W1{infty}-convergence of the discrete free boundary for obstacle problems

We examine the discrete free boundaries arising from a finiteelement discretization of a variational inequality. We giveL error bounds for the Hausdorff distance of the discrete andtrue free boundary, as well as for the normals. The theoreticalresults are confirmed by numerical experiments in two and threedimensions.     

Submanifolds in five-dimensional pseudo-Euclidean spaces and four-dimensional FRW universes

Equations for submanifolds, which correspond to embeddings of the four-dimensional FRW universes in five-dimensional pseudo-Euclidean spaces, are presented in convenient form in general case. Several specific examples are considered.     

Azimuthal correlations of secondary particles in collisions between gold nuclei and track-emulsion nuclei at a gold-nucleus energy of 10.6 GeV per nucleon

Charged secondaries from collisions of gold nuclei with track-emulsion nuclei showed azimuthal correlations consisting in (i) the asymmetric emission of projectile and target fragments in opposite directions and (ii) an azimuthal quasicollinearity of shower particles in individual events. The measurement errors were investigated and taken into account. The experimental data in question can be interpreted within the model of Gaussian distributions of transverse momentum components.     

Special features of deuteron production in <Superscript>16</Superscript>O<Emphasis Type="Italic">p</Emphasis> collisions at a momentum of 3.25 GeV/<Emphasis Type="Italic">c</Emphasis> per nucleon

New experimental data on the dependences of the mean multiplicities and kinematical characteristics of deuterons produced in ¹⁶Op collisions at a momentum of 3.25 GeV/c per nucleon on the degree of excitation of the fragmenting nucleus are presented. These experimental data are compared with the predictions of the cascade-fragmentation-evaporation model.     

The development of an electromotive force in a semiconductor placed in an inhomogeneous magnetic field

The possibility of development of an electromotive force (emf) in a semiconductor placed only in an inhomogeneous magnetic field is shown. The conditions and the experimental evidence of its appearance are presented.     

Muon-electron events in high-energy proton-proton collisions

The tube models of nuclear production are questioned by pointing out that they cannot explain the dependence of the inclusive rapidity distribution width and the two-particle correlation function on the atomic number of the target nucleus.     

Inelastic interactions of protons with photoemulsion nuclei at 4·5 GeV/c

In inelastic collisions of protons with photoemulsion nuclei at 4·5 GeV/c, data have been obtained on multiplicity of shower particles, energy spectrum of fast secondary protons with (2·5±0·1) GeV average energy, and energy spectrum of produced charged pions with (640±±50) MeV average energy. The multiplicity, angular distributions, and energy of particles arising from splitting target-nuclei are also determined: the proton spectrum is approximated by the power dependenceE ^- with=1·4±0·1. The distribution of protons and-mesons over rapiditiesy=0·5 In[(E+p)/(E–p)] have been obtained. The average multiplicity for secondary particles coincide with the predicted values given by the cascade-evaporation model.Dedicated to the 25th anniversary of the Joint Institute for Nuclear Research.The authors would like to express their gratitude to the synchrophasotron group of JINR and to the group of S. J. Ljubomilov for the assistance in the experiment, to V. S. Barashenkov and V. V. Ivanov for the assistance in the cascade-evaporation model calculations, and also to the laboratories which took part in the scanning and measurement.     

Phenomenological analysis of the channels of the production of three and four alpha particles in <Superscript>16</Superscript>O<Emphasis Type="Italic">p</Emphasis> collisions at 3.25 GeV/<Emphasis Type="Italic">c</Emphasis> per nucleon

A phenomenological analysis of the channels of the production of three and four alpha particles in ¹⁶Op collisions at 3.25 GeV/c per nucleon is performed for the first time under conditions of 4π geometry. The experimentally observed azimuthal asymmetries and collinearity are described on the basis of a phenomenological model that assumes that the excitation of the nucleus involved is peripheral and that its decay is statistical. It is shown that the azimuthal asymmetries in question are due to the transverse motion of the fragmenting nucleus. The mean transverse momentum of alpha particles and the collinearity of their emission in the reaction plane are found to be independent of the transverse-momentum transfer to the nucleus involved.     

Proton production in <Superscript>16</Superscript>O<Emphasis Type="Italic">p</Emphasis> collisions at 3.25 GeV/<Emphasis Type="Italic">c</Emphasis> per nucleon

The momentum features of protons originating as fragments from ¹⁶Op interactions at 3.25 GeV/c per nucleon are analyzed for the first time under conditions of 4π geometry. It is found that the mechanisms of the production of all protons traveling in the forward direction in the rest frame of the fragmenting nucleus (with the exception of evaporated protons) do not depend on either the primary energy or the target-nucleus type, this regularity being quite universal for the formation of such protons. It is shown that there is a strong correlation between the shape of the momentum spectrum of protons appearing as fragments from such interactions, especially slow protons, and the degree of the excitation of the fragmenting nucleus.