Refine
Year of publication
Document Type
- Article (399)
- Preprint (314)
- Working Paper (1)
Language
- English (714)
Has Fulltext
- yes (714)
Is part of the Bibliography
- no (714)
Keywords
- BESIII (20)
- e +-e − Experiments (20)
- Branching fraction (15)
- Particle and Resonance Production (9)
- Charm Physics (6)
- Quarkonium (6)
- Spectroscopy (6)
- Hadronic decays (5)
- QCD (5)
- Branching fractions (4)
Using a total of 11.0 fb−1 of e+e− collision data with center-of-mass energies between 4.009 GeV and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e+e−→Ξ−Ξ¯+ by means of a single baryon-tag method. After performing a fit to the dressed cross section of e+e−→Ξ−Ξ¯+, no significant ψ(4230) or ψ(4260) resonance is observed in the Ξ−Ξ¯+ final states, and upper limits at the 90\% confidence level on ΓeeB for the processes ψ(4230)/ψ(4260)→Ξ−Ξ¯+ are determined. In addition, an excited Ξ baryon at 1820 MeV/c2 is observed with a statistical significance of 6.2 ∼ 6.5σ by including the systematic uncertainty, and the mass and width are measured to be M=(1825.5±4.7±4.7)~MeV/c2 and Γ=(17.0±15.0±7.9)~MeV, which confirms the existence of the JP=32− state Ξ(1820).
Using a total of 9.0 fb−1 of e+e− collision data with center-of-mass energies between 4.15 and 4.30 GeV collected by the BESIII detector, we search for the processes e+e−→γX(3872) with X(3872)→π0χcJ for J=0,1,2. We report the first observation of X(3872)→π0χc1, a new decay mode of the X(3872), with a statistical significance of more than 5σ. Normalizing to the previously established process e+e−→γX(3872) with X(3872)→π+π−J/ψ, we find B(X(3872)→π0χc1)/B(X(3872)→π+π−J/ψ)=0.88+0.33−0.27±0.10, where the first error is statistical and the second is systematic. We set 90% confidence level upper limits on the corresponding ratios for the decays to π0χc0 and π0χc2 of 19 and 1.1, respectively.
Using 448.1 × 106 ψ(3686) events collected with the BESIII detector at BEPCII, we employ a single-baryon tagging technique to make the first observation of ψ(3686) → Ξ(1530)−Ξ¯(1530)+ and Ξ(1530)−Ξ¯+ decays with a statistical significance of more than 10σ and 5.0σ, respectively. The branching fractions are measured to be B[ψ(3686)→Ξ(1530)−Ξ¯(1530)+] = (11.45 ± 0.40 ± 0.59) × 10−5 and B[ψ(3686)→Ξ(1530)−Ξ¯+] = (0.70 ± 0.11 ± 0.04) × 10−5. The angular distribution parameter for ψ(3686) → Ξ(1530)−Ξ¯(1530)+ is determined to be α = 0.40 ± 0.24 ± 0.06, which agrees with the theoretical predictions within 1σ. The first uncertainties are statistical, and the second systematic.
The Born cross section for the process e+e−→pp¯ is measured using the initial state radiation technique with an undetected photon. This analysis is based on datasets corresponding to an integrated luminosity of 7.5 fb−1, collected with the BESIII detector at the BEPCII collider at center of mass energies between 3.773 and 4.600 GeV. The Born cross section for the process e+e−→pp¯ and the proton effective form factor are determined in the pp¯ invariant mass range between 2.0 and 3.8 GeV/c2 divided into 30 intervals. The proton form factor ratio (|GE|/|GM|) is measured in 3 intervals of the pp¯ invariant mass between 2.0 and 3.0 GeV/c2.
