Title: Anomalous evolution of the near-side jet peak shape in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
Author: Adam, Jaroslav; Adamová, Dagmar; Aggarwal, Madan M; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Nikita; Ahammed, Zubayer; Ahmad, Shafiq F; Ahn, Sang Un; Aiola, Salvatore; Alme, Johan; Helstrup, Håvard; Hetland, Kristin Fanebust; Kileng, Bjarte; Altinpinar, Sedat; Djuvsland, Øystein; Lønne, Per-Ivar
Subject: Physics
Description: The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a $p_{\mathrm{T}}$ region inaccessible by direct jet identification. In these measurements pseudorapidity ($\Delta\eta$) and azimuthal differences ($\Delta\varphi$) are used to extract the shape of the near-side peak formed by particles associated to a higher $p_{\mathrm{T}}$ trigger particle ($1 p_{\mathrm{T, trig}} $ 8 GeV/c). A combined fit of the near-side peak and long-range correlations is applied to the data allowing the extraction of the centrality evolution of the peak shape in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV. A significant broadening of the peak in the $\Delta\eta$ direction at low $p_{\mathrm{T}}$ is found from peripheral to central collisions, which vanishes above 4 GeV/c, while in the $\Delta\varphi$ direction the peak is almost independent of centrality. For the 10% most central collisions and $1 p_{\mathrm{T, assoc}} $ 2 GeV/c,...
Is part of: Physical review letters, 2017
Identifier: 0031-9007 (ISSN); 1079-7114 (E-ISSN); 10.1103/PhysRevLett.119.102301 (DOI)