Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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JUSTIFICATION OF CRITERIA FOR LOCAL PREDICTION OF IMPACT SAFETY BY REGISTERING NATURAL ELECTROMAGNETIC RADIATION AT THE MINES OF AO «SUEK-KUZBASS»

The relevance of the study is caused by the need to improve geophysical methods for monitoring the stress state and forecasting geodynamic phenomena in the mines of Kuzbass, including geodynamic control systems and geo-location. The main aim is to substantiate rational methods for measuring electromagnetic radiation parameters in conditions of intensive mechanized mining of coal seams and to establish criteria values of these parameters for local prediction of impact hazard based on comparison with the main geomechanical parameters (stress concentration coefficient and distance from the coal mining contour to their maximum point) obtained using the direct basic method of drilling fines extraction. Objects: mine workings of purifying lava purification on the Kirov coalmine and when sinking preparatory workings on the coalmine Esaulskaya. Methods: analysis of scientific and practical results obtained by the electromagnetic radiation methos, which experimental and theoretical bases have been developed in different organizatons. Results. The interrelation of the amplitude, shape, pulse repetition frequency, intervals between them with the stress level, crack opening, and the rate of their development is established. «The Angel» hardware complex was developed and is constantly being improved. Its complex tests were carried out at a number of ore and coal deposits. Based on the results of industrial experimental studies the authors proved the possibility of using the method and equipment for recording electromagnetic radiation for solving a wide range of engineering and geological tasks related to geological underground exploration, diagnosing zones of tectonic disturbances, displacements and deformations. The relationship of the electromagnetic radiation parameters with the stress concentration in the array and the distance to their maximum was experimentally proved, and the features of the dynamics of changes in these parameters over time were established. Criteria values are established and a nomogram is proposed for the local prediction of impact hazard in the treatment and preparatory workings of Kuzbass mines

Outcomes of Cryoballoon Ablation in High- and Low-Volume Atrial Fibrillation Ablation Centres: A Russian Pilot Survey

Purpose. The results of cryoballoon ablation (CBA) procedure have been mainly derived from studies conducted in experienced atrial fibrillation (AF) ablation centres. Here, we report on CBA efficacy and complications resulting from real practice of this procedure at both high- and low-volume centres. Methods. Among 62 Russian centres performing AF ablation, 15 (24%) used CBA technology for pulmonary vein isolation. The centres were asked to provide a detailed description of all CBA procedures performed and complications, if encountered. Results. Thirteen sites completed interviews on all CBAs in their centres (>95% of CBAs in Russia). Six sites were high-volume AF ablation (>100 AF cases/year) centres, and 7 were low-volume AF ablation. There was no statistical difference in arrhythmia-free rates between high- and low-volume centres (64.6 versus 60.8% at 6 months). Major complications developed in 1.5% of patients and were equally distributed between high- and low-volume centres. Minor procedure-related events were encountered in 8% of patients and were more prevalent in high-volume centres. Total event and vascular access site event rates were higher in women than in men. Conclusions. CBA has an acceptable efficacy profile in real practice. In less experienced AF ablation centres, the major complication rate is equal to that in high-volume centres

Outcomes of Cryoballoon Ablation in High-and Low-Volume Atrial Fibrillation Ablation Centres: A Russian Pilot Survey

properly cited. Purpose. The results of cryoballoon ablation (CBA) procedure have been mainly derived from studies conducted in experienced atrial fibrillation (AF) ablation centres. Here, we report on CBA efficacy and complications resulting from real practice of this procedure at both high-and low-volume centres. Methods. Among 62 Russian centres performing AF ablation, 15 (24%) used CBA technology for pulmonary vein isolation. The centres were asked to provide a detailed description of all CBA procedures performed and complications, if encountered. Results. Thirteen sites completed interviews on all CBAs in their centres (>95% of CBAs in Russia). Six sites were high-volume AF ablation (>100 AF cases/year) centres, and 7 were low-volume AF ablation. There was no statistical difference in arrhythmia-free rates between high-and low-volume centres (64.6 versus 60.8% at 6 months). Major complications developed in 1.5% of patients and were equally distributed between high-and low-volume centres. Minor procedurerelated events were encountered in 8% of patients and were more prevalent in high-volume centres. Total event and vascular access site event rates were higher in women than in men. Conclusions. CBA has an acceptable efficacy profile in real practice. In less experienced AF ablation centres, the major complication rate is equal to that in high-volume centres

