Measurement of the 1H(γ, p)π0 reaction using a novel nucleon spin polarimeter.

We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon. The measurement pioneers a novel polarimetry technique, which can be applied to many other nuclear and hadron physics experiments. The commissioning reaction of 1H(γ, p)π0 in the range 0.4

Accurate test of chiral dynamics in the γp→π0p reaction.

A precision measurement of the differential cross sections dσ/dΩ and the linearly polarized photon asymmetry Σ≡(dσ⊥-dσ∥)/(dσ⊥+dσ∥) for the γp→π0p reaction in the near-threshold region has been performed with a tagged photon beam and almost 4π detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multiphoton detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the S- and all three P-wave amplitudes for the first time and provide the most stringent test to date of the predictions of chiral perturbation theory and its energy region of agreement with experiment.

[Comparison of conventional renal clearance values with differently evaluated results of radioisotope nephrography (author's transl)]. / Vergleich konventioneller Nierenclearancewerte mit verschiedenen Auswerteergebnissen der Radioisotopennephrographie.

81 patients with renal abnormalities or renal disorders of different genesis and severity with and without restricted renal function were investigated by means of the classical PAH- and inulin-clearance. Furthermore a radioisotope nephrography was carried out after application of I 131-Hippuran followed by Cr 51-EDTA. In addition the activity reduction was measured above the shoulder, as well as the activity in serum samples and urine samples gained 30 min after application. A comparison of the clearance values found with those of conventional clearance resulted in poor correlation for I 131-Hippuran (r = 0.54) and no correlation for Cr51-EDTA. Of the many parameters of the radioisotope nephrogram curves only the following are able to give sufficient quantitative functional results: The parameters connected with the rise of the curve between the 48rh and 120rh s and those connected with the slope of the secant. This is also true for the values of activity measured in the urine.