123206973
The interior of the charge transition density and the structure of low-lying states in deformed nuclei
The RPA calculations of charge transition densities (CTD) rho lambda mu nu (r) for the E2 transitions from the ground state to the low-lying Ipi Knu =2+2nu and 2+0nu states in 164Dy predict rather strong peaks of single-particle nature in the interior of the CTD. A simple explanation of the results is given. The reliability of the results obtained, their possible application to the study of the structure of low-lying states and some predictions for nuclei of the rare-earth region are discussed.
125434188
RPA description of dipole oscillations in deformed sodium clusters
117583655
Overlap of metal clusters and nuclear structure physics
121516467
CollectiveEλ excitations of surface character in spherical and deformed sodium clusters: vibrating potential model
The self-consistent vibrating potential model (VPM) is extended for the description ofEλ surface collective excitations in alkali metal clusters with practically any kind of static deformation. The case of spherical clusters is also covered. Any single-particle potentials and valence electron densities for which the coefficients of the multipole expansion are known can be used within the model. The strength function method incorporated into the model allows one to avoid solving the equations for every state and, as a result, simplifies the calculations drastically. The model is of a quite general character and can also be used for description of giant resonances in atomic nuclei if the Coulomb terms are neglected. The VPM is applied to calculate theE1,E2 andE3 excitations in spherical (Na8, Na20 and Na40) and deformed (Na10, Na18 and Na26) clusters.
116346471
APPLICATION OF NUCLEAR THEORY METHODS TO NEW FAMILY OF FERMI SYSTEM
Duo to a remarkable progress in experimental techniques, the new family of .small Fermi systems (SFS) (metal clusters, fullerencs, helium clusters and quantum dots) was discovered about ten years ago. As was established, those Fermi systems have a striking similarity with atomic nuclei (see re­views and conference proceedings [1-9]). The most remarkable feature of now SFS is that they possess a mean field of the same kind as in atomic iniclci which allows one to investigate SFS by nuclear theory methods. If recent investigations of SFS have mainly been limited to atoms and atomic nuclei, our present possibilities have become much wider, We have really obtained a good chance for studying both a common behavior of SFS and a wonderful variety of their properties. In the present paper, the particular properties of the new SFS as well as the application of nuclear physics methods to their description are briefly reviewed. The properties of the new SFS and atomic nuclei are continually compared. The main attention is paid to metal clusters (MC) or, more precisely, to E\ giant resonances (GR) in this system. Iri Sec.2, the sketch of basic properties of MC as well as the perspectives of their investigation arc given. Sec.3 is devoted to the description of E\ GR in MC, In Sec.3 the properties of fullerencs, helium clusters and quantum dots are outlined. In Sec.4 the conclusions are presented.
15271453
On instability of hadronic string with heavy quarks at its ends
The quark mass dependence of the energy spectrum in the Nambu--Goto string with point--like masses (quarks) at its ends is analyzed. To this end, linearized equations of motion and boundary conditions in this model are considered. It is shown that for sufficiently large quark masses, the first excited state in string spectrum may be arbitrary close to the ground state. Obviously this points to infrared instability in the system under consideration. Possible modifications of string model which could remove this drawback are discussed.
120508035
Covariant formalism for a relativistic string in a constant homogeneous electromagnetic field
16251774
Spectral zeta functions for a cylinder and a circle
Spectral zeta functions ζ(s) for the massless scalar fields obeying the Dirichlet and Neumann boundary conditions on a surface of an infinite cylinder are constructed. These functions are defined explicitly in a finite domain of the complex plane s containing the closed interval of real axis −1⩽Re s⩽0. Proceeding from this the spectral zeta functions for the boundary conditions given on a circle (boundary value problem on a plane) are obtained without any additional calculations. The Casimir energy for the relevant field configurations is deduced.
119947614
Bremsstrahlung approximation for inclusive processes
5898616
Non-smoothness of the boundary and the relevant heat kernel coefficients
The contributions to the heat kernel coefficients generated by the corners of the boundary are studied. For this purpose the internal and external sectors of a wedge and a cone are considered. These sectors are obtained by introducing, inside the wedge, a cylindrical boundary. Transition to a cone is accomplished by identification of the wedge sides. The basic result of the paper is the calculation of the individual contributions to the heat kernel coefficients generated by the boundary singularities. In the course of this analysis certain patterns, that are followed by these contributions, are revealed. The implications of the obtained results in calculations of the vacuum energy for regions with nonsmooth boundary are discussed. The rules for obtaining all the heat kernel coefficients for the minus Laplace operator defined on a polygon or in its cylindrical generalization are formulated.