A measurement is presented of elliptic (𝑣2) and triangular (𝑣3) azimuthal anisotropy coefficients for charged particles produced in Pb+Pb collisions at √𝑠NN=5.02 TeV using a dataset corresponding to an integrated luminosity of 0.44nb−1 collected with the ATLAS detector at the LHC in 2018. The values of 𝑣2 and 𝑣3 are measured for charged particles over a wide range of transverse momentum (𝑝T), 1–400 GeV, and Pb+Pb collision centrality, 0–60%, using the scalar-product and multiparticle cumulant methods. These methods are sensitive to event-by-event fluctuations and nonflow effects in the measurements of azimuthal anisotropies. Positive values of 𝑣2 are observed up to a 𝑝T of approximately 100 GeV from both methods across all centrality intervals. Positive values of 𝑣3 are observed up to approximately 25 GeV using both methods, though the application of the three-subevent technique to the multiparticle cumulant method leads to significant changes at the highest 𝑝T. At high 𝑝T (𝑝T⪆10 GeV), charged particles are dominantly from jet fragmentation. These jets, and hence the measurements presented here, are sensitive to the path-length dependence of parton energy loss in the quark-gluon plasma produced in Pb+Pb collisions.

Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N.J., et al. (2025). Azimuthal anisotropies of charged particles with high transverse momentum in Pb+Pb collisions at √𝑠NN=5.02 TeV with the ATLAS detector. PHYSICAL REVIEW C, 112(2), 024910-1-024910-34 [10.1103/d46f-yl4n].

Azimuthal anisotropies of charged particles with high transverse momentum in Pb+Pb collisions at √𝑠NN=5.02 TeV with the ATLAS detector

Alberghi, G. L.;Alfonsi, F.;Ballabene, E.;Bellagamba, L.;Bianco, G.;Boscherini, D.;Bruni, A.;Carratta, G.;Cremonini, D.;De Castro, S.;Fabbri, F.;Fabbri, L.;Franchini, M.;Gabrielli, A.;Giacobbe, B.;Lasagni Manghi, F.;Levrini, G.;Nechaeva, S.;Polini, A.;Rinaldi, L.;Romano, M.;Sanzani, E.;Sbarra, C.;Sbrizzi, A.;Semprini-Cesari, N.;Sioli, M.;Todome, K.;Valentinetti, S.;Villa, M.;Vittori, C.;Vivarelli, I.;Zoccoli, A.;
2025

Abstract

A measurement is presented of elliptic (𝑣2) and triangular (𝑣3) azimuthal anisotropy coefficients for charged particles produced in Pb+Pb collisions at √𝑠NN=5.02 TeV using a dataset corresponding to an integrated luminosity of 0.44nb−1 collected with the ATLAS detector at the LHC in 2018. The values of 𝑣2 and 𝑣3 are measured for charged particles over a wide range of transverse momentum (𝑝T), 1–400 GeV, and Pb+Pb collision centrality, 0–60%, using the scalar-product and multiparticle cumulant methods. These methods are sensitive to event-by-event fluctuations and nonflow effects in the measurements of azimuthal anisotropies. Positive values of 𝑣2 are observed up to a 𝑝T of approximately 100 GeV from both methods across all centrality intervals. Positive values of 𝑣3 are observed up to approximately 25 GeV using both methods, though the application of the three-subevent technique to the multiparticle cumulant method leads to significant changes at the highest 𝑝T. At high 𝑝T (𝑝T⪆10 GeV), charged particles are dominantly from jet fragmentation. These jets, and hence the measurements presented here, are sensitive to the path-length dependence of parton energy loss in the quark-gluon plasma produced in Pb+Pb collisions.
2025
Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N.J., et al. (2025). Azimuthal anisotropies of charged particles with high transverse momentum in Pb+Pb collisions at √��NN=5.02 TeV with the ATLAS detector. PHYSICAL REVIEW C, 112(2), 024910-1-024910-34 [10.1103/d46f-yl4n].
Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboelela, M.; Aboulhorma, A.; Abramowicz, H.; Abulaiti, Y...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1044376
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