arXiv subjects

Panos Christakoglou

Publications and source records attributed to Panos Christakoglou.

8 recordsLinked to original sources

arXiv2024

Probing the magnetic field strength dependence of the Chiral Magnetic Effect

The article presents a study aimed at probing the dependence of the Chiral Magnetic Effect (CME) on the magnetic field strength using the Anomalous Viscous Fluid Dynamics (AVFD) model in Pb--Pb at LHC energies. The results demonstrate the quadratic dependence of the correlators used for the study of the CME in heavy ion collisions on the number of spectators, a proxy of the magnitude of the magnetic field. The article also presents the extension of this approach to a two dimensional space, formed by both the aforementioned proxy of the magnetic field strength but also a proxy of the final state ellipticity, a key ingredient of the background in these measurements, for each centrality interval. This provides an exciting possibility to experiments to isolate the background contributions from the potential CME signal.

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arXiv2022

Global constraint on the magnitude of anomalous chiral effects in heavy-ion collisions

When searching for anomalous chiral effects in heavy-ion collisions, one of the most crucial points is the relationship between the signal and the background. In this letter, we present a simulation in a modified blast wave model at LHC energy, which can simultaneously characterize the majority of measurable quantities, in particular, the chiral magnetic effect (CME) and the chiral magnetic wave (CMW) observables. Such a universal description, for the first time, naturally and quantitatively unifies the CME and the CMW studies and brings to light the connection with the local charge conservation (LCC) background. Moreover, a simple phenomenological approach is performed to introduce the signals, aiming at quantifying the maximum allowable strength of the signals within experimental precision. Such a constraint provides a novel perspective to understand the experimental data and sheds new light on the study of anomalous chiral effects as well as charge dependent correlations.

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arXiv2021

Systematic study of the Chiral Magnetic Effect with the AVFD model at LHC energies

We present a systematic study of the correlators used experimentally to probe the Chiral Magnetic Effect (CME) using the Anomalous Viscous Fluid Dynamics (AVFD) model in Pb--Pb and Xe--Xe collisions at LHC energies. We find a parametrization that describes the dependence of these correlators on the value of the axial current density ($n_5/\mathrm{s}$), which dictates the CME signal, and on the parameter that governs the background in these measurements i.e., the percentage of local charge conservation (LCC) within an event. This allows to deduce the values of $n_5/\mathrm{s}$ and the LCC percentage that provide a quantitative description of the centrality dependence of the experimental measurements. We find that the results in Xe--Xe collisions at $\sqrt{s_{\mathrm{NN}}} = 5.44$~TeV are consistent with a background only scenario. On the other hand, the model needs a significant non-zero value of $n_5/\mathrm{s}$ to match the measurements in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$~TeV.

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arXiv2013

Results on angular correlations with ALICE

Angular correlations are a sensitive probe of the transport properties of the system produced in nucleus-nucleus collisions. Similar studies performed in p-Pb collisions have recently revealed intriguing features as well. In this article, we review the latest results on charged and identified particle correlations obtained with the ALICE detector at the LHC in both Pb-Pb and p-Pb events.

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arXiv2011

First results on the event-by-event fluctuations and correlations in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV

Fluctuations of thermodynamic quantities are fundamental for the study of the QGP phase transition. Among several observables calculated on an event-by-event basis, the different measures of the charge and mean transverse momentum fluctuations are of particular interest since they are considered to be indicators of the existence and of the order of this transition as well as of the thermalization in heavy--ion collisions. In this article, we review the first results from the event-by-event physics program of the ALICE experiment at the LHC in Pb--Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV. The experimental results will be compared to previously published data and available model predictions.

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arXiv2011

Charge dependent azimuthal correlations in Pb--Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV

Separation of charges along the extreme magnetic field created in non-central relativistic heavy--ion collisions is predicted to be a signature of local parity violation in strong interactions. We report on results for charge dependent two particle azimuthal correlations with respect to the reaction plane for Pb--Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV recorded in 2010 with ALICE at the LHC. The results are compared with measurements at RHIC energies and against currently available model predictions for LHC. Systematic studies of possible background effects including comparison with conventional (parity-even) correlations simulated with Monte Carlo event generators of heavy--ion collisions are also presented.

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arXiv2010

Commissioning of the Silicon Strip Detector (SSD) of ALICE

The latest results from the commissioning of the SSD with cosmics are presented in this paper. The hardware status of the detector, the front-end electronics, cooling, data acquisition and issues related to the on-line monitoring are shown. In addition, the procedures implemented and followed to address the alignment with the rest of the ITS sub-detectors along with both on-line and off-line calibration strategies are described. Finally, results from simulations as well as from the reconstruction of cosmic data demonstrating the performance of the detector are presented, proving that the SSD is ready for the forthcoming proton-proton data taking.

physics.ins-det↗

arXiv2009

Event by event physics in ALICE

Fluctuations of thermodynamic quantities are fundamental for the study of the QGP phase transition. The ALICE experiment is well suited for precise event-by-event measurements of various quantities. In this article, we review the capabilities of ALICE to study the fluctuations of several key observables such as the net charge, the temperature, and the particle ratios. Among the observables related to correlations, we review the balance functions and the long range correlations.

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