At the Tevatron and LHC experiments jets are copiously produced. However, due to soft collinear divergencies, narrow jets tend to be of low mass. Of particular interest are those uncommon events where a jet of very large mass is obtained. The large mass yield a new perturbative scale which provides us with a glimpse into the mechanism of showering in a new kinematical regime. Maybe more importantly, narrow jets of electroweak masses (or above) are the focus of various beyond the standard model (SM) searches related to strong dynamics & extra dimension, supersymmetry and even the celebrated Higgs boson. Thus, we discuss some of the theory of massive boosted jets, recent experimental effort at the CDF experiment and a new technique to distinguish between non-SM signals and QCD backgrounds.
