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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) atomic X-ray spectroscopy is one of the most useful methods for investigation of the
-nucleus strong interaction. Since the X-ray energy is shifted and/or broadened due to the
-nucleus strong interaction compared to those calculated from electromagnetic interaction alone, the measurement of the energy shift,
E, and the width,
, give us information on the
-nucleus potential. A serious problem in the measurement is the significant background derived from in-flight
decay. A novel method of identifying stopped
events using the nuclear emulsion was developed to realize the first
atomic X-ray spectroscopy experiment as the J-PARC E07 experiment, which also aimed at searching for
and
hypernuclei in the emulsion. The X-rays emitted from
Br and
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.
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:1 パーセンタイル:57.36(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.
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:9 パーセンタイル:89.08(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.
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.
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:28 パーセンタイル:95.36(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.
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:63.81We performed hypernuclear spectroscopy with the
reaction at J-PARC to investigate the
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.
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:82.61A high statistics scattering experiment has been performed at the K1.8 beamline in the J-PARC Hadron Experimental Facility. Data for momentum-tagged
beam running in a liquid hydrogen target were accumulated by detecting the
reaction with a high intensity
beam of 20 M/spill. The number of the
beam was about
in total. The
elastic scattering and the
inelastic scattering events were successfully observed with about 100 times larger statistics than that in past experiments.
Jung, W.*; Ahn, J. K.*; 長谷川 勝一; Hicks, K.*; Hwang, S.*; 市川 裕大; Kim, S.*; 佐甲 博之; 佐藤 進; 谷田 聖
JPS Conference Proceedings (Internet), 27, p.011007_1 - 011007_6, 2019/11
We have developed HypTPC consists of TPC and the trigger hodoscope for the J-PARC hadron experiments. The TPC Hodoscope has large scintillators of 80 7
1 cm
to cover the TPC. Especially, we have developed a readout circuit for multiple MPPCs to detect photons generated over a large area of the scintillator. A general methods of applying voltage to multiple MPPCs are parallel and series connections. In the case of parallel connections, a signal has a long tail due to the large sensor capacitance. MEG collaboration used four MPPC segments as a serial connection. However, in the case of a series connection, the requiring bias voltage is very high, and the gain is low. To avoid this problem, we have developed a new individual biasing method with a summing amplifier for stable multiple MPPC readouts. We also made prototype detectors and performed a cosmic-ray test. Brief descriptions of our prototypes and preliminary results of the cosmic-ray test are presented in this article.
中田 祥之*; 長谷川 勝一; 早川 修平*; 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.
JPS Conference Proceedings (Internet), 26, p.023024_1 - 023024_5, 2019/11
J-PARC E40 aims to measure the differential cross sections of the elastic scatterings and the
conversion. A clear peak of
was observed in a missing mass spectrum of the
reaction and recoil protons from the
elastic scattering were successfully observed in the data taken in the summer 2018. The rest of data taking is coming in the spring 2019.
Yang, S. B.*; 長谷川 勝一; 早川 修平*; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 田村 裕和*; 谷田 聖; et al.
JPS Conference Proceedings (Internet), 26, p.023015_1 - 023015_5, 2019/11
We performed a gamma-ray spectroscopy of at J-PARC Hadron Experimental Facility in 2015. It is the first measurement of
rays emitted from
-shell hypernuclei. In this experiment, we determined the energy spacing between the ground state spin doublet,
and
states, as 316 keV. The excitation energies of
and
states are also determined to be 895 and 1266 keV, respectively. The energy spacing is found to be well reproduced by shell-model calculations which describe
- and
-shell
hypernuclei well. The results show that the present theories of the
interaction describe not only the light hypernuclei but also a heavier hypernucleus.
本多 良太郎*; 長谷川 勝一; 早川 修平; 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.
JPS Conference Proceedings (Internet), 26, p.023014_1 - 023014_4, 2019/11
We measured the reaction spectra at 1.8 GeV/
for the graphite and the polyethylene targets in the J-PARC E05 pilot experiment. By comparing the spectra for these two targets, it was found that
in the
B nucleus is quite broadened. Furthermore, we also compared broadness of
with
obtained in the
spectrum.
seems to be much more broadened in nuclei than
. We gave a possible interpretation, which is related to compositeness of decuplet baryons, for this situation.
中川 真菜美*; 長谷川 勝一; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 田村 裕和; 谷田 聖; et al.
JPS Conference Proceedings (Internet), 26, p.023005_1 - 023005_3, 2019/11
The interaction is not much studied than the
interaction. To understand the
interaction, we study
hypernuclei. As for the
hypernucleus, only the ground state of
has been observed. To obtain more information about the
interaction, the excited state should be studied. Therefore, we measure the missing-mass of the
He
reaction at
GeV/
and
2-14
at the J-PARC K1.8 beam line. The ground state of
is observed whereas a peak of the excited states is not observed. We also observe suppression of the
quasi-free process at smaller angles.
Kim, S. H.*; 市川 裕大; 佐甲 博之; 長谷川 勝一; 早川 修平*; 七村 拓野*; 佐藤 進; 谷田 聖; 吉田 純也; 他11名*
Nuclear Instruments and Methods in Physics Research A, 940, p.359 - 370, 2019/10
被引用回数:5 パーセンタイル:52.09(Instruments & Instrumentation)We have developed a gas electron multiplier (GEM)-based time projection chamber (TPC) for the H-dibaryon search experiment at J-PARC. High-rate beam particles enter a TPC gas volume of approximately 0.2 m
, in a direction perpendicular to the electric field. A long-rectangular hollow section is located inside the TPC volume to accommodate a diamond target. We commissioned the TPC using 230 MeV protons with beam rates of up to 1 MHz. The TPC data acquisition system collected 5768 pad signals in full readout mode, with almost 100% efficiency, at a preset trigger rate of 230 Hz. We operated the TPC in an Ar/CH
gas mixture (90/10) without a magnetic field. The spatial resolutions on the pad plane are measured to be 400-700
m, which correspond to 230-300
m in a magnetic field of 1 T. We confirmed high tracking capability at beam rates of up to 1 MHz.
