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
$$ J/\psi \to \gamma {K}_S^0{K}_S^0{\pi}^0 $$
J
/
ψ
→
γ
K
S
0
K
...S
0
π
0
are performed within the
$$ {K}_S^0{K}_S^0{\pi}^0 $$
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
$$ {K}_S^0{K}_S^0{\pi}^0 $$
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
$$ 1391.7\pm {0.7}_{-0.3}^{+11.3} $$
1391.7
±
0.7
−
0.3
+
11.3
MeV/
c
2
and a width of
$$ 60.8\pm {1.2}_{-12.0}^{+5.5} $$
60.8
±
1.2
−
12.0
+
5.5
MeV, and the
η
(1475) with a mass of
$$ 1507.6\pm {1.6}_{-32.2}^{+15.5} $$
1507.6
±
1.6
−
32.2
+
15.5
MeV/
c
2
and a width of
$$ 115.8\pm {2.4}_{-10.9}^{+14.8} $$
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
$$ {K}_S^0{K}_S^0{\pi}^0 $$
K
S
0
K
S
0
π
0
invariant mass spectrum deteriorates significantly.
Ten hadronic final states of the h c decays are investigated via the process ψ(3686) → π0 hc, using a data sample of (448.1 ± 2.9) × 106 ψ(3686) events collected with the BESIII detector. The decay ...channel hc → K+ K− π+ π− π0 is observed for the first time and has a measured significance of 6.0σ. The corresponding branching fraction is determined to be B(hc → K+ K− π+ π− π0) = (3.3 ± 0.6 ± 0.6) × 10−3 (where the uncertainties are statistical and systematic, respectively). Evidence for the decays hc → π+ π− π0η and hc → K0S K ± π∓π+π − is found with a significance of 3.6σ and 3.8σ, respectively. The corresponding branching fractions (and upper limits) are obtained to be B(hc → π+ π− π0η) = (7.2 ± 1.8 ± 1.3 ) × 10−3(< 1.8 × 10−2) and B(hc → K0S K ± π∓π+π−) = (2.8 ± 0.9 ± 0.5) × 10−3 (< 4.7 × 10− 3). Upper limits on the branching fractions for the final states hc → K+ K− π0, K+ K−η, K+ K− π+ π−η, 2(K+K−)π0, K+ K− π0η, K0 SK ± π∓, and p¯p π0 π0 are determined at a confidence level of 90%.
Using 6.32 fb-1 of e+e- collision data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay D$^+_s$ → K+π+π- ...and determine the amplitudes of the various intermediate states. The absolute branching fraction of D$^+_s$ → K+π+π- is measured to be (6.11 ± 0.18stat. ± 0.11syst.) x 10-3. The branching fractions of the dominant intermediate processes D$^+_s$ → K+ρ0, ρ0 → π+π- and D$^+_s$ → K*(892)0π+, K*(892)0 → K+π- are determined to be (1.96 ± 0.19stat. ± 0.23syst.) x 10-3 and (1.85 ± 0.12stat. ± 0.13syst.) x 10-3, respectively. The intermediate resonances f0(500), f0(980), and f0(1370) are observed for the first time in this channel.
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.
We propose a new semileptonic tag method to study the doubly Cabibbo-suppressed D decay in ψ(3770) → DD reaction. Utilizing the dataset corresponding to an integrated luminosity of 2.93 fb−1 at a ...center-of-mass energy of 3.773 GeV collected by the BESIII detector, we determine the branching fraction for D+ → K+ π+ π− π0 to be (1.03 ± 0.1 2 stat ± 0.0 6syst) × 10−3, in which the contributions from narrow intermediate resonances, D+ → K+ η, D+ → K+ ω, and D+ → K+ ϕ have been excluded. Combining the world average of the branching fraction of D+ → K− π+ π+ π0, we determine B (D+ → K+ π+ π− π0 )/B(D+ → K− π+ π+ π0) = (1.65 ± 0.21) % , corresponding to (5.73 ± 0.73) tan 4θc, where θc is the Cabibbo mixing angle. These results are consistent with our previous measurement with hadronic tags but are significantly larger than other doubly Cabibbo-suppressed decays in the charm sector.
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