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Yang, S.*; 谷田 聖; Belle Collaboration*; 他196名*
Physical Review D, 108(3), p.L031104_1 - L031104_6, 2023/08
被引用回数:3 パーセンタイル:46.51(Astronomy & Astrophysics)We observe a narrow peaking structure in the invariant-mass spectrum near the
threshold. The peak is clearly seen in 1.5 million events of
decay using the
data sample collected by the Belle detector at the KEKB asymmetric-energy
collider. We try two approaches to explain this structure: as a new resonance and as a cusp at the
threshold. The best fit is obtained with a coherent sum of a Flatt
function and a constant background amplitude with the
(
), while the fits to Breit-Wigner functions are unfavored by more than 7
. The best fit explains the structure as a cusp at the
threshold, and the obtained parameters are consistent with the known properties of
. The observation gives the first identification of a threshold cusp in hadrons from the spectrum shape.
Abudinn, F.*; 谷田 聖; Belle II Collaboration*; 他413名*
Physical Review D, 107(7), p.072002_1 - 072002_24, 2023/04
被引用回数:9 パーセンタイル:77.72(Astronomy & Astrophysics)We present measurements of the first to fourth moments of the lepton mass squared of
decays for
and with
a hadronic system containing a charm quark. These results use a sample of electron-positron collisions at the
resonance corresponding to
of integrated luminosity and collected by the Belle II experiment in 2019 and 2020. To identify the
system and reconstruct
, one of the
mesons from an
decay is fully reconstructed in a hadronic decay mode using a multivariate
tagging algorithm. We report raw and central moments for
up to
, probing up to 77% of the accessible
phase space. This is the first measurement of moments in the experimentally challenging range of
.
Yin, J. H.*; 谷田 聖; Belle Collaboration*; 他193名*
Physical Review D, 107(5), p.052004_1 - 052004_8, 2023/03
被引用回数:3 パーセンタイル:46.51(Astronomy & Astrophysics)We present a search for the decay in the
data sample collected at the Belle detector, where the
is produced in
and
decays. We do not observe a signal, and set 90% credible upper limits for two different models of the decay processes: if the decay products are distributed uniformly in phase space,
; if
is concentrated near the mass of the
pair in the process
,
.
Tang, S. S.*; 谷田 聖; Belle Collaboration*; 他173名*
Physical Review D, 107(3), p.032005_1 - 032005_6, 2023/02
被引用回数:2 パーセンタイル:34.85(Astronomy & Astrophysics)Based on a data sample of 983 fb collected with the Belle detector at the KEKB asymmetric-energy
collider, we present the study of the heavy-flavor-conserving decay
with
reconstructed via its
decay mode. The branching fraction ratio
is measured to be
. Combing with the world average value of
, the branching fraction
is deduced to be
. Here, the uncertainties above are statistical, systematic, and from
, respectively.
Li, Y.*; 谷田 聖; Belle Collaboration*; 他187名*
Physical Review D, 107(3), p.032001_1 - 032001_11, 2023/02
被引用回数:1 パーセンタイル:19.69(Astronomy & Astrophysics)We present the first search for the weak radiative decays and
using a data sample of 980~fb
collected by the Belle detector operating at the KEKB asymmetric-energy
collider. There are no evident
or
signals. Taking the decays
and
as normalization channels, the upper limits at 90% credibility level on the ratios of branching fractions
and
are determined. We obtain the upper limits at 90% credibility level on the absolute branching fractions
and
.
Li, L. K.*; 谷田 聖; Belle Collaboration*; 他197名*
Physical Review D, 107(3), p.033003_1 - 033003_9, 2023/02
被引用回数:0 パーセンタイル:0.00(Astronomy & Astrophysics)We present measurements of the branching fractions for the singly Cabibbo-suppressed decays and
, and the doubly Cabibbo-suppressed decay
, based on 980
of data recorded by the Belle experiment at the KEKB
collider. We measure these modes relative to the Cabibbo-favored modes
and
. Our results for the ratios of branching fractions are
,
, and
, where the uncertainties are statistical and systematic, respectively. The second value corresponds to
, where
is the Cabibbo angle; this value is larger than other measured ratios of branching fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored decay. Multiplying these results by world average values for
and
yields
,
, and
, where the third uncertainty is due to the branching fraction of the normalization mode. The first two results are consistent with, but more precise than, the current world averages. The last result is the first measurement of this branching fraction.
Choudhury, S.*; 谷田 聖; Belle Collaboration*; 他198名*
Physical Review D, 107(3), p.L031102_1 - L031102_6, 2023/02
被引用回数:8 パーセンタイル:77.72(Astronomy & Astrophysics)We measure the ratio of branching fractions for the decays to
and
using
and
samples, where
stands for
(
or
), with
fb
of data collected at the
resonance with the Belle detector. We find the decay rate ratio of
over
to be
, which is the most precise measurement to date. The first and second uncertainties are statistical and systematic, respectively, and the third uncertainty is systematic due to the assumption of isospin symmetry in
.
