Refine
Year of publication
Language
- English (240)
Has Fulltext
- yes (240)
Is part of the Bibliography
- no (240)
Keywords
- BESIII (17)
- e +-e − Experiments (12)
- Branching fraction (9)
- Particle and Resonance Production (7)
- Hadronic decays (5)
- Spectroscopy (5)
- Branching fractions (4)
- Charm Physics (4)
- Lepton colliders (4)
- Quarkonium (4)
Institute
- Physik (238)
Ten hadronic final states of the ℎ𝑐 decays are investigated via the process 𝜓(3686)→𝜋0ℎ𝑐, 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→𝐾0𝑆𝐾±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→𝐾0𝑆𝐾±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, 𝐾0𝑆𝐾±𝜋∓, and 𝑝¯𝑝𝜋0𝜋0 are determined at a confidence level of 90%.
Using a data sample of 448.1×106 𝜓(3686) events collected with the BESIII detector operating at the BEPCII, we perform search for the hadronic transition ℎ𝑐→𝜋+𝜋−𝐽/𝜓 via 𝜓(3686)→𝜋0ℎ𝑐. No signals of the transition are observed, and the upper limit on the product branching fraction ℬ(𝜓(3686)→𝜋0ℎ𝑐)ℬ(ℎ𝑐→𝜋+𝜋−𝐽/𝜓) at the 90% confidence level (C.L.) is determined to be 2.0×10−6. This is the most stringent upper limit to date.
Using 5.9 pb−1 of e+e− annihilation data collected at center-of-mass energies from 3.640 to 3.701 GeV with the BESIII detector at the BEPCII Collider, we measure the observed cross sections of e+e−→K0SX (where X=anything). From a fit to these observed cross sections with the sum of continuum and ψ(3686) and J/ψ Breit-Wigner functions and considering initial state radiation and the BEPCII beam energy spread, we obtain for the first time the inclusive decay branching fraction B(ψ(3686)→K0SX)=(16.04±0.29±0.90)%, where the first uncertainty is statistical and the second is systematic.
Measurement of the e+e−→π+π− cross section between 600 and 900 MeV using initial state radiation
(2016)
We extract the e+e− →π+π− cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb−1 taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor |Fπ|2 as well as the contribution of the measured cross section to the leading-order hadronic vacuum polarization contribution to (g−2)μ. We find this value to be aππ,LO μ (600–900 MeV) = (368.2 ±2.5stat±3.3sys) ·10−10, which is between the corresponding values using the BaBar or KLOE data.
We report the first observation of the decay Λ+c→Σ−π+π+π0, based on data obtained in e+e− annihilations with an integrated luminosity of 567~pb−1 at s√=4.6~GeV. The data were collected with the BESIII detector at the BEPCII storage rings. The absolute branching fraction B(Λ+c→Σ−π+π+π0) is determined to be (2.11±0.33(stat.)±0.14(syst.))%. In addition, an improved measurement of B(Λ+c→Σ−π+π+) is determined as (1.81±0.17(stat.)±0.09(syst.))%.
Relative fractions and phases of the intermediate decays are determined. With the detection efficiency estimated by the results of the amplitude analysis, the branching fraction of Dþ s → K−Kþπþπ0 decay is measured to be ð5.42 0.10stat 0.17systÞ%.
We report the first measurement of the absolute branching fraction for Λ+c→Λμ+νμ. This measurement is based on a sample of e+e− annihilation data at a center-of-mass energy of s√=4.6 GeV collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pb−1. The branching fraction is determined to be B(Λ+c→Λμ+νμ)=(3.49±0.46(stat)±0.27(syst))%. In addition, we calculate the ratio B(Λ+c→Λμ+νμ)/B(Λ+c→Λe+νe) to be 0.96±0.16(stat)±0.04(syst).
We study the decays of J/ψ and ψ(3686) to the final states Σ(1385)0Σ¯(1385)0 and Ξ0Ξ¯0 based on a single baryon tag method using data samples of (1310.6±7.0)×106 J/ψ and (447.9±2.9)×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider. The decays to Σ(1385)0Σ¯(1385)0 are observed for the first time. The measured branching fractions of J/ψ and ψ(3686)→Ξ0Ξ¯0 are in good agreement with, and much more precise, than the previously published results. The angular parameters for these decays are also measured for the first time. The measured angular decay parameter for J/ψ→Σ(1385)0Σ¯(1385)0, α=−0.64±0.03±0.10, is found to be negative, different to the other decay processes in this measurement. In addition, the "12\% rule" and isospin symmetry in the J/ψ and ψ(3686)→ΞΞ¯ and Σ(1385)Σ¯(1385) systems are tested.
Using data samples collected with the BESIII detector at the BEPCII collider at six center-of-mass energies between 4.008 and 4.600 GeV, we observe the processes e+e− → φφω and e+e− → φφφ. The Born cross sections are measured and the ratio of the cross sections σ(e+e− → φφω)/σ(e+e− → φφφ) is estimated to be 1.75 ± 0.22 ± 0.19 averaged over six energy points, where the first uncertainty is statistical and the second is systematic. The results represent first measurements of these interactions.
The electromagnetic process is studied with the initial-state-radiation technique using 7.5 fb−1 of data collected by the BESIII experiment at seven energy points from 3.773 to 4.600 GeV. The Born cross section and the effective form factor of the proton are measured from the production threshold to 3.0 GeV/ using the invariant-mass spectrum. The ratio of electric and magnetic form factors of the proton is determined from the analysis of the proton-helicity angular distribution.