Equilibrium States in the Quadruple–Kerr Solution

The extended quadruple–Kerr metric is used to consider equilibrium states of four collinear Kerr particles. We explain our previous failure to solve numerically the full set of the balance equations, and we derive a self–consistent system of the axis conditions leading to the equilibrium of all four constituents which can be black holes or hyperextreme objects. The equilibrium configurations obtained in this paper exhibit similar features with those occurring in the systems of two Kerr particles, for instance, the balance of four Kerr black holes with positive masses does not seem possible. Equilibrium states of two identical compound Kerr objects are also discussed.     

Basic principles of technological shaping of optical properties and radiation hardness of PWO crystals

Technological conditions ensuring growth of optically homogeneous lead tungstate (PWO) crystals are reported. It is shown that the basic scintillator characteristics of PWO grown from highly purified raw material and properly doped with lanthanides are mainly determined by inclusions of oxides W_1−yL_yO_3−x (L=Y, La, Gd; 0<x<0.3). Moreover, surface-located inclusions with structure close to tungstenite may also be of importance. It is demonstrated that the scintillation properties can be intentionally designed by varying the oxygen content in the inclusions x and the surface structure. The optimal value for x and the most favorable surface structure are achieved by proper thermal regimes and environment content during the crystal annealing. The results enabled low-cost fabrication of PWO scintillators with steady and reproducible characteristics acceptable for the CERN project ALICE and ensured production of PWO on an industrial scale by “North Crystals” company at a rate of 125–135 crystals per year from every growth apparatus.     

Some insight into the structure of the nuclei 19F, 19Ne, 21Ne, 21Na, 23Na and 23Mg through the generator coordinate method and the projected Hartree-Fock method

Structures of two sets of mirror nuclei ¹⁹Ne, ²¹Na, ²³Mg and ¹⁹F, ²¹Ne, ²³Na were studied comparatively by means of the electromagnetic properties of the even-parity states, calculated with the generator coordinate method and with mixing of projected Hartree-Fock determinants. The present results are compared with those of complete diagonalization. In particular, collective features of these nuclei are investigated by comparing the various microscopic results with the predictions of the simple rotational model.     

The nucleon-nucleon potential in the nonrelativistic quark model

The effective nucleon-nucleon potential is presented in the model with two three-quark clusters. The potential is nonlocal and nonadiabatic.The shape of the local adiabatic part strongly depends on the definition of the effective potential and on the choice of the subspace used in the calculation. To get some information about the repulsive core and the weak attractive part, one has also to take into account the nonlocal terms. Then for commonly used quark-quark interactions, a repulsive core is obtained, which is not very sensitive to the choice of the parameters of the quark-quark interaction; beyond the core there is a weak attraction.The trial function is constructed as a mixture of NN, ΔΔ and different coloured baryon-coloured baryon configurations. The trial function is an antisymmetric colour singlet with isospin T = 0, spin S = 1 and orbital angular momentum L = 0.