Jet reconstruction and substructure measurements in ATLAS and CMS with first Run-2 data

Abstract

Jets play an important role in LHC physics but jet reconstruction and calibration in the high pile-up environment of the 2015 and 2016 data-taking periods pose unique challenges. The ATLAS and CMS experiments have improved their jet reconstruction and correction methods compared to Run I in order to better clean jets of the additional particles generated in pile-up interactions. Beyond jets formed from the hadronization of quarks and gluons, hadronic decays of highly boosted heavy particles, such as top quarks or Z, W or H bosons, in a single fat jet is gaining importance in the search for new physics at the highest possible energies. The LHC experiments have used the time between the LHC Run I and Run II to refine the methods used to identify such boosted decays and make them more robust in the presence of the high pile-up encountered in Run II. The application of this work to early Run II data are presented.