Engineering topics
Chen, Y. Q.
Publications and source records attributed to Chen, Y. Q..
Study of Λ c + → Λ μ + ν μ and test of lepton flavor universality with Λ c + → Λ ℓ + ν ℓ decays
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Measurement of e + e − → ϕ π + π − cross sections at center-of-mass energies from 2.00 to 3.08 GeV
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Determination of the C P -even fraction of D 0 → K S 0 π + π − π 0
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Cross-section measurements of e + e − → ϕ K + K − and e + e − → ϕ K S 0 K S 0 at center-of-mass energies between 3.7730 GeV and 4.7008 GeV
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Search for baryon and lepton number violating decays of Ξ 0 hyperons
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First simultaneous measurement of Ξ 0 and Ξ ¯ 0 asymmetry parameters in ψ ( 3686 ) decay
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First Study of Reaction Ξ 0 n → Ξ − p Using Ξ 0 -Nucleus Scattering at an Electron-Positron Collider
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Search for the semi-leptonic decays Λ c + → Λ π + π - e + ν e and Λ c + → p K S 0 π - e + ν e
We search for the semi-leptonic decays $Λ^+_c$ → Λπ + π - e + ν e and $Λ^+_c$ → p$K^0_S$π - e + ν e in a sample of 4.5 fb -1 of e + e - annihilation data collected in the center-of-mass energy region between 4.600 GeV and 4.699 GeV by the BESIII detector at the BEPCII. No significant signals are observed, and the upper limits on the decay branching fractions are set to be B($Λ^+_c$ → Λπ + π - e + ν e ) < 3.9 × 10 -4 and B($Λ^+_c$ → p$K^0_S$π - e + ν e ) < 3.3 × 10 -4 at the 90% confidence level, respectively
Precision Measurement of the Decay Σ + → p γ in the Process J / ψ → Σ + Σ ¯ −
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Precision measurement of the matrix elements for η → π + π − π 0 and η → π 0 π 0 π 0 decays
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Observation of the decay χ c J → Ω − Ω ¯ +
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First direct measurement of the absolute branching fraction of Σ + → Λ e + ν e
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Measurement of the e + e − → Λ Λ ¯ cross section from threshold to 3.00 GeV using events with initial-state radiation
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Measurements of the Electric and Magnetic Form Factors of the Neutron for Timelike Momentum Transfer
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Observation of Three Charmoniumlike States with J P C = 1 − − in e + e − → D * 0 D * − π +
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Measurements of the branching fractions of the inclusive decays D 0 ( D + ) → π + π + π - X
Using e + e - annihilation data corresponding to an integrated luminosity of 2.93 fb -1 taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we report the first measurements of the branching fractions of the inclusive decays D 0 → π + π + π - X and D + → π + π + π - X, where pions from $K^0_S$ decays have been excluded from the → π + π + π - system and X denotes any possible particle combination. The branching fractions of D 0 (D + ) → π + π + π - X are determined to be B(D 0 → π + π + π - X) = (17.60 ± 0.11 ± 0.22)% and B(D + → π + π + π - X) = (15.25 ± 0.09 ± 0.18)%, where the first uncertainties are statistical and the second systematic.
Search for an axion-like particle in radiative $J/ψ$ decays
We search for an axion-like particle (ALP) a through the process $\psi$(3686) → π + π – J/$\psi$, J/$\psi$ → γa, a → γγ in a data sample of (2.71 ± 0.01) x 10 9 $\psi$(3686) events collected by the BESIII detector. No significant ALP signal is observed over the expected background, and the upper limits on the branching fraction of the decay J/$\psi$ → γa and the ALP-photon coupling constant g aγγ are set at 95% confidence level in the mass range of 0.165 ≤ m a ≤ 2.84 GeV/c 2 . The limits on $\mathscr{B}$(J/$\psi$ → γa) range from 8.3 x 10 –8 to 1.8 x 10 –6 over the search region, and the constraints on the ALP-photon coupling are the most stringent to date for 0.165 ≤ m a ≤ 1.468 GeV/c 2 .