Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

Scientific paper - Original scientific paper

• Author: S. Acharya
• Author: ...
• Author: Tome Antičić
• Author: ...
• Author: Filip Erhardt
• Author: ...
• Author: Sven Gotovac
• Author: ...
• Author: Marko Jerčić
• Author: ...
• Author: Petra Lončar
• Author: ...
• Author: Eugen Mudnić
• Author: ...
• Author: Mirko Planinić
• Author: ...
• Author: Nikola Poljak
• Author: ...
• Author: Goran Simatović
• Author: ...
• Author: Antonija Utrobičić
• Author: ...
• Author: Linda Vicković
• Author: ...
• Author: N. Zurlo
• Collaboration: A Large Ion Collider Experiment Collaboration
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The first measurement at the LHC of charge-dependent directed flow (v1) relative to the spectator plane is presented for Pb-Pb collisions at √sNN p = 5.02 TeV. Results are reported for charged hadrons and D0 mesons for the transverse momentum intervals pT > 0.2 GeV=c and 3 < pT < 6 GeV=c in the 5%–40% and 10%–40% centrality classes, respectively. The difference between the positively and negatively charged hadron v1 has a positive slope as a function of pseudorapidity η, dΔv1=dη = [1.68 ± 0.49(stat) x 0.41(syst) × 10^−4. The same measurement for D^0 and D¯ ^0 mesons yields a positive value dΔv1/dη = [4.9 ± 1.7(stat) ± 0.6(syst) × 10^−1, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on th e dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv1 of charged hadrons and D0 mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv1=dη for both light flavor and charmed hadrons.

• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review Letters
• Numbering: vol. 125, no. 2, 022301
• p-ISSN: 0031-9007
• e-ISSN: 1079-7114
• DOI: https://doi.org/10.1103/PhysRevLett.125.022301
• URN:NBN: urn:nbn:hr:217:679751
• Publication: 2020
• Document URL: https://link.aps.org/doi/10.1103/PhysRevLett.125.022301
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2020 CERN, for the ALICE Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Received 25 November 2019; revised 22 April 2020; accepted 19 May 2020; published 6 July 2020.
• Created on: 2020-10-10 19:13:02