Direct observation of the dead-cone effect in quantum chromodynamics

The direct measurement of the QCD dead cone in charm quark fragmentation is reported, using iterative declustering of jets tagged with a fully reconstructed charmed hadron

Transverse-momentum and event-shape dependence of D-meson flow harmonics in Pb–Pb collisions at √sNN = 5.02 TeV

The elliptic and triangular flow coefficients v2 and v3 of prompt D0, D+, and D∗+ mesons were measured at midrapidity (|y| < 0.8) in Pb–Pb collisions at the centre-of-mass energy per nucleon pair of √sNN = 5.02 TeV with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays in the transverse momentum interval 1 < pT < 36 GeV/c in central (0–10%) and semi-central (30–50%) collisions. Compared to pions, protons, and J/ψ mesons, the average D-meson vn harmonics are compatible within uncertainties with a mass hierarchy for pT 3 GeV/c, and are similar to those of charged pions for higher pT. The coupling of the charm quark to the light quarks in the underlying medium is further investigated with the application of the event-shape engineering (ESE) technique to the D-meson v2 and pT-differential yields. The D-meson v2 is correlated with average bulk elliptic flow in both central and semi-central collisions. Within the current precision, the ratios of per-event Dmeson yields in the ESE-selected and unbiased samples are found to be compatible with unity. All the measurements are found to be reasonably well described by theoretical calculations including the effects of charm-quark transport and the recombination of charm quarks with light quarks in a hydrodynamically expanding medium

Global baryon number conservation encoded in net-proton fluctuations measured in Pb–Pb collisions at √sNN=2.76 TeV

Experimental results are presented on event-by-event net-proton fluctuation measurements in Pb–Pb collisions at √sNN=2.76 TeV, recorded by the ALICE detector at the CERN LHC. These measurements have as their ultimate goal an experimental test of Lattice QCD (LQCD) predictions on second and higher order cumulants of net-baryon distributions to search for critical behavior near the QCD phase boundary. Before confronting them with LQCD predictions, account has to be taken of correlations stemming from baryon number conservation as well as fluctuations of participating nucleons. Both effects influence the experimental measurements and are usually not considered in theoretical calculations. For the first time, it is shown that event-by-event baryon number conservation leads to subtle long-range correlations arising from very early interactions in the collisions

HΛ3 and H‾Λ‾3 lifetime measurement in Pb–Pb collisions at √sNN=5.02 TeV via two-body decay

An improved value for the lifetime of the (anti-)hypertriton has been obtained using the data sample of Pb–Pb collisions at √sNN = 5.02 TeV collected by the ALICE experiment at the LHC. The (anti-)hypertriton has been reconstructed via its charged two-body mesonic decay channel and the lifetime has been determined from an exponential fit to the dN/d(ct) spectrum. The measured value, τ = 242+34 −38 (stat.) ± 17 (syst.) ps, is compatible with representative theoretical predictions, thus contributing to the solution of the longstanding hypertriton lifetime puzzle

Measuring KS0K± interactions using Pb–Pb collisions at √sNN=2.76 TeV

We present the first ever measurements of femtoscopic correlations between the K0 S and K± particles. The analysis was performed on the data from Pb–Pb collisions at √sNN = 2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a0(980) resonance. The extracted kaon source radius and correlation strength parameters for K0 SK− are found to be equal within the experimental uncertainties to those for K0 SK+. Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a0 resonance are tested. Our results are also compatible with the interpretation of the a0 having a tetraquark structure instead of that of a diquar

Multiplicity dependence of inclusive J/ψ production at midrapidity in pp collisions at √s=13 TeV

Measurements of the inclusive J/ψ yield as a function of charged-particle pseudorapidity density dNch/dη in pp collisions at √s = 13 TeV with ALICE at the LHC are reported. The J/ψ meson yield is measured at midrapidity (|y| < 0.9) in the dielectron channel, for events selected based on the charged-particle multiplicity at midrapidity (|η| < 1) and at forward rapidity (−3.7 < η < −1.7 and 2.8 < η < 5.1); both observables are normalized to their corresponding averages in minimum bias events. The increase of the normalized J/ψ yield with normalized dNch/dη is significantly stronger than linear and dependent on the transverse momentum. The data are compared to theoretical predictions, which describe the observed trends well, albeit not always quantitatively