657 research outputs found

    New method for measuring longitudinal fuctuations and directed flow in ultrarelativistic heavy ion reactions

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    It has been shown in recent ALICE@LHC measurements that the odd flow harmonics, in particular a directed flow, v1, occurred to be weak and dominated by random fluctuations. In this work we propose a new method, which makes the measurements more sensitive to the flow patterns showing global collective symmetries. We demonstrate how the longitudinal center of mass rapidity fluctuations can be identified, and then the collective flow analysis can be performed in the event-by-event center of mass frame. Such a method can be very effective in separating the flow patterns originating from random fluctuations, and the flow patterns originating from the global symmetry of the initial state.Comment: 8 pages, 2 figure

    HYDRO + JETS (HYDJET++) event generator for Pb+Pb collisions at LHC

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    The Monte Carlo event generator HYDJET++ is one of the few generators, designed for the calculations of heavy-ion collisions at ultrarelativistic energies, which combine treatment of soft hydro-like processes with the description of jets traversing the hot and dense partonic medium. The model is employed to study the azimuthal anisotropy phenomena, dihadron angular correlations and event-by-event (EbyE) fluctuations of the anisotropic flow in Pb+Pb collisions at sNN=2.76\sqrt{s_{NN}} = 2.76 TeV. The interplay of soft and hard processes describes the violation of the mass hierarchy of meson and baryon elliptic and triangular flows at p_T > 2 GeV/c, the fall-off of the flow harmonics at intermediate transverse momenta, and the worsening of the number-of-constituent-quark (NCQ) scaling of elliptic/triangular flow at LHC compared to RHIC energies. The cross-talk of v_2 and v_3 leads to emergence of higher order harmonics in the model and to appearance of the ridge structure in dihadron angular correlations in a broad pseudorapidity range. HYDJET++ possesses also the dynamical EbyE fluctuations of the anisotropic flow. The model results agree well with the experimental data.Comment: 8 pages, 6 figures, contribution to Proceedings of the Winter Workshop on Nuclear Dynamics 201

    Comparative efficacy of medication and cardiac resynchronization therapy in patients with heart failure with reduced ejection fraction

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    Aim. To compare the effectiveness of standard conservative therapy for heart failure (HF) with the inclusion of sacubitril/valsartan combination and device therapy.Material and methods. The study included 64 patients from 38 to 73 years old (45 men and 19 women; mean age, 59,5±0,9 years) hospitalized in Baku (Azerbaijan) hospital due to NYHA class II-IV HF. The patients were divided into the experimental (group 1) and control (group 2) groups. The experimental group included 33 patients who took sacubitril/valsartan twice a day in combination with other drugs for standard HF therapy. The control group included 31 patients after cardiac resynchronization therapy. We compared clinical and hemodynamic parameters (including 6-minute walk test and echocardiography data) before and 6 months after treatment, as well as blood concentration of brain natriuretic peptide (BNP). In addition, Kaplan-Meier survival curves were analyzed.Results. As a result of 6-month therapy, clinical condition of patients in both groups was improved. In the experimental group, some parameters were significantly better than in the control one. So, the differences regarded distance in 6-minute walk test (pu=0,002), changes in HF class (pu=0,017), LV ESD (pu=0,006), LV EDD (pu=0,001) and blood BNP concentrations (pu<0,001).Conclusion. The use of sacubitril/valsartan combination as part of standard HF therapy was accompanied by a significant improvement in the clinical, hemodynamic and biochemical parameters of patients with HF compared with device therapy

    Influence of resonance decays on triangular flow in heavy-ion collisions

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    Anisotropic flow in relativistic collisions of heavy-ions yields important information about the state of the hot and dense matter created in the collision. Study of triangular flow in Pb+Pb collisions at LHC was performed using HYDJET++ Monte Carlo generator. HYDJET++ combines both hydrodynamics-driven soft part together with hard jet-part, giving a realistic prediction for vast number of hadron species. The model also enables study of influence of final-state interactions on flow of created hadrons. Triangular flow patterns of pions, kaons and protons were studied. We found that resonance decays influence significantly the shape of the distributions

    Higher harmonics of azimuthal anisotropy in relativistic heavy ion collisions in HYDJET++ model

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    The LHC data on azimuthal anisotropy harmonics from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the framework of the HYDJET++ model. The cross-talk of elliptic v2v_2 and triangular v3v_3 flow in the model generates both even and odd harmonics of higher order. Comparison with the experimental data shows that this mechanism is able to reproduce the pTp_{\rm T} and centrality dependencies of quadrangular flow v4v_4, and also the basic trends for pentagonal v5v_5 and hexagonal v6v_6 flows.Comment: 12 pages including 13 figures as EPS-files; prepared using LaTeX package for publication in the European Physical Journal
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