Li, L. K.*; 谷田 聖; Belle Collaboration*; 他204名*
Physical Review D, 107(3), p.032004_1 - 032004_9, 2023/02
被引用回数:4 パーセンタイル:55.83(Astronomy & Astrophysics)We present a study of a singly Cabibbo-suppressed decay and a Cabibbo-favored decay
based on 980
of data collected by the Belle detector, operating at the KEKB energy-asymmetric
collider. We measure their branching fractions relative to
:
and
. Combining with the world average
, we have the absolute branching fractions:
and
. The first and second uncertainties are statistical and systematic, respectively, while the third ones arise from the uncertainty on
. The mode
is observed for the first time and has a statistical significance of
. The branching fraction of
has been measured with a threefold improvement in precision over previous results and is found to be consistent with the world average.
Han, X.*; 谷田 聖; Belle Collaboration*; 他170名*
Journal of High Energy Physics (Internet), 2023(1), p.55_1 - 55_12, 2023/01
被引用回数:3 パーセンタイル:34.85(Physics, Particles & Fields)Using a data sample of 980 fb collected with the Belle detector at the KEKB asymmetric-energy
collider, we study for the first time the singly Cabibbo-suppressed decays
and
and the doubly Cabibbo-suppressed decay
. Evidence for an
signal in the
mode is reported with a significance of
including systematic uncertainties. The ratio of branching fractions to the normalization mode
is measured to be
No significant signals of
and
modes are found. The upper limits at
confidence level on ratios of branching fractions are determined to be
and
Zhu, W. J.*; 谷田 聖; Belle Collaboration*; 他174名*
Physical Review D, 107(1), p.012006_1 - 012006_10, 2023/01
被引用回数:2 パーセンタイル:34.85(Astronomy & Astrophysics)Using of data collected on and around the
resonances with the Belle detector at the KEKB collider, we measure the cross section of
from threshold to
via initial-state radiation. From a multi-parameter fit assuming
exists in the
final state according to previous measurement by BESIII, the resonant parameters of
are determined to be
(statistical and systematic errors, respectively),
and, depending on the possible presence of interfering resonances,
,
,
or
. The branching fraction of
decay is determined to be approximately 20%. Additionally, the branching fraction for
is measured to be
. However, there is no significant observed
signal in the
final states in this analysis, and correspondingly the upper limit for
is determined to be either
(for two fits), or
(remaining two fits), at 90% confidence level.
Krohn, J.-F.*; 谷田 聖; Belle Collaboration*; 他198名*
Physical Review D, 107(1), p.012003_1 - 012003_12, 2023/01
被引用回数:1 パーセンタイル:19.69(Astronomy & Astrophysics)Using
meson pairs recorded by the Belle experiment at the KEKB
collider, we report the branching fractions
and
; the quoted uncertainties are statistical and systematic, respectively. A measurement of the ratio of these branching fractions is also presented,
, where systematic uncertainties due to the
meson reconstruction cancel out. Furthermore, we report a new QCD factorization test based on the measured ratios for
and
decays at squared momentum transfer values equivalent to the mass of the
or
hadron. The parameters
are measured to be
and
, where the last uncertainties account for all external inputs. These values are approximately
lower than those expected from theoretical predictions. Subsequently, flavor
symmetry is tested by measuring the ratios for pions and kaons,
, as well as for different particle species. The ratio is consistent with unity and therefore no evidence for
symmetry breaking effects is found at the
precision level.
Li, Y. B.*; 谷田 聖; Belle Collaboration*; 他194名*
Physical Review Letters, 130(3), p.031901_1 - 031901_7, 2023/01
被引用回数:15 パーセンタイル:91.25(Physics, Multidisciplinary)We present the study of decays based on
events collected with the Belle detector at the KEKB asymmetric-energy
collider. The
candidates are reconstructed via their decay to
and
decays to
and
final states. The corresponding branching fractions are measured to be
and
, which are consistent with the world average values with improved precision. A new structure is found in the
spectrum with a significance of
including systematic uncertainty. The structure is possibly an excited
and is tentatively named
. Its mass and width are measured to be
MeV/
and
MeV, respectively. The products of branching fractions for the
are measured to be
and
. Here, the first and second uncertainties are statistical and systematic, respectively.
Pang, T.*; 谷田 聖; Belle Collaboration*; 他206名*
Physical Review D, 106(5), p.L051103_1 - L051103_8, 2022/09
被引用回数:0 パーセンタイル:0.00(Astronomy & Astrophysics)We report the results of the first search for the decay using
of data collected at the
resonance with the Belle detector at the KEKB asymmetric-energy
collider. We observe no signal and set a 90% confidence-level upper limit of
on the
branching fraction.
