Search results for " Heavy"
showing 10 items of 447 documents
First measurement of quarkonium polarization in nuclear collisions at the LHC
2021
The polarization of inclusive J/$\psi$ and $\Upsilon(1{\rm S})$ produced in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=5.02$ TeV at the LHC is measured with the ALICE detector. The study is carried out by reconstructing the quarkonium through its decay to muon pairs in the rapidity region $2.5<y<4$ and measuring the polar and azimuthal angular distributions of the muons. The polarization parameters $\lambda_{\theta}$, $\lambda_{\phi}$ and $\lambda_{\theta\phi}$ are measured in the helicity and Collins-Soper reference frames, in the transverse momentum interval $2<p_{\rm T}<10$ GeV/$c$ and $p_{\rm T}<15$ GeV/$c$ for the J/$\psi$ and $\Upsilon(1{\rm S})$, respectively. The polarization parameter…
Performance of the ALICE experiment at the CERN LHC
2014
ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.
Nucleon dissociation and incoherent J/ψ photoproduction on nuclei in ion ultraperipheral collisions at the CERN Large Hadron Collider
2019
Using the general notion of cross section fluctuations in hadron-nucleus scattering at high energies, we derive an expression for the cross section of incoherent J / ψ photoproduction on heavy nuclei d σ γ A → J / ψ Y / d t , which includes both elastic d σ γ p → J / ψ p / d t and proton-dissociation d σ γ p → J / ψ Y / d t photoproduction on target nucleons. We find that, with good accuracy, d σ γ A → J / ψ Y / d t can be expressed as a product of the sum of the d σ γ p → J / ψ p / d t and d σ γ p → J / ψ Y / d t cross sections, which have been measured at HERA, and the common nuclear shadowing factor, which is calculated using the leading twist nuclear shadowing model. Our prediction for …
Analysis of the Mobility of Heavy Metals in Sludge for the Sewage Treatment Plant in Daleszyce
2020
Osady ściekowe są produktem ubocznym procesów oczyszczania ścieków. Wykazują jednak wysokie właściwości nawo-zowe oraz glebotwórcze, jednak nie zawsze mogą być one wykorzystane w tym celu. Dwa główne kryteria ograniczające ich przyrodnicze wykorzystanie to zawartość metali ciężkich oraz jaj pasożytów. Osady ściekowe pobrane z oczyszczalni ścieków w Daleszycach zostały poddane analizie zawartości metali ciężkich. W tym celu wykonano analizę specjacyjną, pozwalającą podzielić całkowitą zawartość metali na cztery frakcje mobilności. Mobilność określa zdolność pierwiastka, lub któregoś z jego form, do przemieszczania się w środowisku. Badania wykonano, stosując czteroetapową procedurę BCR. Wyni…
Highly occupied gauge theories in 2 + 1 dimensions : a self-similar attractor
2019
Motivated by the boost-invariant Glasma state in the initial stages in heavy-ion collisions, we perform classical-statistical simulations of SU(2) gauge theory in 2+1 dimensional space-time both with and without a scalar field in the adjoint representation. We show that irrespective of the details of the initial condition, the far-from-equilibrium evolution of these highly occupied systems approaches a unique universal attractor at high momenta that is the same for the gauge and scalar sectors. We extract the scaling exponents and the form of the distribution function close to this non-thermal fixed point. We find that the dynamics are governed by an energy cascade to higher momenta with sc…
Cross section for bb¯ production via dielectrons in d + Au collisions at √sNN = 200 GeV
2015
We report a measurement of e+e− pairs from semileptonic heavy-flavor decays in d + Au collisions at √sNN = 200 GeV. By exploring the mass and transverse-momentum dependence of the yield, the bottom decay contribution can be isolated from charm, and quantified by comparison to PYTHIA and MC@NLO simulations. The resulting bb¯-production cross section is σdAu bb¯ = 1.37 ± 0.28 (stat) ± 0.46 (syst) mb, which is equivalent to a nucleon-nucleon cross section of σ NN bb = 3.4 ± 0.8 (stat) ± 1.1 (syst) μb. peerReviewed
"Table 7" of "Cross section for $b\bar{b}$ production via dielectrons in d$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV"
2023
$b\bar{b}$ cross section
The Utility of Ground Bryophytes in the Assessment of Soil Condition in Heavy Metal-Polluted Grasslands
2022
Bryophytes are commonly used in biomonitoring heavy metal pollution, whereas the bioindicative value of bryophyte communities is a less known issue. The aim of the present study is to recognize the utility of the bryophyte community’s structure in the assessment of soil condition in heavy metal-polluted, dry grasslands. The study plots are examined with respect to bryophytes; vascular plants; concentrations of Zn, Pb, Cd, and As in the soil; total nitrogen and organic carbon content in the soil; and soil pH. The results show that both bryophyte species richness and composition greatly depend on soil chemical characteristics, including heavy-metal pollution levels and soil pH. Three groups o…
The Influence of Industrial Waste on the Magnetic Properties of Salt-Affected Soils from Two Soda Ash Manufacturing Sites
2021
The aim of this study was to characterize the impact of soda ash manufacturing on the magnetic properties of soils located in the agricultural landscape in north-central Poland. Two study sites were chosen: Mątwy (SM) and Janikowo (SJ). Highly saline soils with halophyte communities were selected in order to develop an understanding of the relationship between salinization of water–soil interface and the potential contamination risk of the environment. Basic chemical and physicochemical properties of topsoil (0–25 cm) and water (surface and groundwater) samples from five locations were characterized. The characteristics of soil contamination were based on the content of sel…
Marine Invertebrates as Bioindicators of Heavy Metal Pollution
2015
The marine environment presents a range of anthropogenic contaminants. According to the World Health Organization, more than 100,000 chemicals are released into the global environment every year as a consequence of their production, use and disposal. The fate of a chemical substance depends on physical-chemical properties, in combination with the characteristics of the environment where it is released. Among the substances that accumulate in the sea, for anthropogenic activities, metals/metalloids have a leading position. Some of these have a biological role but their bioaccumulation is injurious. Chemical pollutants can cause effects on organisms, biodiversity and human health. Various eff…