0000000000603102

AUTHOR

Panos Kostarakis

0000-0002-1549-7721

showing 6 related works from this author

Measurement of transverse energy at midrapidity in Pb-Pb collisions atsNN=2.76TeV

2016

We report the transverse energy ($E_{\mathrm T}$) measured with ALICE at midrapidity in Pb-Pb collisions at ${\sqrt{s_{\mathrm {NN}}}}$ = 2.76 TeV as a function of centrality. The transverse energy was measured using identified single particle tracks. The measurement was cross checked using the electromagnetic calorimeters and the transverse momentum distributions of identified particles previously reported by ALICE. The results are compared to theoretical models as well as to results from other experiments. The mean $E_{\mathrm T}$ per unit pseudorapidity ($\eta$), $\langle $d$E_{\mathrm T}/$d$\eta \rangle$, in 0-5% central collisions is 1737 $\pm$ 6(stat.) $\pm$ 97(sys.) GeV. We find a si…

Quantum chromodynamicsPhysicsParticle physics010308 nuclear & particles physicsKinetic energy01 natural sciencesNuclear physicsPseudorapidity0103 physical sciencesHigh Energy Physics::ExperimentRapidityImpact parameterNuclear Experiment010306 general physicsNucleonCentralityGlauberPhysical Review C
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Anisotropic Flow of Charged Particles in Pb-Pb Collisions atsNN=5.02  TeV

2016

We report the first results of elliptic (v2), triangular (v3), and quadrangular (v4) flow of charged particles in Pb-Pb collisions at a center-of-mass energy per nucleon pair of √sNN=5.02  TeV with the ALICE detector at the CERN Large Hadron Collider. The measurements are performed in the central pseudorapidity region |η|<0.8 and for the transverse momentum range 0.2<pT<5  GeV/c. The anisotropic flow is measured using two-particle correlations with a pseudorapidity gap greater than one unit and with the multiparticle cumulant method. Compared to results from Pb-Pb collisions at √sNN=2.76  TeV, the anisotropic flow coefficients v2, v3, and v4 are found to increase by (3.0±0.6)%, (4.3±1.4)%, …

PhysicsRange (particle radiation)Large Hadron Collider010308 nuclear & particles physicsElliptic flowGeneral Physics and Astronomy01 natural sciences7. Clean energyCharged particleNuclear physicsPseudorapidity0103 physical sciencesQuark–gluon plasmaHigh Energy Physics::ExperimentNuclear Experiment010306 general physicsNucleonAnisotropyPhysical Review Letters
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Study of the leptonic decays of the Z0 boson

1990

Measurements are presented of the cross section ratios Rℓ = σℓ(e+e-→ℓ+ℓ -)/σhh(e+e-→hadrons) for ℓ = e, μ and τ using data taken from a scan around the Z0. The results are Re = (5.09±0.32±0.18)%, Rμ = (4.96±0.35±0.17)% and Rτ,=(4.72±0.38± 0.29)% where, for the ratio Re, the t-channel contribution has been subtracted. These results are consistent with the hypothesis of lepton universality and test this hypothesis at the energy scale s ∼ 8300 GeV2. The absolute cross sections σℓ(e+e-→ℓ +ℓ-) have also been measured. From the cross sections the leptonic partial widths Γe = (83.2±3.0±2.4) MeV, (ΓeΓμ) 1/2=(84.6±3.0±2.4) MeV and (ΓeΓτ) 1/2=(82.6±3.3±3.2) MeV have been extracted. Assuming lepton un…

PhysicsNuclear and High Energy PhysicsParticle physics[PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex]010308 nuclear & particles physicsElectron–positron annihilationHadronWidth ratio01 natural sciences7. Clean energyNuclear physics0103 physical sciencesPhysique des particules élémentaires[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Neutrino010306 general physicsParticle Physics - ExperimentLeptonBosonPhysics Letters B
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Centrality Dependence of the Charged-Particle Multiplicity Density at Midrapidity in Pb-Pb Collisions atsNN=5.02  TeV

