  Understanding the properties of the quark-gluon plasma (QGP) that is produced
in ultra-relativistic nucleus-nucleus collisions has been one of the top
priorities of the heavy ion program at the LHC. Energetic jets are produced and
subsequently quenched in the collisions. Such jet quenching phenomena provide
promising tools to probe the medium properties by studying the modification of
jets due to the medium interactions. Significant modifications of jet shapes
have been measured. In this talk we focus on the calculation of jet shapes in
both proton-proton and lead-lead collisions using soft-collinear effective
theory (SCET), with Glauber gluon interactions in the medium. Large logarithms
in jet shapes are resummed at next-to-leading logarithmic (NLL) accuracy by the
renormalization-group evolution between hierarchical jet scales. The medium
interactions contribute as power corrections, and we calculate the modification
of jet shapes at leading order in opacity with the static QGP model.
Preliminary results are presented with good agreement with the recent CMS jet
shape measurements.
