Shape of Dipole Radiative Strength Function for Asymmetric Nuclei

The semiclassical method for description of the radiative strength function is used for asymmetric nuclei with $N \ne Z$. The theory is based on the linearized Vlasov-Landau equations in two-component finite Fermi liquid. The dependence of the shape $E1$ strength on the coupling constant between proton and neutron subsystems was studied.Comment: Latex, 4 pages; 2 *.ps files with figures. Poster Report of Eleventh Inter. Symp. on Capture Gamma-Ray Spectroscopy and Rel. Topics, Prague, 2-6 September, 2002 (to be published in proceedings

Observation of a Vector Charmoniumlike State at 4.7 GeV/c2 and Search for Zcs in e+e- →k+K-J/ψ

Using data samples with an integrated luminosity of 5.85 fb-1 collected at center-of-mass energies from 4.61 to 4.95 GeV with the BESIII detector operating at the BEPCII storage ring, we measure the cross section for the process e+e-→K+K-J/ψ. A new resonance with a mass of M=4708-15+17±21 MeV/c2 and a width of Γ=126-23+27±30 MeV is observed in the energy-dependent line shape of the e+e-→K+K-J/ψ cross section with a significance over 5σ. The K+J/ψ system is also investigated to search for charged charmoniumlike states, but no significant Zcs+ states are observed. Upper limits on the Born cross sections for e+e-→K-Zcs(3985)+/K-Zcs(4000)++c.c. with Zcs(3985)±/Zcs(4000)±→K±J/ψ are reported at 90% confidence levels. The ratio of branching fractions {[B(Zcs(3985)+→K+J/ψ)]/B[Zcs(3985)+→(D¯0Ds∗++D¯∗0Ds+)]} is measured to be less than 0.03 at 90% confidence level. © 2023 authors. Published by the American Physical Society

Measurements of the absolute branching fractions of ω- Decays and test of the Δi=1/2 rule

Based on a dataset of (27.12±0.10)×108 ψ(3686) events collected at the BESIII experiment, the absolute branching fractions of the three dominant ω- decays are measured to be Bω-→Ξ0π-=(25.03±0.44±0.53)%, Bω-→Ξ-π0=(8.43±0.52±0.28)%, and Bω-→ΛK-=(66.3±0.8±2.0)%, where the first and second uncertainties are statistical and systematic, respectively. The ratio between Bω-→Ξ0π- and Bω-→Ξ-π0 is determined to be 2.97±0.19±0.11, which is in good agreement with the PDG value of 2.74±0.15, but greater by more than four standard deviations than the theoretical prediction of 2 obtained from the ΔI=1/2 rule. © 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.<br/

Observation of a Vector Charmoniumlike State at 4.7 GeV/c2 and Search for Zcs in e+e- →k+K-J/ψ

Using data samples with an integrated luminosity of 5.85 fb-1 collected at center-of-mass energies from 4.61 to 4.95 GeV with the BESIII detector operating at the BEPCII storage ring, we measure the cross section for the process e+e-→K+K-J/ψ. A new resonance with a mass of M=4708-15+17±21 MeV/c2 and a width of Γ=126-23+27±30 MeV is observed in the energy-dependent line shape of the e+e-→K+K-J/ψ cross section with a significance over 5σ. The K+J/ψ system is also investigated to search for charged charmoniumlike states, but no significant Zcs+ states are observed. Upper limits on the Born cross sections for e+e-→K-Zcs(3985)+/K-Zcs(4000)++c.c. with Zcs(3985)±/Zcs(4000)±→K±J/ψ are reported at 90% confidence levels. The ratio of branching fractions {[B(Zcs(3985)+→K+J/ψ)]/B[Zcs(3985)+→(D¯0Ds∗++D¯∗0Ds+)]} is measured to be less than 0.03 at 90% confidence level. © 2023 authors. Published by the American Physical Society

Observation of the ψ (3686) decays into ς+ ς ¯ -ω and ς+ ς ¯ -φ

Based on (2712.4±14.3)×106 events recorded at the ψ(3686) nominal mass collected with the BESIII detector operating at the BEPCII collider, the ψ(3686)→ς+ς¯-ω and ς+ς¯-φ decays are observed for the first time with statistical significances of 13.8σ and 7.6σ, respectively. The corresponding branching fractions are measured to be B(ψ(3686)→ς+ς¯-ω)=(1.89±0.18±0.21)×10-5 and B(ψ(3686)→ς+ς¯-φ)=(2.96±0.54±0.41)×10-6, where the first uncertainties are statistical and the second systematic.<br/

