Yu. E. Pokrovsky

Analysis of intermediate-energy heavy-ion collisions within relativistic mean-field two-fluid model☆

A three-dimensional realization of the relativistic mean-field two-fluid model is described. First results of analyzing the inclusive data on the yield of nuclear fragments and pions, as well as the Plastic-Ball rapidity distributions of nuclear fragments are presented. For comparison, calculations within the conventional relativistic hydrodynamical model with the same mean fields are also performed. In spite of a pronounced sensitivity of the nuclear dynamics to the nuclear equation of state (more precisely, to the form of the mean fields), it is found that all the analyzed observables, except the pion spectra, appear to be fairly insensitive to it. The sensitivity to the nuclear stopping power is slightly higher. The original sensitivity of the rapidity distributions to the stopping power is smeared out by the Plastic-Ball filter and selection criterion. Nevertheless, one can conclude that the stopping power induced by the Cugnon parametrization of the nucleon-nucleon cross sections is not quite sufficient for a more adequate reproduction of the experimental data.

Photon emission in Pb + Pb collisions at SpS and LHC

Abstract The yield of direct photons in Pb + Pb collisions at SpS and LHC energies is evaluated with emphasis on estimates of possible uncertainties. The possibility of experimental observation of direct photons at LHC is discussed. Predictions of several models at SpS energy are compared.

Dark matter bodies in star and planet structures

The lowest frequency of the dipole f mode (surface gravity wave) of the Sun and some other stars is shown to be close to the orbital frequency of a trial body near the star surface, as well as the wave amplitude is shown to be resonantly increased to the values large enough to be observed. Therefore the Sun is considered to be a sensitive detector for hypothetical compact cosmic bodies made of dark matter particles. In this connection some possible characteristics of the dark matter bodies (DMB) are discussed, and DMB orbits in the Sun are calculated within a standard solar model in order to compare the wave amplitudes with data for the solar surface oscillations, and to estimate the masses and radii of the DMB. As well, some possible phenomena in star and planet structures are discussed with special attention on generation of flares of high X-ray classes, specific behavior of the Moon dust, formation of short-time vertical flows in deserts, oceans, and atmospheres on the Earth and other planets.

Direct hadron production in ultrarelativistic heavy-ion collisions

Hadrons emitted by the pre-surface layer of quark-gluon plasma (QGP) before phase transition into hadronic gas are considered as possible source of direct information about QGP. It is shown that these hadrons dominate at soft p_t if QGP is created in ultrarelativistic heavy ion collisions.Abstract Hadrons emitted by the pre-surface layer of a quark-gluon plasma (QGP) before the phase transition into a hadronic gas are considered as possible sources of direct information about QGP. It is shown that if QGP is created in ultrarelativistic heavy-ion collisions, then these hadrons strongly contribute at soft p t at SpS energy and dominate up to an order of magnitude at LHC energy.

QCD, colorless quark-gluon clusters and hadron plasma

Abstract A new physical level of the effective hadron structure which may be seen at intermediate value of 4-momentum transfer | t | = 1−10GeV 2 is proposed and possible existence of a new hadron phase (Hadron Plasma) is predicted.

Compact clumps of dark matter near the solar surface

The solar surface oscillations observed in the Crimean Astrophysical Observatory (CrAO) at the frequency 104.1890 μHz and in the Solar and Heliospheric Observatory (SoHO) at 220.72 μHz are considered as a result of existence of Compact Clumps of Dark Matter (CCDM) at orbits near the solar surface. These CCDM have to emit Gravitational Waves (GW) which are estimated to be the most intensive ones expected in the vicinity of the Earth and can be easily detected in the near future by means of the Evolved Laser Interferometer Space Antenna (eLISA). In addition to CCDMCrAO and CCDMSoHO some other CCDM may exist in the solar structure. It is shown that GW radiated by most of these CCDM could be detected by eLISA even if the respective solar surface oscillations are too small to be observed.

Compact dark matter objects, asteroseismology, and gravitational waves radiated by sun

The solar surface oscillations observed by Crimean Astrophysical Observatory and Solar Helioseismic Observatory are considered to be excited by a small fraction of Dark Matter in form of Compact Dark Matter Objects (CDMO) in the solar structure. Gravitational Waves (GW) radiated by these CDMO are predicted to be the strongest at the Earth and are easily detectable by European Laser Interferometer Space Antenna or by Gravitational-Wave Observatory “Dulkyn” which can solve two the most challenging tasks in the modern physics: direct detection of GW and DM.

Compact Colorless Quark-Gluon Clusters in IAE Bag Model and Intermediate Structure of SU(3) Hadrons. Pion and Nucleon Electromagnetic form Factors

Within a framework of modified version of a bag model (IAE bag) which leads to a new physical picture of effective hadron structure, possibly appearing at 4-momentum transfer │t│=1–10 GeV2, electromagnetic form factors of pion and nucleons are considered.