Recent Experimental Tests of Special Relativity

We review our recent Michelson-Morley (MM) and Kennedy-Thorndike (KT) experiment, which tests Lorentz invariance in the photon sector, and report first results of our ongoing atomic clock test of Lorentz invariance in the matter sector. The MM-KT experiment compares a cryogenic microwave resonator to a hydrogen maser, and has set the most stringent limit on a number of parameters in alternative theories to special relativity. We also report first results of a test of Lorentz invariance in the SME (Standard Model Extension) matter sector, using Zeeman transitions in a laser cooled Cs atomic fountain clock. We describe the experiment together with the theoretical model and analysis. Recent experimental results are presented and we give a first estimate of components of the $\tilde{c}^p$ parameters of the SME matter sector. A full analysis of systematic effects is still in progress, and will be the subject of a future publication together with our final results. If confirmed, the present limits would correspond to first ever measurements of some $\tilde{c}^p$ components, and improvements by 11 and 14 orders of magnitude on others.Comment: 29 pages. Contribution to Springer Lecture Notes, "Special Relativity - Will it survive the next 100 years ?", Proceedings, Potsdam, 200

The pure rotational spectrum of 15ND2 observed by millimetre and submillimetre-wave spectroscopy

none7noThe pure rotational spectrum of the amidogen radical 15ND2 has been observed between 264 and 1051 GHz with a source-modulation millimetre- and submillimetre-wave spectrometer. A total of 346 transitions were identified, although not all of them were resolved, because of the complexity of the fine and hyperfine structures. The set of spectroscopic parameters determined from the analysis of the spectrum refers to rotational, centrifugal distortion and electron spin-rotation interaction terms. Moreover, the hyperfine constants relative to the electronic spin-nuclear spin interaction for both deuterium and nitrogen nuclei and to the nuclear rotation–nuclear spin interaction for nitrogen were also successfully fitted. This work provides the first laboratory observation and spectroscopic characterization of the fully substituted isotopologue of the astrophysically important species NH2.mixedMelosso, Mattia; Conversazioni, Beatrice; Esposti, Claudio Degli; Dore, Luca; Cané, Elisabetta; Tamassia, Filippo*; Bizzocchi, LucaMelosso, Mattia; Conversazioni, Beatrice; Esposti, Claudio Degli; Dore, Luca; Cané, Elisabetta; Tamassia, Filippo*; Bizzocchi, Luc

Electric discharge phenomena in irradiated dielectrics may reduce the reliability of space and thermonuclear equipment

Translated from Russian (Fiz. Khim. Obrab. Mater. 1997 (5) 37-44)Available from British Library Document Supply Centre-DSC:9023.190(9695)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo