A
bstract
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
.
18
stat
.
±
0
.
11
syst
.
)
×
10
−
3
. The branching fractions of the dominant intermediate processes
D
s
+
→ K
+
ρ
0
, ρ
0
→ π
+
π
−
and
D
s
+
→ K
*
(892)
0
π
+
, K
*
(892)
0
→ K
+
π
−
are determined to be (1
.
96
±
0
.
19
stat
.
±
0
.
23
syst
.
)
×
10
−
3
and (1
.
85
±
0
.
12
stat
.
±
0
.
13
syst
.
)
×
10
−
3
, respectively. The intermediate resonances
f
0
(500),
f
0
(980), and
f
0
(1370) are observed for the first time in this channel.
A
bstract
The Born cross sections of the
e
+
e
−
→ D
*+
D
*
−
and
e
+
e
−
→ D
*+
D
−
processes are measured using
e
+
e
−
collision data collected with the BESIII experiment at center-of-mass ...energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15
.
7 fb
−
1
. The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.
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 15
.
6 fb
−
1
of
e
+
e
−
collision data collected at twenty-four center-of-mass energies from 4
.
0 to 4
.
6 GeV with the BESIII detector, the helicity amplitudes of the process
e
+
e
...−
→
π
+
π
−
ω
are analyzed for the first time. Born cross section measurements of two-body intermediate resonance states with statistical significance greater than 5
σ
are presented, such as
f
0
(500),
f
0
(980),
f
2
(1270),
f
0
(1370),
b
1
(1235)
±
, and
ρ
(1450)
±
. In addition, evidence of a resonance state in
e
+
e
−
→
π
+
π
−
ω
production is found. The mass of this state obtained by line shape fitting is about 4
.
2 GeV/
c
2
, which is consistent with the production of
ψ
(4160) or
Y
(4220).
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
Recenzirano
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 (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
.
.
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.
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
Based on
e
+
e
−
collision samples corresponding to an integrated luminosity of 4.4 fb
−
1
collected with the BESIII detector at center-of-mass energies between 4
.
6 GeV and 4
.
7 GeV, a ...partial wave analysis of the charmed baryon hadronic decay
Λ
c
+
→
Λ
π
+
π
0
is performed, and the decays
Λ
c
+
→
Λ
ρ
(770)
+
and
Λ
c
+
→
Σ(1385)
π
are studied for the first time. Making use of the world-average branching fraction
B
Λ
c
+
→
Λ
π
+
π
0
, their branching fractions are determined to be
B
Λ
c
+
→
Λ
ρ
770
+
=
4.06
±
0.30
±
0.35
±
0.23
×
10
−
2
,
B
Λ
c
+
→
Σ
1385
+
π
0
=
5.86
±
0.49
±
0.52
±
0.35
×
10
−
3
,
B
Λ
c
+
→
Σ
1385
0
π
+
=
6.47
±
0.59
±
0.66
±
0.38
×
10
−
3
,
where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions
B
Λ
c
+
→
Λ
π
+
π
0
and
B
Σ
1385
→
Λ
π
. In addition, the decay asymmetry parameters are measured to be
α
Λ
ρ
(770)+
= − 0.763 ± 0.053 ± 0.045,
α
Σ
1385
+
π
0
=
−
0.917
±
0.069
±
0.056
, and
α
Σ
1385
0
π
+
=
−
0.789
±
0.098
±
0.056
.
A
bstract
Using data samples with an integrated luminosity of 19 fb
−
1
at twenty-eight center-of-mass energies from 3.872 GeV to 4.700 GeV collected with the BESIII detector at the BEPCII ...electron-positron collider, the process
e
+
e
−
→
ηπ
+
π
−
and the intermediate process
e
+
e
−
→
ηρ
0
are studied for the first time. The Born cross sections are measured. No significant resonance structure is observed in the cross section lineshape.
