Pileup Identification for HLT Jets in Run II

Pile up jet identification\cite{CMS-PAS-JME-13-005} is an important procedure for data analysis and physics phenomena observation. For LHC Run2, this work is trying to be implemented on the trigger and done online mostly. By utilizing the internal properties' differences of prompt jet and pileup jet, we get a preliminary result which seems to be promising: around 53\% background rejection rate with 90\% signal efficiency. In addition, methods to mitigate pileup jet dependence are studied and explored.