小池 武志*; 長谷川 勝一; 早川 修平*; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 杉村 仁志; 田村 裕和; et al.
AIP Conference Proceedings 2130, p.020011_1 - 020011_9, 2019/07
被引用回数:2 パーセンタイル:73.18Experimental results from the J-PARC E13 experiments are summarized. A new experimental set up of E13 has established a platform for the future -ray hypernuclear spectroscopy at J-PARC using kaon beams. New
rays are identified in
He and
F. The energy of 1.406 MeV for the
He
transition confirmed a sizable effect of Charge Symmetry Breaking (CSB) in
interaction in the
hypernuclear system. The identification of four
rays in
F is made for the first time in
shell hypernuclei. Especially, energy spacing of the ground state doublet is found to be 315.5 keV. A good agreement with two theoretical calculations suggests that the theoretical formalism used in
shell hypernuclei is also applicable to heavier hypernuclei. Lastly, an overview of the future J-PARC E63 experiment is given.
永江 知文*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 金原 慎二; 七村 拓野*; 成木 恵; et al.
AIP Conference Proceedings 2130, p.020015_1 - 020015_9, 2019/07
被引用回数:11 パーセンタイル:98.69For the full understanding of baryon-baryon interactions in flavor , the
interaction is the last missing piece of information. So far, we have revealed the
interaction to be attractive (
MeV), and
interaction to be repulsive in the medium to heavy mass-number region. The
bonding energy is weakly attractive. While we have a few experimental observations suggesting the
interaction would be attractive, there still exist large theoretical ambiguities weather it is attractive or not. Experimental determinations on the existence of bound states of
hypernuclei by observing bound-state peaks are strongly awaited. In this report, a new preliminary result on the missing-mass spectrum of a
C
reaction, which strongly suggests the existence of
-hypernuclear bound states, is presented.
江川 弘行; 足利 沙希子; 長谷川 勝一; 橋本 直; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 金原 慎二*; 七村 拓野; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.021D02_1 - 021D02_11, 2019/02
被引用回数:23 パーセンタイル:83.91(Physics, Multidisciplinary)A double- hypernucleus,
, was observed by the J-PARC E07 collaborationin nuclear emulsions tagged by the
reaction. This event was interpreted as a production and decay of
,
, or
via
capture in
.By assuming the capture in the atomic 3D state, the binding energy of two
hyperons
(
)of these double-
hypernuclei are obtained to be
,
, and
, respectively. Based on the kinematic fitting,
is the most likely explanation for the observed event.
Yang, S. B.*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; 谷田 聖; et al.
Physical Review Letters, 120(13), p.132505_1 - 132505_5, 2018/03
被引用回数:8 パーセンタイル:55.82(Physics, Multidisciplinary)We report on the first observation of rays emitted from an
-shell hypernucleus,
F. The energy spacing between the ground state doublet,
and
states, of
F is determined to be
keV by measuring the
-ray energy of the
transition. In addition, three
-ray peaks are observed and assigned as
,
, and
transitions. The excitation energies of the
and
states are determined to be
keV and
keV, respectively. It is found that the ground state doublet spacing is well described by theoretical models based on existing
- and
-shell hypernuclear data.
後神 利志*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 今井 憲一; 市川 裕大; 七村 拓野; 成木 恵; 佐甲 博之; et al.
JPS Conference Proceedings (Internet), 18, p.011031_1 - 011031_6, 2017/11
The missing mass spectroscopy of hypernuclei is planned at the Japan Proton Accelerator Research Complex (J-PARC) by using the
reaction. We are constructing a new magnetic spectrometer, S-2S, which has a better momentum resolution [
(FHWM)] than that of an existing spectrometer (SKS) at J-PARC. S-2S would give us an opportunity to confirm the existence of
hypernuclei as a peak structure owing to both the high momentum resolution and its reasonably large solid angle. Brief descriptions of our experiment and of its preparation status are presentedin this article.
田村 裕和*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; Hwang, S.; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 17, p.011004_1 - 011004_11, 2017/07
The present status and future prospects of precision -ray spectroscopy of
hypernuclei are described. A new experiment (J-PARC E13) has been performed at the J-PARC K1.8 line employing a newly-developed germanium (Ge) detector array, Hyperball-J, via the
reaction on
He and
F targets. This is the first study of
-shell and
-shell
hypernuclei with Ge detectors. The
He target spectrum exhibited a
-ray peak of
at
MeV. Compared with the energy (
MeV) of the corresponding transition for the mirror hypernucleus,
, the present result clearly indicates a large charge symmetry breaking (CSB) effect. This decisive data for CSB allows a stringent test of baryon-baryon interaction models. As for the
F target run, a preliminary spectrum shows several
-ray peaks assigned to
transitions. Future plans of
-ray spectroscopy are also discussed.
中川 真菜美*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; Hwang, S.; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 17, p.012009_1 - 012009_4, 2017/07
One of the main items of the J-PARC E13 experiment is the search for excited states of the He hypernucleus via the
He
reaction at 1.5 GeV/c. The missing-mass spectrum of the
He
reaction was obtained in an angular range from 0 to 20 degrees. We show the count-base spectrum of the missing-mass in the angular range from 2 to 14 degrees. The ground state of
He and
He were clearly observed in the missing-mass spectrum. We also show three missing-mass spectra divided by the reaction angle.