0000000000387632
AUTHOR
S. Krohn
Toward a New Test of the Relativistic Time Dilation Factor by Laser Spectroscopy of Fast Ions in a Storage Ring
The frequency measurement of Doppler-shifted optical lines of ions circulating in a storage ring at high speed permits a sensitive test of the relativistic Doppler-formula and, hence, the time dilation factor γSR of special relativity. Previous measurements at the storage ring TSR with 7Li+ at v = 0.065c gave a new, improved limit, but were hampered by the large observed linewidth, exceeding the natural width 15-fold. Recently we have identified the broadening to be caused by velocity-changing processes in the storage ring. Saturation spectroscopy has proven to be largely immune against these effects and has yielded linewidths only a few MHz larger than the natural one. This is the major in…
Improved test of time dilation in special relativity.
An improved test of time dilation in special relativity has been performed using laser spectroscopy on fast ions at the heavy-ion storage-ring TSR in Heidelberg. The Doppler-shifted frequencies of a two-level transition in 7 Li + ions at v = 0.064c have been measured in the forward and backward direction to an accuracy of Δν/ν = 1 × 10 - 9 using collinear saturation spectroscopy. The result confirms the relativistic Doppler formula and sets a new limit of 2.2 × 10 - 7 for deviations from the time dilation factor γ S R = (1 - ν 2 /c 2 ) - 1 / 2 .
Psoriasis predisposition and occupational triggering factors in the appraisal of occupational medical expertises
Summary Background Psoriasis is an immune-mediated disease with a genetic background. Local psoriatic changes can be triggered by exogenous mechanical or irritant factors. Causative occupational factors have to be distinguished from the spontaneous course of psoriasis in occupational medical evaluations. The objective of this work is to demonstrate the medico-legal grounds for a homogenous assessment. Patients and methods The presented recommendations were developed in a working group for Occupational and Environmental Dermatology (ABD) and the German contact dermatitis group (DKG) of the German Dermatologic Society (DDG) based on the German medico-legal framework. Results Causality between…