Inhaltszusammenfassung

The jet radial structure and particle transverse momentum ($p_{\rm T}$) composition within jets are presented in centrality-selected Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of $R=0.3$ at midrapidity $|\eta_\mathrm{ch\,jet}|<0.6$ for transverse momenta $p_\mathrm{T,\,ch\,jet}=30$-$120$ GeV/$c$. Jet$-$hadron correlations in relative azimuth and pseudorapidity space ($\Delta\varphi$...The jet radial structure and particle transverse momentum ($p_{\rm T}$) composition within jets are presented in centrality-selected Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of $R=0.3$ at midrapidity $|\eta_\mathrm{ch\,jet}|<0.6$ for transverse momenta $p_\mathrm{T,\,ch\,jet}=30$-$120$ GeV/$c$. Jet$-$hadron correlations in relative azimuth and pseudorapidity space ($\Delta\varphi$, $\Delta\eta$) are measured to study the distribution of the associated particles around the jet axis for different $p_\mathrm{T, assoc}$-ranges between 1 and 20 GeV/$c$. The data in Pb$-$Pb collisions are compared to reference distributions for pp collisions, obtained using embedded PYTHIA simulations. The number of high-$p_{\rm T}$ associate particles ($4<p_\mathrm{T, assoc}<20$ GeV/$c$) in Pb$-$Pb collisions is found to be suppressed compared to the reference by 30 to 10\%, depending on centrality. The radial particle distribution relative to the jet axis shows a moderate modification in Pb$-$Pb collisions with respect to PYTHIA. High-$p_{\rm T}$ associate particles are slightly more collimated in Pb$-$Pb collisions compared to the reference, while low-$p_{\rm T}$ associate particle tend to be broadened. The results, which are compatible with both previous jet$-$hadron-related measurements from the CMS Collaboration and jet shape measurements from the ALICE Collaboration at higher $p_{\rm T}$, support the currently established picture of in-medium parton energy loss.» weiterlesen» einklappen

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DDC Sachgruppe:
Physik