12), p.123D01_1 - 123D01_17, 2022/12

 被引用回数:0 パーセンタイル:0.01(Physics, Multidisciplinary)

$$Xi^-$$ atomic X-ray spectroscopy is one of the most useful methods for investigation of the $$Xi$$-nucleus strong interaction. Since the X-ray energy is shifted and/or broadened due to the $$Xi$$-nucleus strong interaction compared to those calculated from electromagnetic interaction alone, the measurement of the energy shift, $$Delta$$E, and the width, $$Gamma$$, give us information on the $$Xi$$-nucleus potential. A serious problem in the measurement is the significant background derived from in-flight $$Xi^-$$ decay. A novel method of identifying stopped $$Xi^-$$ events using the nuclear emulsion was developed to realize the first $$Xi^-$$ atomic X-ray spectroscopy experiment as the J-PARC E07 experiment, which also aimed at searching for $$LambdaLambda$$ and $$Xi^-$$ hypernuclei in the emulsion. The X-rays emitted from $$Xi^-$$ Br and $$Xi^-$$ Ag atoms were measured using germanium detectors. No clear peaks were observed in the obtained spectra. However, we succeeded in reducing the background to 1/170 by this method employing coincidence measurements using nuclear emulsion and X-ray detectors.


Measurement of differential cross sections for $$Sigma^+ p$$ 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:0 パーセンタイル:0.01(Physics, Multidisciplinary)

We performed a novel $$Sigma^+p$$ scattering experiment at the J-PARC Hadron Experimental Facility. Approximately 2400 $$Sigma^+p$$ elastic scattering events were identified from $$4.9 times 10^7$$ tagged $$Sigma^+$$ particles in the $$Sigma^+$$ momentum range 0.44 - 0.80 GeV/c. The differential cross sections of the $$Sigma^+p$$ 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 $$^3S_1$$ and $$^1P_1$$ 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 $$20^circ<|delta_{^3S_1}|<35^circ$$. If the sign of $$delta_{^3S_1}$$ is assumed to be negative, the interaction in this channel is moderately repulsive, as the Nijmegen extended-sort-core models predicted.



青木 健; 清水 厚志; 飯垣 和彦; 沖田 将一朗; 長谷川 武史; 水田 直紀; 佐藤 博之; 坂場 成昭

JAEA-Review 2022-016, 193 Pages, 2022/08





青木 健; 清水 厚志; 飯垣 和彦; 沖田 将一朗; 長谷川 武史; 水田 直紀; 佐藤 博之; 坂場 成昭

JAEA-Technology 2022-011, 60 Pages, 2022/07




Probing gluon spin-momentum correlations in transversely polarized protons through midrapidity isolated direct photons in $$p^uparrow+p$$ collisions at $$sqrt{s}$$=200 GeV

Acharya, 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:3 パーセンタイル:57.66(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 $$p^uparrow+p$$ collisions at $$sqrt{s}$$=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.


Measurement of displacement cross section for proton in the kinetic energy range from 0.4 GeV to 3 GeV

明午 伸一郎; 松田 洋樹; 岩元 洋介; 吉田 誠*; 長谷川 勝一; 前川 藤夫; 岩元 大樹; 中本 建志*; 石田 卓*; 牧村 俊助*

JPS Conference Proceedings (Internet), 33, p.011050_1 - 011050_6, 2021/03



Study of $$Lambda$$ identification method by the $$pi^-p to K^0Lambda$$ reaction for a $$Lambda p$$ 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 $$pi^-p to K^0Lambda$$ reaction is an important elementary process to produce $$Lambda$$ from a proton target and is a key for a $$Lambda p$$ scattering experiment where the momentum of $$Lambda$$ should be tagged from the missing momentum of the $$(pi^-,K^0)$$ reaction. However, the $$(pi^-,K^0)$$ spectroscopy method has not been established yet due to the difficulty of the $$K^0$$ detection. Therefore, we have proposed a new $$K^0$$ detection method where $$pi^+$$ and $$pi^-$$ from the $$K^0$$ decay are measured by a forward magnetic spectrometer and a detector cluster surrounding the target, respectively. The feasibility of the $$K^0$$ detection method was confirmed by analyzing the J-PARC E40 data taken with such a detector system. In the analysis, $$Lambda$$'s were successfully identified in the missing mass spectrum of the $$pi^-p to K^0 X$$ reaction.


Transverse single-spin asymmetries of midrapidity $$pi^0$$ and $$eta$$ mesons in polarized $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=200$$ GeV

Acharya, U. A.*; 長谷川 勝一; 今井 憲一*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他309名*

Physical Review D, 103(5), p.052009_1 - 052009_10, 2021/03

 被引用回数:3 パーセンタイル:46.7(Astronomy & Astrophysics)

We present a measurement of the transverse single-spin asymmetry for $$pi^0$$ and $$eta$$ mesons in $$p^uparrow$$$$+$$$$p$$ collisions in the pseudorapidity range $$|eta|< 0.35$$ and at a center-of-mass energy of 200 GeV with the PHENIX detector at the Relativistic Heavy Ion Collider. In comparison with previous measurements in this kinematic region, these results have a factor of 3 smaller uncertainties. As hadrons, $$pi^0$$ and $$eta$$ mesons are sensitive to both initial- and final-state nonperturbative effects for a mix of parton flavors. Comparisons of the differences in their transverse single-spin asymmetries have the potential to disentangle the possible effects of strangeness, isospin, or mass. These results can constrain the twist-3 trigluon collinear correlation function as well as the gluon Sivers function.


Transverse momentum dependent forward neutron single spin asymmetries in transversely polarized $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=200$$ GeV

Acharya, U. A.*; 長谷川 勝一; 今井 憲一*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他308名*

Physical Review D, 103(3), p.032007_1 - 032007_8, 2021/02

 被引用回数:1 パーセンタイル:18.72(Astronomy & Astrophysics)

In 2015, the PHENIX collaboration has measured very forward ($$eta > 6.8$$) single-spin asymmetries of inclusive neutrons in transversely polarized proton-proton and proton-nucleus collisions at a center of mass energy of 200 GeV. A previous publication from this data set concentrated on the nuclear dependence of such asymmetries. In this measurement the explicit transverse-momentum dependence of inclusive neutron single spin asymmetries for proton-proton collisions is extracted using a bootstrapping-unfolding technique on the transverse momenta. This explicit transverse-momentum dependence will help improve the understanding of the mechanisms that create these asymmetries.


Observation of Coulomb-assisted nuclear bound state of $$Xi^-$$-$$^{14}$$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:27 パーセンタイル:97.14(Physics, Multidisciplinary)

In an emulsion-counter hybrid experiment performed at J-PARC, a $$Xi^-$$ absorption event was observed which decayed into twin single-$$Lambda$$ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as $$Xi^{-} + ^{14}$$N$$ rightarrow ^{10}_Lambda$$Be + $$^5_Lambda$$He. For the binding energy of the $$Xi^{-}$$ hyperon in the $$Xi^-$$-$$^{14}$$N system a value of $$1.27 pm 0.21$$ MeV was deduced. The energy level of $$Xi^-$$ is likely a nuclear $$1p$$ state which indicates a weak $${Xi}N$$-$$LambdaLambda$$ coupling.


Study on the baryon interaction by $$Xi$$ hypernuclear spectroscopy with the $$(K^-, K^+)$$ reaction

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:0.09

We performed $$Xi$$ hypernuclear spectroscopy with the $$(K^-, K^+)$$ reaction at J-PARC to investigate the $$Xi N$$ 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.


Study of $$Sigma N$$ interaction from the $$Sigma p$$ scattering experiment at J-PARC

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:88.4

A high statistics $$Sigma p$$ scattering experiment has been performed at the K1.8 beamline in the J-PARC Hadron Experimental Facility. Data for momentum-tagged $$Sigma^-$$ beam running in a liquid hydrogen target were accumulated by detecting the $$pi^{-}p to {K}^{+}{Sigma}^{-}$$ reaction with a high intensity $$pi^-$$ beam of 20 M/spill. The number of the $$Sigma^-$$ beam was about $$1.7 times 10^7$$ in total. The $$Sigma^- p$$ elastic scattering and the $$Sigma^- p to Lambda n$$ inelastic scattering events were successfully observed with about 100 times larger statistics than that in past experiments.


Production of $$pi^0$$ and $$eta$$ mesons in U$$+$$U collisions at $$sqrt{s_{_{NN}}}=192$$ GeV

Acharya, U.*; 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397名*

Physical Review C, 102(6), p.064905_1 - 064905_13, 2020/12

 被引用回数:2 パーセンタイル:34.22(Physics, Nuclear)

The PHENIX experiment at the Relativistic Heavy Ion Collider measured $$pi^0$$ and $$eta$$ mesons at midrapidity in U$$+$$U collisions at $$sqrt{s_{_{NN}}}=192$$ GeV in a wide transverse momentum range. Measurements were performed in the $$pi^0(eta)rightarrowgammagamma$$ decay modes. A strong suppression of $$pi^0$$ and $$eta$$ meson production at high transverse momentum was observed in central U$$+$$U collisions relative to binary scaled $$p$$$$+$$$$p$$ results. Yields of $$pi^0$$ and $$eta$$ mesons measured in U$$+$$U collisions show similar suppression pattern to the ones measured in Au$$+$$Au collisions at $$sqrt{s_{_{NN}}}=200$$ GeV for similar numbers of participant nucleons. The $$eta$$/$$pi^0$$ ratios do not show dependence on centrality or transverse momentum, and are consistent with previously measured values in hadron-hadron, hadron-nucleus, nucleus-nucleus, and $$e^+e^-$$ collisions.


Measurement of jet-medium interactions via direct photon-hadron correlations in Au+Au and $$d$$+Au collisions at $$sqrt{s_{_{NN}}}=200$$ GeV

Acharya, U.*; 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572名*

Physical Review C, 102(5), p.054910_1 - 054910_11, 2020/11

 被引用回数:0 パーセンタイル:0.02(Physics, Nuclear)

We present direct photon-hadron correlations in 200 GeV/A Au$$+$$Au, $$d$$$$+$$Au and $$p$$$$+$$$$p$$ collisions, for direct photon $$p_T$$ from 5 - 12 GeV/$$c$$, collected by the PHENIX Collaboration in the years from 2006 to 2011. We observe no significant modification of jet fragmentation in $$d$$$$+$$Au collisions, indicating that cold nuclear matter effects are small or absent. Hadrons carrying a large fraction of the quark's momentum are suppressed in Au$$+$$Au compared to $$p$$$$+$$$$p$$ and $$d$$$$+$$Au. As the momentum fraction decreases, the yield of hadrons in Au$$+$$Au increases to an excess over the yield in $$p$$$$+$$$$p$$ collisions. The excess is at large angles and at low hadron $$p_T$$ and is most pronounced for hadrons associated with lower momentum direct photons. Comparison to theoretical calculations suggests that the hadron excess arises from medium response to energy deposited by jets.


Production of $$bbar{b}$$ at forward rapidity in $$p+p$$ collisions at $$sqrt{s}=510$$ GeV

Acharya, U.*; 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344名*

Physical Review D, 102(9), p.092002_1 - 092002_14, 2020/11

 被引用回数:0 パーセンタイル:0.01(Astronomy & Astrophysics)

