The author’s lecture courses available online seem to be overloaded with demonstration materials. Therefore, some of these materials, especially those relating to various experiments, are presented here separately. It is aimed at providing a clear explanation of modern experiments related to the spin of the particle.

When the scattering amplitude is known, the various scattering observables can be constructed. In the tensorial construction of the effective interaction all terms that involve the spin observables ϭ_{1 •} ϭ₂^., S or S_1,2 produce spin-flip (S =1) transitions in the projectile and in the  target. Nucleons 1 and 2 are indicated here, and S = s₁ + s₂ is a total two-nucleon spin. Experiments that explore possibilities like those presented above are very important. It would be interesting to compare the obtained measurement results with certain model predictions, which would be allowed for a transition transferring spin as well as orbital angular momentum.

In order to investigate the possible sensitivity of a small wavelength probe to the details of nuclear structure, polarized protons are often chosen. In addition, a ⁸⁹Y target can be used as a nuclear sample. The low-lying excitations in it are separated well enough to be resolved and have a well-known almost pure single particle character. Moreover, for comparison here we can choose as targets the neighboring nuclei ⁸⁹Y  and ⁹⁰Zr. Both of these nuclei have been thoroughly studied and exhibit a rich spectroscopy.

The inelastic scattering of polarized protons at E_p 20 MeV is represented here in experiments from the odd–A spherical nucleus ⁸⁹Y and the neighboring even-even nucleus ⁹⁰Zr, as well as from the nucleus ⁹²Mo. The corresponding microscopic and macroscopic DWBA (CC) calculations are also investigated. Special attention is paid to the analysis of results for such states in ⁸⁹Y  as 9/2⁺ (0.91 MeV), 3/2^- (1.50 MeV) and 5/2^- (1.74 MeV) that have been sufficiently studied in terms of their structure. For example, they have been treated as nearly pure one-quasiparticle states. It is shown that here, at low proton energies E_p, a strong influence of the spin-flip part of the interaction is recognized. In contrast, there are cases where only one non-spin-flip excitation is sufficient to perform the experiment. In particular, this concerns the 9/2⁺ (0.91 MeV) ⁸⁹Y excitation but at large E_p values (800 MeV). Moreover, there are cases when even in the range of medium values of E_pthe spin-flip part of the interaction is neglected. Here we present examples of non-spin-flip transitions even at low proton energies (20 MeV). The corresponding references are given in the Appendix.

Chapter Five is recommended to students studying experimental nuclear physics at universities and polytechnic schools. It can be used as a guide to understanding elements of quantum mechanics. Such a guide, in the author’s opinion, can eliminate the existing gap in the available scientific literature.