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RUSSIAN DATA LAKE PROTOTYPE AS AN APPROACH TOWARDS NATIONAL FEDERATED STORAGE FOR MEGASCIENCE
No full textA substantial data volume growth will appear with the start of the HL-LHC era. It is not well coveredby the current LHC computing model, even taking into account the hardware evolution. The WLCGDOMA project was established to provide data management and storage researches. National data laker&d's, as a part of the DOMA project, should address the study of possible technology solutions forthe organization of intelligent distributed federated storage. This talk will present the current status ofthe Russian Scientific Data lake prototype and the methodology, which is used for the validation andfunctional testing of deployed infrastructure
Unified quark-hadron EoS and critical endpoint in the QCD phase diagram
No full textWe present a recent development towards a unified description of quark-hadron matter in the QCD phase diagram that is based on a cluster decomposition of the generalized Beth-Uhlenbeck approach to quark matter, selfconsistently coupled to Polyakov-loop and mesonic background fields. The Mott dissociation of hadrons under extreme conditions of temperature and density is triggered by chiral symmetry restoration and confining aspects are modeled by the coupling to the background mean fields. First results for the QCD phase diagram with the capability to describe critical endpoints as well as crossover-all-over are presented and an excellent agreement with lattice QCD on the temperature axis is obtained
Measurement of the radiation environment of the ATLAS cavern in 2017–2018 with ATLAS-GaAsPix detectors
No full textA network of ten GaAs:Cr semiconductor Timepix detectors with GaAs:Cr sensors was installed in the ATLAS cavern at CERN's LHC during the shutdown periods 2015–2016 and 2016–2017 in the framework of a cooperation between ATLAS and the Medipix2 Collaboration. The purpose was to augment the existing system of measuring and characterising the radiation environment in the ATLAS cavern that is based on ATLAS-TPX devices with pixelated silicon sensors. The detectors were in continuous operation during 13 TeV proton-proton collisions in 2017–2018. Data were recorded during proton-proton bunch crossings, and during times without bunch crossings (LHC physics runs) as well as between the physics runs. The overall level of particle radiation as well as the ratio between neutral and charged particles were measured. The detectors recorded all interactions of charge particles, neutrons and photons in GaAs sensors, in which the signal was higher than 6.5 keV in individual pixels. This made it possible to register clusters (tracks) of individual radiation particles interacting in the detectors sensors. During LHC beam-beam collisions, these were all particles represented in the radiation field. In the periods without beam-beam collisions, these were photons and electrons resulting from radioactivity induced during previous collisions in GaAs detectors and in surrounding construction materials, namely by neutrons
Kinetic Processes in Fullerene Solutions
No full textIn solutions, fullerenes, carbon nanoparticles with size of the order of one nanometer, exhibit a number of interesting properties and kinetic effects. A large part of these effects is connected with the ability of these macromolecules to form aggregates (or clusters), in which the nanoparticles are bound together by dispersion interactions. In this review, we present results of modeling of the kinetics of clusters formation and growth in fullerene C solutions of different polarity. The basic approach is the numerical solution of a system of kinetic equations of nucleation theory, applied here for the description of aggregation of fullerenes and accompanying effects. The non-monotonous time dependence of fullerene concentration during dissolution was investigated. A molecular-colloidal solution transition in polar systems is described. In addition, a model description of the critical effect of cluster decomposition after water addition to certain fullerene solutions is presented
Method of Nonperturbing Measurements of the Electron Bunch Length Based on Coherent Diffraction Radiation
No full textA simple nonperturbing technique for the electron relativistic bunch diagnostics has been proposed which does not require the use of an interferometer for spectral measurements. The interferometer functions are performed by a slit target in which diffraction radiation is generated. The measurements of electron bunch length are carried out by shifting one half of the target relative to the other. A good agreement with the results of measuring the coherent radiation spectrum of relativistic electron bunches has been obtained
Geant4 FTF model description of the latest data by the NA61/SHINE collaboration on interactions
No full textIt is shown that the Geant4 FTF model, which does not include the simulation of the hard parton-parton scattering and the formation of the quark-gluon plasma (QGP), describes well the NA61/SHINE data on meson distributions for the interactions at 5.2, 6.1, 7.6 and 8.8 GeV. At higher energies, 11.9 and 16.8 GeV, the model underestimates the data. This is considered as an indication of the formation of QGP at higher energies in central collisions of light and intermediate nuclei than in collisions of heavy nuclei ( GeV)
Cluster dynamics studied with the phase-space Minimum Spanning Tree approach
No full textThe origin of weakly bound objects like clusters and hypernuclei, observed in heavy-ion collisions, is of theoretical and experimental interest. It is in the focus of the experiments at the BNL Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) since it is not evident how such weakly bound objects can survive in an environment whose hadronic decay products point to a temperature of the order of 150 MeV. It is also one of the key research topics in the future facilities of FAIR and NICA, which are under construction in Darmstadt (Germany) and Dubna (Russia), respectively. The first results on the cluster dynamics within the model-independent cluster recognition library “phase-space minimum spanning tree” (psMST) applied to different transport approaches: PHQMD, PHSD, SMASH, and UrQMD are presented here. The psMST is based on the “minimum spanning tree” (MST) algorithm for the cluster recognition which exploits correlations in coordinate space, and it is extended to correlations of baryons in the clusters in momentum space. The sensitivity of the cluster formation on the microscopic realization of the n-body dynamics and on the potential interactions in heavy-ion collisions is shown
TMDlib2 and TMDplotter: a platform for 3D hadron structure studies
No full textA common library, TMDlib2, for Transverse-Momentum-Dependent distributions (TMDs) and unintegrated parton distributions (uPDFs) is described, which allows for easy access of commonly used TMDs and uPDFs, providing a three-dimensional (3D) picture of the partonic structure of hadrons. The tool TMDplotter allows for web-based plotting of distributions implemented in TMDlib2, together with collinear pdfs as available in LHAPDF
Form-factor-independent test of lepton universality in semileptonic heavy meson and baryon decays
No full textIn the semileptonic decays of heavy mesons and baryons, the lepton-mass dependence factors out in the quadratic cos2θ coefficient of the differential cosθ distribution. We call the corresponding normalized coefficient the convexity parameter. This observation opens the path to a test of lepton universality in semileptonic heavy meson and baryon decays that is independent of form-factor effects. By projecting out the quadratic rate coefficient, dividing out the lepton-mass-dependent factor, and restricting the phase space integration to the τ lepton phase space, one can define optimized partial rates which, in the Standard Model, are the same for all three (e,μ,τ) modes in a given semileptonic decay process. We discuss how the identity is spoiled by new physics effects. We discuss semileptonic heavy meson decays such as B¯0→D(*)+ℓ-ν¯ℓ and Bc-→J/ψ(ηc)ℓ-ν¯ℓ and semileptonic heavy baryon decays such as Λb→Λcℓ-ν¯ℓ for each ℓ=e, μ, τ
Study of Ag -decay at ALTO
No full textThe neutron rich Ag nucleus was populated via induced photofission of UC at the ALTO ISOL facility. Its -decay properties were studied by means of detecting -delayed and neutron activities. The measured half-life T = 0.350(20) s agreed with the earlier data; the -delayed neutron emission branching P = 1.01(24)% was reestablished using and neutron counting