The cross section of bottom quark-antiquark ($$bbar{b}$$) production in $$p+p$$ collisions at $$sqrt{s}=510$$ GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider. The results are based on the yield of high mass, like-sign muon pairs measured within the PHENIX muon arm acceptance ($$1.2 < |y| < 2.2$$). The $$bbar{b}$$ signal is extracted from like-sign dimuons by utilizing the unique properties of neutral $$B$$ meson oscillation. We report a differential cross section of $$dsigma_{bbar{b} rightarrow mu^pmmu^pm}/dy = 0.16 pm 0.01~(mbox{stat}) pm 0.02~(mbox{syst}) pm 0.02~(mbox{global})$$ nb for like-sign muons in the rapidity and $$p_T$$ ranges $$1.2 < |y| < 2.2$$ and $$p_T > 1$$ GeV/$$c$$, and dimuon mass of 5 - 10 GeV/$$c^2$$. The extrapolated total cross section at this energy for $$bbar{b}$$ production is $$13.1 pm 0.6~(mbox{stat}) pm 1.5~(mbox{syst}) pm 2.7~(mbox{global})~mu$$b. The total cross section is compared to a perturbative quantum chromodynamics calculation and is consistent within uncertainties. The azimuthal opening angle between muon pairs from $$bbar{b}$$ decays and their $$p_T$$ distributions are compared to distributions generated using ${sc ps pythia 6}$, which includes next-to-leading order processes. The azimuthal correlations and pair $$p_T$$ distribution are not very well described by ${sc pythia}$ calculations, but are still consistent within uncertainties. Flavor creation and flavor excitation subprocesses are favored over gluon splitting.


Measurement of displacement cross-sections of copper and iron for proton with kinetic energies in the range 0.4 - 3 GeV

松田 洋樹; 明午 伸一郎; 岩元 洋介; 吉田 誠*; 長谷川 勝一; 前川 藤夫; 岩元 大樹; 中本 建志*; 石田 卓*; 牧村 俊助*

Journal of Nuclear Science and Technology, 57(10), p.1141 - 1151, 2020/10

 被引用回数:6 パーセンタイル:73.86(Nuclear Science & Technology)

加速器駆動型核変換システム(ADS)等の陽子ビーム加速器施設におけるビーム窓などの構造材の損傷評価には、原子当たりの弾き出し数(dpa)が損傷指標として広く用いられる。dpaの評価は弾き出し断面積に基づいて行われるものの、20MeV以上のエネルギー領域の陽子に対する弾き出し断面積の実験データは乏しく、計算モデルの間でも約8倍の差が存在している。このため、弾き出し断面積を実験的に取得するのは計算に用いるモデルの評価のために重要となる。弾き出し断面積の取得のため、J-PARCの加速器施設において、0.4-3GeVにわたる陽子エネルギー領域における銅と鉄の断面積を測定した。弾き出し断面積は、損傷を保持するために極低温に冷却された試料における、陽子ビームに金する抵抗率変化により得ることができる。本測定で得られた実験結果を元に、計算モデルの比較検討を行った。広く用いられているNorgertt-Robinson-Torrens (NRT)モデルは、実験値を3.5倍過大評価することが判明した。一方、近年の分子動力学に基づく非熱的再結合補正(arc)モデルは実験値をよく再現したため、銅と鉄の損傷評価にはarcモデルを使うべきであると結論づけられた。


Polarization and cross section of midrapidity $$J/psi$$ production in $$p+p$$ collisions at $$sqrt{s}=510$$ GeV

Acharya, U.*; 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344名*

Physical Review D, 102(7), p.072008_1 - 072008_13, 2020/10

 被引用回数:2 パーセンタイル:21.58(Astronomy & Astrophysics)

The PHENIX experiment has measured the spin alignment for inclusive $$J/psi rightarrow e^{+}e^{-}$$ decays in $$p+p$$ collisions at $$sqrt{s}=510$$ GeV at midrapidity. The angular distributions have been measured in three different polarization frames, and the three decay angular coefficients have been extracted in a full two-dimensional analysis. Previously, PHENIX saw large longitudinal net polarization at forward rapidity at the same collision energy. This analysis at midrapidity, complementary to the previous PHENIX results, sees no sizable polarization in the measured transverse momentum range of $$0.0 < p_T < 10.0$$ GeV/$$c$$. The results are consistent with a previous one-dimensional analysis at midrapidity at $$sqrt{s}=200$$ GeV. The transverse-momentum-dependent cross section for midrapidity $$J/psi$$ production has additionally been measured, and after comparison to world data we find a simple logarithmic dependence of the cross section on $$sqrt{s}$$.


