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[en] Various works on multiplicity fluctuations have investigated the dynamics of particle production process and eventually have tried to reveal a signature of phase transition in ultrarelativistic nuclear collisions. Analysis of fluctuations of spatial patterns has been performed in terms of conventional approach. However, analysis with fractal dynamics on the scaling behavior of the void has not been explored yet. In this work, we have attempted to analyze pion fluctuation in terms of the scaling behavior of the void probability distribution in azimuthal space in ultrarelativistic nuclear collisions in the light of complex networks. A radically different and rigorous method, namely, Visibility Graph, was applied to the data of "3"2S-Ag/Br interaction at an incident energy of 200 GeV per nucleon. The analysis reveals strong scaling behavior of void probability distributions in azimuthal space and a strong centrality dependence.
[en] This work describes an investigation of electron scattering on molecular hydrogen and deuterium measured by the 'Troitsk nu-mass' group. The results of this work are essential for further investigation of the tritium beta-spectrum in search for active and sterile neutrinos in the 'Troitsk nu-mass' and KATRIN experiments as well as astrophysical problems. Electrons were generated by the electron gun with a narrow emission spectrum (less than 0.3 eV) at electron energies of 14, 17, 18.7, 19 and 25 keV. The relative resolution of spectrometer in these measurements was 8.3 · 10-5.
[en] The two-body weak nonleptonic decays of B mesons emitting pseudoscalar (P ) and vector (V ) mesons within the diagrammatic approach at flavor SU(3) symmetry level are presented. Using the decay amplitudes, we are able to relate the branching fractions of B → PV decays induced by both b → c and b → u transitions, which are found to be well consistent with the measured data. We also make predictions for some decays which can be tested in future experiments.
[en] Nowadays the use of distributed collaboration tools is widespread in many areas of people activity. But lack of mobility and certain equipment dependence create difficulties and decelerate development and integration of such technologies. Also, mobile technologies allow individuals to interact with each other without need of traditional office spaces and regardless of location. Hence, realization of special infrastructures on mobile platforms with the help of ad hoc wireless local networks could eliminate hardware attachment and be also useful in terms of scientific approach. Solutions from basic internet messengers to complex software for online collaboration equipment in large-scale workgroups are implementations of tools based on mobile infrastructures. Despite growth of mobile infrastructures, applied distributed solutions in group decision-making and e-collaboration are not common. In this article we propose software complex for real-time collaboration and decision-making based on mobile devices, describe its architecture and evaluate performance.
[en] In this article the problem of scientific projects support throughout their lifecycle in the computer center is considered in every aspect of support. Configuration Management system plays a connecting role in processes related to the provision and support of services of a computer center. In view of strong integration of IT infrastructure components with the use of virtualization, control of infrastructure becomes even more critical to the support of research projects, which means higher requirements for the Configuration Management system. For every aspect of research projects support, the influence of the Configuration Management system is reviewed and development of the corresponding elements of the system is described in the present paper.
[en] A quantum fermionic massless charged particle self-interacting with its own self-generated bosonic electromagnetic field is reanalyzed in the framework of the Fock many-temporal and Feynman proper time approaches. The self-interaction phenomenon structure is discussed within the renormalized quantum Fock space. The quantum electromagnetic charged particle mass origin is suggested.
[en] The dynamics of partons, hadrons and strings in relativistic nucleus-nucleus collisions is analyzed within the novel Parton-Hadron-String Dynamics (PHSD) transport approach, which is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results - including the partonic equation of state - in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current conservation, color neutrality as well as energy-momentum conservation. Since the dynamical quarks and antiquarks become very massive close to the phase transition, the formed resonant 'pre-hadronic' color-dipole states (qq bar or qqq) are of high invariant mass, too, and sequentially decay to the ground-state meson and baryon octets increasing the total entropy. When applying the PHSD approach to Pb+Pb collisions at 158A GeV, we find a significant effect of the partonic phase on the production of multistrange antibaryons due to a slightly enhanced ss bar pair production from massive time-like gluon decay and a larger formation of antibaryons in the hadronization process
[en] In recent years Hagedorn states have been used to explain the physics close to the critical temperature within a hadron gas. Because of their large decay widths, these massive resonances lower η/s to near the AdS/CFT limit within the hadron gas phase. A comparison of the Hagedorn model to recent lattice results is made and it is found that for both Tc = 176 MeV and Tc = 196 MeV, the hadrons can reach chemical equilibrium almost immediately, well before the chemical freeze-out temperatures found in thermal fits for a hadron gas without Hagedorn states. In this paper we also observe the effects of Hagedorn states on the K+/π+ horn seen at AGS, SPS, and RHIC
[en] The first-principle approach to the dense state of QCD matter, i.e., the lattice-QCD simulation at finite baryon density, is not under theoretical control for the moment. The effective model study based on QCD symmetries is a practical alternative. However, the model parameters that are fixed by hadronic properties in the vacuum may have unknown dependence on the baryon chemical potential. We propose a new prescription to constrain the effective model parameters by the matching condition with the thermal Statistical Model. In the transitional region where thermal quantities blow up in the Statistical Model, deconfined quarks and gluons should smoothly take over the relevant degrees of freedom from hadrons and resonances. We use the Polyakov-loop coupled Nambu-Jona-Lasinio (PNJL) model as an effective description in the quark side and show how the matching condition is satisfied by a simple ansaetz on the Polyakov loop potential. Our results favor a phase diagram with the chiral phase transition located at slightly higher temperature than deconfinement which stays close to the chemical freeze-out points
[en] We discuss the possibility of a nonvanishing spin tensor in relativistic hydrodynamics and its relevance to the description of Quark-Gluon-Plasma evolution in relativistic heavy ion collisions. After a short historical introduction, we report on some recent theoretical results for fully equilibrated fluids