The integrated cross section $widetildesigma$ for a special type of double polarized proton-deuteron scattering constitutes a null test forvtime-invariance violating but P-parity conserving effects. Using the Glauber theory for the $pd$ elastic scatt
ering and different types of phenomenological T-odd P-even NN-interactions we show that the contribution of the lowest mass meson exchange, i.e. the $rho$-meson, to the null-test signal $widetildesigma$ vanishes. Variation of the cross section $widetildesigma$ due to strong hadronic and Coulomb interaction is studied and its energy dependence is calculated in the GeV region.
Mechanisms of the charge exchange reaction $dpto {pp}_{!s} Npi$, where ${pp}_{!s}$ is a two-proton system at low excitation energy, are studied at beam energies 1 -- 2 GeV and for invariant masses $M_X$ of the final $Npi $ system that correspond to t
he formation of the $Delta(1232)$ isobar. The direct mechanism, where the initial proton is excited into the $Delta(1232)$, dominates and explains the existing data on the unpolarized differential cross section and spherical tensor analyzing power $T_{22}$ for $M_X> 1.2$ GeV/$c^2$. However, this model fails to describe $T_{20}.
Antiproton scattering off $^3He$ and $^4He$ targets is considered at beam energies below 300 MeV within the Glauber-Sitenko approach, utilizing the $bar N N$ amplitudes of the Julich model as input. A good agreement with available data on differentia
l $bar p ^4He$ cross sections and on $bar p ^3He$ and $pbar ^4He$ reaction cross sections is obtained. Predictions for polarized total $bar p ^3$He cross sections are presented, calculated within the single-scattering approximation and including Coulomb-nuclear interference effects. The kinetics of the polarization buildup is discussed.
A formalism for spin observables of the reaction $pdto ~^3Heeta$ is derived in a model independent way. The general case with a full set of six independent spin amplitudes is studied. Furthermore, approximations by five and four spin amplitudes a
re investigated in the near threshold region. This region is of great interest to search for a quasi-bound $^3He-eta$ state, in particular, by measurement of energy dependence of relative phases of s- and p-wave amplitudes. Complete polarization experiments, allowing determination of spin amplitudes, are analyzed. It is shown that measurement of only analyzing powers and spin correlation coefficients hardly allows one to separate the s- and p-wave amplitudes, but additional measurement of polarization transfer coefficients simplifies this problem. Specific observables, given by products of one s- and one p-wave amplitudes, are found. Measurement of these observables will provide new independent information on the $^3He-eta$ pole position.