Cross sections of the process 𝑒+𝑒−→𝜋0𝜋0𝐽/𝜓 at center-of-mass energies between 3.808 and 4.600 GeV are measured with high precision by using 12.4 fb−1 of data samples collected with the BESIII detector operating at the BEPCII collider facility. A fit to the measured energy-dependent cross sections confirms the existence of the charmoniumlike state 𝑌(4220). The mass and width of the 𝑌(4220) are determined to be (4220.4±2.4±2.3) MeV/𝑐2 and (46.2±4.7±2.1) MeV, respectively, where the first uncertainties are statistical and the second systematic. The mass and width are consistent with those measured in the process 𝑒+𝑒−→𝜋+𝜋−𝐽/𝜓. The neutral charmonium-like state 𝑍𝑐(3900)0 is observed prominently in the 𝜋0𝐽/𝜓 invariant-mass spectrum, and, for the first time, an amplitude analysis is performed to study its properties. The spin-parity of 𝑍𝑐(3900)0 is determined to be 𝐽𝑃=1+, and the pole position is (3893.1±2.2±3.0)−𝑖(22.2±2.6±7.0) MeV/𝑐2, which is consistent with previous studies of electrically charged 𝑍𝑐(3900)±. In addition, cross sections of 𝑒+𝑒− → 𝜋0𝑍𝑐(3900)0 → 𝜋0𝜋0𝐽/𝜓 are extracted, and the corresponding line shape is found to agree with that of the 𝑌(4220).
We study ηc production at center-of-mass energies s√ from 4.18 to 4.60 GeV in e+e− annihilation data collected with the BESIII detector operating at the BEPCII storage ring, corresponding to 7.3 fb−1 of integrated luminosity. We measure the cross sections of the three different exclusive reactions e+e−→ηcπ+π−π0, e+e−→ηcπ+π−, and e+e−→ηcπ0γ. We find significant ηc production in e+e−→ηcπ+π−π0 at s√ of 4.23 GeV and 4.26 GeV and observe a significant energy-dependent Born cross section that we measure to be consistent with the production via the intermediate Y(4260) resonance. In addition, we perform a search for a charmonium-like Zc state close to the DD¯ threshold that decays to ηcπ, involving ground state charmonium, and observe no signal. Corresponding upper limits on the cross section of ηc and Zc production are provided, where the yields are not found to be significant.
Based on 2.93~fb−1 e+e− collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report the measurements of the absolute branching fractions of D0→K+K−π0π0, D0→K0SK0Sπ+π−, D0→K0SK−π+π0, D0→K0SK+π−π0, D+→K+K−π+π0, D+→K0SK+π0π0, D+→K0SK−π+π+, D+→K0SK+π+π−, and D+→K0SK0Sπ+π0. The decays D0→K+K−π0π0, D0→K0SK−π+π0, D0→K0SK+π−π0, D+→K0SK0Sπ+π0, and D+→K0SK+π0π0 are observed for the first time. The branching fractions of the decays D0→K0SK0Sπ+π−, D+→K+K−π+π0, D+→K0SK−π+π+, and D+→K0SK+π+π− are measured with improved precision compared to the world-average values.
Using a data sample of (448.1±2.9)×106 ψ(3686) decays collected by the BESIII detector at the Beijing Electron Positron Collider (BEPCII), we observe the decays χcJ→ϕϕη (J=0, 1, 2), where the χcJ are produced via the radiative processes ψ(3686)→γχcJ. The branching fractions are measured to be B(χc0→ϕϕη)=(8.41±0.74±0.62)×10−4, B(χc1→ϕϕη)=(2.96±0.43±0.22)×10−4, and B(χc2→ϕϕη)=(5.33±0.52±0.39)×10−4, where the first uncertainties are statistical and the second are systematic. We also search for intermediate states in the ϕϕ or ηϕ combinations, but no significant structure is seen due to the limited statistics.
We report the first observation of D+→τ+ντ with a significance of 5.1σ. We measure B(D+→τ+ντ)=(1.20±0.24stat.±0.12syst.)×10−3. Taking the world average B(D+→μ+νμ)=(3.74±0.17)×10−4, we obtain Rτ/μ=Γ(D+→τ+ντ)/Γ(D+→μ+νμ)=3.21±0.64stat.±0.43syst., which is consistent with the Standard Model expectation of lepton flavor universality. Using external inputs, our results give values for the D+ decay constant fD+ and the CKM matrix element |Vcd| that are consistent with, but less precise than, other determinations.
We measured the branching fractions of the decays χcJ→Σ−Σ¯+ for the first time using the final states nn¯π+π−. The data sample exploited here is 448.1×106 ψ(3686) events collected with BESIII. We find B(χcJ→Σ−Σ¯+)=(51.3±2.4±4.1)×10−5,(5.7±1.4±0.6)×10−5,and (4.4±1.7±0.5)×10−5, for J=0,1,2, respectively, where the first uncertainties are statistical and the second systematic.