  We present the analysis of the semi-inclusive distribution of reconstructed
charged particle jets recoiling from a high pT hadron trigger in central Pb Pb
collisions at $\sqrt{s_{NN}}=2.76$ TeV. We measure, subtract and unfold the
large underlying event background in such collisions, utilizing a novel
technique that does not impose fragmentation bias on the measured jet
population. The Pb Pb measurements are compared to a pp PYTHIA reference
distribution generated at the same $\sqrt{s}$. Modification of jet structure
due to quenching is explored by varying the cone radius $R$ (0.2, 0.4) and the
lower pT cutoff of charged particle constituents (0.15, 2.0 GeV/$c$).
