On the $\sigma_L/\sigma_T$ Ratio in Polarized Vector Meson Photoproduction
We study the spin-dependent cross-sections of vector meson photoproduction for longitudinally and transversely polarized photons within a QCD- model. The dependence of the $\sigma_T/\sigma_L$ ratio on the photon virtuality and on the meson wave function is analysed.
Digital signal processors have made it possible to control scanned probe microscopes using straightforward software emulations of analog circuits. Using a system consisting of a commercially available digital signal processor board interfaced to analog I/O, we have developed algorithms for self‐optimizing feedback, raster generation (with hysteresis correction, sample tilt compensation, and scan rotation), lock‐in detection, and automatic tip‐sample approach. We also discuss an instruction parser that takes advantage of the digital architecture to allow automatic operation for extended periods.