Czank, T.*; 谷田 聖; Belle Collaboration*; 他209名*
Physical Review D, 106(1), p.012003_1 - 012003_10, 2022/07
被引用回数:10 パーセンタイル:62.02(Astronomy & Astrophysics)We search for a new gauge boson that couples only to heavy leptons and their corresponding neutrinos in the process
, using a 643 fb
data sample collected by the Belle experiment at or near the
resonances at the KEKB collider. For the first time, effects due to initial state radiation are used in estimating the detection efficiency. No signal is observed in the mass range of 0.212
and we set an upper limit on the coupling strength,
, constraining
as a possible contributor to the anomalous magnetic dipole moment of muon.
Jeon, H. B.*; 谷田 聖; Belle Collaboration*; 他219名*
Physical Review D, 106(1), p.012006_1 - 012006_9, 2022/07
被引用回数:0 パーセンタイル:0.00(Astronomy & Astrophysics)We report the first search for the penguin-dominated process using the full data sample of
pairs collected with the Belle detector at the KEKB asymmetric-energy
collider. We do not observe any statistically significant signal yield in the
-pair invariant mass range 1 GeV/
3 GeV/
, and set the following upper limits at 90% confidence level:
,
, and
. Further, 90% confidence upper limits have also been set in the range of [0.7-2.9]
on the
branching fraction in bins of
.
Patra, S.*; 谷田 聖; Belle Collaboration*; 他216名*
Journal of High Energy Physics (Internet), 2022(5), p.95_1 - 95_17, 2022/05
被引用回数:7 パーセンタイル:57.73(Physics, Particles & Fields)We present a search for the charged lepton-flavor-violating decays and radiative charged lepton-flavour-violating decays
[
] using the 158 million
sample collected by the Belle detector at the KEKB collider. This search uses
mesons produced in
transitions. We do not find any significant signal, so we provide upper limits on the branching fractions at the 90% confidence level.
Li, Y. B.*; 谷田 聖; Belle Collaboration*; 他203名*
Physical Review D, 105(9), p.L091101_1 - L091101_7, 2022/05
被引用回数:12 パーセンタイル:72.70(Astronomy & Astrophysics)We present the first observation of the decay and present measurements of the branching fraction ratios of the
decays compared to the reference mode
, (
or
). This analysis is based on 89.5 fb
, 711 fb
, and 121.1 fb
data samples collected with the Belle detector at the KEKB asymmetric-energy
collider at the center-of-mass energies of 10.52 GeV, 10.58 GeV, and 10.86 GeV, respectively. The
signal yields are extracted by fitting
and
spectra. The branching fraction ratios
and
are measured to be
and
, respectively. The ratio of
is measured to be
, which is consistent with the expectation of lepton flavor universality.
居波 賢二*; 谷田 聖; Belle Collaboration*; 他186名*
Journal of High Energy Physics (Internet), 2022(4), p.110_1 - 110_13, 2022/04
被引用回数:12 パーセンタイル:75.32(Physics, Particles & Fields)We report a measurement of the electric dipole moment of the lepton (
) using an 833~fb
data sample collected near the
resonance, with the Belle detector at the KEKB asymmetric-energy
collider. Using an optimal observable method, we obtain the real and imaginary parts of
as
and
, respectively. These results are consistent with null electric dipole moment at the present level of experimental sensitivity and improve the sensitivity by about a factor of three.
Bloomfield, T.*; 谷田 聖; Belle Collaboration*; 他212名*
Physical Review D, 105(7), p.072007_1 - 072007_13, 2022/04
被引用回数:3 パーセンタイル:31.14(Astronomy & Astrophysics)We measure the branching fractions and asymmetries for the decays
and
, using a data sample of
pairs collected at the
resonance with the Belle detector at the KEKB
collider. The branching fractions obtained and direct
asymmetries are
,
,
, and
. The measurements of
are the most precise to date and are in good agreement with previous results, as is the measurement of
. The measurement of
for
is the first for this mode, and the value is consistent with Standard Model expectations.
Chen, Y.-C.*; 谷田 聖; Belle Collaboration*; 他175名*
Physical Review Letters, 128(14), p.142005_1 - 142005_8, 2022/04
被引用回数:3 パーセンタイル:40.77(Physics, Multidisciplinary)The measurement of two-particle angular correlation functions in high-multiplicity collisions at
GeV is reported. In this study, the
of hadronic
annihilation data collected by the Belle detector at KEKB are used. Two-particle angular correlation functions are measured in the full relative azimuthal angle (
) and three units of pseudorapidity (
), defined by either the electron beam axis or the event-shape thrust axis, and are studied as a function of charged-particle multiplicity. The measurement in the thrust axis analysis, with mostly outgoing quark pairs determining the reference axis, is sensitive to the region of additional soft gluon emissions. No significant anisotropic collective behavior is observed with either coordinate analyses. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various event generators and are expected to provide new constraints to the phenomenological models in the low-energy regime.