Section I. Particles and Nuclei optimization of the basis) results in more high precision at essentially less dimensions of the basis in comparison with the known calculations [1] in traditional approach In addition to the energies and r.m.s radii, the density distributions, formfactors, pair correlation functions and momentum distributions are analyzed for three and four nucleons with a number of commonly used interaction potentials (Minnesota, Afnan-Tang. F.ikemeier-Haekenbroich etc.) as well as with our version of potential K2 [2] with small repulsion at short distances. Comparison of the results is carried out, and the convergence with the basis dimension increase is analyzed in the cases of spinless approximation [2,3] for the nuclear interaction potential, isospin representation with spin-dependent potentials, and the approach without use of the isospin quantum number. We find the hierarchy of configurations for symmetric and asymmetric (with respect to permutation o\" identical particles) wave function components with the increase of the basis dimension, and it is shown for the optimal choice of the basis functions that each of the involved asymmetric Gaussian component needs a few (about 3) symmetric ones to be involved into consideration because of their dominant role Due to the essential deer ase of the number of equations in comparison with that in traditional approaches, precise study of nuclei containing up to six nucleons with central exchange NN-potentials becoues possible. The minimum number of equations in our approach as well as the optimization schemes for constructing the optimal basis gives a possibility to present the results of precise calculations in the form of a short list of parameters of the explicit wave function (in Gaussian representation) which can be directly used by other researches for studying the processes with the nuclei *H, 'He and ''He involved

References

1. K.Varga, Y.Suzuki. Phys Rev.C v 52, JVs 6, 1995, p 2885-2905 2. B.E.Grinyuk, l.V.Simenog Ukr.J Phys, v 45 JVsl, 2000, p.2l-3O. 3. B E Grinyuk, l.V.Simenog. Ukr.J Phys , v 45, JV«4-5, 2000, p.625-633.

UZ0201734

SKYRMION DEFORMATION IN FINITE NUCLEI

Vaklisliicv IJ.T.

theoretical Physics Department ami Institute of Applied Physics National University of Uzbekistan, Tashkent, Uzbekistan

The possible modification of nucleon properties in the nuclear medium is currently a much discussed topic in low energy hadron physics. One way to consider such problems is to describe the nucleon as a topological soliton and then study the influence of baryonic matter on the properties of such solitons, making use of the independent panicle picture which has been so successful I in describing many properties of nuclei. There exist already some works where nucleons described as Skyrme-type solitons embedded in infinite nuclear matter have been considered [1,2]. The results of these studies were in qualitative agreement with experimental indications and with results of other authors using different approaches. On the quantitative level, however, there is a too large renormalization of the nucleons' effective mass in nuclear matter. The quantitative value of this renonnalization is about 40% for the normal nuclear matter density. It is therefore difficult to relate this modification of the nucleon self-energy in the medium to the nucleon mass in free space because such

111 Section I. Panicles ;tnd Nuclei calculations consider only the special case when a nucleon is placed in the center of U\e heavy nucleus. The infinite nuclear matter approach allows one only to consider properties of nucleons placed near the center of heavy nuclei where the density is constant. One can expect that taking into account nonspherical effects, i.e. deformation of the skyrmion in the finite nucleus, would improve the results also on the quantitative level Density changes play an important role when the nucleon is placed at sufficiently large distances from the center of nucleus. Some approach to deformation of the interacting two skyrmions in the Skyrme model has been made in the work [3], where changes in the nucleon shape are investigated by letting the nucleon to deform under the strong interactions with another nucleon. On the other hand, rotational and vibrational excitations of deformed skyrmions also have been considered for baryon number equal to one (B--I) system [4). In the number of works [5] effort has been made to investigate the axially .symmetric lew skyrmionic (B>1) systems, because of spherically symmetric configurations in the skyrme model do not give bound skyrmionic systems [6] even if the solutions of the model in the finite nuclei have been considered [7]. In the present work we consider properties o\' the deformed nucleon embedded into medium —heavy and heavy finite nuclei. Deformation effects are introduced by the distortion of the profile function of chira! field under the action of the external field (which parametrizes the baryonic density within a given nucleus). Wi; calculate modifications of nucleon properties in finite nuclei Their dependence on the distance between the centers of the skyrmion under consideration and the nucleus will be considered.

1. A.M. Rakhimov, MM. Musakhanov, F.O. Khanna and U.T. Yakhshiev, Phys. Rev C58, 1738(1998). 2. A.M. Rakhimov, F.C. Khanna, U.T. Yakhshiev, MM Musakhanov, Nucl Phys. A643, 383 (1998); M. Musakhanov, A. Rakhimov, U Yakhshiev, Z. Kanokov. Phys. Atom. Nucl. (Russ. J. Nucl. Phys.) 62, 1988 (1999) 3. A. Rakhimov, T. Okazaki, MM. Musakhanov, h". Khanna, Phys Lett B378, 12(1996). 4. C. Hajduk, B. Schwesinger, Phys. Lett B378. 171 (1984), C Hajduk, B Schwesinger, Nucl. Phys A453, 620 (1986). 5 V B Kopeliovich, BE. Stem, Sov. J. Jl-TP Lett 45, 165 (1987); V A Nikolaev, Sov. J. Part Nucl. 20, 40! (1989), T Kurihara, II Kanada, T. Otofuji, S. Sailo, Prog. Theor. Phys. 81, 858(1989). 6. E.B Bogomolniy, V.A. Fateev, Sov. J. Nucl. Phys. 37, 228 (1983)., 7. U.I. Yakhshiev, N.A.Taylanov, Uzb. J. Phys. 2, 114 (2000).

UZ0201735

A STUDY OF THE NIICLEON TRANSFER REACTIONS ON BORON NUCLEI

'Burtebaev N., 'Baklybaev M.K., 'Duysebacv B.A., 'Blccliman A. ML, 'Basybekov K.B. 2Arten»ov S.V., 2Kayumov M. A., 2hlarakhodzacv A.A., 2Radyuk G.A., 2Ynklashev B.S., 2Zaparov E.A.

•'institute of Nuclear Physics NNC RK, Ahmtly, Kazakhstan Institute of Nuclear Physics I Izhekistan Academy of Science, Tashkent, Uzbekistan

The differential cross sections of the nucleon transfer reactions on 10B and UB nuclei are measured on alpha and deuteron beams of the 150-cm isochronous cyclotron of the

National Nuclear Center of the Republic of Kazakhstan (Almaty) at energies Eu - 50.5 MeV and A',.* - 25 MeV The analysis of experimental differential cross sections was performed by