Refine
Document Type
- Article (175)
- Preprint (111)
- Working Paper (1)
Language
- English (287)
Has Fulltext
- yes (287)
Is part of the Bibliography
- no (287)
Keywords
- e +-e − Experiments (12)
- BESIII (9)
- Branching fraction (9)
- Particle and Resonance Production (5)
- Quarkonium (5)
- Charm Physics (4)
- Exotics (4)
- Lepton colliders (4)
- Spectroscopy (4)
- Charmed mesons (3)
A determination of the CP-even fraction F+ in the decay D0→K+K−π+π− is presented. Using 2.93 fb−1 of e+e−→ψ(3770)→DD¯ data collected by the BESIII detector, one charm meson is reconstructed in the signal mode and the other in a CP eigenstate or the decay D→K0S,Lπ+π−. Analysis of the relative rates of these double-tagged events yields the result F+=0.730±0.037±0.021, where the first uncertainty is statistical and the second is systematic. This is the first model-independent measurement of F+ in D0→K+K−π+π− decays.
Measurement of e⁺e⁻ → ΛΛ¯η from 3.5106 to 4.6988 GeV and study of ΛΛ¯ mass threshold enhancement
(2023)
Using data samples with a total integrated luminosity of approximately 18 fb−1 collected by the BESIII detector operating at the BEPCII, the process e+e−→ΛΛ¯η is studied at center-of-mass energies between 3.5106 and 4.6988 GeV. The Born cross section for the process e+e−→ΛΛ¯η is measured. No significant structure is observed in the Born cross section line shape. An enhancement near the ΛΛ¯ mass threshold is observed for the first time in the process. The structure can be described by an S-wave Breit-Wigner function. Neglecting contribution of excited Λ states and potential interferences, the mass and width are determined to be (2356±7±17) MeV/c2 and (304±28±54) MeV, respectively, where the first uncertainties are statistical and the second are systematic.
By analyzing 4.48×108 ψ(3686) events collected with the BESIII detector, we observe the decays χcJ→nK0SΛ¯+c.c. (J=0, 1, 2) for the first time, via the radiative transition ψ(3686)→γχcJ. The branching fractions are determined to be (6.67±0.26stat±0.41syst)×10−4, (1.71±0.12stat±0.12syst)×10−4, and (3.66±0.17stat±0.23syst)×10−4 for J=0, 1, and 2, respectively.
Using a data sample of ψ(3770) events collected with the BESIII detector at BEPCII corresponding to an integrated luminosity of 2.9 fb−1, we report a measurement of Λ spin polarization in e+e−→ΛΛ¯ at s√=3.773 GeV. The significance of polarization is found to be 2σ including the systematic uncertainty, which implies a zero phase between the transition amplitudes of the ΛΛ¯ helicity states. This phase can be interpreted in terms of psionic form factors, and is determined to be ΔΦΨ = ΦΨE−ΦΨM = (71+66−46 ± 5)∘. Similarly, the ratio between the form factors is found to be Rψ = |GΨE/GΨM| = 0.48+0.12−0.07 ± 0.04. The first uncertainties are statistical and the second systematic.
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).
Using data taken at 23 center-of-mass energies between 4.0 and 4.6 GeV with the BESIII detector at the BEPCII collider and with a total integrated luminosity of approximately 15 fb−1, the process e+e−→2(pp¯) is studied for the first time. The Born cross sections for e+e−→2(pp¯) are measured, and no significant structure is observed in the lineshape. The baryon pair (pp and p¯p¯) invariant mass spectra are consistent with phase space, therefore no hexaquark or di-baryon state is found.
Based on an 𝑒+𝑒− collision data sample corresponding to an integrated luminosity of 2.93 fb−1 collected with the BESIII detector at √𝑠=3.773 GeV, the first amplitude analysis of the singly Cabibbo-suppressed decay 𝐷+→𝐾+𝐾0𝑆𝜋0 is performed. From the amplitude analysis, the 𝐾*(892)+𝐾0𝑆 component is found to be dominant with a fraction of (57.1±2.6±4.2)%, where the first uncertainty is statistical and the second systematic. In combination with the absolute branching fraction ℬ(𝐷+→𝐾+𝐾0𝑆𝜋0) measured by BESIII, we obtain ℬ(𝐷+→𝐾*(892)+𝐾0𝑆)=(8.69±0.40±0.64±0.51)×10−3, where the third uncertainty is due to the branching fraction ℬ(𝐷+→𝐾+𝐾0𝑆𝜋0). The precision of this result is significantly improved compared to the previous measurement. This result also differs from most of theoretical predictions by about 4𝜎, which may help to improve the understanding of the dynamics behind.
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.
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.