Using a data set of electron-positron collisions corresponding to an integrated luminosity of 293 fb-1 taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, a search for the baryon ...(B) and lepton (L) number violating decays D± → $n(\overline{n})e$± is performed. No signal is observed and the upper limits on the branching fractions at the 90% confidence level are set to be 1.43 × 10-5 for the decays D+(-) → $\overline{n}(n)e$+(-) with Δ|B - L| = 0, and 2.91 × 10-5 for the decays D+(-) → $n(\overline{n})e$+(-) with Δ|B - L| = 2, where Δ|B - L| = denotes the change in the difference between baryon and lepton numbers.
A
bstract
Based on 4.5 fb
−
1
e
+
e
−
collision data collected with BESIII detector at seven energy points between 4.600 and 4.699 GeV, the branching fractions for
$$ {\Lambda}_c^{+}\to p\eta $$
Λ
c
...+
→
pη
and
$$ {\Lambda}_c^{+}\to p\omega $$
Λ
c
+
→
pω
were measured by means of single-tag method. The branching fractions of
$$ {\Lambda}_c^{+}\to p\eta $$
Λ
c
+
→
pη
and
$$ {\Lambda}_c^{+}\to p\omega $$
Λ
c
+
→
pω
are determined to be (1.57
±
0.11
stat
±
0.04
syst
)
×
10
−
3
and (1.11
±
0.20
stat
±
0.07
syst
)
×
10
−
3
, with a statistical significance of greater than 10
σ
and 5.7
σ
, respectively. These results are consistent with the previous measurements by BESIII, LHCb and Belle, and the result of
$$ {\Lambda}_c^{+}\to p\eta $$
Λ
c
+
→
pη
is the most precise to date.
A
bstract
Using data samples with an integrated luminosity of 6
.
4 fb
−
1
collected by the BESIII detector operating at the BEPCII storage ring, the process of
e
+
e
−
→
γϕJ/ψ
is studied. The ...processes of
e
+
e
−
→
ϕχ
c
1
,
c
2
,
χ
c
1
,
c
2
→
γJ/ψ
are observed with a significance of more than 10
σ
. The
$$ \sqrt{s} $$
s
-dependent cross section of
e
+
e
−
→
ϕχ
c
1
,
c
2
is measured between 4.600 and 4.951 GeV, and evidence of a resonance structure is found for the first time in the
ϕχ
c
2
process. We also search for the processes of
e
+
e
−
→
γX
(4140),
γX
(4274) and
γX
(4500) via the
γϕJ/ψ
final state, but no obvious structures are found. The upper limits on the production cross section times the branching fraction for these processes at the 90% confidence level are reported.
A
bstract
A partial wave analysis on the process
e
+
e
−
→
ωπ
+
π
−
is performed using 647 pb
−
1
of data sample collected by using the BESIII detector operating at the BEPCII storage ring at ...center-of-mass (c.m.) energies from 2.000 GeV to 3.080 GeV. The Born cross section of the
e
+
e
−
→
ωπ
+
π
−
process is measured, with precision improved by a factor of 3 compared to that of previous studies. A structure near 2.25 GeV is observed in the energy-dependent cross sections of
e
+
e
−
→
ωπ
+
π
−
and
ωπ
0
π
0
with a statistical significance of 7.6
σ
, and its determined mass and width are 2232 ± 19 ± 27 MeV
/c
2
and 93 ± 53 ± 20 MeV, respectively, where the first and second uncertainties are statistical and systematic, respectively. By analyzing the cross sections of subprocesses
e
+
e
−
→
ωf
0
(500),
ωf
0
(980),
ωf
0
(1370),
ωf
2
(1270), and
b
1
(1235)
π
, a structure, with mass M = 2200 ± 11 ± 17 MeV/
c
2
and width Γ = 74 ± 20 ± 24 MeV, is observed with a combined statistical significance of 7.9
σ
. The measured resonance parameters will help to reveal the nature of vector states around 2.25 GeV.
Tree peony (Paeonia suffruticosa Andrews), a woody deciduous shrub, belongs to the section Moutan DC. in the genus of Paeonia of the Paeoniaceae family. To increase the efficiency of breeding, two ...EST-derived marker systems were developed based on a tree peony expressed sequence tag (EST) database. Using target region amplification polymorphism (TRAP), 19 of 39 primer pairs showed good amplification for 56 accessions with amplicons ranging from 120 to 3,000 bp long, among which 99.3% were polymorphic. In contrast, 7 of 21 primer pairs demonstrated adequate amplification with clear bands for simple sequence repeats (SSRs) developed from ESTs, and a total of 33 alleles were found in 56 accessions. The similarity matrices generated by TRAP and EST-SSR markers were compared, and the Mantel test (r = 0.57778, P = 0.0020) showed a moderate correlation between the two types of molecular markers. TRAP markers were suitable for DNA fingerprinting and EST-SSR markers were more appropriate for discriminating synonyms (the same cultivars with different names due to limited information exchanged among different geographic areas). The two sets of EST-derived markers will be used further for genetic linkage map construction and quantitative trait locus detection in tree peony.
Crucial inputs for a variety of $\textit{CP}$-violation studies can be determined through the analysis of pairs of quantum-entangled neutral $\textit{D}$ mesons, which are produced in the decay of ...the $_ψ$(3770) resonance. The relative strong-phase parameters between $D^0$ and $\bar{D}^0$ in the decays $D^0 → K^0_{S,L}π^+π^–$ are studied using 2.93 fb$^{–1}$ of $e^+e^–$ annihilation data delivered by the BEPCII collider and collected by the BESIII detector at a center-of-mass energy of 3.773 GeV. Results are presented in regions of the phase space of the decay. These are the most precise measurements to date of the strong-phase parameters in $D → K^0_{S,L}π^+π^–$ decays. Using these parameters, the associated uncertainty on the Cabibbo-Kobayashi-Maskawa angle $γ/\phi_3$ is expected to be between 0.7° and 1.2° for an analysis using the decay $B^± → D K^±, D → K^0_Sπ^+π^–$, where $\textit{D}$ represents a superposition of $D^0$ and $\bar{D}^0$ states. This is a factor of 3 smaller than that achievable with previous measurements. Furthermore, these results provide valuable input for charm-mixing studies, other measurements of $\textit{CP}$ violation, and the measurement of strong-phase parameters for other $\textit{D}$-decay modes.
Using a sample of (1310.6 ± 7.0) × 106 J/ψ events recorded with the Beijing Spectrometer III detector at the Beijing Electron Positron Collider II, we report the observation of the decay of the ...(11S0) charmonium state ηc into a pair of ω mesons in the process J/ψ → γωω. The branching fraction is measured for the first time to be B(ηc → ωω) = (2.88 ± 0.10 ± 0.46 ± 0.68) × 10–3, where the first uncertainty is statistical, the second systematic, and the third is from the uncertainty of B(J/ψ → γηc). The mass and width of the ηc are determined as M = (2985.9 ± 0.7 ± 2.1) MeV/c2 and Γ = (33.8 ± 1.6 ± 4.1) MeV.
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