Hyperon production in the threshold region was studied in the reaction pp → K + Λp using the time-of-flight spectrometer COSY-TOF. Exclusive data, covering the full phase-space, were taken at the three different beam momenta of p beam = 2.95, 3.20 and 3.30 GeV/c, corresponding to excess energies of ε = 204, 285 and 316 MeV, respectively. Total cross-sections were deduced for the three beam momenta to be 23.9 ± 0.8 ± 2.0 µb, 28.4 ± 1.3 ± 2.2 µb and 35.0 ± 1.3 ± 3.0 µb. Differential observables including Dalitz plots were obtained. The analysis of the Dalitz plots reveals a strong influence of the

Using the National Synchrotron Light Source (NSLS) at Brookhaven far-infrared absorption in the frequency range 15-45 cm-1 was detected in samples of lysozyme at different hydrations and in water. The absorption is due to the presence of low-frequency (picosecond timescale) motion in the samples, such as are calculated in molecular dynamics simulations. The form of the transmission profile is temperature independent but varies significantly with the degree of hydration of the protein. At higher hydrations the profile resembles closely that of pure water in the region 20-45 cm-1. At a low hydration marked differences are seen with, in particular, the appearance of a transmission minimum at 19 cm-1. The possible origins of the hydration dependence are discussed. The results demonstrate the usefulness of long-wavelength synchrotron radiation for the characterisation of biologically-important low-frequency motions in protein samples.

We describe the spectrometer and experimental stations on the infrared beamline (IR4) at the National Synchrotron Light Source, Brookhaven. We also report measurements of the source characteristics in the range 30–400 μm (25–350 cm−1), including both flux and brightness and compare them with corresponding measurements from a 1000-K blackbody source.

The neutron-proton capture reaction has been measured at E, = 25.6 MeV.From the data the total and the differential cross section at 0" were determined. The results are compared with photodisintegration data and theoretical calculations and found to be in agreement with both.

No abstract