2016

The pseudorapidity density of charged particles, dNch/dη, at midrapidity in Pb-Pb collisions has been measured at a center-of-mass energy per nucleon pair of √sNN=5.02 TeV. For the 5% most central collisions, we measure a value of 1943 ± 54. The rise in dNch/dη as a function of √sNN p is steeper than that observed in proton-proton collisions and follows the trend established by measurements at lower energy. The increase of dNch/dη as a function of the average number of participant nucleons, ⟨Npart⟩, calculated in a Glauber model, is compared with the previous measurement at √sNN=2.76 TeV. A constant factor of about 1.2 describes the increase in dNch/dη from √sNN=2.76 to 5.02 TeV for all cen…

PhysicsParticle physicsLarge Hadron Collider010308 nuclear & particles physicsGeneral Physics and Astronomy01 natural sciencesCharged particleNuclear physicsPseudorapidity0103 physical sciencesQuark–gluon plasmaImpact parameterMultiplicity (chemistry)Nuclear Experiment010306 general physicsNucleonGlauberPhysical Review Letters
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Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p–Pb collisions at sNN=5.02 TeV

2016

The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity ($-0.5 10$ GeV/$c$), the particle ratios are consistent with those reported for pp and Pb-Pb collisions at the LHC energies. At intermediate $p_{\rm T}$ the (anti)proton $R_{\rm pPb}$ shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high $p_{\rm T}$ the charged pion, kaon and (anti)proton $R_{\rm pPb}$ are consistent with unity within statistical and systematic uncertainties.

PhysicsNuclear and High Energy PhysicsParticle physicsProton010308 nuclear & particles physicsNuclear TheoryHadron7. Clean energy01 natural sciencesParticle identificationCharged particleNuclear physicsPionAntiproton0103 physical sciencesQuark–gluon plasmaHigh Energy Physics::ExperimentRapidityNuclear Experiment010306 general physicsPhysics Letters B
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Particle identification in ALICE: a Bayesian approach

2016

We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss ($\mathrm{d}E/\mathrm{d}x$) and time-of-flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels ${\rm K}^0_S \righta…

:Kjerne- og elementærpartikkelfysikk: 431 [VDP]Monte Carlo methodGeneral Physics and AstronomyPID controllerPP01 natural sciencesParticle identificationHigh Energy Physics - ExperimentParticle identificationHigh Energy Physics - Experiment (hep-ex)ALICEHadron-Hadron scattering (experiments)Heavy-ion collisionNuclear and High Energy Physics Hadron-Hadron scattering (experiments) Heavy Ion Experiments Heavy-ion collision Quark gluon plasma Particle identification Bayesianscattering [p p][PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Nuclear Experiment (nucl-ex)Detectors and Experimental TechniquesNuclear ExperimentNuclear ExperimentPhysicsefficiency [particle identification]PB COLLISIONSVDP::Kjerne- og elementærpartikkelfysikk: 431Monte Carlo [numerical calculations]PB COLLISIONS PP PERFORMANCE.:Mathematics and natural scienses: 400::Physics: 430::Nuclear and elementary particle physics: 431 [VDP]PRIRODNE ZNANOSTI. Fizika.Time of flight:Nuclear and elementary particle physics: 431 [VDP]VDP::Nuclear and elementary particle physics: 431performancemomentum spectrum [charged particle]Nuclear and High Energy PhysicsParticle physicsMesoneducationBayesian probabilityFOS: Physical sciencesQuark gluon plasma[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]114 Physical sciencesBayesianNuclear physicsPhysics and Astronomy (all)PionHeavy Ion Experiments0103 physical sciencesddc:530010306 general physics010308 nuclear & particles physicsBayesian approach:Matematikk og naturvitenskap: 400::Fysikk: 430::Kjerne- og elementærpartikkelfysikk: 431 [VDP]ALICE experimentPERFORMANCEparticle identification ; Bayesian approachNATURAL SCIENCES. Physics.PB COLLISIONS; TEV; PP; PERFORMANCEPhysics - Data Analysis Statistics and ProbabilityQuark–gluon plasmaBayesian [statistics]TEVHigh Energy Physics::Experimentparticle identificationData Analysis Statistics and Probability (physics.data-an)
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