Study of η′ → π+π−l+l− decays at BESIII Ai, X. C.; Bakina, O.; Balossino, I. ...
The journal of high energy physics,
16/7, Letnik:
2024, Številka:
7
Journal Article
Recenzirano
Odprti dostop
A
bstract
With a sample of (10087
±
44)
×
10
6
J/ψ
events accumulated with the BESIII detector, we analyze the decays
η
′
→ π
+
π
−
l
+
l
−
(
l
=
e, μ
) via the process
J/ψ → γη
′. The branching ...fractions are measured to be
B
(
η
′
→ π
+
π
−
e
+
e
−
) = (2
.
45
±
0
.
02(stat
.
)
±
0
.
08(syst
.
))
×
10
−
3
and
B
(
η
′
→ π
+
π
−
μ
+
μ
−
) = (2
.
16
±
0
.
12(stat
.
)
±
0
.
06(syst
.
))
×
10
−
5
, and the ratio is
B
η
′
→
π
+
π
−
e
+
e
−
B
η
′
→
π
+
π
−
μ
+
μ
−
=
113.4
±
0.9
stat
.
±
3.7
syst
.
. In addition, by combining the
η
′ →
π
+
π
−
e
+
e
−
and
η
′ →
π
+
π
−
μ
+
μ
−
decays, the slope parameter of the electromagnetic transition form factor is measured to be
b
η
′
= 1.30 ± 0.19 (GeV
/c
2
)
−
2
, which is consistent with previous measurements from BESIII and theoretical predictions from the VMD model. The asymmetry in the angle between the
π
+
π
−
and
l
+
l
−
decay planes, which has the potential to reveal the
CP
-violation originating from an unconventional electric dipole transition, is also investigated. The asymmetry parameters are determined to be
A
CP
η
′
→
π
+
π
−
e
+
e
−
=
−
0.21
±
0.73
stat
.
±
0.01
syst
.
%
and
A
CP
η
′
→
π
+
π
−
μ
+
μ
−
=
0.62
±
4.71
stat
.
±
0.08
syst
.
%
, implying that no evidence of
CP
-violation is observed at the present statistics. Finally, an axion-like particle is searched for via the decay
η
′ →
π
+
π
−
a, a
→
e
+
e
−
, and upper limits of the branching fractions are presented for the mass assumptions of the axion-like particle in the range of 0
−
500 MeV
/c
2
.
A
bstract
Using 24.1 fb
−
1
of
e
+
e
−
collision data collected with the BESIII detector at the BEPCII collider, the Born cross sections and effective form factors of the
e
+
e
−
→
Σ
+
Σ
¯
−
reaction ...are measured. The measurements are performed at center-of-mass energies ranging from 3.510 to 4.951 GeV. No significant evidence for the decay of the charmonium(-like) states,
ψ
(3770),
ψ
(4040),
ψ
(4160),
Y
(4230),
Y
(4360),
ψ
(4415), and
Y
(4660), into a
Σ
+
Σ
¯
−
final state is observed. Consequently, upper limits for the products of the branching fractions and the electronic partial widths at the 90% confidence level are reported for these decays.
Based on the analysis of the electronic structures of Y2O3 doped graphene/Cu interface, experiments are designed to apply Y element to modify graphene/Cu interface and strengthening effects of Y ...modification are analyzed.
Display omitted
•Trace Y-element decoration at the graphene/Cu interface is realized.•Y modification effects on the graphene/Cu interface interaction are explored.•Prepared composites achieve high strength, high ductility and good electrical conductivity.
We investigated the atomic and electronic structures and interface interaction of graphene/copper interface with rare earth elements (REEs) modified using density functional theory. The effect of interface interaction enhancement induced by interfacial modification is revealed, which results in significant improvement of the mechanical properties of graphene/copper. Thereby, we applied a novel strategy to incorporate Y element at the interface of graphene nanoplatelets/copper (GNPs/Cu) to improve mechanical properties of composites. Tensile tests demonstrated that the yield strength of composites increases by 95.4% via very low fraction (0.2 wt%) of Y modification with elongation comparable to Cu, which exhibits excellent matched relationship between strength and ductility. Simultaneously, the composite equips with improved electrical conductivity compared with that of the matrix. We illustrated the strengthening effects of REEs modification at the interface that give rise to the effective load transfer, in consistence with the theoretical predication. Furthermore, the GNPs/Cu composites with the interface Ce/Sc elements modified were also fabricated, both of which showed excellent strength-ductility combination. Therefore, the universality of the present method is verified for the preparation of metal matrix composites with excellent mechanical properties through interface modification with REEs.
A
bstract
Using
e
+
e
−
collision data corresponding to a total integrated luminosity of 12.9 fb
−
1
collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and ...the effective form factors of the reaction
e
+
e
−
→
Ξ
−
Ξ
¯
+
are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay
ψ
3770
→
Ξ
−
Ξ
¯
+
is observed with a significance of 4.5
σ
by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states
ψ
(4040),
ψ
(4160),
Y
(4230),
Y
(4360),
ψ
(4415), and
Y
(4660), no significant signal of their decay to
Ξ
−
Ξ
¯
+
is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.
