학술논문

Direct measurement of [formula presented] and [formula presented]
Document Type
article
Source
Physical Review D - Particles, Fields, Gravitation and Cosmology. 62(5)
Subject
Nuclear & Particles Physics
Astronomical and Space Sciences
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Quantum Physics
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Language
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.