Conference Presentations

Noise and systematic disturbances are important to characterize when working with low-bandwidth SRF cavities that require tight RF regulation. For a future upgrade at XFEL, we have been investigating the microphonics and noise performance of the tunnel, cryomodule, and RF environment in order to better characterize the expected performance, control, and mitigations needed for the design..

The beam-spin induced polarization of $\Lambda$ and $\bar\Lambda$ hyperons produced in deep-inelastic scattering of longitudinally polarized positrons from unpolarized nucleons has been investigated by the HERMES experiment at a positron beam energy of 27.6 GeV impinging on hydrogen, deuterium, and various heavier gas targets. The two spin-transfer coefficients $D_{LX}$ and $D_{LZ}$ (longitudinal-to-transverse and longitudinal-to-longitudinal, respectively) are extracted and are found to be small and mostly compatible with zero within their statistical and systematic uncertainties, essentially independent of the relevant kinematic variables. [...]