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谷田 聖; Belle Collaboration*
Hadron Spectroscopy and Structure; Proceedings of the 18th International Conference (HADRON 2019), p.183 - 187, 2020/08
(or
) is the lightest charm baryon of which presumable identification by quark models is not known. Currently, its properties are poorly known:
and isospin are not determined and no uncertainty is given in the width measurement. With 980 fb
collision data collected with Belle detector, we perform the determination of quantum number. In this presentation, detail and result of the analysis are presented. We also report recent measurements on other charmed baryons at Belle.
Chilikin, K.*; 谷田 聖; Belle Collaboration*; 他194名*
Journal of High Energy Physics (Internet), 2020(5), p.34_1 - 34_22, 2020/05
被引用回数:2 パーセンタイル:15.20(Physics, Particles & Fields)The first dedicated search for the is carried out using the decays
,
,
, and
with
. No significant signal is found. For the
mass range between
and
, the branching-fraction upper limits are determined to be
,
,
, and
at 90% C. L. The analysis is based on the 711
data sample collected on the
resonance by the Belle detector, which operated at the KEKB asymmetric-energy
collider.
Arifi, A. J.*; 永廣 秀子*; 保坂 淳; 谷田 聖
Physical Review D, 101(9), p.094023_1 - 094023_17, 2020/05
被引用回数:11 パーセンタイル:60.41(Astronomy & Astrophysics)We study three-body decays of by using effective Lagrangians in a non-relativistic framework. We consider the sequential decays through
and
in intermediate states which are dominant contributions. The coupling constants in the effective Lagrangians are computed in the quark model. We demonstrate that the ratio
and angular correlations are sensitive to the spin and parity of
. Thus, the measurement of these observables in experimental facilities such as Belle and LHCb can provide useful constraints to determine the spin and parity of
.
Jia, S.*; 谷田 聖; Belle Collaboration*; 他175名*
Physical Review D, 101(9), p.091101_1 - 091101_8, 2020/05
被引用回数:11 パーセンタイル:60.41(Astronomy & Astrophysics)We report the measurement of via initial-state radiation using a data sample of an integrated luminosity of 921.9 fb
collected with the Belle detector at the
and nearby. We find evidence for an enhancement with a 3.4
significance in the invariant mass of
The measured mass and width are
and
, respectively. The mass, width, and quantum numbers of this enhancement are consistent with the charmonium-like state at 4626 MeV/
recently reported by Belle in
The product of the
cross section and the branching fraction of
is measured from
threshold to 5.6 GeV.
Katrenko, P.*; 谷田 聖; Belle Collaboration*; 他168名*
Physical Review Letters, 124(12), p.122001_1 - 122001_7, 2020/03
被引用回数:2 パーセンタイル:21.38(Physics, Multidisciplinary)We report the first observation of the radiative decay of the into a charmonium state. The statistical significance of the observed signal of
is 6.3 standard deviations including systematics. The branching fraction is calculated to be Br(
) =
. We also searched for
radiative decays into
and
and set upper limits on their branching fractions. These results are obtained from a 24.9 fb
data sample collected with the Belle detector at the KEKB asymmetric-energy
collider at a center-of-mass energy equal to the
mass using
tagging by the
transitions.
Jia, S.*; 谷田 聖; Belle Collaboration*; 他172名*
Physical Review D, 100(11), p.111103_1 - 111103_8, 2019/12
被引用回数:25 パーセンタイル:79.46(Astronomy & Astrophysics)Using a data sample of 921.9 fb collected with the Belle detector, we study the process of
via initial-state radiation. We report the first observation of a vector charmoniumlike state decaying to
with a significance of 5.9
, including the systematic uncertainties. The measured mass and width are
and
, respectively. The product of the
cross section and the branching fraction of
is measured from the
threshold to 5.59 GeV.
川崎 新吾*; 橋本 直; 谷田 聖; 他72名*
JPS Conference Proceedings (Internet), 26, p.022009_1 - 022009_5, 2019/11
The spectral shape of the baryon was measured via the in-flight
reaction at the J-PARC K1.8BR beam-line (J-PARC E31). The second E31 physics run was carried out in January and February, 2018. Approximately
kaons were irradiated on the deuteron target. The missing mass spectrum for the
where the residual final-state particles were
and
(
"
" spectrum) was measured for the first time.
