We report on a comparison of two possible Λ+c spin hypotheses, J = 1/2 and 3/2, via the process e+e− → Λ+ c¯Λ−c , using the angular distributions of Λ+c decays into pK0S , Λπ+, Σ0π+, and Σ+π0. The ...data were recorded at √ s = 4.6 GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb−1. The Λ+c spin is determined to be J = 1/2, with this value favored over the 3/2 hypothesis with a significance corresponding to more than 6 Gaussian standard deviations.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The decays ψ2(3823) → γχc0,1,2, π+ π– J/ψ, π0π0 J/ψ, ηJ/ψ, and π0J/ψ are searched for using the reaction e+e– → π+π– ψ2(3823) in a 19 fb–1 data sample collected at center-of-mass energies between 4.1 ...and 4.7 GeV with the BESIII detector. The process ψ2(3823) → γχc1 is observed in a 9 fb–1 data sample in the center-of-mass energy range 4.3–4.7 GeV, which confirms a previous observation but with a higher significance of 11.8σ, and evidence for ψ2(3823) → γχc2 is found with a significance of 3.2σ for the first time. The branching-fraction ratio $\frac{B(ψ_{2}(3823)→γχ_{c2})}{B(ψ_{2}(3823)→γχ_{c1})}$ is determined. No significant ψ2(3823) signals are observed for any of the other decay channels. Upper limits of branching-fraction ratios for ψ2(3823) → π+π– J/ψ, π0π0 J/ψ, η J/ψ, π0 J/ψ, γχc0 relative to ψ2(3823) → γχc1 are reported. The process e+e– → π0π0 ψ2(3823) is also searched for, and we find evidence for the process with a significance of 4.3σ. The average cross-section ratio $\frac{σ(e^{+}e^{–} → π^{0}π^{0} ψ_{2}(3823))} {σ(e^{+}e^{–} → π^{+}π^{–} ψ_{2}(3823))}$ is also determined.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We measure the branching fractions for seven D-s(+) two-body decays to pseudoscalar mesons, by analyzing data collected at root s = 4:178 similar to 4:226 GeV with the BESIII detector at the BEPCII ...collider. The branching fractions are determined to be B(D-s(+) -> K+eta ') = (2:68 +/- 0:17 +/- 0:17 +/- 0:08) x 10(-3), B(D-s(+) -> eta 'pi(+)) = (37:8 +/- 0:4 +/- 2:1 +/- 1:2) x 10(-3), B(D-s(+) -> K+eta) = (1:62 +/- 0:10 +/- 0:03 +/- 0:05) x 10(-3), B(D-s(+) -> eta pi(+)) = (17:41 +/- 0:18 +/- 0:27 +/- 0:54) x 10(-3), B(D-s(+) -> (K+Ks0)) = (15:02 +/- 0:10 +/- 0:27 +/- 0:47) x 10(-3), B(D-s(+) -> K-s(0)pi(+)) = (1:109 +/- 0:034 +/- 0:023 +/- 0:035) x 10(-3), B(D-s(+) -> K+pi(0)) = (0:748 +/- 0:049 +/- 0:018 +/- 0:023) x 10(-3), where the first uncertainties are statistical, the second are systematic, and the third are from external input branching fraction of the normalization mode D-s(+) -> K+K-pi(+). Precision of our measurements is significantly improved compared with that of the current world average values.
In Ref. 1 the BESIII collaboration published a cross section measurement of the process e+e−→π+π− in the energy range between 600 and 900 MeV. In this corrigendum, we report a corrected evaluation of ...the statistical errors in terms of a fully propagated covariance matrix. The correction also yields a reduced statistical uncertainty for the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, which now reads as aμππ,LO(600−900MeV)=(368.2±1.5stat±3.3syst)×10−10. The central values of the cross section measurement and of aμππ,LO, as well as the systematic uncertainties remain unchanged.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report a study of the e+e−→D+D−π+π− process using e+e− collision data samples with an integrated luminosity of 2.5fb−1 at center-of-mass energies from 4.36 to 4.60GeV, collected with the BESIII ...detector at the BEPCII storage ring. The D1(2420)+ is observed in the D+π+π− mass spectrum. The mass and width of the D1(2420)+ are measured to be (2427.2±1.0stat.±1.2syst.)MeV/c2 and (23.2±2.3stat.±2.3syst.)MeV, respectively. In addition, the Born cross sections of the e+e−→D1(2420)+D−+c.c.→D+D−π+π− and e+e−→ψ(3770)π+π−→D+D−π+π− processes are measured as a function of the center-of-mass energy.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
