Energy profile and hadron fragmentation inside jets
Yang-Ting Chien (Los Alamos)

The jet shape and the jet fragmentation function describe transverse and longitudinal distribution of QCD radiations inside jets. Their precise calculations suffer from large logarithms of angular parameters which enter the observable and the jet definitions, especially for jets with small radii. In this talk I will explain how we can manage to resum these logarithms using soft-collinear effective theory. These observables receive dominant contributions from collinear radiations and the factorization theorems simplify dramatically. The characteristic jet scales can be identified and the logarithms are resummed using renormalization group and DGLAP evolution equations. In the end I will show the comparison with the LHC data with very nice agreement. Our work provide novel frameworks and have established as the baseline for the studies of jet substructure modifications in heavy ion collisions.