Quenching of the Deuteron in Flight

We investigate the Lorentz contraction of a deuteron in flight. Our starting point is the Blankenbecler-Sugar projection of the Bethe-Salpeter equation to a 3-dimensional quasi potential equation, wqhich we apply for the deuteron bound in an harmonic oscillator potential (for an analytical result) and by the Bonn NN potential for a more realistic estimate. We find substantial quenching with increasing external momenta and a significant modification of the high momentum spectrum of the deuteron.Comment: 11 pages, 4 figure

Correction due to finite speed of light in absolute gravimeters

Correction due to finite speed of light is among the most inconsistent ones in absolute gravimetry. Formulas reported by different authors yield corrections scattered up to 8 $\mu$Gal with no obvious reasons. The problem, though noted before, has never been studied, and nowadays the correction is rather postulated than rigorously proven. In this paper we make an attempt to revise the subject. Like other authors, we use physical models based on signal delays and the Doppler effect, however, in implementing the models we additionally introduce two scales of time associated with moving and resting reflectors, derive a set of rules to switch between the scales, and establish the equivalence of trajectory distortions as obtained from either time delay or distance progression. The obtained results enabled us to produce accurate correction formulas for different types of instruments, and to explain the differences in the results obtained by other authors. We found that the correction derived from the Doppler effect is accountable only for $\frac23$ of the total correction due to finite speed of light, if no signal delays are considered. Another major source of inconsistency was found in the tacit use of simplified trajectory models

Improvements of the MPG-2 transportable absolute ballistic gravimeter

The MPG-2 (Max-Planck-Gravimeter) is a transportable absolute gravimeter built on a classical free-fall scheme to measure the local gravity value. With significant improvements and further investigations in recent years, the standard deviation of the mean for a typical measurement over 12 h to 24 h is 1.0 mu Gal to 3.0 mu Gal (1 mu Gal = 10(-8) ms(-2)), and the combined standard uncertainty is estimated to be less than 10 mu Gal. The major improvements include the new interferometer design and alignment, longer drop length, reduced recoil effects and demagnetization of the falling body. The revised uncertainty budget and new measurement results of MPG-2 are reported. The results of observations at the reference gravity station Bad Homburg confirmed the revised uncertainty budget