Электронный каталог

Статья

Disentangling Sources of Momentum Fluctuations in Xe+Xe and Pb+Pb Collisions with the ATLAS Detector / F.Ahmadov, I.N.Aleksandrov, V.A.Bednyakov, I.R.Boyko, G.Chelkov, A.Cheplakov, M.V.Chizhov, D.V.Dedovich, M.Demichev, A.R.Didenko, M.I.Gostkin, S.N.Karpov, Z.M.Karpova, U.Kruchonak, V.Kukhtin, E.Ladygin, V.Lyubushkin, T.Lyubushkina, S.Malyukov, M.Mineev, E.Plotnikova, I.N.Potrap, N.A.Rusakovich, M.Shiyakova, A.Soloshenko, T.Turtuvshin, A.Tropina, A.Vasyukov, I.Yeletskikh, A.Zhemchugov, N.I.Zimine, Y.Kulchitsky, [ATLAS Collab.] // Physical Review Letters [Electronic resource]. – 2024. – Vol. 133, No. 25. – P. 252301. – URL: https://doi.org/10.1103/PhysRevLett.133.252301. – Bibliogr.: 54.

High-energy nuclear collisions create a quark-gluon plasma, whose initial condition and subsequent expansion vary from event to event, impacting the distribution of the eventwise average transverse momentum [𝑃⁡([𝑝T])]. Disentangling the contributions from fluctuations in the nuclear overlap size (geometrical component) and other sources at a fixed size (intrinsic component) remains a challenge. This problem is addressed by measuring the mean, variance, and skewness of 𝑃⁡([𝑝T]) in *2*0*8 Pb +*2*0*8Pb and *1*2*9Xe +*1*2*9 Xe collisions at √𝑠NN=5.02 and 5.44 TeV, respectively, using the ATLAS detector at the LHC. All observables show distinct features in ultracentral collisions, which are explained by a suppression of the geometrical component as the overlap area reaches its maximum. These results demonstrate a new technique to separate geometrical and intrinsic fluctuations, providing constraints on initial conditions and properties of the quark-gluon plasma, such as the speed of sound.



ОИЯИ = ОИЯИ (JINR)2024