Summary of studies of the η meson production with polarized proton beam at COSY‐11
We report on the COSY‐11 measurements of the analysing power for the pp→ppη reaction and interpret the results in the framework of the meson exchange models.
POLARIZATION PHENOMENA IN NUCLEAR REACTIONS.
The recent appearance of high-intensity polarized beams with a small energy spread has made feasible a number of experiments which could not have been considered just a few years ago. In many reactions, polarization parameters can often be measured almost as easily as cross sections. The volume of experimental data can thus be expected to increase rapidly; the results should be precise and reliable. The problem of explaining the measurements and drawing from them all the information about nuclear structure and nuclear reaction mechanisms that they contain is likely to severely challenge standard reaction theories.
POLARIZATION OF PROTONS FROM DEUTERON STRIPPING REACTIONS
The proton polarization angular distributions from the following reactions have been measured: ${\mathrm{C}}^{12}(d,p){\mathrm{C}}^{13*}(3.09 \mathrm{MeV},{l}_{n}=0)$; ${\mathrm{Mg}}^{24}(d,p){\mathrm{Mg}}^{25}(\mathrm{g}.\mathrm{s}.,{l}_{n}=2,\mathrm{and} 0.58 \mathrm{MeV},{l}_{n}=0)$; ${\mathrm{Be}}^{9}(d,p){\mathrm{Be}}^{10}(\mathrm{g}.\mathrm{s}.,{l}_{n}=1,\mathrm{and} 3.37 \mathrm{MeV},{l}_{n}=1)$; ${\mathrm{Si}}^{28}(d,p){\mathrm{Si}}^{29*}(1.28 \mathrm{MeV},{l}_{n}=2)$. The incident deuteron energy was 15 MeV. Carbon and helium were used as polarization analyzers. The results are discussed in terms of distorted-wave theory. In addition to the polarization measurements, the differential cross section of deuterons elastically scattered from aluminum, silicon, and beryllium has been determined.