Helicity amplitude analysis of χcJ→ ϕϕ Balossino, I.; Bettoni, D.; Chen, G. ...
The journal of high energy physics,
05/2023, Letnik:
2023, Številka:
5
Journal Article
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Odprti dostop
A
bstract
Using (447.9
±
2.3) million
ψ
(3686) events collected with the BESIII detector, the decays of
χ
cJ
→ ϕϕ
(
J
= 0
,
1
,
2) have been studied via the decay
ψ
(3686)
→ γχ
cJ
. The branching ...fractions of the decays
χ
cJ
→ ϕϕ
(
J
= 0
,
1
,
2) are determined to be (8
.
59 ± 0
.
27 ± 0
.
20) × 10
−
4
, (4
.
26 ± 0
.
13 ± 0
.
15) × 10
−
4
, and (12
.
67 ± 0
.
28 ± 0
.
33) × 10
−
4
, respectively, which are the most precise measurements to date. From a helicity amplitude analysis of the process
ψ
(3686)
→ γχ
cJ
, χ
cJ
→ ϕϕ, ϕ → K
+
K
−
, the polarization parameters of the
χ
cJ
→ ϕϕ
decays are determined for the first time.
A
bstract
Using a sample of (10
.
09
±
0
.
04)
×
10
9
J/ψ
decays collected with the BESIII detector, partial wave analyses of the decay
J
/
ψ
→
γ
K
S
0
K
S
0
π
0
are performed within the
K
S
0
K
S
0
...π
0
invariant mass region below 1.6 GeV/
c
2
. The covariant tensor amplitude method is used in both mass independent and mass dependent approaches. Both analysis approaches exhibit dominant pseudoscalar and axial vector components, and show good consistency for the other individual components. Furthermore, the mass dependent analysis reveals that the
K
S
0
K
S
0
π
0
invariant mass spectrum for the pseudoscalar component can be well described with two isoscalar resonant states using relativistic Breit-Wigner model, i.e., the
η
(1405) with a mass of
1391.7
±
0.7
−
0.3
+
11.3
MeV/
c
2
and a width of
60.8
±
1.2
−
12.0
+
5.5
MeV, and the
η
(1475) with a mass of
1507.6
±
1.6
−
32.2
+
15.5
MeV/
c
2
and a width of
115.8
±
2.4
−
10.9
+
14.8
MeV. The first and second uncertainties are statistical and systematic, respectively. Alternate models for the pseudoscalar component are also tested, but the description of the
K
S
0
K
S
0
π
0
invariant mass spectrum deteriorates significantly.
A
bstract
Using (448
.
1
±
2
.
9)
×
10
6
ψ
(3686) events collected with the BESIII detector at the BEPCII collider, the decay
ψ
(3686)
→
Σ
−
Σ
¯
+
is observed for the first time with a branching ...fraction of (2
.
82
±
0
.
04
stat
.
±
0
.
08
syst
.
)
×
10
−
4
, and the angular parameter
α
Σ
−
is measured to be 0
.
96
±
0
.
09
stat
.
±
0
.
03
syst
.
.
We present the results of the first IceCube search for dark matter annihilation in the center of the Earth. Weakly interacting massive particles (WIMPs), candidates for dark matter, can scatter off ...nuclei inside the Earth and fall below its escape velocity. Over time the captured WIMPs will be accumulated and may eventually self-annihilate. Among the annihilation products only neutrinos can escape from the center of the Earth. Large-scale neutrino telescopes, such as the cubic kilometer IceCube Neutrino Observatory located at the South Pole, can be used to search for such neutrino fluxes. Data from 327 days of detector livetime during 2011/2012 were analyzed. No excess beyond the expected background from atmospheric neutrinos was detected. The derived upper limits on the annihilation rate of WIMPs in the Earth and the resulting muon flux are an order of magnitude stronger than the limits of the last analysis performed with data from IceCube's predecessor AMANDA. The limits can be translated in terms of a spin-independent WIMP-nucleon cross section. For a WIMP mass of 50 GeV this analysis results in the most restrictive limits achieved with IceCube data.