小松 雄哉*; 市川 裕大; 成木 恵*; 谷田 聖; 他24名*
JPS Conference Proceedings (Internet), 26, p.022029_1 - 022029_4, 2019/11
A di-quark correlation has been proposed to describe the internal structure of hadrons, especially those of exotic ones. Nevertheless it lacks a conclusive experimental evidence. The J-PARC E50 experiment performs charmed baryon spectroscopy at J-PARC high-momentum beam line to investigate the role of di-quark correlations in baryons. The energy levels of the excited sates are measured by a missing-mass technique for the first time, and the production rates and decay branching ratios are also measured.
Mizuk, R.*; 谷田 聖; Belle Collaboration*; 他181名*
Journal of High Energy Physics (Internet), 2019(10), p.220_1 - 220_26, 2019/10
被引用回数:31 パーセンタイル:84.46(Physics, Particles & Fields)We report a new measurement of the (
) cross sections at energies from 10.52 to 11.02 GeV using data collected with the Belle detector at the KEKB asymmetric-energy
collider. We observe a new structure in the energy dependence of the cross sections; if described by a Breit-Wigner function its mass and width are found to be
MeV/
and
MeV, where the first error is statistical and the second is systematic. The global significance of the new structure that includes a systematic uncertainty is 6.7 standard deviations. We also find evidence for the
process at the energy 10.52 GeV, which is below the
threshold.
Jia, S.*; 谷田 聖; Belle Collaboration*; 他193名*
Physical Review D, 100(3), p.032006_1 - 032006_11, 2019/08
被引用回数:21 パーセンタイル:74.46(Astronomy & Astrophysics)Using data samples of collisions collected at the
,
, and
resonances with the Belle detector, we search for the three-body decay of the
baryon to
. This decay is predicted to dominate for models describing the
as a
molecule. No significant
signals are observed in the studied channels, and 90% credibility level upper limits on the ratios of the branching fractions relative to
decay modes are obtained.
谷田 聖
Proceedings of Science (Internet), 346, p.118_1 - 118_6, 2019/08
The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric collider. The accelerator has already successfully completed the first phase of commissioning in 2016 and first electron positron collisions in Belle II were obtained on April 26, 2018. The design luminosity of SuperKEKB is
cm
s
and the Belle II experiment aims to record 50 ab
of data, a factor of 50 more than the Belle experiment. In this talk, we will explain the idea of a hyperon spin structure study using heavy quark decays: In weak decays of heavy quarks, the daughter quarks are highly polarized. On the other hand, one can naively expect that the fraction of the baryon spin carried by a quark is equal to the polarization transfer of the quark to the baryon. In this way, one can experimentally determine the spin structures of hyperons in decays of heavy quarks. Spin structures of ground state hyperons (i.e.,
and
) are interesting in the context of the proton spin structure puzzle. In addition, excited states can be also studied to identify exotic hyperons. Especially in
, a two pole structure may be seen as a mass dependence of the polarization.
谷田 聖
AIP Conference Proceedings 2130, p.040019_1 - 040019_6, 2019/07
被引用回数:2 パーセンタイル:72.56(Physics, Nuclear)Evidence for a narrow resonance at a mass of about 1665 MeV (just above the combined mass of the
ground state plus the
meson) has been seen in the
mass of the Dalitz plot for
decay at the Belle experiment. Additional evidence for this resonance is found in the partial-wave analysis (PWA) of data on
reactions done independently by several groups, driven by angular distributions of the
reaction by the Crystal Ball collaboration. If a narrow
resonance exists at this mass, then the conventional quark model cannot explain it, and a possible explanation is that it is a crypto-exotic baryon with a dominant meson-baryon component to its wave function. Therefore we have proposed a definitive experiment for
, using the newly built hypTPC detector to establish the existence of the proposed narrow
and determine its spin and parity in just two weeks of beamtime at J-PARC (E72). We will discuss these evidences for the proposed
resonance and introduce the E72 experiment.
谷田 聖
AIP Conference Proceedings 2130, p.040020_1 - 040020_6, 2019/07
被引用回数:1 パーセンタイル:51.67(Physics, Nuclear)The Belle II experiment, now operating at the KEK laboratory in Japan, is a substantial upgrade of both the Belle detector and the KEKB accelerator. It aims to collect 50 times more data than existing B-Factory samples. Belle II is uniquely capable to study the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks. First discovered by Belle, these now number in the dozens, and represent the emergence of a new category within quantum chromodynamics. This talk will present the capabilities of Belle II to explore both exotic and conventional quarkonium physics.
