The jet radial structure and particle transverse momentum (<math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math>) composition within jets are presented in centrality-selected Pb–Pb collisions at <math><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi>NN</mi></mrow></msub></mrow></msqrt><mo>=</mo><mn>2.76</mn></math> TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of <math><mi>R</mi><mo>=</mo><mn>0.3</mn></math> at midrapidity <math><mo>|</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>ch jet</mi></mrow></msub><mo>|</mo><mo>&lt;</mo><mn>0.6</mn></math> for transverse momenta <math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi><mo>,</mo><mspace width="0.2em"></mspace><mi>ch jet</mi></mrow></msub><mo>=</mo><mn>30</mn></math>–120 GeV/c. Jet–hadron correlations in relative azimuth and pseudorapidity space (<math><mi>Δ</mi><mi>φ</mi><mo>,</mo><mi>Δ</mi><mi>η</mi></math>) are measured to study the distribution of the associated particles around the jet axis for different <math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi><mo>,</mo><mi>assoc</mi></mrow></msub></math>-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-<math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math> associate particles (<math><mn>4</mn><mo>&lt;</mo><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi><mo>,</mo><mi>assoc</mi></mrow></msub><mo>&lt;</mo><mn>20</mn></math> 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-<math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math> associate particles are slightly more collimated in Pb–Pb collisions compared to the reference, while low-<math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math> associate particles tend to be broadened. The results, which are presented for the first time down to <math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi><mo>,</mo><mspace width="0.2em"></mspace><mi>ch jet</mi></mrow></msub><mo>=</mo><mn>30</mn></math> GeV/c in Pb–Pb collisions, are compatible with both previous jet–hadron-related measurements from the CMS Collaboration and jet shape measurements from the ALICE Collaboration at higher <math><msub><mrow><mi>p</mi></mrow><mrow><mi>T</mi></mrow></msub></math>, and add further support for the established picture of in-medium parton energy loss.

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Measurement of jet radial profiles in Pb–Pb collisions at TeV