The urgency and relevance of the topic of the dissertation. At present time, the study of the structure of exotic nuclei, which arc bound states of various mesons, and residue nucleus and other interactions is of great interest.Obtaining information about the properties of the eta-mesons and nucleon resonances bound in nucleus arc among the high-priority tasks of the modem fundamental nuclear physics studied. It can be determined that binding energy and width of the cta-meson nuclei, as well as the probabilities of the main decaying modes arc possible experimentally only. Experimental informations which arc obtained by that path arc so essantial to determine the mechanisms of interaction of eta-mesons and nucleon resonances with nucleons of nuclei, on checking the available theoretical predictions and models for the restoration of chiral symmetry in dense nuclear matter.
At the present time, there arc not practically experimental apparatus for determining the luminosity of reactions on the internal target of accelerators. Because of used apparatus and their scientific methods arc not able to give information about nuclear reactions in internal target, a accurit experimental resutls arc not achieved. Therefore, cstabilishing research methods on the internal target of accelerators, creating experimental facilities which arc aimed to study exotic nuclei structure and nucleon resonances in a nuclear medium, as well as creating methods of determination of the luminosity of reactions on the internal target of the accelerator and making an apparatus that is aimed to accomplish it and unperturbed the Nuclotron beam is considered as actual issues.
In our Republic, great attention is paid to the development of theoretical physics and the conduct of fundamental research on these areas at the world level. In this respect, significant results have been achieved in nuclear physics and elementary particle physics, a substantial gained results should be emphasized In particular: in solving existing problems in the field of accelerator technology and their practical application; in the development and creation of methods in determining the luminosity of reactions on accelerators; studying the properties of various mesons and nucleon resonances in a nuclear medium; in creation of a necessary installations for studying the structure of exotic nuclear. In accordance with the "Strategy of actions on further development of the Republic of Uzbekistan", the actual task is to improve the efficiency of the industry on the basis of theoretical and practical research in the field of the atomic nucleus and elementary particle physics by introducing innovative technologies in determining the problem of the origin of the elementary mass particles and verification of theoretical models of quantum chromodynamics.
This research work corresponds to the tasks approved in the state normative Documents, in the Decrees of the Presidentof the Republic of Uzbekistan No. PR-1443 “On the priorities of industry development of the Republic of Uzbekistan in 2011-2015” of 15 December 2010 and No.PR-2789 “On measures to further improve the activities of the Academy of Sciences, organization, management and funding research activities” of 17 February 2017, and the Decree of the President of the Republic of Uzbekistan No.PD-4958 “On the further improvement of the system of postgraduate education” of 16 February 2017.
The aim of the research is to determine the peculiarities of the exotic nuclei structure and study the properties of eta-mesons and nucleon resonances in nuclear medium.
The scientific novelty of the research is based on the following results obtained for the first time:
New experimental estimations arc obtained for the total cross-section for the eta-mesic nucleus production in the dl2C interaction on = 11 ± 8 pb at a deuteron beam energy of 2.1 GeV/nuclcon;
Binding energy of the SH(1535)-resonance Eg(Sn) = (50.3 ± 20) MeV in the exotic nucleus of carbon is determined on the average by three energies of incident nucleon (1.5, 1.9 and 2.1 GeV/nuclcon) of the Nuclotron. This value was calculated from the detected peak in the effective mass spectrum of the л p-pair from the decay of the Sn(1535)-resonance at the level (1484.7 ± 20) MeV/с2, the width of the peak turned out to be equal to (36.1 ± 9) MeV/c2;
New values arc obtained for the r|-meson binding energy in the exotic carbon nucleus under the assumption that the mass defect of the Sn(1535)-resonance is the result of the fusion of the q-meson and the nucleon in the nucleus (taking into account that the nucleon binding energy Am = Т.Ъ MeV): Eg(q) = (43 ± 20) MeV
Calibration algorithm is identified by calculating the proportionality coefficient between the true and the measured reaction luminosity for 8-elcctron for the 29Cu and 47Ag targets of the Nuclotron. The mean true luminosity Le(dCu) = (0.9 ±0.03) x 1030 cm’1 s'1 is obtained for copper target and Le(dAg) = (0.27 ±0.012) x lO^’cm’1 s'1 for silver target.
A new method is proposed to estimate A(1232) resonance production crosssection for the internal target of the Nuclotron. An estimation of the deltaresonance production total cross-section in the pA reaction for different kinetic energies of the incident protons yielded the values: Ct] = 13.15 mb (Tpl = 1.4 GeV), CT2 = 10.80 mb (Tp2 = 1.7 GeV), = 9.86 mb (Tp3 = 1.9 GeV).