Measurement of the cross sections for e+e- →ηπ+π- at center-of-mass energies between 2.00 and 3.08 GeV

Using data samples collected at center-of-mass energies between 2.000 and 3.080 GeV with the BESIII detector operating at the BEPCII collider, a partial-wave analysis is performed on the process e+e-→ηπ+π-. In addition to the dominant e+e-→ρη component, the e+e-→a2(1320)π process is also sizable, contributing up to 24% of the total reaction. The measured cross sections of the process e+e-→ηπ+π- are systematically higher than those of BABAR by more than 3σ at center-of-mass energies between 2.000 and 2.300 GeV. In the cross section line shape for e+e-→a2(1320)π, a resonant structure is observed with a significance of 5.5σ, with M=(2044±31±4) MeV/c2, Γ=(163±69±24) MeV, and BR·Γe+e-R=(34.6±17.1±6.0) eV or (137.1±73.3±2.1) eV. In the cross section line shape for e+e-→ρη, an evidence of a dip structure around 2180 MeV/c2 is observed with statistical significance of 3.0σ. © 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.<br/

Measurements of the absolute branching fractions of ω- Decays and test of the Δi=1/2 rule

Based on a dataset of (27.12±0.10)×108 ψ(3686) events collected at the BESIII experiment, the absolute branching fractions of the three dominant ω- decays are measured to be Bω-→Ξ0π-=(25.03±0.44±0.53)%, Bω-→Ξ-π0=(8.43±0.52±0.28)%, and Bω-→ΛK-=(66.3±0.8±2.0)%, where the first and second uncertainties are statistical and systematic, respectively. The ratio between Bω-→Ξ0π- and Bω-→Ξ-π0 is determined to be 2.97±0.19±0.11, which is in good agreement with the PDG value of 2.74±0.15, but greater by more than four standard deviations than the theoretical prediction of 2 obtained from the ΔI=1/2 rule. © 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.<br/

Observation of a Vector Charmoniumlike State at 4.7 GeV/c2 and Search for Zcs in e+e- →k+K-J/ψ

Using data samples with an integrated luminosity of 5.85 fb-1 collected at center-of-mass energies from 4.61 to 4.95 GeV with the BESIII detector operating at the BEPCII storage ring, we measure the cross section for the process e+e-→K+K-J/ψ. A new resonance with a mass of M=4708-15+17±21 MeV/c2 and a width of Γ=126-23+27±30 MeV is observed in the energy-dependent line shape of the e+e-→K+K-J/ψ cross section with a significance over 5σ. The K+J/ψ system is also investigated to search for charged charmoniumlike states, but no significant Zcs+ states are observed. Upper limits on the Born cross sections for e+e-→K-Zcs(3985)+/K-Zcs(4000)++c.c. with Zcs(3985)±/Zcs(4000)±→K±J/ψ are reported at 90% confidence levels. The ratio of branching fractions {[B(Zcs(3985)+→K+J/ψ)]/B[Zcs(3985)+→(D¯0Ds∗++D¯∗0Ds+)]} is measured to be less than 0.03 at 90% confidence level. © 2023 authors. Published by the American Physical Society

Improved measurement of the branching fractions for J/ψ →γπ0, γη, and γη′

Using a data sample of (1.0087±0.0044)×1010 J/ψ events collected with the BESIII detector, the decays of J/ψ→γπ0(η,η′)→γγγ are studied. Newly measured branching fractions are B(J/ψ→γπ0)=(3.34±0.02±0.09)×10-5, B(J/ψ→γη)=(1.096±0.001±0.019)×10-3, and B(J/ψ→γη′)=(5.40±0.01±0.11)×10-3, where the first uncertainties are statistical and the second are systematic. These results are consistent with the world average values within two standard deviations. The ratio of partial widths Γ(J/ψ→γη′)/Γ(J/ψ→γη) is measured to be 4.93±0.13. The singlet-octet pseudoscalar mixing angle θP is determined to be θP=-(22.11±0.26)° or -(19.34±0.34)° with two different phenomenological models. © 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.<br/