Glyoxal (CHOCHO), the simplest dicarbonyl in the
troposphere, is a potential precursor for secondary organic aerosol (SOA)
and brown carbon (BrC) affecting air quality and climate. The airborne
...measurement of CHOCHO concentrations during the KORUS-AQ (KORea–US Air
Quality study) campaign in 2016 enables detailed quantification of loss
mechanisms pertaining to SOA formation in the real atmosphere. The
production of this molecule was mainly from oxidation of aromatics (59 %)
initiated by hydroxyl radical (OH). CHOCHO loss to aerosol was found to be
the most important removal path (69 %) and contributed to roughly
∼ 20 % (3.7 µg sm−3 ppmv−1 h−1,
normalized with excess CO) of SOA growth in the first 6 h in Seoul
Metropolitan Area. A reactive uptake coefficient (γ) of
∼ 0.008 best represents the loss of CHOCHO by surface uptake
during the campaign. To our knowledge, we show the first field observation
of aerosol surface-area-dependent (Asurf) CHOCHO uptake, which diverges
from the simple surface uptake assumption as Asurf increases in ambient
condition. Specifically, under the low (high) aerosol loading, the CHOCHO
effective uptake rate coefficient, keff,uptake, linearly increases
(levels off) with Asurf; thus, the irreversible surface uptake is a
reasonable (unreasonable) approximation for simulating CHOCHO loss to
aerosol. Dependence on photochemical impact and changes in the chemical and
physical aerosol properties “free water”, as well as aerosol viscosity,
are discussed as other possible factors influencing CHOCHO uptake rate. Our
inferred Henry's law coefficient of CHOCHO, 7.0×108 M atm−1, is ∼ 2 orders of magnitude higher than those
estimated from salting-in effects constrained by inorganic salts only
consistent with laboratory findings that show similar high partitioning into
water-soluble organics, which urges more understanding on CHOCHO solubility
under real atmospheric conditions.
To develop and validate a clinical risk score predictive of risk for colorectal advanced neoplasia for Asia.
A prospective, cross-sectional and multicentre study was carried out in tertiary hospitals ...in 11 Asian cities. The subjects comprise 2752 asymptomatic patients undergoing screening colonoscopy. From a development set of 860 asymptomatic subjects undergoing screening colonoscopy, multiple logistic regression was applied to identify significant risk factors for advanced colorectal neoplasia defined as invasive carcinoma or advanced adenoma. The ORs for significant risk factors were utilised to develop a risk score ranging from 0 to 7 (Asia-Pacific Colorectal Screening (APCS) score). Three tiers of risk were arbitrarily defined: 0-1 'average risk' (AR); 2-3 'moderate risk' (MR); and 4-7 'high risk' (HR). Subjects undergoing screening colonoscopy between July 2006 and December 2007 were prospectively enrolled to form an independent validation group. Each subject had a personal APCS score calculated by summing the points attributed from the presence of risk factors in the individuals. The performance of the APCS score in predicting risk of advanced neoplasia was evaluated.
There were 860 subjects in the derivation set and 1892 subjects in the validation set, with a baseline prevalence of advanced neoplasia of 4.5% and 3%, respectively. Applying the APCS stratification in the validation set, 559 subjects (29.5%) were in the AR tier, 966 subjects (51.1%) in the MR tier and 367 (19.4%) subjects in the HR tier. The prevalence of advanced neoplasia in the AR, MR and HR groups was 1.3, 3.2 and 5.2%, respectively. The subjects in the MR and HR tiers had 2.6-fold (95% CI 1.1 to 6.0) and 4.3-fold (95% CI 1.8 to 10.3) increased prevalence of advanced neoplasia, respectively, than those in the AR tier.
The APCS score based on age, gender, family history and smoking is useful in selecting asymptomatic Asian subjects for priority of colorectal screening.