Measurement of displacement cross section of structural materials utilized in the proton accelerator facilities with the kinematic energy above 400 MeV

明午 伸一郎; 松田 洋樹; 岩元 洋介; 吉田 誠*; 長谷川 勝一; 前川 藤夫; 岩元 大樹; 中本 建志*; 石田 卓*; 牧村 俊助*

EPJ Web of Conferences, 239, p.06006_1 - 06006_4, 2020/09

 被引用回数:0 パーセンタイル:0.1



Measurement of charged pion double spin asymmetries at midrapidity in longitudinally polarized $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=510$$ GeV

Acharya, U.*; 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354名*

Physical Review D, 102(3), p.032001_1 - 032001_9, 2020/08

 被引用回数:2 パーセンタイル:21.58(Astronomy & Astrophysics)

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the longitudinal double spin asymmetries, $$A_{LL}$$, for charged pions at midrapidity ($$|eta| < 0.35$$) in longitudinally polarized $$p$$$$+$$$$p$$ collisions at $$sqrt{s}=510$$ GeV. These measurements are sensitive to the gluon spin contribution to the total spin of the proton in the parton momentum fraction $$x$$ range between 0.04 and 0.09. One can infer the sign of the gluon polarization from the ordering of pion asymmetries with charge alone. The asymmetries are found to be consistent with global quantum-chromodynamics fits of deep-inelastic scattering and data at $$sqrt{s}=200$$ GeV, which show a nonzero positive contribution of gluon spin to the proton spin.


Measurement of $$J/psi$$ at forward and backward rapidity in $$p$$+$$p$$, $$p$$$$+A$$l, $$p$$$$+A$$u, and $$^3$$He+Au collisions at $$sqrt{s_{_{NN}}}$$ = 200 GeV

Acharya, U.*; 長谷川 勝一; 今井 憲一*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他358名*

Physical Review C, 102(1), p.014902_1 - 014902_23, 2020/07

 被引用回数:6 パーセンタイル:71.34(Physics, Nuclear)

Charmonium is a valuable probe in heavy-ion collisions to study the properties of the quark gluon plasma, and is also an interesting probe in small collision systems to study cold nuclear matter effects, which are also present in large collision systems. With the recent observations of collective behavior of produced particles in small system collisions, measurements of the modification of harmonium in small systems have become increasingly relevant. We present the results of $$J/psi$$ measurements at forward and backward rapidity in various small collision systems, $$p$$$$+$$$$p$$, $$p$$$$+$$Al, $$p$$$$+$$Au and $$^3$$He$$+$$Au, at $$sqrt{s_{_{NN}}}$$=200 GeV. The results are presented in the form of the observable $$R_{AB}$$, the nuclear modification factor, a measure of the ratio of the $$J/psi$$ invariant yield compared to the scaled yield in $$p$$$$+$$$$p$$ collisions. We examine the rapidity, transverse momentum, and collision centrality dependence of nuclear effects on $$J/psi$$ production with different projectile sizes $$p$$ and $$^3$$He, and different target sizes Al and Au. The modification is found to be strongly dependent on the target size, but to be very similar for $$p$$$$+$$Au and $$^{3}$$He$$+$$Au. However, for 0% - 20% central collisions at backward rapidity, the modification for $$^{3}$$He$$+$$Au is found to be smaller than that for $$p$$$$+$$Au, with a mean fit to the ratio of $$0.89pm0.03$$(stat)$${pm}0.08$$(syst), possibly indicating final state effects due to the larger projectile size.

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