浅野 秀光*; 橋本 直; 谷田 聖; 他72名*
AIP Conference Proceedings 2130, p.040018_1 - 040018_6, 2019/07
被引用回数:3 パーセンタイル:81.79(Physics, Nuclear)The structure of the hyperon is an important and long-standing issue related to the
-nucleus interaction. The J-PARC E31 experiment has been performed to investigate the
spectrum shape. Because it is hard to form the
directly by a
scattering in free space, E31 uses the
reaction with an incident kaon momentum of 1 GeV/
. We will identify three final states -
,
,
so that the isospin structure of hyperon resonance states produced can be decomposed. The first physics run of the E31 experiment was performed in 2016. To enhance the statistics of the data set, we have performed the second physics run in the beginning of 2018. During the second run of E31, around
kaons impacted on the deuteron target.
岩崎 幸生; 岡 眞; 鈴木 渓*; 吉田 哲也*
International Journal of Modern Physics; Conference Series (Internet), 49, p.1960002_1 - 1960002_6, 2019/07
被引用回数:0 パーセンタイル:0.09(Astronomy & Astrophysics)P波のチャーモニウムメソンに強い磁場がかかったときにスペクトルおよび波動関数がどのように変化するかを磁場の強さの関数として解析した。
Chou, P.-C.*; 谷田 聖; Belle Collaboration*; 他192名*
Physical Review D, 100(1), p.012002_1 - 012002_8, 2019/07
被引用回数:1 パーセンタイル:7.56(Astronomy & Astrophysics)We report the results of a search for the decay . The analysis is performed on a data sample corresponding to an integrated luminosity of
and containing
pairs, collected with the Belle detector at the KEKB asymmetric-energy
collider running at the
resonance energy. We find no evidence for a signal and place an upper limit of
at 90% confidence level.
Bhardwaj, V.*; 谷田 聖; Belle Collaboration*; 他191名*
Physical Review D, 99(11), p.111101_1 - 111101_8, 2019/06
被引用回数:8 パーセンタイル:43.72(Astronomy & Astrophysics)We report a search for and
in
decays. We set an upper limit of
and
at 90% confidence level. We also measure
at 90% confidence level. The results reported here are obtained from
events collected at the
resonance with the Belle detector at the KEKB asymmetric-energy
collider.
Garg, R.*; 谷田 聖; Belle Collaboration*; 他172名*
Physical Review D, 99(7), p.071102_1 - 071102_8, 2019/04
被引用回数:3 パーセンタイル:19.39(Astronomy & Astrophysics)We report the results of a search for the decays. This study is based on a data sample corresponding to an integrated luminosity of 711 fb
, collected at the
resonance with the Belle detector at the KEKB asymmetric-energy
collider. We investigate the
invariant mass distribution in the range 4.0 to 4.6 GeV/
using both
and
decays. We find excesses of events above the background levels, with a significances of 2.1 and 0.9 standard deviations for charged and neutral
decays, respectively, taking into account the systematic uncertainties. These correspond to upper limits on the product of branching fractions,
and
at the 90% confidence level.
岩崎 幸生; 岡 眞; 鈴木 渓*; 吉田 哲也*
Physics Letters B, 790, p.71 - 76, 2019/03
被引用回数:11 パーセンタイル:73.49(Astronomy & Astrophysics)ヘビークォークを含むメソンに強い磁場がかかったときにスペクトルおよび波動関数がどのように変化するかを磁場の強さの関数として解析した。
住浜 水季*; 谷田 聖; Belle Collaboration*; 他184名*
Physical Review Letters, 122(7), p.072501_1 - 072501_7, 2019/02
被引用回数:22 パーセンタイル:80.67(Physics, Multidisciplinary)We report the first observation of the doubly-strange baryon in its decay to
via
decays based on a
data sample collected with the Belle detector at the KEKB asymmetric-energy
collider. The mass and width are measured to be 1610.4
6.0 (stat)
(syst) MeV
and 59.9
4.8 (stat)
(syst) MeV, respectively. We obtain 4.0
evidence of the
with the same data sample. These results shed light on the structure of hyperon resonances with strangeness
.