The decay
D
→
K
-
π
+
is studied in a sample of quantum-correlated
D
D
¯
pairs, based on a data set corresponding to an integrated luminosity of 2.93 fb
-
1
collected at the
ψ
(
3770
)
resonance by ...the BESIII experiment. The asymmetry between
C
P
-odd and
C
P
-even eigenstate decays into
K
-
π
+
is determined to be
A
K
π
=
0.132
±
0.011
±
0.007
, where the first uncertainty is statistical and the second is systematic. This measurement is an update of an earlier study exploiting additional tagging modes, including several decay modes involving a
K
L
0
meson. The branching fractions of the
K
L
0
modes are determined as input to the analysis in a manner that is independent of any strong phase uncertainty. Using the predominantly
C
P
-even tag
D
→
π
+
π
-
π
0
and the ensemble of
C
P
-odd eigenstate tags, the observable
A
K
π
π
π
π
0
is measured to be
0.130
±
0.012
±
0.008
. The two asymmetries are sensitive to
r
D
K
π
cos
δ
D
K
π
, where
r
D
K
π
and
δ
D
K
π
are the ratio of amplitudes and phase difference, respectively, between the doubly Cabibbo-suppressed and Cabibbo-favoured decays. In addition, events containing
D
→
K
-
π
+
tagged by
D
→
K
S
,
L
0
π
+
π
-
are studied in bins of phase space of the three-body decays. This analysis has sensitivity to both
r
D
K
π
cos
δ
D
K
π
and
r
D
K
π
sin
δ
D
K
π
. A fit to
A
K
π
,
A
K
π
π
π
π
0
and the phase-space distribution of the
D
→
K
S
,
L
0
π
+
π
-
tags yields
δ
D
K
π
=
187.6
-
9.7
+
8.9
-
6.4
+
5.4
∘
, where external constraints are applied for
r
D
K
π
and other relevant parameters. This is the most precise measurement of
δ
D
K
π
in quantum-correlated
D
D
¯
decays.
A
bstract
With data samples collected with the BESIII detector at seven energy points at
s
= 3
.
68
−
3
.
71 GeV, corresponding to an integrated luminosity of 333 pb
−
1
, we present a study of the Λ ...transverse polarization in the
e
+
e
−
→
Λ
Λ
¯
reaction. The significance of polarization by combining the seven energy points is found to be 2.6
σ
including the systematic uncertainty, which implies a non-zero phase between the transition amplitudes of the
Λ
Λ
¯
helicity states. The modulus ratio and the relative phase of EM-
psionic
form factors combined with all energy points are measured to be
R
Ψ
=
0.71
−
0.10
+
0.10
±
0.03 and ∆Φ
Ψ
=
23
−
8.0
+
8.8
±
1.6
°
, where the first uncertainties are statistical and the second systematic.
A new receiver for the South Pole Telescope, SPT-3G, was deployed in early 2017 to map the cosmic microwave background at 95, 150, and 220 GHz with
∼
16,000 detectors, 10 times more than its ...predecessor SPTpol. The increase in detector count is made possible by lenslet-coupled trichroic polarization-sensitive pixels fabricated at Argonne National Laboratory, new 68
×
frequency-domain multiplexing readout electronics, and a higher-throughput optical design. The enhanced sensitivity of SPT-3G will enable a wide range of results including constraints on primordial B-mode polarization, measurements of gravitational lensing of the CMB, and a galaxy cluster survey. Here we present an overview of the instrument and its science objectives, highlighting its measured performance and plans for the upcoming 2018 observing season.
Current MRI with the CE T1-weighted sequence plays a limited role in the evaluation of facial neuritis due to prominent normal facial nerve enhancement. Our purpose was to retrospectively investigate ...the usefulness of the CE 3D-FLAIR sequence compared with the CE 3D-T1-FFE sequence in facial neuritis patients.
We assessed 36 consecutive patients who underwent temporal bone MR imaging at 3T for idiopathic facial palsy. Two readers independently reviewed CE 3D-T1-FFE and CE 3D-FLAIR images to determine the degree of enhancement in each of 5 segments of the facial nerve. We compared AUCs using the Z-test, compared diagnostic performance of 2 MR techniques with the McNemar test, and evaluated interobserver agreement. The Pearson χ(2) test was used for each segment of the facial nerve.
The AUC of CE 3D-FLAIR (reader 1, 0.754; reader 2, 0.746) was greater than that of CE 3D-T1-FFE (reader 1, 0.624; reader 2, 0.640; P < .001). The diagnostic sensitivities, specificities, and accuracies were 97.2%, 86.1%, and 91.7%, respectively, for CE 3D-FLAIR, and 100%, 56.9%, and 78.5%, respectively, for CE 3D-T1-FFE. The specificity and accuracy of CE 3D-FLAIR were greater than those of CE 3D-T1-FFE (specificity, P = .029; accuracy, P = .008). The interobserver agreements for CE 3D-FLAIR (κ-value, 0.831) and CE 3D-T1-FFE (κ-value, 0.694) were excellent. Enhancement of the canalicular and anterior genu segments on CE 3D-FLAIR were significantly correlated with the occurrence of facial neuritis (P < .001 for canalicular; P = .032 and 0.020 for anterior genu by reader 1 and reader 2, respectively).
CE 3D-FLAIR can improve the specificity and overall accuracy of MR imaging in patients with idiopathic facial palsy.
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