•A pricing model is proposed to describe pricing mechanism in cloud manufacturing.•Classification of metrics is presented to measure the value formation of a service.•A parametric pricing approach is ...proposed to predict the price by pricing factors.•An ACO-based SVR ensemble is developed to improve the generalization performance.
In a cloud manufacturing environment, deviation of a service price from its value and cost makes on-demand price forecasting a challenging task for the service providers. The main objective of this paper is to present taxonomy of Value Measures and Metrics (VMMs) for pricing decisions over the product life cycle, e.g. the design, manufacturing, and service stages. Furthermore, a parametric pricing approach is proposed to formulate pricing variables, which represent pricing factors and are calculated in terms of VMMs, as well as a regression relation between the pricing variables and price. An Ant Colony Optimization Algorithm (ACO)-based Support Vector Regression (SVR) ensemble is developed to forecast a price. We demonstrate the effectiveness of the proposed methodology with the real-world data of an organization in China. The experimental results show that the proposed method achieves significant generalization performance with the best mean squared error (MSE) and reliable results in randomness of ensemble learning. Thus, the proposed pricing method provides a way to make viable prices for service providers.
The microRNA miR-125b is dysregulated in various human cancers but its underlying mechanisms of action are poorly understood. Here, we report that miR-125b is downregulated in invasive breast cancers ...where it predicts poor patient survival. Hypermethylation of the miR-125b promoter partially accounted for reduction of miR-125b expression in human breast cancer. Ectopic restoration of miR-125b expression in breast cancer cells suppressed proliferation, induced G(1) cell-cycle arrest in vitro, and inhibited tumorigenesis in vivo. We identified the ETS1 gene as a novel direct target of miR-125b. siRNA-mediated ETS1 knockdown phenocopied the effect of miR-125b in breast cell lines and ETS1 overexpression in invasive breast cancer tissues also correlated with poor patient prognosis. Taken together, our findings point to an important role for miR-125b in the molecular etiology of invasive breast cancer, and they suggest miR-125b as a potential theranostic tool in this disease.
In this paper, we present a semi-coupled theory to compute the temperature variation due to the tide-generating force. The tidal volume strain is first derived in a pure elastic homogeneous sphere, ...in terms of the classic Love’s solution. Then the temperature variation is obtained by solving the inhomogeneous heat conduction equation by considering both the isothermal and adiabatic conditions on the surface. The results show that the magnitude of the tidal temperature variation can be more than 1 mK, which is detectable by the current precision thermometer.
In order to accelerate the tendon-bone healing processes and achieve the efficient osteointegration between the tendon graft and bone tunnel, we aim to design bioactive electrospun nanofiber ...membranes combined with tendon stem/progenitor cells (TSPCs) to promote osteogenic regeneration of the tendon and bone interface.
In this study, nanofiber membranes of polycaprolactone (PCL), PCL/collagen I (COL-1) hybrid nanofiber membranes, poly(dopamine) (PDA)-coated PCL nanofiber membranes and PDA-coated PCL/COL-1 hybrid nanofiber membranes were successfully fabricated by electrospinning. The biochemical characteristics and nanofibrous morphology of the membranes, as well as the characterization of rat TSPCs, were defined in vitro. After co-culture with different types of electrospun nanofiber membranes in vitro, cell proliferation, viability, adhesion and osteogenic differentiation of TSPCs were evaluated at different time points.
Among all the membranes, the performance of the PCL/COL-1 (volume ratio: 2:1 v/v) group was superior in terms of its ability to support the adhesion, proliferation, and osteogenic differentiation of TSPCs. No benefit was found in this study to include PDA coating on cell adhesion, proliferation and osteogenic differentiation of TSPCs.
The PCL/COL-1 hybrid electrospun nanofiber membranes are biocompatible, biomimetic, easily fabricated, and are capable of supporting cell adhesion, proliferation, and osteogenic differentiation of TSPCs. These bioactive electrospun nanofiber membranes may act as a suitable functional biomimetic scaffold in tendon-bone tissue engineering applications to enhance tendon-bone healing abilities.
A
bstract
Using
e
+
e
−
collision data collected with the BESIII detector at the BEPCII collider at center-of-mass energies between 3.510 and 4.914 GeV, corresponding to an integrated luminosity of ...25 fb
−
1
, we measure the Born cross sections for the process
e
+
e
−
→
K
−
Ξ
¯
+
Λ
/
Σ
0
at thirty-five energy points with a partial-reconstruction strategy. By fitting the dressed cross sections of
e
+
e
−
→
K
−
Ξ
¯
+
Λ
/
Σ
0
, evidence for
ψ
4160
→
K
−
Ξ
¯
+
Λ
is found for the first time with a significance of 4.4
σ
, including systematic uncertainties. No evidence for other possible resonances is found. In addition, the products of electronic partial width and branching fraction for all assumed resonances decaying into
K
−
Ξ
¯
+
Λ
/
Σ
0
are determined.
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