Measurement of jet suppression in central Pb–Pb collisions at sNN=2.76 TeV

The transverse momentum (pTpT) spectrum and nuclear modification factor (RAARAA) of reconstructed jets in 0–10% and 10–30% central Pb–Pb collisions at sNN=2.76 TeV were measured. Jets were reconstructed using the anti-kTkT jet algorithm with a resolution parameter of R=0.2R=0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet pTpT spectra are reported in the pseudorapidity interval of |ηjet|<0.5|ηjet|<0.5 for 405 GeV/cpT>5 GeV/c to suppress jets constructed from the combinatorial background in Pb–Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb–Pb collisions had a negligible effect on the RAARAA. The nuclear modification factor RAARAA was found to be 0.28±0.040.28±0.04 in 0–10% and 0.35±0.040.35±0.04 in 10–30% collisions, independent of pT,jet within the uncertainties of the measurement. The observed suppression is in fair agreement with expectations from two model calculations with different approaches to jet quenching.