2004/06/10 by G. Rong, Rong, G.
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0406027
6 pages, 7 figures, To appear in the proceedings of 39th Recontres de Moriond on Electroweak Interactions and Unified Theories, LaThuile, Aosta Valley, Italy, 21-28 March, 2004
arxiv created 2004/06/10 · arxiv updated 2009/12/01
Using a data sample of 17.7 \rm pb-1 collected at 3.773 GeV with the BES-II detector at the BEPC, the cross sections for D0 D0 and D+D- productions at 3.773 GeV have been measured. From the data sample about 33 \rm pb-1 taken around 3.773 GeV, 3 purely leptonic decay events of D+ → μ+ν are observed. The branching fraction and the decay constant are measured to be BF(D+ → μ+ν)=(0.120+0.092+0.010-0.063-0.009) % and fD=(365+121+32-113-28) MeV. The semileptonic decay branching fractions for D0 → K-e+ν, D0 → π-e+ν and D+ → K0 e+ν are measured to be BF(D0 → K-e+νe)=(3.52 ± 0.36± 0.25)%, BF(D0 → π-e+νe)=(0.36 ± 0.14± 0.03)% and BF(D+ → K0 e+νe)=(8.64 ± 1.51± 0.72)%. The vector form factors are determined to be |fK+(0)| = 0.75 ± 0.04 ± 0.03 and |fπ+(0)| = 0.76 ± 0.15 ± 0.06. The ratio of the two form factors is extracted to be |fπ+(0)/fK+(0)|= 1.01 ± 0.20 ± 0.08. The ratio of the decay widths is measured to be Γ(D0 → K-e+ν)/Γ(D+ → K0 e+ν) =1.04± 0.21 ± 0.08. From the data sample of about 27 \rm pb-1, the evidence of ψ(3770) → J/ψπ+π- non-D D decay is observed. The branching fraction is determined to be BF(ψ(3770) → J/ψπ+π-)=(0.34± 0.14 ± 0.08)%, corresponding to the partial width of Γ(ψ(3770) → J/ψπ+π-) = (80 ± 32 ± 21) keV.