Direct measurement of [formula presented] and [formula presented]

Author(s): Bai, JZ; Ban, Y; Bian, JG; Blum, I; Chen, GP; Chen, HF; Chen, J; Chen, JC; Chen, Y; Chen, YB; Chen, YQ; Cheng, BS; Cui, XZ; Ding, HL; Dong, LY; Du, ZZ; Dunwoodie, W; Gao, CS; Gao, ML; Gao, SQ; Gratton, P; Gu, JH; Gu, SD; Gu, WX; Gu, YF; Guo, YN; Guo, ZJ; Han, SW; Han, Y; Harris, FA; He, J; He, JT; He, KL; He, M; Heng, YK; Hitlin, DG; Hu, GY; Hu, HM; Hu, JL; Hu, QH; Hu, T; Hu, XQ; Huang, YZ; Huang, GS; Izen, JM; Jiang, CH; Jin, Y; Jones, BD; Ju, X; Ke, ZJ; Kelsey, MH; Kim, BK; Kong, D; Lai, YF; Lang, PF; Lankford, A; Li, CG; Li, D; Li, HB; Li, J; Li, JC; Li, PQ; Li, RB; Li, W; Li, WG; Li, XH; Li, XN; Liu, HM; Liu, J; Liu, RG; Liu, Y; Lou, XC; Lowery, B; Lu, F; Lu, JG; Luo, XL; Ma, EC; Ma, JM; Malchow, R; Mandelkern, M; Mao, HS; Mao, ZP; Meng, XC; Nie, J; Olsen, SL | Abstract: The first measurement of (Formula presented) and an upper limit for (Formula presented) are determined from 22.3 (Formula presented) of (Formula presented) annihilation data at a c.m. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied to charm threshold data to determine the charge of the D meson in the recoil from (Formula presented) reconstructed (Formula presented) (Formula presented) mesons. The branching fractions (Formula presented) and (Formula presented) are determined from 10 events with a reconstructed D and a recoiling (Formula presented) In addition, a 90% C.L. upper limit of (Formula presented) is determined from a search for semileptonic decays of the (Formula presented) © 2000 The American Physical Society.