A new technique is applied to data collected at the 0(3770) resonance to derive charmed-Dmeson branching fractions without relying on the measurement of D-production cross sections. Measurements are presented for three decay modes of the D° (K~TT + , D~ * and K-TT + TT 0 ) and four decay modes of the D + (K~7r + 7r + , K-TT + TT + TT 0 , K$<7T + , and tf 5°i r + ir 0 ). The resulting branching fractions are significantly larger than previous measurements.

We present measurements of the two-body decays of the J/$ into a vector and a pseudoscalar meson. The data, taken with the Mark I11 detector at the SLAC e + e -storage ring SPEAR, consist of 5.8 X lo6 produced J/+'s. The branching ratios for the J/$ decays into pn, pg, pq', on0, og, wg', $17, r#Jgl, and K*K are measured; an upper limit on J / $ -~T ' is obtained. Using the measured branching ratios we obtain parameters of a phenomenological model of J/$ decays, indicating that the g and g' are consistent with being composed only of light and strange quarks. The model is used to obtain the mixing angle in the pseudoscalar nonet. The m a 0 electromagnetic form factor is determined. The upper limit on J/*-+r#Jno is used to study the contributions from electromagnetic doubly-Okubo-Zweig-Iizuka-suppressed decays of the J/+.

A phase-diversity wave-front sensor has been developed and tested at the Lockheed Palo Alto Research Labs (LPARL). The sensor consists of two CCD-array focal planes that record the best-focus image of an adaptive imaging system and an image that is defocused. This information is used to generate an object-independent function that is the input to a LPARL-developed neural network algorithm known as the General Regression Neural Network (GRNN). The GRNN algorithm calculates the wave-front errors that are present in the adaptive optics system. A control algorithm uses the calculated values to correct the errors in the optical system. Simulation studies and closed-loop experimental results are presented.

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