CERN-LHC. The transverse momentum ($p_{\mathrm{T}}$) spectrum and nuclear modification factor (${R}_{\mathrm{AA}}$) of reconstructed jets in $0$-$10$% and $10$-$30$% central Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV were measured. Jets were reconstructed from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal), with the anti-$k_{\mathrm{T}}$ jet algorithm with a resolution parameter of $R=0.2$. The jet $p_{\mathrm{T}}$ spectra are reported in the pseudorapidity interval of $|{\eta}_{\rm jet}|<0.5$ for $40<{p}_{\mathrm{T,~jet}}<120$ GeV/$c$ in $0$-$10$% and for $30<{p}_{\mathrm{T,~jet}}<100$ GeV/$c$ in $10$-$30$% collisions. Reconstructed jets were required to contain a leading charged particle with $p_{\mathrm{T}}>5$ GeV/$c$ to suppress jets constructed from the combinatorial background in Pb--Pb collisions. The nuclear modification factor is obtained by dividing the jet spectrum measured in Pb--Pb by that in pp collisions scaled by the number of independent nucleon--nucleon collisions estimated using a Glauber model. ${R}_{\mathrm{AA}}$ is found to be $0.28\pm0.04$ in $0$-$10$% and $0.35\pm0.04$ in $10$-$30$% collisions, independent of ${p}_{\mathrm{T,~jet}}$ within the uncertainties of the measurement.

Ratios of jet spectra with different leading track $p_{\mathrm{T}}$ requirements ("$0$ over $5$", "$3$ over $5$", "$7$ over $5$" and "$10$ over $5$") for $R=0.2$ jets in 0-10% most central Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV.